WO2019239628A1

WO2019239628A1 - Converter and motor control device

Info

Publication number: WO2019239628A1
Application number: PCT/JP2019/003034
Authority: WO
Inventors: 良知林; 聡小塚
Original assignee: 三菱電機株式会社
Priority date: 2018-06-11
Filing date: 2019-01-29
Publication date: 2019-12-19
Also published as: CN112219348A; TW202002479A; WO2019239469A1; TWI705647B

Abstract

Provided is a converter (1-1) comprising: a power module (22) including AC terminals (11, 12, 13) connected to an AC power supply (3), a DC terminal (14) and a DC terminal (15), and a plurality of switching elements; a base driving circuit (27); and a control power supply unit (29). The converter (1-1) comprises a voltage phase detection unit (24) that detects a voltage phase of an AC voltage on the basis of a signal flowing to emitters of a plurality of switching elements connected to the DC terminal (14) or a signal flowing to a ground and serving as a reference potential for the control power supply unit (29), and generates and outputs a phase detection signal indicative of the detected voltage phase. The converter (1-1) comprises a base driving signal generation unit (26) that generates, on the basis of the phase detection signal, a driving signal for controlling on/off operations of a plurality of switching elements.

Description

Converter and motor control device

The present invention relates to a converter and a motor control device that convert AC power into DC power.

In industrial machines such as machine tools, manufacturing machines, and robots, converters using a power regeneration system that returns regenerative power to an AC power source as an input power source are often used for energy saving. The converter using the power regeneration system operates as a DC / AC converter that converts DC power supplied from the motor drive device to AC power during motor regeneration, thereby converting the regenerative power generated by the motor into AC. Return to power. Hereinafter, the operation of the converter that returns the regenerative power to the AC power supply is referred to as a regenerative operation. In the regenerative operation, if the timing at which the switching elements constituting the converter are turned on deviates from the voltage phase of the AC power supply, the voltage difference increases, and an excessive current may flow to stop the motor drive device. Therefore, in the converter, the voltage phase of the AC power supply is detected, and a drive signal that controls the on / off operation of the switching element during the regenerative operation is generated based on the detected phase information. Hereinafter, the voltage phase of the AC power supply may be simply referred to as a voltage phase. As a voltage phase detection method, a method of detecting a zero cross point of a line voltage of an AC power supply and detecting a voltage phase based on the detected zero cross point is common. The zero cross point is a timing at which the voltage becomes zero when the line voltage of the AC power source changes from negative to positive or from positive to negative. However, in this voltage phase detection method, the timing at which the line voltage of the AC power supply zero-crosses overlaps with the timing at which the switching element during the regenerative operation is turned on or off. Spike-like distortion occurs in the voltage. For this reason, there is a possibility that a zero-cross point detection error occurs due to voltage fluctuation, and the voltage phase is erroneously detected.

In order to solve such a problem, Patent Document 1 discloses a technique for detecting the voltage phase of the AC power supply by the zero crossing 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 voltage phase of the AC power supply is detected by the phase detection unit. The phase detector is mounted on a printed circuit board provided in the power regeneration converter. According to the technique disclosed in Patent Literature 1, since the voltage phase of the AC power supply is detected by the zero cross of the phase voltage, a phase detection signal that alternately changes between a high level and a low level between the zero cross points is generated. . The timing at which the level of the phase detection signal changes can be made different from the timing at which the switching element is turned on or off. As a result, voltage phase detection can be performed without being affected by spike-like distortion of the power supply voltage caused by the on / off operation of the switching element.

JP 2004-180427 A

In the technique disclosed in Patent Document 1, the phase of the AC voltage applied between the AC power supply terminal of the power regeneration converter and the AC power supply terminal of the power module configured by a plurality of switching elements is detected by the phase detection unit. Detected. This AC voltage is a voltage applied to the pattern (copper foil) on the printed circuit board. However, since the value of the current flowing between the AC power supply terminal of the power regeneration converter and the AC power supply terminal of the power module increases as the converter capacity increases, the converter capacity increases depending on the pattern on the printed circuit board. It becomes difficult to supply power. Therefore, generally, in a large-capacity converter, power is supplied using a conductor such as a bus bar. When a conductor such as a bus bar is used in this way, in the technique disclosed in Patent Document 1, a harness is connected to the bus bar, for example, in order to detect the phase of the AC voltage in the phase detection unit provided on the printed circuit board. In addition, since the phase detector detects the AC voltage phase via the harness, there is a problem that the structure becomes complicated.

The present invention has been made in view of the above, and an object thereof is to obtain a converter capable of detecting the voltage phase of an AC power supply with a simple configuration.

In order to solve the above-described problems and achieve the object, a converter according to the present invention is disposed between an AC power source that is an input power source and a motor driving device that performs variable speed control of the motor, and supplies DC power to the motor driving device. In a converter having a power regeneration function for supplying regenerative power when the motor decelerates to an AC power supply, an AC terminal connected to the AC power supply, a first terminal connected to a high potential side DC wiring, and a low potential A power module having a plurality of switching elements and a drive circuit for driving each of the plurality of switching elements. The converter includes a control power supply unit that generates electric power supplied to the plurality of switching elements and electric power supplied to the drive circuit, a signal that flows to the emitters of the plurality of switching elements connected to the first terminal, or a control power supply A voltage phase detection unit that detects a voltage phase of the AC voltage based on a signal flowing in the ground serving as a reference potential of the unit, generates a phase detection signal indicating the detected voltage phase, and outputs the phase detection signal. The converter includes a drive signal generation unit that generates a drive signal for controlling the on / off operation of the plurality of switching elements based on the phase detection signal.

