TW202002479A - Convertor and motor control device - Google Patents

Abstract

This invention provides a convertor (1-1) comprising a power module (22) having an AC terminal (11, 12, 13), a DC terminal (14) and a DC terminal (15) connected to an AC power source (3) and having a plurality of switching elements; a base drive circuit (27); and a control power supply portion (29). The convertor (1-1) comprises a voltage phase detection portion (24) for detecting the voltage phase of the AC voltage based on a signal flowing in an emitter of a plurality of switching elements connected to the DC terminal (14) or a signal flowing in a ground which is a reference potential of the control power supply portion (29), and generating a phase detection signal showing the detected voltage phase and outputting; the convertor (1-1) comprises a base drive signal generating unit (26) for generating a drive signal for controlling a turn-on and turn-off operation of the plurality of switching elements based on the phase detection signal.

Description

Inverter and motor control device

The invention relates to an inverter and a motor control device that convert AC power to DC power.

In industrial machines such as machine tools, manufacturing machines, and robots, a large number of converters are used for energy saving. This converter uses a power regeneration method of an AC power source that sends regenerative power back to the input power source. The inverter adopting the power regeneration method is used as a DC-AC conversion device that converts the DC power supplied by the motor drive device into AC power when the motor is regenerated, thereby returning the regenerated power of the induced electromotive force generated by the motor back to the AC power supply . Hereinafter, the operation of the inverter that returns the regenerative power to the AC power source is called a regenerative operation. During the regenerative operation, if the timing of the switching element constituting the inverter is shifted from the phase of the voltage of the AC power supply, the voltage difference increases, and there is a possibility that an excessive current flows to stop the motor drive device. Therefore, the converter detects the voltage phase of the AC power supply and generates a driving signal for controlling the on-off operation of the switching element in the regeneration operation based on the detected phase information. In the following, the voltage phase of the AC power supply is sometimes referred to as the voltage phase. As for the detection method of the voltage phase, the general method is to detect the zero crossing point of the line voltage of the AC power supply, and detect the voltage phase according to the detected zero crossing point. Zero crossing point refers to the time when the line voltage of the AC power source changes from negative to positive or from positive to negative, and the voltage becomes zero. However, in this voltage phase detection method, since the timing of the zero-crossing of the line voltage of the AC power supply overlaps with the timing of the on or off of the switching element during the regeneration operation, it is near the zero-crossing point of the line voltage of the AC power supply. The voltage produces surge distortion. Therefore, erroneous detection of the zero-crossing point occurs due to voltage fluctuation, and there is a possibility that the voltage phase is erroneously detected.

In order to solve this problem, Patent Literature 1 discloses a technique for detecting the voltage phase of an AC power supply based on the zero crossing point of the phase voltage. In the technique disclosed in Patent Document 1, a phase detection unit that detects the voltage phase of the AC power supply is connected to the AC terminal of the power regeneration converter, and the phase detection unit detects the voltage phase of the AC power supply. The phase detection unit is constructed on the printed wiring board provided in the power regeneration converter. According to the technique disclosed in Patent Document 1, since the voltage phase of the AC power supply is detected based on the zero crossing of the phase voltage, a phase detection signal that alternately changes the High level and the Low level between the zero crossing points is generated. In addition, the timing of the change of the level of the phase detection signal and the timing of the switching element on or off can be different. Thereby, the phase of the voltage can be detected without being affected by the surge-like distortion of the power supply voltage caused by the on-off operation of the switching element. [Prior Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2014-180427

[Problems to be solved by the invention]

In the technique shown in Patent Document 1, the phase detection unit detects the phase of the AC voltage applied between the AC power terminal of the power regeneration converter and the AC power terminal of the power module composed of a plurality of switching elements. This AC voltage is the voltage applied to the pattern (copper foil) on the printed wiring board. However, as the capacity of the converter is larger, the current value flowing between the AC power terminal of the power regeneration converter and the AC power terminal of the power module is larger. When the capacity of the inverter increases, it is difficult to print by The pattern on the wiring board supplies power. Therefore, conductors such as busbars are generally used for power supply in large-capacity converters. When a conductor such as a bus bar is used in this way, in the technique shown in Patent Document 1, in order to detect the phase of the AC voltage with the phase detection unit provided on the printed wiring board, for example, a wire harness is connected to the bus bar to become a phase detection unit The structure of detecting the phase of the AC voltage through the bus bar and the wire harness has a problem of complicated structure.

The present invention was developed in view of the above circumstances, and an object thereof is to obtain a converter that can detect the voltage phase of an AC power supply with a simple configuration. [Technical means to solve the problem]

In order to solve the above-mentioned problems and achieve the objective, the inverter of the present invention is arranged between an AC power supply of an input power supply and a motor driving device which controls a motor at a variable speed, and is provided with a method for supplying DC power to the motor driving device and decelerating the motor The regenerative power is returned to the power regeneration function of the AC power source. The converter is provided with a power module having an AC terminal connected to the AC power source, a first terminal connected to the DC wiring on the high potential side, and a DC connected to the low potential side The second terminal of the wiring, and has a plurality of switching elements; and a drive circuit, which drives each of the plurality of switching elements. The converter is provided with: a control power supply unit that generates power supplied to a plurality of switching elements and power supplied to a drive circuit; and a voltage phase detection unit based on the emitter of the plurality of switching elements connected to the first terminal The flowing signal, or a signal flowing through the ground that becomes the reference potential of the control power supply section, detects the voltage phase of the AC voltage, and generates and outputs a phase detection signal that shows the detected voltage phase. The converter is provided with: a driving signal generating part which generates a driving signal for controlling the on and off actions of a plurality of switching elements based on the phase detection signal. [Effect of invention]

The converter of the invention achieves the effect that the voltage phase of the AC power supply can be detected by a simple structure.

The inverter and motor control device according to the embodiment of the present invention will be described in detail below based on the drawings, but the present invention is not limited to this embodiment.

Embodiment 1. Fig. 1 is a diagram showing the configuration of an inverter and a motor control device according to the first embodiment. As shown in FIG. 1, the inverter 1-1 of Embodiment 1 is provided between an AC power supply 3 of a three-phase AC power supply that generates a three-phase AC voltage and a motor drive device 4. Inverter 1-1 converts the AC voltage from AC power supply 3 that generates a three-phase AC voltage to DC voltage when the motor is running, and outputs it to motor drive device 4, and when the motor decelerates, it regenerates by regeneration The power is sent back to the AC power source 3. The motor drive device 4 receives the DC voltage supplied by the inverter 1-1 and controls the motor 5 at a variable speed. In addition, the motor control device of the first embodiment is a device including an inverter 1-1 and a motor drive device 4 that receives a supply of DC voltage from the inverter 1-1 and controls the motor 5 at a variable speed.

Inverter 1-1 is equipped with: smoothing capacitor 21 storing DC power, power module 22, bus voltage detection section 23, voltage phase detection section 24, bus current detection section 25, and base drive signal generation as a drive signal generation section The unit 26, the base drive circuit 27 as a drive circuit, the regeneration control unit 28 as a signal control unit, and the control power supply unit 29.

The power module 22 includes three AC terminals 11, 12, 13, a DC terminal 14 connected to the first terminal of the DC wiring on the high potential side, and a DC terminal 15 connected to the second terminal of the DC wiring on the low potential side. The AC terminal 11 is connected to one end of the AC wiring 51. The other end of the AC wiring 51 is connected to one end of the reactor 2-1. The other end of the reactor 2-1 is connected to one end of the AC wiring 91. The other end of the AC wiring 91 is connected to the terminal 3R of the AC power supply 3. The terminal 3R is a terminal that outputs the AC voltage of the R phase of the first phase. The AC voltage of the R phase is applied to the AC terminal 11 via the reactor 2-1.

The AC terminal 12 is connected to one end of the AC wiring 52. The other end of the AC wiring 52 is connected to one end of the reactor 2-2. The other end of the reactor 2-2 is connected to one end of the AC wiring 92. The other end of the AC wiring 92 is connected to the terminal 3S of the AC power supply 3. The terminal 3S is a terminal that outputs the AC voltage of the S phase of the second phase. The AC voltage of the S phase is applied to the AC terminal 12 via the reactor 2-2.

The AC terminal 13 is connected to one end of the AC wiring 53. The other end of the AC wiring 53 is connected to one end of the reactor 2-3. The other end of the reactor 2-3 is connected to one end of the AC wiring 93. The other end of the AC wiring 93 is connected to the terminal 3T of the AC power supply 3. Terminal 3T is a terminal that outputs the AC voltage of the T phase of the third phase. The AC voltage of the T phase is applied to the AC terminal 13 via the reactor 2-3. In the following, when the reactors 2-1, 2-2, and 2-3 are not distinguished, the reactor 2 may be called.

The DC terminal 14 is connected to one end of the positive bus bar 70P of the DC wiring on the high potential side. The other end of the positive bus bar 70P is connected to the output terminal 6-1 of the inverter 1-1. The output terminal 6-1 is a DC terminal on the high potential side. The output terminal 6-1 is connected to one end of the positive bus 71P. The positive electrode bus 71P is a DC wiring provided on the high potential side between the inverter 1-1 and the motor drive device 4. The other end of the positive electrode bus 71P is connected to the DC terminal 17 of the motor drive device 4. The DC terminal 17 is a DC terminal on the high potential side. The DC terminal 14 of the power module 22 is electrically connected to the DC terminal 17 of the motor drive device 4 via the positive bus 70P, the output terminal 6-1, and the positive bus 71P.

The DC terminal 15 is connected to one end of the negative bus bar 70N of the DC wiring on the low potential side. The other end of the negative bus bar 70N is connected to the output terminal 6-2 of the inverter 1-1. The output terminal 6-2 is a DC terminal on the low potential side. The output terminal 6-2 is connected to one end of the negative bus 71N. The negative electrode bus 71N is a DC wiring provided on the low potential side between the inverter 1-1 and the motor drive device 4. The other end of the negative electrode bus 71N is connected to the DC terminal 18 of the motor drive device 4. The DC terminal 18 is a DC terminal on the low potential side. The DC terminal 15 of the power module 22 is electrically connected to the DC terminal 18 of the motor drive device 4 via the negative bus 70N, the output terminal 6-2, and the negative bus 71N.

The terminal 21a on the high potential side of the smoothing capacitor 21 is connected to the positive bus bar 70P. Symbol 80P denotes a connection point between the terminal 21a on the high potential side of the smoothing capacitor 21 and the positive bus bar 70P. By connecting the terminal 21a on the high potential side of the smoothing capacitor 21 to the positive bus bar 70P, the terminal 21a on the high potential side of the smoothing capacitor 21 is electrically connected to the DC terminal 14 of the power module 22, and further connected to the motor driving device 4 The DC terminal 17 is electrically connected.

The terminal 21b on the low potential side of the smoothing capacitor 21 is connected to the negative bus bar 70N. In FIG. 1, symbol 80N represents the connection point between the terminal 21b on the low potential side of the smoothing capacitor 21 and the negative bus bar 70N. By connecting the terminal 21b on the low potential side of the smoothing capacitor 21 to the negative bus bar 70N, the terminal 21b on the low potential side of the smoothing capacitor 21 is electrically connected to the DC terminal 15 of the power module 22, and further connected to the motor driving device 4 The DC terminal 18 is electrically connected.

The power module 22 includes six rectifier elements D1, D2, D3, D4, D5, D6 and six regeneration switching elements S1, S2, in addition to the AC terminals 11, 12, 13 and the DC terminals 14, 15. S3, S4, S5, S6. Hereinafter, the six rectifying elements D1, D2, D3, D4, D5, and D6 are sometimes referred to as rectifying elements D1 to D6, and the switching elements S1, S2, S3, S4, S5, and S6 are referred to as switching elements S1 to S6. .

The rectifying element D1 is connected in antiparallel to the switching element S1. Specifically, the negative electrode of the cathode of the rectifying element D1 is connected to the collector of the switching element S1, and the positive electrode of the anode of the rectifying element D1 is connected to the emitter of the switching element S1. The rectifier element D1 and the switching element S1 constitute a power element. Similarly, the rectifying element D2 and the switching element S2 constitute a power element, the rectifying element D3 and the switching element S3 constitute a power element, the rectifying element D4 and the switching element S4 constitute a power element, the rectifying element D5 and the switching element S5 constitutes a power element, and the rectifying element D6 and the switching element S6 constitute a power element.

For each of the rectifying elements D1 to D6, for example, a diode, a Schottky barrier diode, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) can be used. Each of the six rectifying elements D1, D2, D3, D4, D5, and D6 may be an element having a rectifying effect, and is not limited to these elements.

The switching element S1 and the switching element S2 are connected in series by a wiring 8-1. The first arm is constituted by the switching element S1, the switching element S2, the rectifying element D1, the rectifying element D2, and the wiring 8-1. One end of the wiring 8-1 is connected to the emitter of the switching element S1. The other end of the wiring 8-1 is connected to the collector of the switching element S2. The wiring 8-1 is connected to one end of the wiring 9-1. Symbol 501 denotes the connection point of the wiring 8-1 and the wiring 9-1. The other end of the wiring 9-1 is connected to the AC terminal 11. As a result, the emitter of the switching element S1 and the collector of the switching element S2 are electrically connected to the AC terminal 11. Since the AC terminal 11 is electrically connected to the terminal 3R of the AC power supply 3 via the reactor 2-1, etc., the rectifying element D1 and the switching element S1 constitute a power element for the positive pole of the R phase, and the rectifying element D2 and the switching element S2 constitute Power element for negative pole of R phase. The collector of the switching element S1 is connected to the DC terminal 14 via a wiring 9-4. The emitter of the switching element S2 is connected to the DC terminal 15 via a wiring 9-5.

The switching element S3 and the switching element S4 are connected in series by wiring 8-2. The second arm is constituted by the switching element S3, the switching element S4, the rectifying element D3, the rectifying element D4, and the wiring 8-2. One end of the wiring 8-2 is connected to the emitter of the switching element S3. The other end of the wiring 8-2 is connected to the collector of the switching element S4. The wiring 8-2 is connected to one end of the wiring 9-2. Symbol 502 indicates the connection point of the wiring 8-2 and the wiring 9-2. The other end of the wiring 9-2 is connected to the AC terminal 12. Accordingly, the emitter of the switching element S3 and the collector of the switching element S4 are electrically connected to the AC terminal 12. Since the AC terminal 12 is electrically connected to the terminal 3S of the AC power supply 3 via the reactor 2-2, etc., the rectifier element D3 and the switching element S3 constitute a power element for the positive pole of the S phase, and the rectifier element D4 and the switching element S4 are The power element for the negative electrode of the S phase. The collector of the switching element S3 is connected to the DC terminal 14 via a wiring 9-4. The emitter of the switching element S4 is connected to the DC terminal 15 via a wiring 9-5.

The switching element S5 and the switching element S6 are connected in series by wiring 8-3. The third arm is constituted by the switching element S5, the switching element S6, the rectifying element D5, the rectifying element D6, and the wiring 8-3. One end of the wiring 8-3 is connected to the emitter of the switching element S5. The other end of the wiring 8-3 is connected to the collector of the switching element S6. The wiring 8-3 is connected to one end of the wiring 9-3. Symbol 503 denotes the connection point of the wiring 8-3 and the wiring 9-3. The other end of the wiring 9-3 is connected to the AC terminal 13. As a result, the emitter of the switching element S5 and the collector of the switching element S6 are electrically connected to the AC terminal 13. Since the AC terminal 13 is electrically connected to the terminal 3T of the AC power supply 3 via reactors 2-3, etc., the rectifying element D5 and the switching element S5 constitute a power element for the positive pole of the T phase, and the rectifying element D6 and the switching element S6 are The power element for the negative electrode of the T phase. The collector of the switching element S5 is connected to the DC terminal 14 via a wiring 9-4. The emitter of the switching element S6 is connected to the DC terminal 15 via a wiring 9-5.

The DC terminal 14 is electrically connected to the collectors of the switching element S1, the switching element S3, and the switching element S5 constituting the upper arm. The DC terminal 15 is electrically connected to the emitters of the switching element S2, the switching element S4, and the switching element S6 constituting the lower arm. The DC terminal 14 and the DC terminal 15 of the power module 22 are connected in parallel with a series circuit composed of a switching element S1 and a switching element S2, a series circuit composed of a switching element S3 and a switching element S4, and by a switch A series circuit composed of the element S5 and the switching element S6. In addition, the inverter 1-1 of the first embodiment is connected to a three-phase AC power supply 3, but a single-phase AC power supply may be connected instead of the three-phase AC power supply 3. When a single-phase AC power supply is connected, the power module 22 has four power components.

The bus voltage detection unit 23 detects the voltage applied to the terminals 21a and 21b of the smoothing capacitor 21, and outputs voltage information indicating the detected voltage as the bus voltage VPN. Since the terminal 21a of the smoothing capacitor 21 is connected to the DC terminal 14 of the power module 22 via the positive bus 70P, and the terminal 21b of the smoothing capacitor 21 is connected to the DC terminal 15 of the power module 22 via the negative bus 70N, it is applied to the smoothing capacitor The voltage of the terminal 21a and the terminal 21b of 21 is equal to the voltage applied to the DC terminal 14 and the DC terminal 15 of the power module 22.

The bus current detection unit 25 is provided between, for example, the DC terminal 14 of the positive bus 70P and the connection point 80P. The bus current detection unit 25 detects the current flowing in the positive bus 70P, and outputs current information indicating the detected current as the bus current IPN. The bus current detection unit 25 may be a current sensor using a CT (Current Transformer) current transformer, or a current sensor using a shunt resistor. The bus current detection unit 25 may be a combination of these. The bus current detection unit 25 may be provided between the DC terminal 18 of the negative bus 70N and the connection point 80N, for example, to detect the current flowing in the negative bus 70N.