The converter according to the present invention has an effect that the voltage phase of the AC power supply can be detected with a simple configuration.

The figure which shows the structure of the converter which concerns on Embodiment 1, and a motor control apparatus. The figure which shows the structural example of the control power supply part shown in FIG. The figure which shows the structural example of the regeneration control part shown in FIG. 1 is a diagram illustrating a configuration example of a base drive circuit illustrated in FIG. The figure which shows the structural example of the 1st voltage application part shown in FIG. The figure which shows the structural example of the 2nd voltage application part shown in FIG. The figure which shows the structural example of the 3rd voltage application part shown in FIG. The figure which shows the structural example of the 4th voltage application part shown in FIG. The figure which shows the structural example of the 5th voltage application part shown in FIG. The figure which shows the structural example of the 6th voltage application part shown in FIG. The figure for demonstrating operation | movement of the voltage phase detection part shown in FIG. Time chart for explaining the operation of the converter shown in FIG. The figure which shows the inductance which exists between an alternating current power supply and the alternating current terminal of a power module, and the inductance which exists between the emitter of the switching element arrange | positioned at the positive electrode side of a power module, and the alternating current terminal of a power module The figure which shows the structure of the converter and motor control apparatus which concern on Embodiment 2. The figure which shows waveforms, such as a line voltage, a base drive signal, and a phase detection signal, which are generated during the regenerative operation of the converter according to the first embodiment. The figure which shows waveforms, such as a phase voltage, a base drive signal, and a phase detection signal which arise at the time of regeneration operation | movement of the converter which concerns on Embodiment 1. The figure which shows the structural example of the voltage phase detection part shown in FIG. The figure which shows the waveform of the R phase phase detection signal produced | generated by the voltage phase detection part which concerns on Embodiment 2, and the waveform of the R phase phase voltage which generate | occur | produces based on the said phase detection signal The figure which shows the structure of the converter and motor control apparatus which concern on Embodiment 3. FIG. 19 is a diagram for explaining the operation of the input voltage detection unit shown in FIG. The figure which shows the structure of the converter and motor control apparatus which concern on Embodiment 4. The figure which uses for description of the RST axis | shaft and dq axis | shaft used by control of Embodiment 4. The figure which shows the structural example of the regeneration control part shown in FIG. The figure which shows the structure of the converter and motor control apparatus which concern on Embodiment 5. FIG. 24 is a waveform diagram showing the behavior when the motor driving device shown in FIG. 24 operates the motor. The figure which shows the structural example of the overload detection part shown in FIG. The figure which shows the structure of the converter and motor control apparatus which concern on Embodiment 6. Waveform diagram for explaining steady-state overload protection in the sixth embodiment The figure which shows the structural example of the overload detection part shown in FIG. First waveform diagram for explaining the operation of the temperature rise estimation unit in the sixth embodiment Second waveform diagram for explaining the operation of the temperature rise estimation unit in the sixth embodiment The figure which shows the structure of the converter and motor control apparatus which concern on Embodiment 7. Flowchart showing operation of converter and motor control unit according to embodiment 7. The figure which shows the structure of the converter and motor control apparatus which concern on Embodiment 8. Flowchart showing the operation of the converter and motor drive device according to the eighth embodiment. The figure which shows the structure of the converter and motor control apparatus which concern on Embodiment 9. Flowchart showing the operation of the converter, motor drive device and host control device according to Embodiment 9 The figure which shows the structure of the converter and motor control apparatus which concern on Embodiment 10. FIG. 10 shows a configuration example of a bus voltage determination circuit in the tenth embodiment. Flowchart showing the operation of the converter in the tenth embodiment. Flowchart showing the operation of the motor control unit (motor control unit 4A) in the tenth embodiment. Flowchart showing the operation of the motor control unit (motor control unit 400A) in the tenth embodiment.

Hereinafter, a converter and a motor control device according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a configuration of a converter and a motor control device according to the first embodiment. As shown in FIG. 1, converter 1-1 according to the first embodiment is provided between an AC power supply 3 that is a three-phase AC power supply that generates a three-phase AC voltage and a motor drive device 4. The converter 1-1 converts the AC voltage from the AC power source 3 that generates a three-phase AC voltage during powering of the motor into a DC voltage and outputs the DC voltage to the motor driving device 4. When the motor decelerates, the converter 1-1 generates regenerative power by a regenerative operation. Return to AC power source 3. The motor driving device 4 receives the DC voltage supplied from the converter 1-1 and controls the motor 5 at a variable speed. The motor control apparatus according to the first embodiment is an apparatus including a converter 1-1 and a motor driving device 4 that receives DC power from the converter 1-1 and controls the motor 5 at a variable speed.

The converter 1-1 includes a smoothing capacitor 21 that stores DC power, a power module 22, a bus voltage detector 23, a voltage phase detector 24, a bus current detector 25, and a base drive that is a drive signal generator. The signal generation unit 26 includes a base drive circuit 27 that is a drive circuit, a regeneration control unit 28 that is a signal control unit, and a control power supply unit 29.

The power module 22 includes three

AC terminals

11, 12, 13, a DC terminal 14 that is a first terminal to which a high potential side DC wiring is connected, and a second terminal to which a low potential side DC wiring is connected. A certain DC terminal 15 is provided. 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 an AC wiring 91. The other end of the AC wiring 91 is connected to the terminal 3 R of the AC power supply 3. The terminal 3R is a terminal to which an R-phase AC voltage that is a first phase is output. The R-phase AC voltage is applied to the AC terminal 11 via the reactor 2-1.

AC terminal 12 is connected to one end of 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 3 S of the AC power supply 3. The terminal 3S is a terminal to which an S-phase AC voltage that is the second phase is output. The S-phase AC voltage is applied to the AC terminal 12 via the reactor 2-2.

AC terminal 13 is connected to one end of 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 source 3. The terminal 3T is a terminal to which a T-phase AC voltage that is a third phase is output. The T-phase AC voltage is applied to the AC terminal 13 via the reactor 2-3. Hereinafter, the reactors 2-1, 2-2, and 2-3 may be referred to as a reactor 2 when they are not distinguished.

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

The DC terminal 15 is connected to one end of a negative electrode bus 70N which is a DC wiring on the low potential side. The other end of the negative electrode bus 70N is connected to the output terminal 6-2 of the converter 1-1. The output terminal 6-2 is a DC terminal on the low potential side. One end of the negative electrode bus 71N is connected to the output terminal 6-2. The negative electrode bus 71N is a low potential side DC wiring provided between the converter 1-1 and the motor driving device 4. The other end of the negative electrode bus 71N is connected to the DC terminal 18 of the motor driving 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 driving device 4 through the negative electrode bus 70N, the output terminal 6-2, and the negative electrode bus 71N.

The terminal 21a on the high potential side of the smoothing capacitor 21 is connected to the positive electrode bus 70P. Reference numeral 80P represents a connection point between the high potential side terminal 21a of the smoothing capacitor 21 and the positive electrode bus 70P. By connecting the high-potential side terminal 21a of the smoothing capacitor 21 to the positive electrode bus 70P, the high-potential side terminal 21a of the smoothing capacitor 21 is electrically connected to the DC terminal 14 of the power module 22 and further driven by a motor. It is electrically connected to the DC terminal 17 of the device 4.

The low potential side terminal 21b of the smoothing capacitor 21 is connected to the negative electrode bus 70N. In FIG. 1, reference numeral 80N represents a connection point between the low potential side terminal 21b of the smoothing capacitor 21 and the negative electrode bus 70N. By connecting the low-potential side terminal 21b of the smoothing capacitor 21 to the negative electrode bus 70N, the low-potential side terminal 21b of the smoothing capacitor 21 is electrically connected to the DC terminal 15 of the power module 22 and further driven by a motor. It is electrically connected to the DC terminal 18 of the device 4.

In addition to the

AC terminals

11, 12, 13 and the

DC terminals

14, 15, the power module 22 includes six rectifying elements D 1, D 2, D 3, D 4, D 5, D 6 and 6 switching elements S 1, S 2 for regeneration. , S3, S4, S5, and S6. Hereinafter, the six rectifying elements D1, D2, D3, D4, D5, and D6 may be referred to as rectifying elements D1 to D6, and the switching elements S1, S2, S3, S4, S5, and S6 may be referred to as switching elements S1 to S6. is there.

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

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

Switching element S1 and switching element S2 are connected in series by wiring 8-1. The switching element S1, the switching element S2, the rectifying element D1, the rectifying element D2, and the wiring 8-1 constitute a first arm. 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. One end of the wiring 9-1 is connected to the wiring 8-1. Reference numeral 501 represents a connection point between the wiring 8-1 and the wiring 9-1. The other end of the wiring 9-1 is connected to the AC terminal 11. Thereby, 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 through the reactor 2-1, etc., the rectifying element D1 and the switching element S1 constitute a power element for an R-phase positive electrode, and the rectifying element D2 and switching element S2 constitute a power element for an R-phase negative electrode. The collector of the switching element S1 is connected to the DC terminal 14 via the wiring 9-4. The emitter of the switching element S2 is connected to the DC terminal 15 via the wiring 9-5.

Switching element S3 and switching element S4 are connected in series by wiring 8-2. Switching element S3, switching element S4, rectifying element D3, rectifying element D4, and wiring 8-2 constitute a second arm. 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. One end of the wiring 9-2 is connected to the wiring 8-2. Reference numeral 502 represents a connection point between the wiring 8-2 and the wiring 9-2. The other end of the wiring 9-2 is connected to the AC terminal 12. Thus, 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 or the like, the rectifying element D3 and the switching element S3 constitute a power element for the S-phase positive electrode, and the rectifying element D4 and switching element S4 constitute an S-phase negative power element. The collector of the switching element S3 is connected to the DC terminal 14 via the wiring 9-4. The emitter of the switching element S4 is connected to the DC terminal 15 through the wiring 9-5.

Switching element S5 and switching element S6 are connected in series by wiring 8-3. Switching element S5, switching element S6, rectifying element D5, rectifying element D6 and wiring 8-3 constitute a third arm. 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. One end of the wiring 9-3 is connected to the wiring 8-3. Reference numeral 503 represents a connection point between the wiring 8-3 and the wiring 9-2. The other end of the wiring 9-3 is connected to the AC terminal 13. Thereby, the emitter of switching element S5 and the collector of switching element S6 are electrically connected to AC terminal 13. Since the AC terminal 13 is electrically connected to the terminal 3T of the AC power supply 3 via the reactor 2-3 or the like, the rectifying element D5 and the switching element S5 constitute a power element for a T-phase positive electrode, and the rectifying element D6 and switching element S6 constitute a T-phase negative power element. The collector of the switching element S5 is connected to the DC terminal 14 via the wiring 9-4. The emitter of the switching element S6 is connected to the DC terminal 15 via the 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 that constitute 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 to 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, a switching element S5 and a switching element. The series circuit constituted by S6 is connected in parallel. The converter 1-1 according to the first embodiment is connected to the 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 elements.