The control power supply unit 29 generates power for driving the switching elements S1 to S6 of the power module 22 and generates power for driving the base drive circuit 27. As mentioned above, the emitter of the switching element S1 is connected to the R phase of the AC power supply 3 via the reactor 2-1, and the emitter of the switching element S3 is connected to the S phase of the AC power supply 3 via the reactor 2-2. The emitter of the element S5 is connected to the T phase of the AC power supply 3 via the reactor 2-3. Therefore, in order to drive each element of the switching elements S1, S3, and S5 disposed on the positive side, the base drive circuit 27 must be grounded to separate the drive signal generating circuit that drives each element of the switching elements S1, S3, and S5. That is, it is necessary to insulate the generating circuits of the drive signals corresponding to the switching elements S1, S3, and S5 from each other. On the other hand, since the emitters of the switching elements S2, S4, and S6 arranged on the negative side are connected to the DC terminal 15 of the power module 22, the grounding of the potential reference of the emitters of the switching elements S2, S4, and S6 is the same . Therefore, in the base drive circuit 27, the ground of the generating circuit for driving the drive signals for driving the switching elements S2, S4, and S6 disposed on the negative side may be the same. Therefore, in order to operate the base drive circuit 27, it is necessary to have at least four insulated power supplies.

FIG. 2 is a diagram showing a configuration example of the control power supply unit shown in FIG. 1. As shown in FIG. 2, the control power supply unit 29 includes a main power supply 31, a power supply control IC (Integrated Circuit) 32, a switching element 33, an insulating transformer 30, a plurality of rectifying elements D21, D22, D23, D24, capacitors C21, C22, C23, C24, and feedback unit 34.

The insulating transformer 30 is composed of a primary coil N11 and a plurality of secondary coils N21, N22, N23, and N24. Each of the plurality of secondary coils N21, N22, N23, and N24 is insulated between adjacent coils. The IC32 for power supply control includes a power supply terminal VCC, a feedback terminal FB, a gate signal output terminal SW, and a ground terminal GND.

The positive terminal of the main power supply 31 is connected to the winding start side terminal of the primary coil N11 and the power supply terminal VCC of the power supply control IC 32. The winding end terminal of the primary coil N11 is connected to the drain terminal D of the switching element 33. The source terminal S of the switching element 33 is connected to the negative terminal of the main power supply 31 and the GND terminal of the power supply control IC 32. The gate G of the switching element 33 is connected to the SW terminal of the power supply control IC 32.

The anode of the rectifier element D21 is connected to the winding end terminal of the secondary coil N21, and the cathode of the rectifier element D21 is connected to one end of the capacitor C21. The other end of the capacitor C21 is connected to the winding start side terminal of the secondary coil N21 via a wiring 291. The connection point between the cathode of the rectifying element D21 and one end of the capacitor C21 is connected to one end of the wiring 291-1. The connection point of the other end of the capacitor C21 and the wiring 291 is connected to one end of the wiring 291-2. The wiring 291-2 is connected to the ground VRPGND that becomes the reference potential of the voltage VRP generated in the wiring 291-1. The voltage VRP is equal to the voltage applied between one end and the other end of the capacitor C21. The other ends of the wiring 291-1 and the wiring 291-2 are connected to the base drive circuit 27 shown in FIG.

The anode of the rectifier element D22 is connected to the winding end terminal of the secondary coil N22, and the cathode of the rectifier element D22 is connected to one end of the capacitor C22. The other end of the capacitor C22 is connected to the winding start side terminal of the secondary coil N22 via a wiring 292. The connection point between the cathode of the rectifying element D22 and one end of the capacitor C22 is connected to one end of the wiring 292-1. The connection point of the other end of the capacitor C22 and the wiring 292 is connected to one end of the wiring 292-2. The wiring 292-2 is connected to the ground VSPGND that becomes the reference potential of the voltage VSP generated in the wiring 292-1. The voltage VSP is equal to the voltage applied between one end and the other end of the capacitor C22. The other ends of the wiring 292-1 and the wiring 292-2 are connected to the base drive circuit 27 shown in FIG.

The anode of the rectifier element D23 is connected to the winding end terminal of the secondary coil N23, and the cathode of the rectifier element D23 is connected to one end of the capacitor C23. The other end of the capacitor C23 is connected to the winding start side terminal of the secondary coil N23 via a wiring 293. The connection point between the cathode of the rectifying element D23 and one end of the capacitor C23 is connected to one end of the wiring 293-1. The connection point of the other end of the capacitor C23 and the wiring 293 is connected to one end of the wiring 293-2. The wiring 293-2 is connected to the ground VTPGND that becomes the reference potential of the voltage VTP generated in the wiring 293-1. The voltage VTP is equal to the voltage applied between one end and the other end of the capacitor C23.

The anode of the rectifier element D24 is connected to the winding end terminal of the secondary coil N24, and the cathode of the rectifier element D24 is connected to one end of the capacitor C24. The other end of the capacitor C24 is connected to the winding start side terminal of the secondary coil N24 via a wiring 294. The connection point between the cathode of the rectifying element D24 and one end of the capacitor C24 is connected to one end of the wiring 294-1. The connection point of the other end of the capacitor C24 and the wiring 294 is connected to one end of the wiring 294-2. The wiring 294-2 is connected to the ground VNGND that becomes the reference potential of the voltage VN generated in the wiring 294-1. The voltage VN is equal to the voltage applied between one end and the other end of the capacitor C24. The voltage VN is input to the feedback unit 34. The feedback unit 34 can use, for example, an optocoupler. The feedback unit 34 converts the voltage VN into a voltage value that can be handled by the power supply control IC 32 when the FB terminal of the power supply control IC 32 is insulated from the secondary coil N24, and Input the converted voltage value to the FB terminal of power supply control IC32. By using the feedback section 34, the insulation of the circuit on the primary coil N11 side and the circuits on the secondary coil N21 to N24 sides can be maintained.

In the control power supply section 29, by equalizing the number of turns of the secondary coils N21, N22, N23 and the number of turns of the secondary coil N24, the voltage generated in each of the capacitors C21, C22, C23 and the capacitor C24 The voltage generated in is almost equal.

Next, the operation of the control power supply unit 29 will be described. The power supply control IC 32 generates a control signal that controls the on-off operation of the switching element 33 based on the voltage VN output from the feedback unit 34. The power supply control IC 32 outputs the generated control signal from the SW terminal, and the output control signal is input to the gate of the switching element 33. As a result, the switching element 33 repeats the on-off operation to maintain the value of the voltage VN input to the feedback section 34 at a specific value.

The voltage phase detection unit 24 shown in FIG. 1 detects the voltage phase of the AC power supply 3 and outputs phase information showing the detected voltage phase to the base drive signal generation unit 26 as a phase detection signal. The phase detection signal is a signal with a potential of High level or Low level. The details of the voltage phase detection method and the phase detection signal by the voltage phase detection unit 24 will be described in detail later.

The base drive signal generating section 26 generates six base drive signals SRP, SRN, SSP, SSN, STP, and STN based on the phase detection signal output from the voltage phase detection section 24 to drive the switching elements S1 to S6 and output to Regeneration control unit 28. Each of the six base drive signals SRP, SRN, SSP, SSN, STP, and STN is a signal that takes a high level or a low level potential. The base drive signal SRP is a signal for driving the switching element S1 for the positive side of the R phase. The base driving signal SRN is a signal for driving the switching element S2 for the negative side of the R phase. The base drive signal SSP is a signal for driving the switching element S3 for the positive side of the S phase. The base driving signal SSN is a signal for driving the switching element S4 for the negative side of the S phase. The base driving signal STP is a signal for driving the switching element S5 for the positive side of the T phase. The base driving signal STN is a signal for driving the switching element S6 for the negative side of the T phase. The following six types of base drive signals SRP, SRN, SSP, SSN, STP, and STN are sometimes referred to as base drive signals SRP to STN.

Based on the bus current IPN and the bus voltage VPN, the regeneration control unit 28 determines whether to continue the transmission of the base drive signal SRP from the base drive signal generation unit 26 to the STN to the base drive circuit 27, or to stop from The base driving signals SRP to STN output by the base driving signal generating unit 26 are transmitted to the base driving circuit 27. When the regeneration control unit 28 determines that the base drive signals SRP to STN are to be continuously transmitted to the base drive circuit 27, the base drive signals SRP to STN are continuously input to the base drive circuit 27. When the regeneration control unit 28 judges that the transmission of the base drive signals SRP to STN to the base drive circuit 27 is to be stopped, the base drive signals SRP to STN stop input to the base drive circuit 27.

Fig. 3 is a diagram showing a configuration example of the regeneration control unit shown in Fig. 1. As shown in FIG. 3, the regeneration control unit 28 includes a regeneration start determination unit 60, a regeneration stop determination unit 61, a logical OR circuit 62, and an NPN transistor 63. The regeneration start determination unit 60 inputs the bus voltage VPN. The regeneration start determination unit 60 has a function of determining whether to start the regeneration operation by the power module 22 shown in FIG. 1 based on the bus voltage VPN. The regeneration start determination unit 60 includes a subtractor 64 and a comparator 65. The subtractor 64 inputs the bus voltage VPN and the reference voltage Vref. The reference voltage Vref is a voltage preset according to the voltage of the AC power supply 3. In addition, the method of generating the reference voltage Vref is, for example, a method of detecting the voltage of the AC power supply 3 to generate the reference voltage Vref, a method of generating the reference voltage Vref based on the bus voltage VPN output from the bus voltage detection unit 23, and any method is conventional. Those skilled in the art will omit detailed description here. The subtractor 64 calculates the difference voltage ΔV of the difference between the bus voltage VPN and the reference voltage Vref.

The differential voltage ΔV is input to the positive terminal of the comparator 65. The negative terminal of the comparator 65 inputs the threshold voltage Vo. The comparator 65 compares the difference voltage ΔV with the threshold voltage Vo and outputs a signal with a potential at a high level or a low level. For example, when the difference voltage ΔV is greater than the threshold voltage Vo, a high level signal is output. The signal of the high level is a signal indicating that the regeneration operation by the power module 22 starts when the bus voltage VPN is higher than a certain value. When the difference voltage ΔV does not reach the threshold voltage Vo, a signal of Low level is output. The signal output from the comparator 65 is input to the logical OR circuit 62 as the output signal of the regeneration start determination unit 60.

In addition, in the regeneration start determination unit 60 of the regeneration control unit 28 of the first embodiment, immediately after the start of the regeneration operation in the power module 22, the difference voltage ΔV and the threshold voltage Vo become the difference voltage ΔV <the threshold voltage Vo Therefore, it is preferable to provide, for example, a hysteresis function in the comparator 65, a one-way trigger circuit in the output of the comparator 65, or configure the regeneration start determination unit 60 to continue from the start of the regeneration operation until a certain period elapses Perform regeneration.

The regeneration stop determination unit 61 inputs the bus current IPN. The regeneration stop determination unit 61 has a function of determining whether to stop the regeneration operation in the power module 22 based on the bus current IPN. The regeneration stop determination unit 61 includes a comparator 66. The positive terminal of the comparator 66 inputs the threshold current Iref. The negative terminal of the comparator 66 receives the bus current IPN. The comparator 66 compares the bus current IPN and the threshold current Iref and outputs a signal with a potential at a high level or a low level. For example, when the bus current IPN is greater than the threshold current Iref, a low level signal is output. When the bus current IPN does not reach the threshold current Iref, a high level signal is output. The signal output from the comparator 66 is input to the logical OR circuit 62 as the output signal of the regeneration stop determination unit 61.

The output of the logical OR circuit 62 is connected to the base of the NPN transistor 63. The regeneration signal Ron of the output signal of the logical OR circuit 62 is input to the base of the NPN transistor 63. The collector of the NPN transistor 63 is connected to the base drive signal generator 26 shown in FIG. The collector of the NPN transistor 63 is input with the base drive signals SRP to STN output from the base drive signal generation section 26. The emitter of the NPN transistor 63 is connected to the base drive circuit 27.

Next, the operation of the regeneration control unit 28 will be described. As described above, the logical OR circuit 62 inputs each output signal of the regeneration start determination unit 60 and the regeneration stop determination unit 61. When any output signal is High level, the logical OR circuit 62 outputs a High level signal. When the logic OR circuit 62 outputs a high-level signal, the NPN transistor 63 becomes conductive, so that the base drive signals SRP to STN are input to the base drive circuit 27 shown in FIG. 1. In the base driving circuit 27, the base driving signals SRP to STN are converted into signals that can be processed by each power element of the power module 22 to generate the converted base driving signals SRP', SRN', SSP', SSN', STP', STN'. The generated base drive signals SRP', SRN', SSP', SSN', STP', and STN' are input to the bases of the switching elements S1 to S6. Thereby, the switching elements S1 to S6 are turned on and off, that is, the power module 22 is regenerated. Hereinafter, the base driving signals SRP', SRN', SSP', SSN', STP', and STN' are sometimes referred to as base driving signals SRP' to STN'. The details of the base drive circuit 27 will be described later.

On the other hand, when the output signals of the regeneration start determination unit 60 and the regeneration stop determination unit 61 are at a low level, the logical OR circuit 62 outputs a signal at a low level. When the logic OR circuit 62 outputs a low level signal, the NPN transistor 63 becomes off, blocking the input of the base drive signals SRP to STN to the base drive circuit 27 shown in FIG. 1. As a result, all the switching elements S1 to S6 are turned off, and the regeneration operation is stopped.

In this way, when at least one of the regeneration start determination unit 60 and the regeneration stop determination unit 61 outputs a signal of High level, the regeneration operation is continued, and both the regeneration start determination unit 60 and the regeneration stop determination unit 61 output In the case of a low level signal, the regeneration operation is stopped.

Next, the base drive circuit 27 will be described. As mentioned above, the base drive circuit 27 has the base drive signals SRP, SRN, SSP, SSN, STP, and STN output from the regeneration control unit 28 into base drive signals SRP that can be processed by the power module 22 , SRN', SSP', SSN', STP', STN' and input to the function of the base of the switching elements S1 to S6 of the power module 22. FIG. 4 is a diagram showing a configuration example of the base drive circuit 27 shown in FIG. The base drive circuit 27 shown in FIG. 4 includes a base control circuit 35 and a voltage application unit 36.

The base control circuit 35 is provided with an electrical signal that isolates the signal input to the base control circuit 35, and outputs an output signal with the same potential as the input signal to the voltage applying section 36, that is, the input signal is at a high level In this case, the output signal of the high level is output, and the function of outputting the output signal of the low level when the input signal is the low level. For example, in the case where the base drive signal SRP taking the potential of the High level is input to the base control circuit 35, the base control circuit 35 is in the state of being electrically insulated from the base drive signal SRP and will take the High bit The signal of the quasi-potential is output to the voltage applying section 36. The base control circuit 35 may use, for example, an optical coupler, an insulated pulse transformer, etc., but the components constituting the base control circuit 35 are not limited to these. If the input signal and the output signal can be electrically insulated, they can be transmitted and It suffices if the input signal is the output signal of the same potential.

The base control circuit 35 is provided with: a control circuit 35A that electrically insulates and converts the base drive signal SRP to the same potential as the base drive signal SRP; and electrically isolates and converts the base drive signal SRN to the base The control circuit 35B of the pole drive signal SRN is a signal of the same potential; the control circuit 35C that electrically isolates and converts the base drive signal SSP to a signal of the same potential as the base drive signal SSP; the base drive signal SSN is electrically A control circuit 35D that insulates and converts the signal to the same potential as the base drive signal SSN; a control circuit 35E that electrically insulates and converts the base drive signal STP to the same potential as the base drive signal STP; and will The control circuit 35F that electrically isolates and converts the base drive signal STN into a signal at the same potential as the base drive signal STN.

The voltage applying unit 36 inputs the output signal of the base control circuit 35. The plurality of outputs of the voltage applying section 36 are connected to the bases of the switching elements S1 to S6 of the power module 22. The voltage applying unit 36 includes: a first voltage applying unit 36A that generates and outputs the base drive signal SRP' based on the output signal of the control circuit 35A; and generates and outputs a base drive signal SRN' based on the output signal of the control circuit 35B The second voltage applying part 36B; and the third voltage applying part 36C that generates and outputs the base driving signal SSP' according to the output signal of the control circuit 35C. In addition, the voltage applying unit 36 includes: a fourth voltage applying unit 36D that generates and outputs the base driving signal SSN′ based on the output signal of the control circuit 35D; and generates and outputs the base driving signal STP based on the output signal of the control circuit 35E 'Fifth voltage applying part 36E; and the sixth voltage applying part 36F that generates and outputs the base drive signal STN' according to the output signal of the control circuit 35F.

FIG. 5 is a diagram showing a configuration example of the first voltage applying section shown in FIG. 4. The first voltage applying unit 36A shown in FIG. 5 includes an NPN transistor 37, a PNP transistor 38, and a base resistance 39. The base of the NPN transistor 37 and the base of the PNP transistor 38 are connected to each other, and the output of the control circuit 35A is connected to each base. The emitter of the NPN transistor 37 and the emitter of the PNP transistor 38 are connected to each other, and each emitter is connected to one end of the base resistor 39. The other end of the base resistor 39 is connected to the base of the switching element S1. The collector of the NPN transistor 37 is connected to the wiring 291-1 shown in FIG. As a result, the voltage VRP generated by the control power supply unit 29 shown in FIG. 2 is applied to the collector of the NPN transistor 37. The collector of the PNP transistor 38 and the emitter of the switching element S1 are connected to each other, and are further connected to the wiring 291-2 shown in FIG. 2. Thereby, the collector of the PNP transistor 38 and the emitter of the switching element S1 are electrically connected to the ground VRPGND shown in FIG. 2.