The bus voltage detector 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. The terminal 21a of the smoothing capacitor 21 is connected to the DC terminal 14 of the power module 22 via the positive electrode 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 electrode bus 70N. Therefore, the voltage applied to the

terminals

21 a and 21 b of the smoothing capacitor 21 is equal to the voltage applied to the

DC terminals

14 and 15 of the power module 22.

The bus current detection unit 25 is provided between the DC terminal 14 and the connection point 80P on the positive bus 70P, for example. Bus current detector 25 detects a current flowing through positive electrode bus 70P, and outputs current information indicating the detected current as bus current IPN. The bus current detection unit 25 may be a current sensor using an instrumental current transformer called CT (Current Transformer), or may be a current sensor using a shunt resistor. The bus current detector 25 may be a combination of these. For example, the bus current detection unit 25 may be provided between the DC terminal 15 and the connection point 80N on the negative electrode bus 70N to detect a current flowing through the negative electrode bus 70N.

The control power supply unit 29 generates power for driving the switching elements S1 to S6 of the power module 22 and power for driving the base drive circuit 27. As described 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 of the AC power supply 3 via the reactor 2-2. The emitter of the switching 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 of the switching elements S1, S3, and S5 arranged on the positive electrode side, the base drive circuit 27 sets the ground of the drive signal generation circuit that drives each of the switching elements S1, S3, and S5. It is necessary to divide. That is, it is necessary to insulate drive signal generation circuits 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, S6 arranged on the negative electrode side are connected to the DC terminal 15 of the power module 22, they serve as reference potentials for the emitters of the switching elements S2, S4, S6. The ground is the same. Therefore, in the base drive circuit 27, the ground of the drive signal generation circuit for driving the switching elements S2, S4, S6 arranged on the negative electrode side can be made the same. Therefore, in order to operate the base drive circuit 27, at least four insulated power supplies are required.

FIG. 2 is a diagram showing a configuration example of the control power supply unit shown in FIG. 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 rectifier elements D21, D22, D23, and D24. , Capacitors C21, C22, C23, C24, and a feedback unit 34.

The insulating transformer 30 includes a primary winding N11 and a plurality of secondary windings N21, N22, N23, and N24. Each of the plurality of secondary windings N21, N22, N23, N24 is insulated between adjacent windings. The power supply control IC 32 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 winding N11 and the power supply terminal VCC of the power supply control IC 32. The winding end side terminal of the primary winding 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 rectifying element D21 is connected to the winding end side terminal of the secondary winding N21, and the cathode of the rectifying 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 winding N21 via the wiring 291. One end of the wiring 291-1 is connected to a connection point between the cathode of the rectifying element D21 and one end of the capacitor C21. One end of the wiring 291-2 is connected to a connection point between the other end of the capacitor C21 and the wiring 291. A ground VRPGND serving as a reference potential of the voltage VRP generated in the wiring 291-1 is connected to the wiring 291-2. 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 wirings 291-1 and 291-2 are connected to the base drive circuit 27 shown in FIG.

The anode of the rectifying element D22 is connected to the winding end side terminal of the secondary winding N22, and the cathode of the rectifying 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 winding N22 via the wiring 292. One end of the wiring 292-1 is connected to a connection point between the cathode of the rectifying element D22 and one end of the capacitor C22. One end of the wiring 292-2 is connected to the connection point between the other end of the capacitor C22 and the wiring 292. A ground VSPGND which is a reference potential of the voltage VSP generated in the wiring 292-1 is connected to the wiring 292-2. 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 rectifying element D23 is connected to the winding end side terminal of the secondary winding N23, and the cathode of the rectifying 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 winding N23 via the wiring 293. One end of the wiring 293-1 is connected to a connection point between the cathode of the rectifying element D23 and one end of the capacitor C23. One end of the wiring 293-2 is connected to the connection point between the other end of the capacitor C23 and the wiring 293. The wiring 293-2 is connected to a ground VTPGND that serves as a 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 rectifying element D24 is connected to the winding end side terminal of the secondary winding N24, and the cathode of the rectifying 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 winding N24 via the wiring 294. One end of the wiring 294-1 is connected to a connection point between the cathode of the rectifying element D24 and one end of the capacitor C24. One end of the wiring 294-2 is connected to a connection point between the other end of the capacitor C24 and the wiring 294. The wiring 294-2 is connected to the ground VNGGND that serves as a reference potential for 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. For example, a photocoupler is used for the feedback unit 34. The feedback unit 34 sets the voltage VN to a voltage value that can be handled by the power supply control IC 32 in a state where the FB terminal of the power supply control IC 32 and the secondary winding N24 are insulated. The voltage value after conversion is input to the FB terminal of the power supply control IC 32. By using the feedback unit 34, it is possible to maintain insulation between the circuit on the primary winding N11 side and the circuit on the secondary winding N21 to N24 side.

In the control power supply unit 29, the number of turns of each of the secondary windings N21, N22, and N23 is made equal to the number of turns of the secondary winding N24, so that the voltage generated in each of the capacitors C21, C22, and C23 is the capacitor C24. Is almost equal to the voltage generated in

The operation of the control power supply unit 29 will be described. The power supply control IC 32 generates a control signal for controlling 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 G of the switching element 33. As a result, the switching element 33 repeats the on / off operation, and the value of the voltage VN input to the feedback unit 34 is maintained at a specific value.

The voltage phase detector 24 shown in FIG. 1 detects the voltage phase of the AC power supply 3, and outputs phase information indicating the detected voltage phase to the base drive signal generator 26 as a phase detection signal. The phase detection signal is a signal that takes a high level or low level potential. The voltage phase detection method by the voltage phase detector 24 and details of the phase detection signal will be described later.

Based on the phase detection signal output from the voltage phase detector 24, the base drive signal generator 26 has six types of base drive signals SRP, SRN, SSP, SSN, STP, for driving the switching elements S1 to S6. An STN is generated and output to the regeneration control unit 28. Each of the six types of base drive signals SRP, SRN, SSP, SSN, STP, and STN is a signal that takes a High level or 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 drive 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 drive signal SSN is a signal for driving the switching element S4 for the negative side of the S phase. The base drive signal STP is a signal for driving the switching element S5 for the positive side of the T phase. The base drive signal STN is a signal for driving the switching element S6 for the negative side of the T phase. Hereinafter, the six types of base drive signals SRP, SRN, SSP, SSN, STP, and STN may be 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 continues to transmit the base drive signal SRP output from the base drive signal generation unit 26 to the base drive circuit 27 of the STN, or the base drive signal. It is determined whether to stop transmission of the STN to the base drive circuit 27 from the base drive signal SRP output from the generation unit 26. If the regeneration control unit 28 determines that the transmission of the STN from the base drive signal SRP to the base drive circuit 27 is continued, the STN is continuously input to the base drive circuit 27 from the base drive signal SRP. When the regeneration control unit 28 determines that the transmission of the STN from the base drive signal SRP to the base drive circuit 27 is stopped, the input of the STN from the base drive signal SRP to the base drive circuit 27 is stopped.

FIG. 3 is a diagram illustrating a configuration example of the regeneration control unit illustrated 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, an OR circuit 62, and an NPN transistor 63. The bus voltage VPN is input to the regeneration start determination unit 60 in the regeneration start determination unit 60. 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 subtracter 64 and a comparator 65. The subtractor 64 receives the bus voltage VPN and the reference voltage Vref. The reference voltage Vref is a voltage set in advance based on the voltage of the AC power supply 3. The reference voltage Vref is generated by a method of generating the reference voltage Vref by detecting the voltage of the AC power supply 3, a method of generating the reference voltage Vref based on the bus voltage VPN output from the bus voltage detector 23, and the like. However, any method is publicly known, and a detailed description thereof is omitted here. The subtractor 64 calculates a difference voltage ΔV that is a difference between the bus voltage VPN and the reference voltage Vref.

The difference voltage ΔV is input to the plus terminal of the comparator 65. The threshold voltage Vo is input to the negative terminal of the comparator 65. The comparator 65 compares the difference voltage ΔV and the threshold voltage Vo, and outputs a signal that takes a high level or low level potential. For example, when the difference voltage ΔV is larger than the threshold voltage Vo, a high level signal is output. The high level signal is a signal indicating that the regenerative operation by the power module 22 is started when the bus voltage VPN becomes higher than a certain value. When the difference voltage ΔV is less than the threshold voltage Vo, a low level signal is output. A signal output from the comparator 65 is input to the OR circuit 62 as an output signal of the regeneration start determination unit 60.

In the regeneration start determination unit 60 of the regeneration control unit 28 according to 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 are such that the difference voltage ΔV <the threshold voltage Vo. Therefore, for example, a hysteresis function is provided in the comparator 65, a one-shot trigger circuit is provided in the output of the comparator 65, or a regeneration start determination is made so that the regeneration operation continues until a certain period elapses after the regeneration operation starts. It is desirable to constitute part 60.

The regenerative stop determination unit 61 receives 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 threshold current Iref is input to the plus terminal of the comparator 66. The bus current IPN is input to the negative terminal of the comparator 66. The comparator 66 compares the bus current IPN and the threshold current Iref, and outputs a signal that takes a High level or Low level potential. For example, when the bus current IPN is larger than the threshold current Iref, a low level signal is output. When the bus current IPN becomes less than the threshold current Iref, a high level signal is output. A signal output from the comparator 66 is input to the OR circuit 62 as an output signal of the regeneration stop determination unit 61.