FIG. 6 is a diagram showing a configuration example of the second voltage applying section shown in FIG. 4. As shown in FIG. 6, the second voltage applying unit 36B includes the NPN transistor 37, the PNP transistor 38 and the base resistance 39 in the same manner as the first voltage applying unit 36A. In the second voltage applying unit 36B, the base of the NPN transistor 37 and the base of the PNP transistor 38 are connected to the output of the control circuit 35B. In the second voltage applying unit 36B, the other end of the base resistance 39 is connected to the base of the switching element S2. In addition, in the second voltage applying section 36B, the collector of the NPN transistor 37 is connected to the wiring 294-1 shown in FIG. 2. With this, the voltage VN generated by the control power supply unit 29 shown in FIG. 2 is applied to the collector of the NPN transistor 37. In the second voltage applying unit 36B, the collector of the PNP transistor 38 and the emitter of the switching element S2 are connected to the wiring 294-2 shown in FIG. 2. As a result, the collector of the PNP transistor 38 and the emitter of the switching element S2 are electrically connected to the ground VNGND shown in FIG. 2.

FIG. 7 is a diagram showing a configuration example of the third voltage applying section shown in FIG. 4. As shown in FIG. 7, the third voltage applying unit 36C includes the NPN transistor 37, the PNP transistor 38 and the base resistance 39 in the same manner as the first voltage applying unit 36A. In the third voltage applying unit 36C, the base of the NPN transistor 37 and the base of the PNP transistor 38 are connected to the output of the control circuit 35C. In the third voltage applying section 36C, the other end of the base resistor 39 is connected to the base of the switching element S3. In addition, in the third voltage applying section 36C, the collector of the NPN transistor 37 is connected to the wiring 292-1 shown in FIG. 2. As a result, the voltage VSP generated by the control power supply unit 29 shown in FIG. 2 is applied to the collector of the NPN transistor 37. In the third voltage applying unit 36C, the collector of the PNP transistor 38 and the emitter of the switching element S3 are connected to the wiring 292-2 shown in FIG. 2. As a result, the collector of the PNP transistor 38 and the emitter of the switching element S3 are electrically connected to the ground VSPGND shown in FIG. 2.

FIG. 8 is a diagram showing a configuration example of the fourth voltage applying section shown in FIG. 4. As shown in FIG. 8, like the first voltage applying unit 36A, the fourth voltage applying unit 36D includes an NPN transistor 37, a PNP transistor 38 and a base resistance 39. In the fourth voltage applying unit 36D, the base of the NPN transistor 37 and the base of the PNP transistor 38 are connected to the output of the control circuit 35D. In addition, in the fourth voltage applying portion 36D, the other end of the base resistor 39 is connected to the base of the switching element S4. In addition, in the fourth voltage applying portion 36D, the collector of the NPN transistor 37 is connected to the wiring 294-1 shown in FIG. 2. With this, the voltage VN generated by the control power supply unit 29 shown in FIG. 2 is applied to the collector of the NPN transistor 37. In the fourth voltage applying unit 36D, the collector of the PNP transistor 38 and the emitter of the switching element S4 are connected to the wiring 294-2 shown in FIG. 2. As a result, the collector of the PNP transistor 38 and the emitter of the switching element S4 are electrically connected to the ground VNGND shown in FIG. 2.

FIG. 9 is a diagram showing a configuration example of a fifth voltage applying section shown in FIG. 4. As shown in FIG. 9, like the first voltage applying section 36A, the fifth voltage applying section 36E includes an NPN transistor 37, a PNP transistor 38 and a base resistance 39. In the fifth voltage applying unit 36E, the base of the NPN transistor 37 and the base of the PNP transistor 38 are connected to the output of the control circuit 35E. In addition, in the fifth voltage applying portion 36E, the other end of the base resistance 39 is connected to the base of the switching element S5. In addition, in the fifth voltage applying portion 36E, the collector of the NPN transistor 37 is connected to the wiring 293-1 shown in FIG. 2. As a result, the voltage VTP generated by the control power supply unit 29 shown in FIG. 2 is applied to the collector of the NPN transistor 37. In the fifth voltage applying unit 36E, the collector of the PNP transistor 38 and the emitter of the switching element S5 are connected to the wiring 293-2 shown in FIG. 2. As a result, the collector of the PNP transistor 38 and the emitter of the switching element S5 are electrically connected to the ground VTPGND shown in FIG. 2.

FIG. 10 is a diagram showing a configuration example of a sixth voltage applying section shown in FIG. 4. As shown in FIG. 10, the sixth voltage applying unit 36F includes the NPN transistor 37, the PNP transistor 38, and the base resistance 39 in the same manner as the first voltage applying unit 36A. In the sixth voltage applying unit 36F, the base of the NPN transistor 37 and the base of the PNP transistor 38 are connected to the output of the control circuit 35F. In the sixth voltage applying unit 36F, the other end of the base resistance 39 is connected to the base of the switching element S6. In the sixth voltage applying unit 36F, the collector of the NPN transistor 37 is connected to the wiring 294-1 shown in FIG. 2. With this, the voltage VN generated by the control power supply unit 29 shown in FIG. 2 is applied to the collector of the NPN transistor 37. In the sixth voltage applying unit 36F, the collector of the PNP transistor 38 and the emitter of the switching element S6 are connected to the wiring 294-2 shown in FIG. 2. As a result, the collector of the PNP transistor 38 and the emitter of the switching element S6 are electrically connected to the ground VNGND shown in FIG. 2.

Next, the operation of the base drive circuit 27 will be described. Here, the operation of the base drive circuit 27 will be described using the first voltage applying unit 36A shown in FIG. 5. When the base drive signal SRP of the switching element S1 is output from the regeneration control unit 28, the control circuit 35A generates and outputs a signal insulated from the base drive signal SRP. When the signal of the High level is input by the first voltage applying section 36A, the PNP transistor 38 is turned off and the NPN transistor 37 is turned on. Thereby, the wiring 291-1 and the base of the switching element S1 are turned on via the base resistance 39, and the electric charge is charged between the electrode of the base and the emitter of the switching element S1. When the charge is charged, the voltage VBE applied between the base and emitter electrodes of the switching element S1 exceeds a predetermined threshold voltage, and the switching element S1 is turned on. Hereinafter, the voltage applied between the base and emitter electrodes of the switching element S1 is referred to as a voltage VBE. When the voltage VBE rises to the voltage VRP, the charging between the base of the switching element S1 and the electrode of the emitter via the base resistor 39 ends.

When the signal of Low level is input by the first voltage applying part 36A, the NPN transistor 37 is turned off and the PNP transistor 38 is turned on. As a result, the ground VRPGND and the base of the switching element S1 are turned on via the base resistor 39, and the charge charged between the electrode of the base and the emitter of the switching element S1 is discharged. The switching element S1 is turned off when the voltage VBE applied between the base and emitter electrodes of the switching element S1 does not reach a predetermined threshold voltage due to the discharge of charge. When the voltage VBE decreases to the ground VRPGND, the discharge of the charge charged between the base of the switching element S1 and the electrode of the emitter ends.

The other switching elements also operate on the same principle, so the description is omitted. In addition, when the base drive signal SRP is not output from the regeneration control unit 28, that is, the regeneration operation is not performed, the base drive circuit 27 does not operate, and the switching elements S1 to S6 do not perform on-off operations And remain in the off state.

As described above, the base drive circuit 27 converts the base drive signals SRP, SRN, SSP, SSN, STP, and STN output by the regeneration control unit 28 into the power module 22 using the power supplies generated in the control power supply unit 29 The base drive signals SRP', SRN', SSP', SSN', STP', and STN' that can be processed, and the switching elements S1 to S6 are turned on and off.

Next, the regeneration operation in inverter 1-1 will be described using FIGS. 11 and 12. FIG. 11 is a diagram for explaining the operation of the voltage phase detection unit shown in FIG. 1. As described above, the emitters of the switching elements S1, S3, and S5 disposed on the positive side of the power module 22 are connected to the R-phase, S-phase, and T-phase of the AC power supply 3 through the reactor 2. The emitters of the switching elements S1, S3, and S5 are connected to the grounds VRPGND, VSPGND, and VTPGND of the control power supply 29.

The voltage phase detection unit 24 shown in FIG. 11 detects the R-phase input voltage VR1 based on the signal generated by the ground VRPGND connected to the wiring 291-2. The R-phase input voltage VR1 is equivalent to the voltage applied between the AC terminal 11 and the AC terminal 12 shown in FIG. In addition, the voltage phase detection unit 24 detects the S-phase input voltage VS1 based on the signal generated by the ground VSPGND connected to the wiring 292-2. The S-phase input voltage VS1 is equivalent to the voltage applied between the AC terminal 12 and the AC terminal 13 shown in FIG. In addition, the voltage phase detection unit 24 detects the T-phase input voltage VT1 based on the signal generated by the ground VTPGND connected to the wiring 293-2. The T-phase input voltage VT1 is equivalent to the voltage applied between the AC terminal 13 and the AC terminal 11 shown in FIG. Since the emitters of the switching elements S1, S3, and S5 are connected to the grounds VRPGND, VSPGND, and VTPGND of the control power supply section 29, the voltage phase detection section 24 is based on the signals flowing in the emitters of the switching elements S1, S3, and S5. It is a signal flowing in the ground which becomes the reference potential of the control power supply unit 29, and the voltage of the AC voltage when the switching elements S1 to S6 are turned on and off is detected in such a manner that AC power is regenerated from the power module 22 to the AC power supply 3 Phase, and generate and output a phase detection signal showing the detected voltage phase.

Fig. 12 is a time chart for explaining the operation of the inverter shown in Fig. 1; In Figure 12, the waveforms of the line voltages VR-S, VS-T, VT-R, VS-R, VT-S, and VR-T output from the AC power supply 3 are displayed in order from the top. The waveforms of the six phase detection signals, the waveforms of the base drive signals SRP to STN, and the waveforms of the regenerative currents (Irr, Isr, Itr) flowing in the R phase, T phase, and S phase. The line voltage VR-S and the line voltage VS-R correspond to the aforementioned R-phase input voltage VR1, and change complementarily. The line voltage VS-T and the line voltage VT-S correspond to the aforementioned S-phase input voltage VS1, and change complementarily. The line voltage VR-T and the line voltage VT-R correspond to the aforementioned T-phase input voltage VT1, and change complementarily. The regenerative current refers to the current flowing from the motor drive device 4 shown in FIG. 1 toward the AC power source 3 through the switching elements S1 to S6 during the regenerative operation.

In addition, the line voltage VR-S detects the voltage difference from the R phase based on the S phase, and the line voltage VS-R detects the voltage difference from the S phase based on the R phase. The voltage phase of the line voltage VR-S and the line voltage VS-R are shifted by 180 degrees. Similarly, the line voltage VS-T is based on the T phase to detect the voltage difference with the S phase, and the line voltage VT-S is based on the S phase to detect the voltage difference with the T phase. The voltage VS-T and the line voltage VT-S have a phase shift of 180 degrees. The line voltage VT-R is based on the R phase to detect the voltage difference with the T phase. In contrast, the line voltage VR-T is based on the T phase to detect the voltage difference with the R phase. The line voltage VT- The voltage phase of R and the line voltage VR-T is shifted by 180 degrees.

The voltage phase detection unit 24 estimates the line voltage VR-S, line voltage VS-R, line voltage VS-T, line voltage VT-S based on the R-phase input voltage VR1, the S-phase input voltage VS1 and the T-phase input voltage VT1 The line voltage VR-T and the line voltage VT-R extract the zero crossing points of each line voltage according to the estimation result, and treat the extracted zero crossing points as the phase detection signal. This phase detection signal is output to the base drive signal generating section 26. FIG. 12 illustrates each phase detection signal output by the voltage phase detection unit 24. In Figure 12, the RS-line phase detection signal, SR-line phase detection signal, ST-line phase detection signal, TS-line phase detection signal, TR-line phase detection signal, and RT-line phase detection are displayed in order from the top Signal. For example, the phase detection signal between the RS lines takes the value of High in the interval (phase interval) where the difference between the line voltage VR-S and the line voltage VS-R is positive, and takes Low in the negative interval (phase interval) The value of the level. The voltage phase detection unit 24 generates a phase detection signal whose level changes in accordance with each line voltage.

Next, the base drive signal generating section 26 generates the base drive signals SRP to STN according to the phase detection signals shown in FIG. 12 by the method shown below.

When the potential of the line voltage VR-S is at its maximum, the base drive signal generating unit 26 sets the base drive signals SRP and SSN to the High level and turns on the control switching element S1 and the switching element S4.

When the potential of the line voltage VS-T is at its maximum, the base drive signal generating unit 26 sets the base drive signals SSP and STN to the High level and turns on the control switching element S3 and the switching element S6.

When the potential of the line voltage VT-R is at its maximum, the base drive signal generating unit 26 sets the base drive signals STP and SRN to the High level and turns on the control switching element S5 and the switching element S2.

When the potential of the line voltage VS-R is at its maximum, the base drive signal generating unit 26 sets the base drive signals SSP and SRN to the High level and turns on the control switching element S3 and the switching element S2.

When the potential of the line voltage VT-S is at its maximum, the base drive signal generation unit 26 sets the base drive signals STP and SSN to the High level and turns on the control switching element S5 and the switching element S4.

When the potential of the line voltage VR-T is at its maximum, the base drive signal generation unit 26 sets the base drive signals SRP and STN to the High level and turns on the control switching element S1 and the switching element S6.

Next, the current flowing when the switching elements S1 to S6 are turned on or turned off according to the base driving signal will be described. Hereinafter, the ON operation or the OFF operation of the switching elements S1 to S6 may be referred to as a switching operation. In addition, FIG. 1 shows the R-phase current Ir, the S-phase current Is, and the T-phase current It indicated by arrows from the AC power supply 3 toward the inverter 1-1. Here, the directions of the arrows will be followed The flowing current is treated as a forward current, and the waveforms of the three regenerative currents shown in Figure 12 are described accordingly.

As described above, when the switching elements S1 to S6 perform switching operations, the R-phase regeneration current Irr, the S-phase regeneration current Isr, and the T-phase regeneration current Itr shown in FIG. 12 flow. From time t20 to t40, since the potential of the line voltage VR-S becomes the maximum, the switching elements S1 and S4 are turned on and the other switching elements are turned off. Thereby, the smoothing capacitor 21 and the R-S of the AC power supply 3 are connected via the impedance of the reactor 2. Therefore, the regenerative current flows through the on-state switching elements S1 and S4 to the R phase and the S phase.

Similarly, from time t40 to t60, since the potential of the line voltage VR-T becomes the maximum, the switching elements S1 and S6 are turned on and the other switching elements are turned off. Thereby, the smoothing capacitor 21 and the R-T of the AC power supply 3 are connected via the impedance of the reactor 2. Therefore, the regenerative current flows through the R-phase and T-phase through the on-state switching elements S1 and S6.

In addition, even in the case of a switching operation, when the relationship between the voltage between the terminals of the smoothing capacitor 21 and the voltage of the AC power supply 3 and the voltage between the terminals of the smoothing capacitor 21> the voltage of the AC power supply 3 does not hold, the regeneration current does not flow . The regenerative current uses the voltage difference between the voltage between the terminals of the smoothing capacitor 21 and the voltage of the AC power source 3 to flow in a state where the flow is limited by the impedance of the reactor 2.

Here, inductance due to various wirings exists between the AC terminal 11 and the switching element S1. Similarly, between the AC terminal 12 and the switching element S3, and between the AC terminal 13 and the switching element S5, inductance due to various wirings also exists. Figure 13 shows the inductance between the AC power supply and the AC terminal of the power module, and the inductance between the emitter of the switching element arranged on the positive side of the power module and the AC terminal of the power module Figure.

The inductance LR is the inductance of the reactor 2-1 shown in FIG. The inductance LS is the inductance of the reactor 2-2 shown in Fig. 1. The inductance LT is the inductance of the reactor 2-3 shown in Fig. 1. The inductance LR1 is caused by the wiring provided between the AC terminal 11 and the emitter of the switching element S1. The inductance LS1 is caused by the wiring provided between the AC terminal 12 and the emitter of the switching element S3. The inductance LT1 is caused by the wiring provided between the AC terminal 13 and the emitter of the switching element S5. The R-phase input voltage VR1 is a voltage applied to the emitter of the switching element S1. The R-phase voltage VR2 is a voltage applied between the inductor LR and the AC terminal 11. The S-phase input voltage VS1 is the voltage applied to the emitter of the switching element S3. The S-phase voltage VS2 is a voltage applied between the inductor LS and the AC terminal 12. The T-phase input voltage VT1 is the voltage applied to the emitter of the switching element S5. The T-phase voltage VT2 is a voltage applied between the inductor LT and the AC terminal 13.

Here, in the inverter 1-1 of the first embodiment, as described above, the R-phase input voltage VR1 is detected based on the signal generated by the ground VRPGND connected to the wiring 291-2, and the ground VSPGND connected to the wiring 292-2 The generated signal detects the S-phase input voltage VS1, and detects the T-phase input voltage VT1 based on the signal generated by the ground VTPGND connected to the wiring 293-2. Therefore, when viewing the power module 22 from the AC power supply 3, there is an inductance LR in the wiring connecting the terminal 3R of the AC power supply 3 and the AC terminal 11, and the inductance LR1 in the wiring connecting the AC terminal 11 and the switching element S1 and the cause Inductance of wiring 291-2. In addition, an inductance LS exists in the wiring connecting the terminal 3S of the AC power supply 3 and the AC terminal 12, and an inductance LS1 and an inductance due to the wiring 292-2 exist in the wiring connecting the AC terminal 12 and the switching element S3. In addition, an inductance LT exists in the wiring connecting the terminal 3T of the AC power supply 3 and the AC terminal 13, and an inductance LT1 and an inductance due to the wiring 293-2 exist in the wiring connecting the AC terminal 13 and the switching element S5. Therefore, compared with the technique shown in Patent Document 1, the inductance component of the AC power supply 3 to the switching elements S1, S3, and S5 becomes larger. Therefore, for example, when an external device other than the inverter 1-1 is connected to the AC power source 3, even if the voltage applied from the AC power source 3 to the AC terminals 11, 12, 13 fluctuates due to the regeneration operation of the external device The voltage fluctuation can also be slowed by the above inductance component.