The output of the OR circuit 62 is connected to the base of the NPN transistor 63. A regenerative on signal Ron that is an output signal of the OR circuit 62 is input to the base of the NPN transistor 63. A base drive signal generator 26 shown in FIG. 1 is connected to the collector of the NPN transistor 63. STN is input to the collector of the NPN transistor 63 from the base drive signal SRP that is the output of the base drive signal generator 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 output signals of the regeneration start determination unit 60 and the regeneration stop determination unit 61 are input to the OR circuit 62. When any output signal is at a high level, the OR circuit 62 outputs a high level signal. When the OR circuit 62 outputs a high level signal, the NPN transistor 63 is turned on, and the base drive signals SRP to STN are input to the base drive circuit 27 shown in FIG. In the base drive circuit 27, the base drive signal SRP is converted into a signal that can be handled by each power element of the power module 22, and the converted base drive signals SRP ′, SRN ′, SSP ′, SSN are converted signals. ', STP', STN 'are generated. The generated base drive signals SRP ', SRN', SSP ', SSN', STP ', STN' are input to the bases of the switching elements S1 to S6. Thereby, the on / off operation of the switching elements S1 to S6, that is, the regenerative operation of the power module 22 is performed. Hereinafter, the base drive signals SRP ', SRN', SSP ', SSN', STP ', STN' may be referred to as base drive signals SRP 'to STN'. 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 the Low level, the OR circuit 62 outputs a Low level signal. When the OR circuit 62 outputs a low level signal, the NPN transistor 63 is turned off, and the STN input from the base drive signal SRP to the base drive circuit 27 shown in FIG. 1 is cut off. As a result, all of the switching elements S1 to S6 are turned off, and the regenerative operation is stopped.

Thus, when at least one of the regeneration start determination unit 60 and the regeneration stop determination unit 61 outputs a high level signal, the regeneration operation is continued, and both the regeneration start determination unit 60 and the regeneration stop determination unit 61 When a low level signal is output, the regenerative operation is stopped.

The base drive circuit 27 will be described. As described above, the base drive circuit 27 uses the base drive signals SRP ′, SRN ′, and SSP ′ that the power module 22 can handle the base drive signals SRP, SRN, SSP, SSN, STP, and SSN output from the regeneration control unit 28. , SSN ′, STP ′, STN ′, and has a function of inputting to the bases 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. As shown in FIG. 4, the base drive circuit 27 includes a base control circuit 35 and a voltage application unit 36.

The base control circuit 35 electrically insulates the signal input to the base control circuit 35 and outputs an output signal having the same potential as that of the input signal, that is, when the input signal is at a high level, When the input signal is at a low level, a function of outputting an output signal at a low level to the voltage application unit 36 is provided. For example, when a base drive signal SRP that takes a high-level potential is input to the base control circuit 35, the base control circuit 35 is electrically insulated from the base drive signal SRP, and is at a high-level potential. Is output to the voltage application unit 36. For example, a photocoupler or an insulated pulse transformer is used for the base control circuit 35. However, the components constituting the base control circuit 35 are not limited thereto, and the input signal and the output signal are electrically insulated. Therefore, any device that transmits an output signal having the same potential as the input signal may be used.

The base control circuit 35 electrically insulates the base drive signal SRP and converts it into a signal having the same potential as the base drive signal SRP, and electrically insulates the base drive signal SRN, The control circuit 35B for converting to a signal having the same potential is electrically insulated from the base drive signal SSP, and the control circuit 35C for converting to a signal having the same potential as the base drive signal SSP is electrically insulated from the base drive signal SSN. A control circuit 35D for converting the base drive signal SRN into a signal having the same potential, a control circuit 35E for electrically insulating the base drive signal STP and converting it into a signal having the same potential as the base drive signal STP, and a base drive signal STN Is electrically insulated, and a control circuit 35F that converts the signal to the same potential as the base drive signal STN is provided.

The output signal of the base control circuit 35 is input to the voltage application unit 36. The plurality of outputs of the voltage application unit 36 are connected to the bases of the switching elements S1 to S6 of the power module 22. The voltage application unit 36 generates a base drive signal SRP ′ based on the output signal of the control circuit 35A, and generates a base drive signal SRN ′ based on the output signal of the control circuit 35B. And a second voltage application unit 36B that generates and outputs a base drive signal SSP ′ based on the output signal of the control circuit 35C. The voltage application unit 36 generates a base drive signal SSN ′ based on the output signal of the control circuit 35D, and generates a base drive signal STP ′ based on the output signal of the control circuit 35E. And a fifth voltage application unit 36F that generates and outputs a base drive signal STN ′ based on the output signal of the control circuit 35F.

FIG. 5 is a diagram illustrating a configuration example of the first voltage application unit illustrated in FIG. As shown in FIG. 5, the first voltage application unit 36 A includes an NPN transistor 37, a PNP transistor 38, and a base resistor 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 one end of the base resistor 39 is connected to each of them. 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. Thereby, 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 further connected to the wiring 291-2 shown in FIG. 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.

FIG. 6 is a diagram illustrating a configuration example of the second voltage application unit illustrated in FIG. As shown in FIG. 6, the second voltage application unit 36B includes an NPN transistor 37, a PNP transistor 38, and a base resistor 39, like the first voltage application unit 36A. In the second voltage application unit 36B, the output of the control circuit 35B is connected to the base of the NPN transistor 37 and the base of the PNP transistor 38. In the second voltage application unit 36B, the other end of the base resistor 39 is connected to the base of the switching element S2. In the second voltage application unit 36B, the collector of the NPN transistor 37 is connected to the wiring 294-1 shown in FIG. Thereby, 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 application 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. 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.

FIG. 7 is a diagram illustrating a configuration example of the third voltage applying unit illustrated in FIG. As shown in FIG. 7, the third voltage applying unit 36C includes an NPN transistor 37, a PNP transistor 38, and a base resistor 39, like the first voltage applying unit 36A. In the third voltage applying unit 36C, the output of the control circuit 35C is connected to the base of the NPN transistor 37 and the base of the PNP transistor 38. In the third voltage application unit 36C, the other end of the base resistor 39 is connected to the base of the switching element S3. In the third voltage application unit 36C, the collector of the NPN transistor 37 is connected to the wiring 292-1 shown in FIG. Thereby, 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 application 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. Thereby, 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.