In addition, measures such as the use of filter capacitors to suppress voltage fluctuations may also be considered. However, when the filter capacitors are used, a delay in the voltage phase occurs, which is not good. In the converter 1-1 of the first embodiment, even if the filter capacitor is not used, the fluctuation of the R-phase input voltage VR1 and the like detected by the voltage phase detection unit 24 can be suppressed, for example, in the state where the aforementioned external device is operating When the power supply of the converter 1-1 is turned on, the variation of the signal generated by the ground VRPGND connected to the wiring 291-2 can be suppressed, and the detection accuracy of the R-phase input voltage VR1 of the voltage phase detection section 24 can be improved.

In addition, the larger the power supplied to the motor drive device 4 shown in FIG. 1, the larger the current flowing through the AC terminals 11, 12, and 13 of the inverter 1-1, making the AC terminals 11, 12, and 13 large. It is difficult to directly connect the AC terminals 11, 12, 13 to the voltage phase detection section 24, the base drive signal generating section 26, the regeneration control section 28, the base drive circuit 27, and the control power supply section by bolting or the like 29 printed circuit board. Therefore, it is necessary to connect the AC terminals 11, 12, 13 and the printed wiring board with a bus bar, a wire harness, or the like, resulting in a complicated configuration for detecting the voltage phase of the AC power supply 3. According to the inverter 1-1 of the first embodiment, the voltage phase of the AC power supply 3 can be detected by detecting the R-phase input voltage VR1 and the like using the signal generated by the ground of the wiring 291-2 and the like connected to the pattern wiring on the printed wiring board Therefore, even in the case where the AC terminals 11, 12, 13 are enlarged, it is not necessary to use bus bars, wire harnesses, etc., which can reduce the manufacturing cost of the inverter 1-1, and can also suppress the voltage used to detect the AC power supply 3 The composition of the phase is complicated.

In addition, according to the converter 1-1 of the first embodiment, since the signal generated by the ground connected to the wiring 291-2 or the like can be used, it is possible to carry out a pattern design that can be easily arranged on the printed wiring board to achieve space saving.

Embodiment 2. Fig. 14 is a diagram showing the configuration of an inverter and a motor control device according to the second embodiment. The inverter 1-2 of the second embodiment includes a voltage phase detection unit 24A instead of the voltage phase detection unit 24 shown in FIG. First, the voltage phase detection unit 24 according to the first embodiment will be described based on the R-phase input voltage VR1, the S-phase input voltage VS1, and the T-phase input voltage VT1. The voltage variation of the following will be described later as the configuration of the voltage phase detection unit 24A of the second embodiment.

Fig. 15 is a diagram showing waveforms of line voltage, base drive signal, phase detection signal, etc. generated by the inverter of Embodiment 1 during a regeneration operation. In Figure 15, the waveforms of the base drive signals SRP to STN, the waveforms of the line voltages VR-S, VS-T, and VT-R during the regeneration operation, and the R phase generated during the regeneration operation are sequentially displayed from the top. The waveform of the phase detection signal RSD. As shown in FIG. 15, by switching the base drive signals SRP to STN to the High level and the Low level to perform the on-off operation of the switching elements S1 to S6 shown in FIG. During operation, surge voltage fluctuations occur in the line voltages VR-S, VS-T, and VT-R. When such a voltage fluctuation occurs, for example, the potential of the phase detection signal RSD changes within a short period of time at the zero crossing point of the line voltage VR-S in the order of High level, Low level, and High level.

Fig. 16 is a diagram showing the waveforms of the phase voltage, base drive signal, phase detection signal, etc. generated by the inverter of Embodiment 1 during the regeneration operation. In Figure 16, the waveforms of the base drive signals SRP to STN during the regeneration operation, the phase voltages VR2, VS2, and VT2 during the regeneration operation and the phase detection signal RD generated during the regeneration operation are displayed in order from the top. , SD, TD waveform. As shown in FIG. 16, when the base drive signals SRP to STN are switched to the high level and the low level to perform the on-off operation of the switching elements S1 to S6 shown in FIG. 1, due to the on-off During operation, surge voltage changes occur in the phase voltages VR2, VS2, and VT2. When such a voltage fluctuation occurs, for example, the potential of the phase detection signal RD changes in the order of High level, Low level, and High level at the zero crossing point of the phase voltage VR2 within a short period of time. The phase detection signals SD and TD also change similarly.

As described in the first embodiment, the voltage phase detection unit 24 receives, for example, the R-phase input voltage VR1, etc. However, there is a wiring 291-2 between the AC terminal 11 of the power module 22 and the switching element S1 inductance. With this inductance, the influence of voltage fluctuations caused by the regeneration operation of the external device connected to the AC power supply 3 can be reduced, but the surge-like voltage fluctuations caused by the on-off operations of the switching elements S1 to S6 overlap Wiring 291-2 etc. connected to the switching elements S1 to S6 etc. The voltage fluctuations shown in Fig. 15 and Fig. 16 are due to the phase-to-phase conduction through the rectifier elements D1 to D6 when the switching elements S1 to S6 are switched from on to off or from off to on. The inductance of the reactor 2 and the inductance of the AC terminals 11, 12, 13 divide the voltage. That is, during the regeneration operation of the power module 22, the line voltage, phase voltage, etc. generated by the R-phase input voltage VR1, the S-phase input voltage VS1, and the T-phase input voltage VT1 are easily affected by the regeneration operation Surge voltage fluctuations.

In addition, the voltage phase detection section 24 detects signals transmitted by the wiring 291-2 connected to the switching element S1, the wiring 292-2 connected to the switching element S3, the wiring 293-2 connected to the switching element S5, etc. The R-phase input voltage VR1, the S-phase input voltage VS1, and the T-phase input voltage VT1 are also susceptible to voltage fluctuations caused by oscillations generated when the switching elements S1, S3, and S5 are turned on and off. Therefore, compared with the case where the phase detection signal is generated by detecting the values of the phase voltages VR2, VS2, VT2 applied between the AC terminals 11, 12, 13 of the reactor 2 and the power module 22, the factors of the voltage fluctuation increase. That is, although the voltage phase detection unit 24 shown in Embodiment 1 can reduce the influence of voltage fluctuations caused by the regeneration operation of an external device connected to the AC power supply 3, it is still susceptible to the voltage phase detection unit The problem of the influence of the voltage fluctuation of the regeneration operation of the converter 1-1 of 24. In order to solve this problem, a method of filtering the detected line voltage or phase voltage waveform by a filter capacitor or the like to remove voltage fluctuations, or a method of reducing the switching speed of the switching element to suppress oscillation, etc. may be considered. However, in the case of filtering, a delay from the voltage phase of the original AC power supply 3 occurs, and a correction to match the original voltage phase is required. In addition, when the switching speed is reduced, there is a problem that the switching loss of the power module 22 increases.

In the voltage phase detection section 24A of the second embodiment, the maximum or minimum value of the phase voltage generated by the R-phase input voltage VR1, the S-phase input voltage VS1, and the T-phase input voltage VT1 is detected, or the R-phase The maximum or minimum value of the line voltage generated by the input voltage VR1, the S-phase input voltage VS1, and the T-phase input voltage VT1, thereby detecting the voltage phase of the AC power supply 3.

Next, a method of detecting the maximum value or the minimum value of the phase voltage by the voltage phase detection unit 24A will be described using FIG. 17. FIG. 17 is a diagram showing a configuration example of the voltage phase detection unit shown in FIG. 14.

The voltage phase detection unit 24A includes a neutral point 40, a resistance 41A, a resistance 41B, a resistance 41C, and a phase detection unit 42. One end of each of the resistor 41A, the resistor 41B and the resistor 41C is connected to the neutral point 40. The neutral point 40 is connected to the phase detection unit 42.

The other end of the resistor 41A inputs an R-phase input voltage VR1 that becomes the emitter potential of the switching element S1. The R-phase input voltage VR1 is input to the resistor 41A and input to the phase detection unit 42. The other end of the resistor 41B inputs an S-phase input voltage VS1 that becomes the emitter potential of the switching element S3. The S-phase input voltage VS1 is input to the resistor 41B and input to the phase detection unit 42. A T-phase input voltage VT1 that becomes the emitter potential of the switching element S5 is input to the other end of the resistor 41C. The T-phase input voltage VT1 is input to the resistor 41C and input to the phase detection unit 42.

The phase detection unit 42 generates phase detection signals RD3, SD3, and TD3 based on the input signals. The value of the phase detection signal RD3 corresponds to the value of the R-phase input voltage VR1 based on the potential NG of the neutral point 40. The value of the phase detection signal SD3 corresponds to the value of the S-phase input voltage VS1 based on the potential NG of the neutral point 40. The value of the phase detection signal TD3 corresponds to the value of the T-phase input voltage VT1 based on the potential NG of the neutral point 40.

Next, a method of detecting the minimum value of the phase voltage will be described using FIG. 18. FIG. 18 is a diagram showing the waveform of the R-phase phase detection signal generated by the voltage phase detection unit and the waveform of the R-phase phase voltage generated based on the phase detection signal in Embodiment 2. FIG.

Figure 18 shows the threshold voltage for phase detection, the waveform of the R-phase neutral point reference phase voltage VR3 generated during the regeneration operation of converter 1-2, and the regeneration operation of converter 1-2 The waveform of the phase detection signal RD3 generated by the voltage phase detection unit 24A. The value of the threshold voltage for phase detection is set such that the potential of the phase detection signal RD3 becomes the High level when the phase of the neutral reference voltage VR3 is between 60° and 120°. The threshold voltage system for phase detection is set in the voltage phase detection unit 24A. The neutral point reference phase voltage VR3 is included in the phase detection unit 42, and is calculated by VR3=VR1-NG, for example, based on the potential NG of the neutral point 40.

When the phase of the neutral point reference phase voltage VR3 reaches 60°, the potential of the phase detection signal RD3 changes from the Low level to the High level. When the phase of the neutral point reference phase voltage VR3 reaches 90°, the power of the phase detection signal RD3 changes in the order of High level, Low level, and High level within a short period. When the phase of the neutral point reference phase voltage VR3 reaches 120°, the potential of the phase detection signal RD3 changes from the High level to the Low level. The phase of the neutral point reference phase voltage VR3 is located between 120° and 60° after one cycle, and the potential of the phase detection signal RD3 is maintained at the Low level. The phase 60° after one cycle is equivalent to the phase 420°. When the phase of the neutral point reference phase voltage VR3 reaches 420°, the potential of the phase detection signal RD3 changes from Low level to High level. The center of the neutral point reference phase voltage VR3 is in the range of 120° to 420°, which corresponds to the phase of the neutral point reference phase voltage VR3 of 270°, and when the phase of the neutral point reference phase voltage VR3 is 270°, the neutral point The potential of the reference phase voltage VR3 becomes minimum.

In addition, although not shown in FIG. 18, the waveform of the S-phase phase detection signal generated by the voltage phase detection unit 24A during the regeneration operation of the converter 1-2 and the signal generated from the S-phase phase detection signal The waveform of the phase voltage of the S phase changes with the same tendency as the waveform shown in FIG. 18. In addition, during the regeneration operation of the inverter 1-2, the waveform of the T-phase phase detection signal generated by the voltage phase detection unit 24A and the waveform of the T-phase phase voltage generated based on the T-phase phase detection signal are The same trend as the waveform shown in Figure 18 changes.

As shown in Fig. 18, by setting the value of the phase detection threshold voltage near the potential at which the potential of the neutral point reference phase voltage VR3 becomes the highest, the phase of the neutral point reference phase voltage VR3 is located at 60° to 120° In between, the number of potential changes of the phase detection signal RD3 is one. That is, the number of times affected by the on-off operation of the switching element can be affected only when the phase of the neutral point reference phase voltage VR3 is 90°.

In the vicinity of the phase of the neutral point reference phase voltage VR3 at 90°, the potential of the phase detection signal RD3 changes in the order of High level, Low level, and High level, but compared to the phase of the neutral point reference phase voltage VR3 The width of the interval between 120° and 420°, that is, the width of the interval where the potential of the phase detection signal RD3 is maintained at the Low level, the width of the interval where the potential of the phase detection signal RD3 changes is shorter. Therefore, in the case where the output period of the low level phase detection signal RD3 does not exceed a specific period, by determining this low level phase detection signal RD3 as noise, the influence of voltage fluctuations can be reduced.

In addition, in the voltage phase detection unit 24A of the second embodiment, the phase of the neutral point reference phase voltage VR3 is located in the range of 120° to 420°, and the potential of the phase detection signal RD3 is changed from the High level to the Low level by calculating From the time point to the time point when the Low level changes to the High level, the minimum value of the neutral point reference phase voltage VR3 can be calculated. This time is set to be longer than the specific period used for noise determination as described above. By using the minimum value of the neutral point reference phase voltage VR3, the voltage phase of the AC power supply 3 can be detected.

As described above, according to the converter 1-2 of the second embodiment, even if the phase detection signal is generated based on the signal generated by the ground VRPGND, VSPGND, and VTPGND provided in the control power supply section 29, it will not be turned on and off by the switching element The voltage phase of the AC power supply 3 can be detected due to the influence of the operation.

Furthermore, in the second embodiment, the minimum value of the phase voltage is used to detect the voltage phase, but the converter 1-2 of the second embodiment may not only detect the minimum value of the phase voltage, but also detect the maximum value by The voltage phase is detected in a shorter time. For example, the neutral point reference phase voltage VR3 can be calculated by adding the potential of the phase detection signal RD3 to the high level of the phase detection threshold voltage at the phase of the neutral point reference phase voltage VR3 between 240° and 300° The maximum value. The phase of the maximum value of the neutral point reference phase voltage VR3 corresponds to, for example, the phase 90° and the phase 270° of the neutral point reference phase voltage VR3 shown in FIG. 18.

Moreover, in Embodiment 2, the phase of the neutral reference voltage VR3 is between 60° and 120° and the phase of the neutral reference voltage VR3 is between 240° and 300°, and the phase detection signal RD3 is set For example, the potential of the high level becomes the threshold voltage for phase detection of the high level, but the phase of the switching element that conducts the on-off operation from the neutral point reference phase voltage VR3 is 30°, 90°, 150°, 210°, 270 °, 330°, etc., for example, the phase detection signal RD3 can be set to the neutral point, and the phase of the reference phase voltage VR3 is between 45° to 105° and 225° to 315°, which becomes the high level for phase detection. Threshold voltage.

In addition, in Embodiment 2, the voltage phase is detected by calculating the phase voltage, but the converter 1-2 in Embodiment 2 may also detect the voltage phase by calculating the line voltage. For example, the potential of the phase detection signal can be set as the threshold voltage for phase detection at the high level when the phase of the line voltage is between 45° and 135°. In this case, the phase of the line voltage is between 135° and 405°, the potential of the phase detection signal becomes the Low level, and the center point of the phase of the line voltage is 135° to 405°, which is equivalent to the line voltage of phase 270° Becomes the minimum value.

In addition, the voltage phase detection unit 24 and the regeneration control unit 28 of the first embodiment and the voltage phase detection unit 24A and the regeneration control unit 28 of the second embodiment can be constituted by using hardware such as an optical coupler, a logic IC, etc. Circuits, composite circuits, programmed processors, parallel programmed processors, ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), Or these combinations can also be made up of software.

In addition, according to the converter 1-1 of the first embodiment and the converter 1-2 of the second embodiment, the signal transmitted by the pattern wiring on the printed wiring board can be used to calculate the line voltage VR-S and the line voltage VS as the line voltage -T and line voltage VT-R, and R-phase input voltage VR1, S-phase input voltage VS1 and T-phase input voltage VT1 which become phase voltages. Therefore, these voltages can be used for power failure detection. The detection of power failure refers to a state where power from the AC power supply 3 is not supplied to the inverter. The detection of power failure will be described in detail in Embodiment 3 described later.

In addition, according to the converter 1-1 of the first embodiment and the converter 1-2 of the second embodiment, the line voltage VR-S and the line voltage VS-T calculated based on the signal transmitted by the pattern wiring on the printed wiring board At least one of the line voltage VT-R, the R-phase input voltage VR1, the S-phase input voltage VS1, and the T-phase input voltage VT1 is used to set the reference voltage Vref of the regeneration control unit 28.

Embodiment 3. Fig. 19 is a diagram showing the configuration of the inverter and the motor control device according to the third embodiment. The inverter 1-3 of the third embodiment has the same structure as the inverter 1-1 shown in FIG. 1, and further includes an input voltage detection unit 43.

First, the operation of the input voltage detection unit 43 of the third embodiment will be described. FIG. 20 is a diagram for explaining the operation of the input voltage detection unit 43 shown in FIG. 19. Fig. 20 has the same structure as Fig. 11 and shows the input voltage detection unit 43 instead of the voltage phase detection unit 24. The input voltage detection unit 43 inputs the signal VR1 generated by the ground VRPGND connected to the wiring 291-2, the signal VS1 generated by the ground VSPGND connected to the wiring 292-2, and the wiring 293-2 also shown in the first embodiment The signal VT1 generated by the ground VTPGND. The input voltage detection unit 43 detects the line voltage or the phase voltage of the AC power supply 3 based on these signals.

According to the third embodiment, since the signal generated by the ground connected to the wiring 291-2 or the like can be used, the complexity of the configuration for detecting the line voltage or the phase voltage of the AC power supply 3 can be suppressed as in the first embodiment. In addition, according to the third embodiment, since the signal generated by the ground connected to the wiring 291-2 or the like can be used, it is also possible to carry out a pattern design that can be easily arranged on the printed wiring board to achieve space saving.

In addition, according to the third embodiment, a power failure detection unit that determines whether a power failure of the AC power supply 3 has occurred based on the output signal of the input voltage detection unit 43 may be added. The power failure detection unit may be a display device or an audio device that only notifies whether a power failure has occurred, or a control device or controller equipped with a control function. In the case of a power failure detection unit, when a power failure occurs in the AC power supply 3, the motor 5 controlled by the motor drive device 4 using the DC power of the inverters 1-3 can quickly control or instruct how to operate.

Embodiment 4. Fig. 21 is a diagram showing the configuration of an inverter and a motor control device according to the fourth embodiment. The inverter 1-4 of the fourth embodiment is provided with an input current detection unit 25A that detects the three-phase input current flowing through the AC wiring 51, 52, and 53 instead of the bus current detection unit 25 shown in FIG.

The converter 1-4 of the fourth embodiment includes a RST-dq coordinate conversion unit 44 as a current value conversion unit and a regeneration control unit 28A. The RST-dq coordinate conversion unit 44 performs coordinate conversion on the output signal of the input current detection unit 25A based on the phase detection signal that becomes the output signal of the voltage phase detection unit 24, thereby calculating the d-axis current Id equivalent to the current of the effective power And the q-axis current Iq corresponding to the current of the ineffective power. The regeneration control unit 28A performs the regeneration start operation and the regeneration stop operation based on the d-axis current Id and the output signal of the bus voltage detection unit 23. As for the voltage phase detection unit, the voltage phase detection unit 24 shown in the first embodiment is used here, but it may be replaced with the voltage phase detection unit 24A shown in the second embodiment. In addition, the input voltage detection unit 43 described in the third embodiment may be added.

In the first and second embodiments, it has been described that each voltage phase detection unit detects the voltage phase of the line voltage or the phase voltage of the AC power supply 3, but it is not limited thereto. In addition to the voltage phase of the line voltage or the phase voltage, at least one of other information such as the power supply angular frequency ω of the AC power supply 3, the R-phase voltage phase θr, the S-phase voltage phase θs, and the T-phase voltage phase θt may be calculated. Hereinafter, the R-phase voltage phase is called a first voltage phase, the S-phase voltage phase is called a second voltage phase, and the T-phase voltage phase is called a third voltage phase.

Next, the RST-dq coordinate conversion unit 44 of the fourth embodiment will be described. The RST-dq coordinate conversion unit 44 has a function of converting the RST axis of the fixed coordinate axis to the dq axis of the rotary coordinate axis. The power phase frequency ω of the AC power supply 3 and the R-phase voltage phase θr are calculated by the voltage phase detection unit 24, and the signal of the RST axis is converted into the signal of the dq axis based on the power angular frequency ω and the R-phase voltage phase θr.

Here, the phase voltages VR, VS, and VT of the AC power supply 3 are represented by the balanced three-phase voltage at the time t, the effective value Ea, the power supply angular frequency ω, and the initial phase α. In this way, the phase voltages VR, VS, and VT of the AC power supply 3 can be expressed as the following formula (1). The initial phase α is the phase of the phase voltage VR when t=0.

[Number 1]

Fig. 22 is a diagram for explaining the RST axis and the dq axis used in the control of the fourth embodiment. In FIG. 22, the RST axis is a fixed coordinate axis showing the R phase, S phase, and T phase of the AC power supply 3. In addition, the dq axis is a rotation coordinate axis that rotates clockwise at the power source angular frequency ω. Here, when the phase of the d-axis with the R-phase axis as the reference is θ, the following equation (2) is established between the two coordinate axes.

[Number 2]

When the voltages Vd and Vq of the dq axis of the rotating coordinate axis are calculated using the above equations (1) and (2), the following equation (3) can be derived.

[Number 3]

First consider the case where θ=0 in the above equation (3). When θ=0 is substituted into equation (3), the following equation (4) can be derived.

[Number 4]

In addition, consider the case where θ=π/2 in the above formula (3). When θ=π/2 is substituted into equation (3), the following equation (5) can be derived.

[Number 5]

As can be seen from the above equations (4) and (5), the above equation (4) can be derived regardless of the value of θ in the above equation (3). That is, the d-axis voltage system is equivalent to the power supply voltage vector. Therefore, the d-axis system corresponds to the effective power direction, and the q-axis system corresponds to the ineffective power direction.

Next, the relationship between the R-phase voltage phase θr and the initial phase α will be described. First, according to the above formula (1), the R-phase voltage VR can be expressed by the following formula (6).

[Number 6]

For example, when the R-phase voltage VR is 0, θr=0 is set, and when the R-phase voltage VR is √2Ea, θr=π/2. In this case, the initial phase α can be set to -π/2. From the above, the above formula (2) can be expressed by the following formula (7).

[Number 7]

The above equation (7) is based on the R phase voltage phase θr calculated by the voltage phase detection unit 24 and the power supply angular frequency ω, and is used in the RST-dq coordinate conversion unit 44 that converts the RST axis to the dq axis formula. Therefore, the input currents Ir, Is, It can be converted into d-axis current Id and q-axis current Iq using the following formula (8).

[Number 8]

As described above, since the d-axis is the effective power and the q-axis is the ineffective power, the d-axis current is the current equivalent to the effective power, and the q-axis current is the current equivalent to the invalid power. Therefore, the d-axis current Id becomes a positive signal during power running operations such as acceleration of the motor. On the other hand, during regeneration operations such as when the motor is decelerating, the d-axis current Id becomes a negative signal.

Generally, when the input currents Ir, Is, It are detected by the inverter and the start and stop of the regeneration operation are controlled, the RST axis of the fixed coordinate axis must be converted to the dq axis of the rotary coordinate axis. Coordinate conversion must have information on the voltage phase of the AC power supply 3. As described above, if the method of this embodiment is used, the voltage phase of the AC power supply 3 can be detected by the signal generated by the ground connected to the wiring 291-2 or the like that becomes the pattern wiring on the printed wiring board, so it can be simplified It is used to detect the voltage phase of AC power supply 3. Therefore, if the voltage phase detection unit 24 or the voltage phase detection unit 24A shown in the present embodiment is used, it is advantageous to reduce the cost of the inverter.

Next, the regeneration control unit 28A in the fourth embodiment will be described. Based on the d-axis current Id and the bus voltage VPN, the regeneration control unit 28A determines whether to continue to transmit the base drive signal SRP output to the STN to the base drive circuit 27 or to stop the base drive circuit 27 transmits the base drive signal SRP to STN output by the base drive signal generation unit 26. When the regeneration control unit 28A determines that the base drive signal SRP to STN continues to be transmitted to the base drive circuit 27, it continues to input the base drive signal SRP to STN to the base drive circuit 27. When the regeneration control unit 28A determines that the transmission of the base drive signal SRP to the STN to the base drive circuit 27 is stopped, the input of the base drive signal SRP to the STN to the base drive circuit 27 is stopped.

FIG. 23 is a diagram showing a configuration example of the regeneration control unit 28A shown in FIG. 21. The regeneration control unit 28A shown in FIG. 23 differs from the configuration of the regeneration control unit 28 shown in FIG. 3 only in that the signal input to the regeneration stop determination unit 61 is changed from the bus current IPN to the d-axis current Id Other operations are the same as the regeneration control unit 28 shown in the first embodiment. In addition, constituent elements that are the same as or equivalent to those in FIG. 3 are given the same symbols. In the regeneration stop determination unit 61, the negative input terminal of the comparator 66 receives the d-axis current Id. When the d-axis current Id is greater than the threshold current Iref, a low level signal is output, and when the d-axis current Id does not reach the threshold current Iref, a high level signal is output.

From the above point of view, even in the converter that detects the input current instead of the bus current, the voltage phase of the AC power supply 3 can be detected. This is beneficial to the cost reduction of the converter.

Embodiment 5. Fig. 24 is a diagram showing the configuration of an inverter and a motor control device according to the fifth embodiment. The inverter 1-5 of the fifth embodiment has the same or equivalent configuration as the inverter 1-4 shown in FIG. 21, and an overload detection unit 45 is further added. In addition, for the same or equivalent constituent elements, the same symbols are used and duplication of description is omitted as appropriate.

The overload detection unit 45 has a function of detecting overload of the converter 1-5 based on the d-axis current Id. Information on whether the inverter 1-5 is in an overload state is notified to the motor driving device 4 or the high-level control device 100 not shown in FIG. 24 (refer to FIG. 34). The high-level control device 100 is a device that transmits a motor operation command to the motor driving device 4.

FIG. 25 is a waveform diagram showing the operation of the motor drive device 4 shown in FIG. 24 when the motor 5 is operated. The horizontal axis is time. From the top, the motor speed N, motor torque Tout, motor output Pout, bus voltage VPN, and d-axis current Id are displayed.

First, the section from t00 to t01 in Fig. 25 will be explained. This interval is the acceleration interval of the motor and the motor power operation interval. Time t00 is the time when the motor starts to accelerate, and time t01 is the time when the motor speed N reaches the target speed. The motor torque Tout increases the motor speed N and the motor output Pout. As the motor output Pout increases, the d-axis current Id increases in the positive direction. When the motor torque Tout decreases, the motor output Pout becomes constant and the peak value of the d-axis current Id becomes constant.

Next, the interval t01 to t02 in FIG. 25 will be described. This section is the section where the motor speed N becomes a certain speed. Unlike the time period t00 to t01, since the motor output Pout is at a low value, the d-axis current Id hardly flows.

Next, the section t02 to t03 in Fig. 25 will be described. This section is the section where the motor decelerates and is the section where the motor is regenerated. Time t02 is the time when the motor starts to decelerate, and time t03 is the time when the motor is stopped. When the motor starts to decelerate, the regenerative power of the motor flows into the smoothing capacitor 21 to increase the bus voltage VPN. According to the aforementioned regeneration control unit 28A, when the bus voltage VPN exceeds a predetermined value, the converter 1-5 starts the power regeneration operation. By the power regeneration operation of the inverter 1-5, the d-axis current Id flows in the negative direction, so that the bus voltage VPN decreases. At time t02, when the motor decelerates, the motor output Pout, that is, the absolute value of the motor's regenerative power increases, causing a larger current to flow, but as the motor speed N decreases, the absolute value of the motor output Pout also decreases. The absolute value of the d-axis current Id flowing in the negative direction also becomes smaller.

As can be seen from FIG. 25, the magnitude of the d-axis current Id depends on the motor output Pout. That is, there is a proportional relationship between the motor output Pout and the d-axis current Id. The d-axis current Id is obtained from the input currents Ir, Is, It. Therefore, as the d-axis current Id increases, the absolute values of the input currents Ir, Is, and It also increase.

If an excessive current continues to flow in the power module 22 loaded on the converter 1-5, the converter 1-5 will become overloaded. At this time, since the same current as the input current Ir, Is, It flows to the power module 22, the d-axis current Id calculated from the input current Ir, Is, It can be monitored to indirectly detect the flow to the power module 22之电。 The current. Since the input currents Ir, Is, It are alternating currents, they flow in both positive and negative directions regardless of when the motor is running or when the motor is regenerating. In contrast, in the case of the d-axis current Id, the current flows in the positive direction when the motor is powered, and the current flows in the negative direction when the motor is regenerated.

Next, the overload detection unit 45 of the fifth embodiment will be described. Fig. 26 is a diagram showing a configuration example of the overload detection unit 45 shown in Fig. 24. The overload detection unit 45 includes a comparator 190, a comparator 191, and a logical OR circuit 192. The negative input terminal of the comparator 190 receives the d-axis current upper limit Idmax, and the positive input terminal of the comparator 190 receives the d-axis current Id. In addition, the positive input terminal of the comparator 191 inputs the d-axis current lower limit value Idmin, and the negative input terminal of the comparator 191 inputs the d-axis current Id. Each output signal of the comparator 190 and the comparator 191 is input to the input terminal of the logical OR circuit 192, and the output signal of the logical OR circuit 192 is processed as the output signal of the overload detection unit 45. Here, when the overload detection unit 45 outputs a high level signal, it determines that the converter 1-5 is in an overload state, and when the overload detection unit 45 outputs a low level signal, it determines that the converter 1-5 is not in an overload state. .

The d-axis current upper limit value Idmax and the d-axis current lower limit value Idmin are determined by the current capacity or electrical specifications of the power module 22 mounted on the inverter 1-5. The d-axis current upper limit Idmax is the current limit value during the power running operation, and the d-axis current lower limit Idmin is the current limit value during the regeneration operation.

With the foregoing configuration, when the d-axis current Id becomes equal to or greater than the d-axis current upper limit value Idmax, the comparator 190 outputs a signal of High level, and the logic OR circuit 192 inputs a signal of High level. In this way, the logical OR circuit 192 outputs a high-level signal so that the overload detection unit 45 outputs a high-level signal. In addition, when the d-axis current Id becomes equal to or lower than the d-axis current lower limit value Idmin, the comparator 191 outputs a signal of high level, and the logic OR circuit 192 inputs a signal of high level. In this way, the logical OR circuit 192 outputs a high-level signal so that the overload detection unit 45 outputs a high-level signal. The signal output by the overload detection unit 45 is notified to the motor drive device 4 or the high-level control device 100 via a communication line omitted in the illustration.

As described above, in the inverter 1-5 of the fifth embodiment, the load state of the inverter 1-5 during motor power operation and motor regeneration is monitored based on the d-axis current Id, and whether it is determined based on the monitoring result Instant overload condition.

According to the configuration of the fifth embodiment, the power supply phase detection unit can be reduced in cost, and a simple configuration for monitoring the overload state of the converter with the d-axis current Id can be realized, which is beneficial to the cost reduction of the converter.

In the fifth embodiment, the d-axis current Id proportional to the motor output Pout is used to determine whether it is an instantaneous overload state, but the q-axis current Iq can also be used to determine whether it is an instantaneous overload state. By using both the d-axis current Id and the q-axis current Iq, both the effective current and the inactive current can be monitored. In this way, the power-on state of the converters 1-5 can be judged more accurately, so it is more accurate to judge whether it is a transient overload state.

Embodiment 6. Fig. 27 is a diagram showing the configuration of an inverter and a motor control device according to the sixth embodiment. The inverter 1-6 of the sixth embodiment has the same or equivalent configuration as the inverter 1-5 shown in FIG. 24. In FIG. 27, the overload detection unit 45 of FIG. 24 is replaced with an overload detection unit 45A. In addition, for the same or equivalent constituent elements, the same symbols are used and duplication of description is omitted as appropriate.

The overload detection unit 45A has a function of detecting the overload of the converter 1-6 in a steady state based on the d-axis current Id. Information on whether the inverter 1-6 is in an overload state is notified to the motor driving device 4 or the high-level control device 100 not shown in FIG. 27 (refer to FIG. 34). The high-level control device 100 is a device that transmits a motor operation command to the motor driving device 4.

Generally speaking, the steady-state overload protection of the power conversion device of the inverter or inverter is to estimate the temperature of the parts loaded in the power conversion device. When the estimated temperature becomes higher than the temperature that should be protected, it is determined as the steady state Overload state, and stop the operation of the power conversion device to protect the power conversion device. In addition, the components mounted on the power conversion device include, for example, power element groups and capacitors related to the power supply of the motor.

As a specific example of the steady state overload protection curve, the overload protection curve shown in FIG. 28 is known. FIG. 28 is a waveform diagram illustrating the comparison of steady-state overload protection in the sixth embodiment. In FIG. 28, the horizontal axis is the energizing current I of the power conversion device, and the vertical axis is the allowable energizing time Ta. These relationships are shown as overload protection characteristics. This overload protection characteristic is used when the power conversion device is continuously energized with a certain energizing current I, and it is used to obtain the time until the temperature rise caused by energization reaches the temperature to be protected. Specifically, the value of the vertical axis from the intersection point of the horizontal axis representing the value of a certain energizing current I along a line drawn parallel to the vertical axis and the overload protection curve shown in the figure is set to be protected temperature.

FIG. 29 is a diagram showing a configuration example of the overload detection unit 45A shown in FIG. 27. As shown in FIG. 29, the overload detection unit 45A includes an absolute value calculation unit 193, a temperature rise estimation unit 194, and a comparator 195. In FIG. 29, the absolute value calculation unit 193 inputs the d-axis current Id. The absolute value calculation unit 193 calculates the absolute value of the d-axis current |Id|. The calculated absolute value of d-axis current |Id| is input to the temperature rise estimation unit 194. The temperature rise estimation unit 194 calculates the temperature rise estimation value Kc based on the overload protection curve determined by the characteristics of the power module 22 and the smoothing capacitor 21 mounted on the inverter 1-6. The calculated temperature rise estimated value Kc is input to the negative input terminal of the comparator 195. The positive input terminal of the comparator 195 inputs the threshold temperature Kref, and the signal indicating the magnitude relationship between the estimated temperature rise Kc and the threshold temperature Kref becomes the output signal of the comparator 195, and the output signal of the comparator 195 becomes the overload detection unit 45A Output signal.