FIG. 8 is a diagram illustrating a configuration example of the fourth voltage application unit illustrated in FIG. 4. As shown in FIG. 8, the fourth voltage application unit 36D includes an NPN transistor 37, a PNP transistor 38, and a base resistor 39, like the first voltage application unit 36A. In the fourth voltage application unit 36D, the output of the control circuit 35D is connected to the base of the NPN transistor 37 and the base of the PNP transistor 38. In the fourth voltage application unit 36D, the other end of the base resistor 39 is connected to the base of the switching element S4. In the fourth voltage application unit 36D, the collector of the NPN transistor 37 is connected to the wiring 294-1 shown in FIG. Thereby, 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 application 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. 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.

FIG. 9 is a diagram illustrating a configuration example of the fifth voltage application unit illustrated in FIG. As shown in FIG. 9, the fifth voltage application unit 36E includes an NPN transistor 37, a PNP transistor 38, and a base resistor 39, like the first voltage application unit 36A. In the fifth voltage application unit 36E, the output of the control circuit 35E is connected to the base of the NPN transistor 37 and the base of the PNP transistor 38. In the fifth voltage application unit 36E, the other end of the base resistor 39 is connected to the base of the switching element S5. In the fifth voltage applying unit 36E, the collector of the NPN transistor 37 is connected to the wiring 293-1 shown in FIG. Thereby, 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 application 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. Thereby, 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.

FIG. 10 is a diagram illustrating a configuration example of the sixth voltage application unit illustrated in FIG. As shown in FIG. 10, the sixth voltage application unit 36F includes an NPN transistor 37, a PNP transistor 38, and a base resistor 39, like the first voltage application unit 36A. In the sixth voltage application unit 36F, the output of the control circuit 35F is connected to the base of the NPN transistor 37 and the base of the PNP transistor 38. In the sixth voltage application unit 36F, the other end of the base resistor 39 is connected to the base of the switching element S6. In the sixth voltage application unit 36F, the collector of the NPN transistor 37 is connected to the wiring 294-1 shown in FIG. Thereby, 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 application 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. 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.

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 application unit 36A shown in FIG. 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 a high level signal is input to the first voltage application unit 36A, the PNP transistor 38 is turned off and the NPN transistor 37 is turned on. As a result, the wiring 291-1 and the base of the switching element S1 become conductive via the base resistor 39, and charges are charged between the base and emitter electrodes of the switching element S1. When the voltage VBE applied between the base and emitter electrodes of the switching element S1 exceeds a predetermined threshold voltage due to the charge being charged, the switching element S1 is turned on. Hereinafter, a 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 and emitter electrodes of the switching element S1 through the base resistor 39 is completed.

When a low level signal is input to the first voltage application unit 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 become conductive through the base resistor 39, and the charge charged between the base and emitter electrodes of the switching element S1 is discharged. When the electric charge is discharged and the voltage VBE applied between the base and emitter electrodes of the switching element S1 becomes less than a predetermined threshold voltage, the switching element S1 is turned off. When the voltage VBE decreases to the ground VRPGND, the discharge of the charge charged between the base and emitter electrodes of the switching element S1 is completed.

Since other switching elements operate on the same principle, the description is omitted. Further, when the base drive signal SRP is not output from the regenerative control unit 28, that is, when the regenerative operation is not performed, the base drive circuit 27 does not operate, and the switching elements S1 to S6 do not perform the on / off operation. Kept off.

As described above, the base drive circuit 27 uses the power supplies generated by the control power supply unit 29 to generate the base drive signals SRP, SPN, SSP, SSN, STP, and STN output from the regeneration control unit 28. Are converted into base drive signals SRP ′, SRN ′, SSP ′, SSN ′, STP ′, and STN ′ that can be handled by the switching elements S1 to S6.

Next, the regenerative operation in the converter 1-1 will be described with reference to FIGS. FIG. 11 is a diagram for explaining the operation of the voltage phase detector shown in FIG. As described above, the emitters of the switching elements S1, S3, and S5 arranged on the positive electrode side of the power module 22 are connected to the R phase, S phase, and T phase of the AC power supply 3 via the reactor 2. The emitters of the switching elements S1, S3, and S5 are connected to the ground VRPGND, VSPGND, and VTPGND of the control power supply unit 29.

As shown in FIG. 11, the voltage phase detector 24 detects the input R-phase voltage VR1 based on a signal generated at the ground VRPGND connected to the wiring 291-2. Input R-phase voltage VR1 is equivalent to a voltage applied between AC terminal 11 and AC terminal 12 shown in FIG. The voltage phase detector 24 detects the input S-phase voltage VS1 based on a signal generated at the ground VSPGND connected to the wiring 292-2. Input S-phase voltage VS1 is equivalent to a voltage applied between AC terminal 12 and AC terminal 13 shown in FIG. The voltage phase detector 24 detects the input T-phase voltage VT1 based on a signal generated at the ground VTPGND connected to the wiring 293-2. Input T-phase voltage VT1 is equivalent to a voltage applied between AC terminal 13 and AC terminal 11 shown in FIG. Since the emitters of the switching elements S1, S3, S5 are connected to the ground VRPGND, VSPGND, VTPGND of the control power supply unit 29, the voltage phase detection unit 24 has a signal flowing through the emitters of the switching elements S1, S3, S5, or The voltage phase of the AC voltage when the switching elements S1 to S6 are turned on / off so that AC power is regenerated from the power module 22 to the AC power source 3 based on a signal flowing to the ground serving as the reference potential of the control power supply unit 29. A phase detection signal indicating the detected voltage phase is generated and output.