Next, the operation of the temperature rise estimation unit 194 will be described with reference to FIGS. 30 and 31. FIG. 30 is a first waveform diagram illustrating the operation of the temperature rise estimation unit 194 in the sixth embodiment, and FIG. 31 is a second waveform diagram illustrating the operation of the temperature rise estimation unit 194 in the sixth embodiment. Specifically, FIG. 30 shows the temperature rise Ka of the power module 22 when the d-axis current Id of the inverters 1-6 continues to flow at a constant value. In addition, FIG. 31 shows the temperature rise Kb of the smoothing capacitor 21 when the d-axis current Id of the inverter 1-6 continues to flow at a constant value. The horizontal axis in any graph represents time.

It can be seen from Fig. 30 and Fig. 31 that the change characteristic of temperature rise is close to that of the delay filter of several orders. Therefore, in the temperature rise estimation unit 194, by using the absolute value of the d-axis current |Id| corresponding to the absolute value of the d-axis current Id as the input signal, the temperature rise estimated value Kc of the power module 22 and the smoothing capacitor 21 can be calculated . Examples of order delay filters are infinite impulse response filter (IIR) filters, moving average filters, etc.

From the above, the overload detection unit 45A estimates the temperature rise of the components mounted on the inverter 1-6 based on the d-axis current Id. When the preset temperature rise estimated value Kc is equal to or higher than the threshold temperature Kref, it is determined to be stable In the state of overload, when the temperature rise estimated value Kc is less than the threshold temperature Kref, it is determined that it is not a steady state overload state. When it is determined to be a steady-state overload state, the overload detection unit 45A outputs a High level signal and notifies the motor drive device 4 or the high-level control device 100 via the communication path. On the other hand, when it is determined that it is not a steady-state overload state, the overload detection unit 45A outputs a signal of Low level. The signals of the high level and the low level are notified to the motor driving device 4 or the high-level control device 100 via the communication path.

As described above, in the inverter 1-6 of the sixth embodiment, the load state of the inverter 1-6 is monitored based on the d-axis current Id, and whether the inverter 1-6 is in a steady-state overload state is determined based on the monitoring result. .

According to the configuration of the sixth embodiment, the power supply phase detection unit can be reduced in cost, and a simple configuration for monitoring the overload state of the converter with the d-axis current Id can be realized, which contributes to the cost reduction of the converter.

In the sixth embodiment, the d-axis current Id proportional to the motor output Pout is used to determine whether it is in a steady state overload state, but the q-axis current Iq may also be used to determine whether it is in a steady state overload state. By using both the d-axis current Id and the q-axis current Iq, both the effective current and the inactive current can be monitored. In this way, the power-on state of the converters 1-6 can be judged more accurately, so it can be judged more accurately whether it is a steady-state overload state.

Embodiment 7. Fig. 32 is a diagram showing the configuration of an inverter and a motor control device according to the seventh embodiment. The converter 1-7 of the seventh embodiment shown in FIG. 32 is in the configuration of the converter 1-5 of the fifth embodiment shown in FIG. 24, omitting the bus voltage detection section 23 and the base drive signal generating section 26 And the illustration of the regeneration control unit 28A, and the motor control unit 4A is added inside the motor drive device 4. The other components are the same as or equivalent to those in FIG. 24, and the same or equivalent components are given the same symbols.

The motor control unit 4A has a function of supplying arbitrary AC power to the motor 5 to control the motor 5 at a variable speed. The output of the overload detection unit 45 in the inverter 1-7 is configured to be input to the motor control unit 4A via the communication path 46. FIG. 32 uses the overload detection unit 45 described in the fifth embodiment, that is, the overload detection unit 45 having a function to determine the instantaneous overload state, but it can also be replaced by the overload detection unit 45A described in the sixth embodiment. That is, the overload detection unit 45A having the function of determining the steady state overload state, or the overload detection unit having both the determination function of the instantaneous overload state and the determination function of the steady state overload state may be used.

The input current detection unit 25A detects the input currents Ir, Is, It input to the power module 22, and inputs the detected input currents Ir, Is, It to the RST-dq coordinate conversion unit 44. The RST-dq coordinate conversion unit 44 calculates the d-axis current Id and the q-axis current Iq from the R-phase voltage phase θr of the AC power supply 3 detected by the voltage phase detection unit 24 and the power supply angular frequency ω, and converts the d-axis current Iq Id is input to the overload detection unit 45. The overload detection unit 45 determines whether the inverter 1-7 is in an overload state based on the d-axis current Id. When it is determined that the inverter 1-7 is in an overload state so that the overload detection unit 45 outputs a signal of High level, the motor control unit 4A controls the AC power in such a manner as to reduce the output of the motor 5.

The technique for reducing the output of the motor 5 can be exemplified by the following technique. (i) The control is performed in such a way that the torque command, which is more restricted than the torque command determined in advance by the motor operation command, causes the motor 5 to operate. (ii) The control is performed in such a manner that the rotation command, which is more restricted than the rotation command determined in advance by the motor operation command, causes the motor 5 to operate. (iii) The motor 5 is controlled to inertia. Specifically, the switching operation for turning on and off the switching elements (not shown) provided inside the motor drive device 4 is stopped, and the motor 5 is brought into the inertial operation state.

Next, the operation of the inverter 1-7 and the motor driving device 4 of the seventh embodiment will be described with reference to FIGS. 32 and 33. Fig. 33 is a flowchart showing the operation of the inverter and motor control unit according to the seventh embodiment. In Fig. 33, symbols are omitted.

The RST-dq coordinate conversion unit 44 is based on the input currents Ir, Is, It detected by the input current detection unit 25A and the R phase voltage phase θr and the power supply angular frequency ω calculated by the voltage phase detection unit 24. The d-axis current Id is calculated (step S101). The overload detection unit 45 determines whether the inverter 1-7 is in an overload state based on the d-axis current Id (step S102). The overload detection unit 45 notifies the determination result to the motor control unit 4A inside the motor drive device 4 via the communication path 46 (step S103). The processing of the above steps S101 to S103 is the processing of the converter 1-7, and the converter 1-7 repeatedly executes the processing of the steps S101 to S103.

The motor control unit 4A receives the determination result of the overload detection unit 45 (step S104). The motor control unit 4A determines whether the inverter 1-7 is in an overload state based on the received determination result (step S105). When the received judgment result is a signal indicating the content of the overload state (the example of the fifth embodiment is a high level signal) (step S105, Yes), the output from the motor 5 is restricted in such a manner as to limit the output of the motor 5 The motor outputs (step S106), and outputs AC power that limits the output of the motor 5 to the motor 5 (step S107). When the received determination result is a signal indicating the content of the non-overload state (the example of Embodiment 5 is a low level signal) (step S105, No), the process proceeds to step S107 without performing the process of step S106. That is, when the received determination result is not in the overload state, the output of the motor 5 is not limited and the AC power under the normal control operation is output to the motor 5 (step S107). The processes of steps S104 to S107 above are processes of the motor control unit 4A, and the motor control unit 4A repeatedly executes the processes of steps S104 to S107.

According to the seventh embodiment, even in the case where the operation of the motor 5 exceeds the assumed operation and the inverter 1-7 is overloaded, since the motor driving device 4 controls the AC power in such a manner as to reduce the output of the motor 5, the conversion can be eliminated The overload state of the converter 1-7 can eliminate the adverse effects such as deterioration of life and damage of the converter 1-7 without stopping the system. Therefore, an inverter with a small capacity can be selected to benefit the cost reduction of industrial machinery.

Embodiment 8. Fig. 34 is a diagram showing the configuration of an inverter and a motor control device according to the eighth embodiment. In FIG. 34, a high-order control device 100, a motor drive device 400, and a motor 500 replacing the motor 5 are added to the inverters 1-7 of Embodiment 7 shown in FIG. 32. The high-level control device 100 has a function of outputting a motor operation command to each of the motor driving devices 4 and 400 via communication paths 47a and 47b, and outputting a motor operation command to each of the motor driving devices 4 and 400. The output of the overload detection unit 45 in the inverter 1-8 is input to the high-level control device 100 via the communication path 46. The motor drive device 400 includes DC terminals 19 and 20 and a motor control unit 400A. The DC terminals 19 and 20 are connected to the DC terminals 17 and 18 of the motor drive device 4 and are also connected to the smoothing capacitor 21 in the inverter 1-8 . The motor control unit 400A supplies arbitrary AC power to the motor 500 to perform variable speed control. In addition, in FIG. 34, an overload detection unit 45 suitable for instantaneous overload detection is used, but the overload detection unit 45 may be replaced with an overload detection unit 45A suitable for steady-state overload detection, or may be used with instantaneous overload detection And the overload detection part of the function of both the steady state overload detection.

The input current detection unit 25A detects the input currents Ir, Is, It input to the power module 22, and inputs the detected input currents Ir, Is, It to the RST-dq coordinate conversion unit 44. The RST-dq coordinate conversion unit 44 calculates the d-axis current Id and the q-axis current Iq from the R-phase voltage phase θr of the AC power supply 3 detected by the voltage phase detection unit 24 and the power supply angular frequency ω, and converts the d-axis current Iq The current Id is input to the overload detection unit 45. The overload detection unit 45 determines whether the inverter 1-8 is in an overload state based on the d-axis current Id. When it is determined that the converter 1-8 is in an overload state, a signal (high level signal) indicating the content of the overload state is notified to the high-level control device 100 via the communication path 46. The high-level control device 100 uses two or either of the corresponding communication paths 47a and 47b to generate a motor operation command that limits the output of the motor to be controlled. The motor control unit 4A of the motor drive device 4 and At least one of the motor control units 400A of the motor drive device 400 instructs. At least one of the motor control unit 4A and the motor control unit 400A controls the AC power in such a manner as to reduce the output of the motor 5 or the motor 500 according to the received motor operation command.

Specific examples are given below for explanation. Here, taking a machine tool including a spindle motor and a servo motor as an example, the motor 5 is set as the spindle motor, and the motor 500 is set as the servo motor. In addition, the high-level control device 100 may or may not be provided on the machine tool.

(i) The high-level control device 100 outputs a motor operation command that reduces the output of the motor 5 of the spindle motor to the motor control unit 4A. (ii) In order not to increase the cycle time, the high-end control device 100 decides to limit the output of the motor 500 of the servo motor whose acceleration time or deceleration time is shorter than the motor 5 of the spindle motor. The high-level control device 100 outputs a motor operation command that maintains the output of the motor 5 of the spindle motor and limits the output of the motor 500 of the servo motor to the motor control unit 4A and the motor control unit 400A.

Next, the operation of the inverter and the motor drive device according to the eighth embodiment will be described with reference to FIGS. 34 and 35. Fig. 35 is a flowchart showing the operation of the inverter and the motor control unit in the eighth embodiment. In Fig. 35, symbols are omitted.

The RST-dq coordinate conversion unit 44 is calculated based on the input currents Ir, Is, It detected by the input current detection unit 25A and the R-phase voltage phase θr calculated by the voltage phase detection unit 24 and the power supply angular frequency ω d-axis current Id (step S201). The overload detection unit 45 determines whether the inverter 1-8 is in an overload state based on the d-axis current Id (step S202). The overload detection unit 45 notifies the high-level control device 100 of the determination result via the communication path 46 (step S203). The processing of the above steps S201 to S203 is the processing of the converter 1-8, and the converter 1-8 repeatedly executes the processing of the steps S201 to S203.

The high-order control device 100 receives the determination result of the overload detection unit 45 (step S204). The high-order control device 100 determines whether the converter 1-8 is in an overload state based on the received determination result (step S205). When the received determination result is a signal indicating the content of the overload state (the example of Embodiment 5 is a high level signal) (step S205, YES), it is determined to limit the output of at least one of the motor 5 and the motor 500 (step S206 ), and outputs a motor operation command that limits the output of the motor to the motor driving device that drives the motor to be controlled (step S207). When the received determination result is a signal indicating the content of the non-overload state (a signal of Low level in the example of Embodiment 5) (step S205, No), the process proceeds to step S207 without performing the process of step S206. That is, when the received determination result is not in the overload state, the output of the motor 5 and the motor 500 is not limited, and a normal motor operation command is output (step S207). The above steps S204-S207 are processes of the high-level control device 100, and the high-level control device 100 repeatedly executes the processes of steps S204-S207.

The motor control unit 4A of the motor drive device 4 and the motor control unit 400A of the motor drive device 400 receive a motor operation command from the high-level control device 100 (step S208), and output AC power to the motor 5 in response to the received motor operation command The motor 500 is operated (step S209). The processes of steps S208 and S209 above are the processes of the motor control units 4A and 400A, and the motor control units 4A and 400A repeatedly execute the processes of steps S208 and S209.

According to the eighth embodiment, even in the case where the operation of the motor 5 and the motor 500 exceeds the assumed operation and the inverter 1-8 is overloaded, the high-order control device 100 will limit the output of at least one of the motor 5 and the motor 500. The operation command is output to the appropriate motor drive device, and the appropriate motor drive device controls the AC power in such a way as to reduce the motor output of the controlled object, so the overload state of the inverter 1-8 can be eliminated, and the system can be eliminated without stopping the system The adverse effects such as deterioration of life and damage of converters 1-8. In addition, in industrial machines like machine tools that use a plurality of motors, motor operation commands are output in a manner that prevents the cycle time from increasing, thereby maintaining the cycle time and eliminating the overload state of inverters 1-8. Therefore, an inverter with a small capacity can be selected to benefit the cost reduction of industrial machinery.

Embodiment 9. Fig. 36 is a diagram showing the configuration of an inverter and a motor control device according to the ninth embodiment. Fig. 36 is the same as or equivalent to the configuration of the inverter 1-8 of the eighth embodiment shown in Fig. 34, except that the inverter control unit 1A is added inside the inverter 1-9, and the inverter control unit 1A The overload detection section 45B is provided inside the. As described above, the overload detection unit 45B is an overload detection unit having functions of both instantaneous overload detection and steady-state overload detection. In addition, the high-level control device 100, the motor drive device 400, the motor drive device 4, and the inverters 1-9 are connected by a daisy chain communication path. Specifically, the inverter control unit 1A of the inverters 1-9 and the motor control unit 4A of the motor drive device 4 are connected by a communication path 46, and the motor control unit 4A of the motor drive device 4 and the motor control of the motor drive device 400 The unit 400A is connected via the communication path 48a, and the motor control unit 400A of the motor drive device 400 and the high-end control device 100 are connected via the communication path 48b. In the foregoing configuration, for example, the motor operation command output by the high-level control device 100 to the motor drive device 4 is input to the motor control unit 4A of the motor drive device 4 via the motor control unit 400A of the motor drive device 400.

In the aforementioned industrial machinery, the transient overload state is generally a case where a plurality of motors operate with a large output. Here, a machine tool composed of a plurality of servo motors and a spindle motor is used as an example for description. Here, it is considered that the motor 5 is a spindle motor and the motor 500 is a servo motor. In the machine tool, there are a plurality of servo motors and spindle motors that accelerate or decelerate simultaneously. Therefore, when the servo motor and the spindle motor operate at maximum output respectively, during the simultaneous acceleration/deceleration operation described above, the maximum output of each motor overlaps to increase the power supplied by the inverter.

In machine tools, the output of the spindle motor is generally larger than that of the servo motor. Therefore, the power supplied by the inverter to each motor drive device is relatively large due to the spindle motor drive device. When the simultaneous acceleration and deceleration operations are performed as described above, the output of the motor 5 of the spindle motor is reduced without passing through the high-order control device 100, whereby the power supplied to the inverter can be quickly reduced.

On the other hand, the steady-state overload state is not a state where the inverter is supplying excessive power, but a severe operation cycle of industrial machinery. The long-term operation causes the temperature of the power modules, smoothing capacitors and other components mounted on the inverter to rise When the allowable temperature is exceeded. In this case, the operation cycle must be corrected. The high-end control device 100 corrects the motor operation command for the motor 5 of the spindle motor, the motor 500 of the servo motor, or both, so as to obtain the average output of the motor during long-term operation The reduction of the sum is better.

Next, the operation of the inverter, the motor drive device, and the high-level control device according to the ninth embodiment will be described with reference to the drawings of FIGS. 36 and 37. Fig. 37 is a flowchart showing the operation of the inverter, motor control unit, and high-order control device according to the ninth embodiment.

The RST-dq coordinate conversion unit 44 is calculated based on the input currents Ir, Is, It detected by the input current detection unit 25A and the R-phase voltage phase θr calculated by the voltage phase detection unit 24 and the power supply angular frequency ω d-axis current Id (step S301). The overload detection unit 45B determines whether the converter 1-9 is in an instantaneous overload state, a steady state overload state, or no abnormality based on the d-axis current Id, that is, determines the overload state of the converter 1-9 (step S302). The overload detection unit 45B notifies the determination result to the motor control unit 4A via the communication path 46 (step S303). The processing of steps S301 to S303 above is the processing of converter 1-9, and converter 1-9 repeats the processing of steps S301 to S303.

The motor control unit 4A receives the determination result of the overload detection unit 45B (step S304). The motor control unit 4A determines whether the inverter 1-9 is in an instant overload state based on the received determination result (step S305). When the received judgment result is a signal indicating the content of the transient overload state (step S305, YES), the motor output from the motor driving device 4 is restricted in a manner that limits the output of the motor 5 (step S306), and the motor is restricted The output AC power is output to the motor 5 (step S307). In addition, when the received determination result is a signal indicating the content of the non-instantaneous overload state (step S305, No), the process proceeds to step S307 without performing the process of step S306. That is, in the case where the received determination result is not an instantaneous overload state, the AC power of the normal control operation is output to the motor 5 without limiting the output of the motor 5 (step S307). In addition, the motor control unit 4A notifies the motor control unit 400A of the determination result of the overload detection unit 45B (step S308). The processes of steps S304 to S308 above are processes of the motor control unit 4A, and the motor control unit 4A repeatedly executes the processes of steps S304 to S308.

The motor control unit 400A receives the determination result of the overload detection unit 45B from the motor control unit 4A via the communication path 48a (step S309), and notifies the high-end control device 100 of the determination result via the communication path 48b (step S310). The processes of steps S309 and S310 above are processes of the motor control unit 400A, and the motor control unit 400A repeatedly executes the processes of steps S309 and S310.

The high-order control device 100 receives the determination result of the overload detection unit 45B from the motor control unit 400A (step S311). The high-order control device 100 determines whether the converter 1-9 is in an instant overload state based on the received determination result (step S312). When the received judgment result is a signal indicating the content of the momentary overload state (step S312, YES), it is determined to limit the output of the motor 500 (step S313), and a motor operation command to limit the motor output is output to the motor controlling the motor 500 The control unit 400A (step S316). On the other hand, when the received determination result is a signal indicating the content of the non-instantaneous overload state (step S312, No), it is further determined whether the converter 1-9 is in the steady state overload state (step S314). When the received judgment result is a signal indicating the content of the steady overload state (step S314, YES), it is decided to change the operation cycle of each axis operated by the servo motor (step S315), and the average value of the motor 500 will be suppressed The motor operation command whose output method is changed is output to the motor control unit 400A that controls the motor 500 (step S316). When the received determination result is a signal indicating the content of the non-steady state overload state (step S314, No), the process proceeds to step S316 without performing the process of step S315. The processing of steps S311 to S316 above is the processing of the high-level control device 100, and the high-level control device 100 repeatedly executes the processing of steps S311 to S316.

The above control is summarized as follows. First, when it is determined that it is an instantaneous overload state, the AC power is output to the motor 5 by the motor control unit 4A without restricting the output of the motor through the high-level control device 100. In parallel with this control, the motor controller 400A and the high-level control device 100 are notified of the momentary overload state. The high-level control device 100 generates a motor operation command for the motor 500 in such a manner as to limit the output of the motor operation of the motor 500 based on the determination result, and outputs it to the motor drive device 400. In the motor driving device 4, the output of the motor 5 is temporarily limited to avoid the transient overload state, and then, the high-level control device 100 reviews the correction of the motor operation command again.

On the other hand, when it is determined to be in a steady state overload state, the motor control unit 4A continues to perform an operation command according to the motor operation command output by the high-level control device 100, and in parallel informs the motor control unit of the steady state overload state 400A and high-level control device 100. The high-level control device 100 generates a motor operation command in a manner to limit the average output of the motor operation of the motor 500 based on the determination result, and outputs it to the motor driving device 400.

In the above description, it is explained that the output of the motor 5 is limited when it is determined to be in an instant overload state, and the output is limited to the motor 500 when it is determined to be in a steady state overload state, but the motor 5 and the motor 500 may also be determined when determined to be in an instant overload state. Both limit output. In addition, when it is determined to be in a steady state overload state, the output of both the motor 5 and the motor 500 may be restricted.

In addition, in the above description, it is explained that the overload detection unit 45B can detect the instantaneous overload state and the steady state overload state respectively. However, regarding the overload state notification method, a dedicated communication line for overload detection can be provided separately, or It is a method to notify the overload status by serial communication, etc.

According to the ninth embodiment, when the inverter 1-9 is in an instant overload state, the motor output can be immediately reduced. In addition, when the inverter 1-9 is in a steady-state overload state, the correction of the motor operation command output from the high-level control device 100 to each motor drive device improves the severe operation cycle, and can reduce the loading on the inverter 1- The temperature of the power module 22 and the smoothing capacitor 21 of 9 rises. With such control, it is possible to eliminate adverse effects such as deterioration of life and damage to the inverter 1-9 without stopping the system. In addition, in industrial machines like machine tools that use a plurality of motors, motor operation commands are output in a manner that prevents the cycle time from increasing, thereby maintaining the cycle time and eliminating the overload state of inverters 1-9. Therefore, an inverter with a small capacity can be selected to benefit the cost reduction of industrial machinery.

Embodiment 10. Fig. 38 is a diagram showing the configuration of an inverter and a motor control device according to the tenth embodiment. The converter 1-10 of the tenth embodiment has the same structure as the converter 1-3 shown in FIG. 19 shown in the third embodiment, but the bus voltage detection unit 23, the voltage phase detection unit 24, and the bus current detection are omitted The unit 25, the base drive signal generating unit 26, and the regeneration control unit 28 are shown, and a power failure detection unit 50 is added inside the inverter 1-10. In addition, in the configuration of FIG. 38, the motor drive device 400, the motor 500, and the high-order control device 100 are added in the same manner as in the eighth and ninth embodiments. In addition, in the configuration of FIG. 38, a DC voltage detection unit 82 for detecting the voltage between the terminals between DC terminals 17-18 is arranged inside the motor drive device 4, and a DC detection terminal 19 is arranged inside the motor drive device 400 A DC voltage detection unit 83 for the voltage between the terminals of -20. In addition, the high-level control device 100, the motor drive device 400, the motor drive device 4, and the inverters 1-10 are connected by a daisy chain communication path. Specifically, the power failure detection unit 50 of the inverter 1-10 and the motor control unit 4A of the motor drive device 4 are connected via a communication path 85, and the motor control unit 4A of the motor drive device 4 and the motor control unit of the motor drive device 400 400A is connected by a communication path 86a, and the motor control unit 400A of the motor drive device 400 and the high-end control device 100 are connected by a communication path 86b. In the foregoing configuration, for example, the motor operation command output by the high-level control device 100 to the motor drive device 4 is input to the motor control unit 4A of the motor drive device 4 via the motor control unit 400A of the motor drive device 400.

As described in Embodiment 3, the power failure detection unit 50 is provided with a power failure detection of the AC power supply 3 based on the output signal of the input voltage detection unit 43, and notification of the power failure information to the motor via the aforementioned communication paths 85, 86a, 86b The functions of the driving device 4, the motor driving device 400, and the high-level control device 100.

The motor control unit 4A has a function of supplying arbitrary AC power to the motor 5 to control the motor 5 at a variable speed, and a function of receiving the detection signal of the DC voltage detection unit 82. The motor control unit 400A has a function of supplying arbitrary AC power to the motor 500 to control the motor 500 at a variable speed, and a function of receiving a detection signal from the DC voltage detection unit 83. The detection signal of the DC voltage detection unit 82 and the detection signal of the DC voltage detection unit 83 are the same as the detection value of the bus voltage detection unit 23 which is the voltage between the terminals of the smoothing capacitor 21.

When power failure occurs in the AC power supply 3, the motor drive device 4 and the motor drive device 400 cannot continue the normal operation of each motor. In addition, if the converter 1-10 performs the power regeneration operation at this time, since the voltage difference between the bus voltage VPN and the AC power supply 3 increases, an excessive current flows, which may cause damage to the power module 22. Therefore, the power regeneration operation cannot be performed when a power failure occurs.

When a power failure occurs, when the motor 5 or motor 500 is in operation, the motor in operation must be stopped. On the other hand, when the motor is decelerated, the regenerative power of the motor is stored in the smoothing capacitor 21 of the inverter 1-10, so that the bus voltage VPN rises. In the original case, when the bus voltage VPN rises, the switching elements S1 to S6 of the power module 22 may be operated to perform the power regeneration operation, but the power regeneration operation cannot be performed due to the aforementioned reasons. As a result, the bus voltage VPN will further increase. Therefore, when the bus voltage VPN exceeds a certain value, the system determines that it is overvoltage and must stop the control of each motor. In this case, it takes time until each motor stops. For example, the feed shaft of the machine tool may collide with the shaft end.

In addition, depending on the characteristics of the motor or the frictional conditions the motor drives such as the gravity shaft, even when the motor is decelerated, it is sometimes necessary to continuously supply AC power from the motor drive device to the motor. That is, in this case, even when the motor is decelerating, since the motor does not generate regenerative power, the DC power stored in the smoothing capacitor 21 is used. In this situation, when the AC power supply 3 fails and the motor is to be stopped, the bus voltage VPN will rapidly decrease. Normally, when the bus voltage VPN is excessively lowered, the motor drive device cannot supply AC power for driving the motor, so it is determined that the voltage is low and the motor control is stopped. In this case, it takes time until each motor stops, and there is also the possibility of shaft end collision.

In order to solve the aforementioned problems, in the tenth embodiment, the determination result of the power failure detection unit 50 of the inverter 1-10 is notified to the motor control unit 4A, the motor control unit 400A, and the high-level control device 100 via the communication paths 85, 86a, and 86b. When the notified determination result is that the AC power supply 3 has a power failure, the motor control unit 4A controls the AC power supplied to the motor 5 based on the detection value of the DC voltage detection unit 82. In addition, the motor control unit 400A supplies AC power so as to decelerate and stop the motor 500. For example, in a machine tool, when the motor 5 is a spindle motor and the motor 500 is a servo motor, when the AC power supply 3 loses power, the servo motor that operates the feed axis must be quickly stopped first. Therefore, the motor 500 corresponding to the servo motor can be safely decelerated and stopped by controlling the bus voltage VPN at an appropriate value by the operation of the motor 5 corresponding to the spindle motor.

As described above, the DC voltage detection unit 82 is the same as the bus voltage VPN detected by the bus voltage detection unit 23. Therefore, the detection value of the DC voltage detection unit 82 can be handled as the bus voltage VPN. Inside the motor control unit 4A, a bus voltage determination circuit that determines the bus voltage VPN is configured. The motor control unit 4A determines the AC power supplied to the motor 5 based on the determination result of the bus voltage determination circuit.

Fig. 39 is a diagram showing a configuration example of a bus voltage determination circuit in the tenth embodiment. In FIG. 39, the bus voltage determination circuit is composed of comparators 196 and 197. The negative input terminal of the comparator 196 receives the bus voltage upper limit VPNmax, and the positive input terminal of the comparator 196 receives the detection value VPN of the DC voltage detection unit 82. The negative input terminal of the comparator 197 receives the detection value VPN of the DC voltage detection unit 82, and the positive input terminal of the comparator 197 receives the bus voltage lower limit VPNmin. The comparator 196 determines whether the bus voltage VPN is greater than or equal to the predetermined bus voltage upper limit VPNmax. The comparator 197 determines whether the bus voltage VPN is below the predetermined bus voltage lower limit VPNmin.

In the case where the comparator 196 outputs a signal of a high level and the comparator 197 outputs a signal of a low level, the bus voltage VPN is in a state of being larger than an appropriate value, and the bus voltage VPN must be reduced. In this case, if the motor 5 equivalent to the spindle motor is accelerated, the motor 5 becomes a power running operation and the bus voltage VPN can be reduced. In addition, when the comparator 196 outputs a low-level signal and the comparator 197 outputs a high-level signal, the bus voltage VPN is in a state smaller than an appropriate value, and the bus voltage VPN must be increased. In this case, if the motor 5 corresponding to the spindle motor is decelerated, the motor 5 becomes a regeneration operation and the bus voltage VPN can be increased.

Next, the operation of the inverter, the motor drive device, and the high-level control device of the tenth embodiment will be described with reference to FIGS. 40, 41, and 42 in addition to FIG. 38. Fig. 40 is a flowchart showing the operation of inverter 1-10 in the tenth embodiment. Fig. 41 is a flowchart showing the operation of the motor control unit 4A in the tenth embodiment. Fig. 42 is a flowchart showing the operation of the motor control unit 400A in the tenth embodiment. In addition, FIGS. 40 to 42 show the respective flowcharts, but they can also be displayed as one graph as in FIG. 37.

First, the operation of inverter 1-10 in the tenth embodiment will be described using FIG. 40. The input voltage detection unit 43 detects the input voltage of the AC power supply 3 as described above (step S401). The power failure detection unit 50 determines whether the AC power supply 3 has a power failure based on the output signal of the input voltage detection unit 43 (step S402). The power failure detection unit 50 notifies the determination result to the motor control unit 4A inside the motor drive device 4 via the communication path 85 (step S403). The processing of the above steps S401 to S403 is the processing of the converter 1-10, and the converter 1-10 repeats the processing of the steps S401 to S403.

Next, the operation of the motor control unit 4A in the tenth embodiment will be described using FIG. 41. The motor control unit 4A receives the determination result of the power failure detection unit 50 (step S501). The motor control unit 4A notifies the received determination result to the motor control unit 400A (step S502), and determines whether the AC power supply 3 has a power failure based on the received determination result (step S503). The motor control unit 4A determines whether the bus voltage VPN detected by the DC voltage detection unit 82 is equal to or greater than the bus voltage upper limit VPNmax when the received determination result is a signal indicating that the power failure has occurred (step S503, YES) (Step S504).

When the bus voltage VPN is greater than or equal to the bus voltage upper limit VPNmax (in the tenth embodiment, the output signal of the comparator 196 is High level and the output signal of the comparator 197 is Low level) (step S504, YES), the motor The control unit 4A controls the motor 5 to accelerate (step S508), and outputs AC power to the motor 5 (step S509).

When the bus voltage VPN does not reach the bus voltage upper limit VPNmax (in the tenth embodiment, the output signal of the comparator 196 is at a low level) (step S504, No), the motor control unit 4A determines whether the bus voltage VPN is a bus The voltage lower limit value VPNmin or less (step S505). When the bus voltage VPN is lower than the bus voltage lower limit VPNmax (in the tenth embodiment, the output signal of the comparator 196 is Low level and the output signal of the comparator 197 is High level) (step S505, YES), the motor The control unit 4A controls the motor 5 to decelerate (step S507), and outputs AC power to the motor 5 (step S509).

The bus voltage VPN is greater than the bus voltage lower limit VPNmin (in the tenth embodiment, the output signal of the comparator 197 is Low level, but in step S505, the output signals of the comparator 196 and the comparator 197 are both Low level Case) (step S505, NO), the motor control unit 4A stops the power supply to the motor 5 to inertia the motor 5 (step S506), and outputs the AC power generated according to the step S506 to the motor 5 ( Step S509). In addition, under this control, since the motor 5 is in the inertial operation, the power supply is stopped.

In addition, in the determination of step S501, when the determination result is a signal indicating that the content of the power failure has not occurred, the processing of steps S504 to S508 is skipped and the processing of step S509 is performed. That is, the motor control unit 4A outputs AC power for causing the motor 5 to operate in accordance with the motor operation command transmitted from the high-level control device 100. The above steps S501 to S509 are processes of the motor control unit 4A, and the motor control unit 4A repeatedly executes the processes of steps S501 to S509. In addition, in the control of step S506, the motor control unit 4A stops the power supply to the motor 5 to inertially operate the motor 5, but it may be controlled to maintain the motor 5 at a constant speed.

Next, the operation of the motor control unit 400A in the tenth embodiment will be described using FIG. 42. The motor control unit 400A receives the determination result on whether or not the power is cut off from the motor control unit 4A via the communication path 86a (step S601). The motor control unit 400A notifies the high-level control device 100 of the determination result of whether or not the power is cut off via the communication path 86b (step S602). The motor control unit 400A determines whether the AC power supply 3 has a power failure based on the determination result received in step S601 (step S603). When the received judgment result is a signal indicating that a power failure has occurred (step S603, YES), the motor control unit 400A changes the motor operation command (step S604) in such a manner as to decelerate the motor 500 (step S604). The AC power of the motor operation command is output to the motor 500 (step S605). On the other hand, when the received determination result is a signal indicating that the content of the power failure has not occurred (step S603, No), the motor control unit 400A skips the process of step S604 and performs the process of step S605. That is, the motor control unit 400A outputs AC power for causing the motor 500 to operate in accordance with the motor operation command transmitted from the high-level control device 100 (step S605). The above steps S601 to S605 are processes of the motor control unit 400A, and the motor control unit 400A repeatedly executes the processes of steps S601 to S605.

In the tenth embodiment, in the case of a power failure of the AC power supply 3, the high-level control device 100 without outputting a motor operation command can be used in the motor drive device 4 and the motor drive device 400, such as the motor 500 driving the feed shaft Stop quickly. For example, when the motor control unit 400A receives the power failure detection signal, the motor 500 is decelerated. At this time, when the deceleration energy at the time of deceleration is stored in the smoothing capacitor 21, the bus voltage VPN rises, but the bus voltage VPN is increased or decreased by the motor 5, so that the bus voltage VPN does not become an overvoltage or a low voltage Next, the motor 500 is stopped. Since the input voltage detection unit 43 detects the signal shown in the third embodiment, it can be realized at low cost, and the power failure detection unit 50 can also be realized at low cost.

In addition, part of the control functions of the inverter and the motor drive device described in the first to tenth embodiments can be constituted by hardware using photocouplers, logic ICs, etc. For example, it can be a single circuit, a composite circuit, a A programmed processor, a parallel programmed processor, ASIC, FPGA, or a combination of these may also be composed of software.

In addition, the configuration shown in the above embodiment is an example showing the contents of the present invention, and it may be combined with other conventionally-known techniques, and a part of the configuration may be omitted or changed without departing from the gist of the present invention.

1-1, 1-2, 1-3, 1-4, 1-5, 1-6, 1-7, 1-8, 1-9, 1-10 1A‧‧‧Inverter Control Department 2. 2-1, 2-2, 2-3‧‧‧ Reactor 3‧‧‧AC power 3R, 3S, 3T, 21a, 21b ‧‧‧ terminals 4. 400‧‧‧Motor drive device 4A, 400A‧‧‧Motor Control Department 5, 500‧‧‧ motor 6-1, 6-2‧‧‧ Output terminals 8-1, 8-2, 8-3, 9-1, 9-2, 9-3, 9-4, 9-5, 291, 291-1, 291-2, 292, 292-1, 292- 2.293,293-1,293-2,294,294-1,294-2‧‧‧Wiring 11, 12, 13 ‧‧‧ AC terminal 14, 15, 17, 18, 19, 20 ‧‧‧ DC terminals 21‧‧‧Smoothing capacitor 22‧‧‧Power Module 23‧‧‧Bus Voltage Detection Department 24、24A‧‧‧Voltage phase detection section 25‧‧‧Bus Current Detection Department 25A‧‧‧Input current detection section 26‧‧‧ Base drive signal generation 27‧‧‧ Base drive circuit 28、28A‧‧‧Regeneration Control Department 29‧‧‧Control Power Supply Department 30‧‧‧Insulation transformer 31‧‧‧Main power supply 32‧‧‧ IC for power supply control 33‧‧‧Switch element 34‧‧‧Feedback 35‧‧‧ Base control circuit 35A, 35B, 35C, 35D, 35E, 35F‧‧‧‧ control circuit 36‧‧‧Voltage application section 36A‧‧‧First voltage application section 36B‧‧‧Second voltage applying section 36C‧‧‧The third voltage application section 36D‧‧‧The fourth voltage application section 36E‧‧‧fifth voltage application section 36F‧‧‧Sixth voltage application section 37, 63‧‧‧ NPN transistor 38‧‧‧PNP transistor 39‧‧‧Base resistance 40‧‧‧Neutral point 41A, 41B, 41C‧‧‧resistance 42‧‧‧Phase detection department 43‧‧‧Input voltage detection section 44‧‧‧RST-dq Coordinate Conversion Department 45、45A、45B‧‧‧Overload detection department 46, 47a, 47b, 48a, 48b, 85, 86a, 86b 50‧‧‧Power Outage Detection Department 51, 52, 53, 91, 92, 93 ‧‧‧ AC wiring 60‧‧‧Regeneration start judgment section 61‧‧‧Regeneration stop judgment section 62‧‧‧Logic OR circuit 64‧‧‧Subtractor 65, 66, 190, 191, 195, 196, 197 70N, 71N‧‧‧Negative bus 70P, 71P‧‧‧ Positive bus 80N, 80P, 501, 502, 503‧‧‧ connection point 82, 83‧‧‧ DC voltage detection department 192‧‧‧Logic OR circuit 193‧‧‧ Absolute Value Calculation Department 194‧‧‧ Temperature rise estimation section 100‧‧‧High-level control device C21, C22, C23, C24 ‧‧‧ capacitor D1, D2, D3, D4, D5, D6, D21, D22, D23, D24 S1, S2, S3, S4, S5, S6‧‧‧‧ switching element IPN‧‧‧bus current SRP~STN, SRP’~STN’‧‧‧ Base drive signal VPN‧‧‧Bus voltage Ir, Is, It‧‧‧phase current N11‧‧‧ primary coil N21, N22, N23, N24 ‧‧‧ secondary coil VCC‧‧‧Power terminal FB‧‧‧Feedback terminal SW‧‧‧Gate signal output terminal GND‧‧‧Ground terminal D‧‧‧ Jiji S‧‧‧Source G‧‧‧Gate VRP, VSP, VTP, VN‧‧‧ voltage VRPGND, VSPGND, VTPGND, VNGND‧‧‧Ground SRP, SRP’, SRN, SRN’, SSP, SSP’, SSN, SSN’, STP, STP’, STN, STN’‧‧‧‧ Base drive signals ΔV‧‧‧Differential voltage Vo‧‧‧threshold voltage Iref‧‧‧limit current Vref‧‧‧reference voltage Ron‧‧‧ regeneration guide signal VR1, VS1, VT1‧‧‧ input voltage VR2, VS2, VT2‧‧‧phase voltage VR-S, VS-T, VT-R, VS-R, VT-S, VR-T‧‧‧ Line voltage Irr, Isr, Itr‧‧‧ Regenerative current LR, LS, LT, LR1, LS1, LT1 RD3, SD3, TD3‧‧‧phase detection signal NG‧‧‧Neutral potential Id‧‧‧d axis current Iq‧‧‧q axis current Idmax‧‧‧d axis current upper limit Idmin‧‧‧d axis current lower limit Kc‧‧‧Estimated value of temperature rise Kref‧‧‧Temperature limit VPNmax‧‧‧bus voltage upper limit VPNmin‧‧‧Bus voltage lower limit

Fig. 1 is a diagram showing the configuration of an inverter and a motor control device according to the first embodiment. FIG. 2 is a diagram showing a configuration example of the control power supply unit shown in FIG. 1. Fig. 3 is a diagram showing a configuration example of the regeneration control unit shown in Fig. 1. FIG. 4 is a diagram showing a configuration example of the base drive circuit shown in FIG. FIG. 5 is a diagram showing a configuration example of the first voltage applying section shown in FIG. 4. FIG. 6 is a diagram showing a configuration example of the second voltage applying section shown in FIG. 4. FIG. 7 is a diagram showing a configuration example of the third voltage applying section shown in FIG. 4. FIG. 8 is a diagram showing a configuration example of the fourth voltage applying section shown in FIG. 4. FIG. 9 is a diagram showing a configuration example of a fifth voltage applying section shown in FIG. 4. FIG. 10 is a diagram showing a configuration example of a sixth voltage applying section shown in FIG. 4. FIG. 11 is a diagram for explaining the operation of the voltage phase detection unit shown in FIG. 1. Fig. 12 is a time chart for explaining the operation of the inverter shown in Fig. 1; Figure 13 shows the inductance between the AC power supply and the AC terminal of the power module, and the inductance between the emitter of the switching element arranged on the positive side of the power module and the AC terminal of the power module Figure. Fig. 14 is a diagram showing the configuration of an inverter and a motor control device according to the second embodiment. Fig. 15 is a diagram showing waveforms of line voltage, base drive signal, phase detection signal, etc. generated by the inverter of Embodiment 1 during a regeneration operation. Fig. 16 is a diagram showing the waveforms of the phase voltage, base drive signal, phase detection signal, etc. generated by the inverter of Embodiment 1 during the regeneration operation. FIG. 17 is a diagram showing a configuration example of the voltage phase detection unit shown in FIG. 14. FIG. 18 is a diagram showing the waveform of the R-phase phase detection signal generated by the voltage phase detection unit of Embodiment 2 and the waveform of the R-phase phase voltage generated based on the phase detection signal. Fig. 19 is a diagram showing the configuration of the inverter and the motor control device according to the third embodiment. Fig. 20 is a diagram for explaining the operation of the input voltage detection unit shown in Fig. 19; Fig. 21 is a diagram showing the configuration of an inverter and a motor control device according to the fourth embodiment. Fig. 22 is a diagram for explaining the RST axis and the dq axis used in the control of the fourth embodiment. Fig. 23 is a diagram showing a configuration example of the regeneration control unit shown in Fig. 21. Fig. 24 is a diagram showing the configuration of an inverter and a motor control device according to the fifth embodiment. FIG. 25 is a waveform diagram showing the operation of the motor driving device shown in FIG. 24 when the motor is operated. Fig. 26 is a diagram showing a configuration example of the overload detection unit shown in Fig. 24. Fig. 27 is a diagram showing the configuration of an inverter and a motor control device according to the sixth embodiment. FIG. 28 is a waveform diagram illustrating the comparison of steady-state overload protection in the sixth embodiment. Fig. 29 is a diagram showing a configuration example of the overload detection unit shown in Fig. 27. Fig. 30 is a first waveform diagram illustrating the operation of the temperature rise estimation unit in the sixth embodiment. Fig. 31 is a second waveform diagram illustrating the operation of the temperature rise estimation unit in the sixth embodiment. Fig. 32 is a diagram showing the configuration of an inverter and a motor control device according to the seventh embodiment. Fig. 33 is a flowchart showing the operation of the inverter and motor control unit according to the seventh embodiment. Fig. 34 is a diagram showing the configuration of an inverter and a motor control device according to the eighth embodiment. Fig. 35 is a flowchart showing the operation of the inverter and the motor drive device according to the eighth embodiment. Fig. 36 is a diagram showing the configuration of an inverter and a motor control device according to the ninth embodiment. Fig. 37 is a flowchart showing the operation of the inverter, motor drive device, and high-order control device according to the ninth embodiment. Fig. 38 is a diagram showing the configuration of an inverter and a motor control device according to the tenth embodiment. Fig. 39 is a diagram showing a configuration example of a bus voltage determination circuit in the tenth embodiment. Fig. 40 is a flowchart showing the operation of the inverter in the tenth embodiment. Fig. 41 is a flowchart showing the operation of the motor control unit (motor control unit 4A) in the tenth embodiment. Fig. 42 is a flowchart showing the operation of the motor control unit (motor control unit 400A) in the tenth embodiment.

1-1‧‧‧Converter

2. 2-1, 2-2, 2-3‧‧‧ Reactor

3‧‧‧AC power

3R, 3S, 3T, 21a, 21b ‧‧‧ terminals

4‧‧‧Motor drive

5‧‧‧Motor

6-1, 6-2‧‧‧ Output terminals

8-1, 8-2, 8-3, 9-1, 9-2, 9-3, 9-4, 9-5‧‧‧Wiring

11, 12, 13 ‧‧‧ AC terminal

14, 15, 17, 18 ‧‧‧ DC terminal

21‧‧‧Smoothing capacitor

22‧‧‧Power Module

23‧‧‧Bus Voltage Detection Department

24‧‧‧Voltage phase detection section

25‧‧‧Bus Current Detection Department

26‧‧‧ Base drive signal generation

27‧‧‧ Base drive circuit

28‧‧‧Regeneration Control Department

29‧‧‧Control Power Supply Department

51, 52, 53, 91, 92, 93 ‧‧‧ AC wiring

70N, 71N‧‧‧Negative bus

70P, 71P‧‧‧ Positive bus

80N, 80P, 501, 502, 503‧‧‧ connection point

D1, D2, D3, D4, D5, D6‧rectifier element

IPN‧‧‧bus current

S1, S2, S3, S4, S5, S6‧‧‧‧ switching element

SRP~STN, SRP’~STN’‧‧‧ Base drive signal

VPN‧‧‧Bus voltage

Ir‧‧‧R phase current

Is‧‧‧S phase current

It‧‧‧T phase current

Claims (23)

An inverter is arranged between an AC power supply of an input power supply and a motor drive device which controls a motor at a variable speed, and is provided with a DC power supply to the motor drive device and a regenerative power when the motor is decelerated to return the AC power supply Power regeneration function, the converter is equipped with: The power module has an AC terminal connected to the aforementioned AC power supply, a first terminal connected to the DC wiring on the high potential side, and a second terminal connected to the DC wiring on the low potential side, and has a plurality of switching elements; The driving circuit drives each of the aforementioned switching elements; The control power supply unit generates power supplied to the plurality of switching elements and power supplied to the drive circuit; The voltage phase detection unit detects the AC voltage based on a signal flowing through the emitters of the plurality of switching elements connected to the first terminal, or a signal flowing through the ground that becomes the reference potential of the control power supply unit Voltage phase, and generates and outputs a phase detection signal indicating the detected voltage phase; and The driving signal generating unit generates a driving signal for controlling the on-off operation of the plurality of switching elements based on the phase detection signal. The converter according to item 1 of the patent application scope, wherein the voltage phase detection unit calculates the phase voltage of the AC voltage and uses at least one of the maximum value and the minimum value of the phase voltage to generate the phase detection Signal. The converter as described in item 2 of the patent application scope uses the phase voltage for the detection of the power failure of the AC power supply. The converter as described in item 2 of the patent application scope is provided with: continuing the transmission of the driving signal output from the driving signal generating section to the driving circuit, or stopping the aforementioned output from the driving signal generating section The signal control part of the transmission of the driving signal to the aforementioned driving circuit; The phase voltage is used as the reference voltage of the signal control unit. The converter according to item 1 of the patent application range, wherein the voltage phase detection unit calculates the line voltage of the AC voltage and uses at least one of the maximum value and the minimum value of the line voltage to generate the phase detection Signal. The converter as described in item 5 of the patent application scope uses the line voltage to detect the power failure of the AC power supply. The converter as described in item 5 of the patent application scope is provided with: continuing the transmission of the driving signal output from the driving signal generating section to the driving circuit, or stopping the aforementioned output from the driving signal generating section The signal control part of the transmission of the driving signal to the aforementioned driving circuit; The line voltage is used as the reference voltage of the signal control unit. The converter as described in item 1 of the patent application scope is provided with: a signal flowing through the emitters of the plurality of switching elements connected to the first terminal or a ground that becomes the reference potential of the control power supply unit The signal flowing in the middle detects the input voltage detection part of the phase voltage or line voltage of the AC power supply. The converter as described in item 8 of the patent application includes a power failure detection unit that uses the line voltage detected by the input voltage detection unit for power failure detection of the AC power supply. The converter described in item 8 of the patent application scope includes a power failure detection unit that uses the phase voltage detected by the input voltage detection unit for the power failure detection of the AC power supply. The converter according to any one of items 1 to 7 of the patent application scope, wherein the AC power supply is a three-phase AC power supply, and the voltage phase detection unit calculates the voltage phase of the first phase of the three-phase AC power supply At least one of the first voltage phase, the second voltage phase of the second phase voltage phase, the third voltage phase of the third phase voltage phase, and the power supply angular frequency. The converter as described in item 11 of the patent application scope is provided with: an input current detection unit that detects the current input to the AC terminal of the power module; and Coordinate conversion of the three-phase input current detected by the input current detection unit based on the phase detection signal, thereby calculating the d-axis current equivalent to the current of the effective power and the q-axis current equivalent to the current of the ineffective power Current value conversion unit. The converter according to item 12 of the patent application scope includes an overload detection unit that detects whether the converter is in an instantaneous overload state based on at least one of the d-axis current and the q-axis current. The converter according to item 13 of the patent application scope, wherein the overload detection unit is based on at least one of the d-axis current and the q-axis current in addition to the determination of whether the converter is in the transient overload state. The current determines whether the inverter is in a steady overload state, and outputs the determination result of the overload detection unit to the motor drive device or a high-level control device that outputs a motor operation command to the motor drive device. The converter according to item 13 or 14 of the patent application scope, wherein the overload detection unit is in a case where the d-axis current is greater than a predetermined allowable d-axis current lower limit value and less than an allowable d-axis current upper limit value, It is determined that the converter is not operating in an instant overload state, and when the d-axis current is below the allowable d-axis current lower limit value or the allowable d-axis current upper limit value or more, it is determined that the converter is momentarily overloaded Action in state. The converter according to any one of claims 13 to 15, wherein the overload detection unit is configured to calculate an absolute value based on at least one of the d-axis current and the q-axis current An absolute value calculation unit, and a filter that inputs the calculation results of the absolute value calculation unit and averages them; When the output result of the filter is greater than or equal to a predetermined allowable absolute value, it is determined that the converter operates in a steady-state overload state. A motor control device with: An inverter as described in any one of claims 13 to 16 and a motor drive device that receives DC current from the inverter and controls the motor at a variable speed. The motor control device as described in item 17 of the patent application range, wherein the motor drive device is a motor operation command output from a higher-order control device when the overload detection unit determines that the overload is determined to be overloaded In a manner of restricting the operation of the motor of the output of the motor, variable speed control of the motor is performed. The motor control device according to item 17 of the patent application scope, wherein, in the case where the determination result of the overload detection unit determines that the overload is performed, the motor operation command is changed in such a manner as to limit the motor operation of the output of the motor, and The control is performed in such a manner that it is output to the aforementioned motor driving device via the high-level control device. The motor control device according to item 18 or 19 of the patent application range, wherein the communication path is daisy-chained in the order of the high-level control device, the motor drive device and the inverter, and the instantaneous overload state is detected by the overload detection unit When the overload detection unit notifies the determination result to the motor drive device, the motor drive device performs a motor operation mode in which the output of the motor is limited compared to the motor operation command output from the high-level control device. Variable speed control of the motor, and notifies the high-level control device of the determination result of the overload detection unit, the high-level control device receives the determination result, and becomes a motor that limits the output of the motor in the case of a transient overload state The motor operation command is changed according to the operation mode, and it is controlled by outputting to the aforementioned motor driving device. The motor control device according to item 18 or 19 of the patent application range, wherein the communication path is daisy-chained in the order of the high-level control device, the motor drive device, and the inverter, and a steady-state overload is detected in the overload detection unit When the overload detection unit notifies the determination result to the motor drive device, the motor drive device performs variable speed control of the motor based on the motor operation command output by the high-level control device, and determines the overload detection unit The result is notified to the high-level control device. The high-level control device receives the determination result. In the case of a steady-state overload state, the operation cycle is changed in a manner that suppresses the average output of the motor, and is output to the motor drive device. Way to control. The motor control device according to any one of items 18 to 21 of the patent application range, wherein, when a power failure of the AC power supply is detected, at least one of the motors driven by the plurality of motor drive devices is decelerated Perform variable speed control. The motor control device according to claim 22, wherein the motor drive device includes: a DC voltage detection device connected between the first terminal and the second terminal and detecting a voltage of a smoothing capacitor storing DC power unit; The motor drive device performs variable speed control in a manner that accelerates a motor different from the motor that performs the deceleration when the detection value of the DC voltage detection unit is equal to or greater than the DC voltage upper limit value; In the case where the detection value of the DC voltage detection unit is equal to or lower than the DC voltage lower limit value, variable speed control is performed in such a manner that a motor different from the motor that performs the deceleration is decelerated; And when the detection value of the DC voltage detection unit is greater than the DC voltage lower limit value and less than the DC voltage upper limit value, the motor decelerating from the decelerating motor is inertially operated or maintained at a certain speed. Variable speed control.

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