FIG. 12 is a time chart for explaining the operation of the converter shown in FIG. FIG. 12 shows, in order from the top, the waveforms of line voltages VR-S, VS-T, VT-R, VS-R, VT-S, and VR-T output from the AC power supply 3, and the line voltages. Waveforms of six types of phase detection signals generated based on the waveforms, waveforms of base drive signals SRP to STN, and waveforms of regenerative currents (Irr, Isr, Itr) flowing in the R phase, T phase, and S phase are shown. The line voltage VR-S and the line voltage VS-R correspond to the aforementioned input R-phase voltage VR1 and change complementarily. The line voltage VS-T and the line voltage VT-S correspond to the input S-phase voltage VS1 and change complementarily. The line voltage VR-T and the line voltage VT-R correspond to the above-described input T-phase voltage VT1 and change complementarily. The regenerative current is a current that flows from the motor driving device 4 shown in FIG. 1 toward the AC power supply 3 via the switching elements S1 to S6 during the regenerative operation.

The line voltage VR-S is obtained by detecting a voltage difference from the R phase with reference to the S phase, whereas the line voltage VS-R is a voltage difference from the S phase with respect to the R phase. Is detected. The voltage phase between the line voltage VR-S and the line voltage VS-R is shifted by 180 degrees. Similarly, the line voltage VS-T is obtained by detecting a voltage difference from the S phase with respect to the T phase, whereas the line voltage VT-S is a voltage with respect to the T phase with respect to the S phase. The difference is detected, and the voltage phase between the line voltage VS-T and the line voltage VT-S is shifted by 180 degrees. The line voltage is a voltage difference with the T phase detected with the R phase as a reference, whereas the line voltage VR-T is a voltage difference with the R phase detected with the T phase as a reference. In other words, the voltage phase between the line voltage and the line voltage VR-T is shifted by 180 degrees.

Based on the input R-phase voltage VR1, the input S-phase voltage VS1, and the input T-phase voltage VT1, the voltage phase detector 24 is configured to detect the line voltage VR-S, the line voltage VS-R, the line voltage VS-T, The voltage VT-S, the line voltage VR-T, and the line voltage VT-R are estimated, and based on the estimated results, a zero cross point of each line voltage is extracted, and the extracted zero cross point is handled as a phase detection signal. This phase detection signal is output to the base drive signal generator 26. Each phase detection signal output from the voltage phase detector 24 is illustrated in FIG. In FIG. 12, in order from the top, the phase detection signal between the RS lines, the phase detection signal between the SR lines, the phase detection signal between the ST lines, the phase detection signal between the TS lines, and the phase between the TR lines A detection signal and an RT line phase detection signal are shown. For example, an RS line phase detection signal takes a high level value in a section (phase section) where the difference between the line voltage VR-S and the line voltage VS-R is positive (phase section), and a negative section (phase section). ) Takes a low level value. The voltage phase detector 24 generates a phase detection signal whose level changes in this way in association with each line voltage.

Next, the base drive signal generator 26 generates an STN from the base drive signal SRP by the following method based on each phase detection signal shown in FIG.

When the potential of the line voltage VR-S is maximum, the base drive signal generation unit 26 sets the base drive signals SRP and SSN to a high level and controls the switching elements S1 and S4 to be on.

When the potential of the line voltage VS-T is the maximum, the base drive signal generator 26 sets the base drive signals SSP and STN to High level, and controls the switching elements S3 and S6 to be on.

When the potential of the line voltage VT-R is maximum, the base drive signal generation unit 26 sets the base drive signals STP and SRN to a high level, and controls the switching elements S5 and S2 to be on.

When the potential of the line voltage VS-R is the maximum, the base drive signal generation unit 26 sets the base drive signals SSP and SRN to a high level and controls the switching elements S3 and S2 to be on.

When the potential of the line voltage VT-S is maximum, the base drive signal generation unit 26 sets the base drive signals STP and SSN to a high level and controls the switching elements S5 and S4 to be on.

When the potential of the line voltage VR-T is the maximum, the base drive signal generator 26 sets the base drive signals SRP and STN to the high level, and controls the switching elements S1 and S6 to be on.

Next, the current that flows when the switching elements S1 to S6 are turned on or off based on the base drive 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. FIG. 1 shows the R-phase current Ir, the S-phase current Is, and the T-phase current It indicated by arrows in the direction from the AC power supply 3 to the converter 1-1. Treated as a positive current, the waveforms of the three regenerative currents shown in FIG. 12 are represented accordingly.

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

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

Even when the switching operation is performed, if the relationship between the voltage between the terminals of the smoothing capacitor 21 and the voltage of the AC power supply 3 does not hold between the voltage between the terminals of the smoothing capacitor 21 and the voltage of the AC power supply 3, Regenerative current does not flow. The regenerative current flows in a state where the flow is limited by the impedance of the reactor 2 while using the voltage difference between the voltage between the terminals of the smoothing capacitor 21 and the voltage of the AC power supply 3.

Here, an inductance caused by various wirings exists between the AC terminal 11 and the switching element S1. Similarly, inductances caused by various wirings also exist between the AC terminal 12 and the switching element S3 and between the AC terminal 13 and the switching element S5. FIG. 13 shows the inductance existing between the AC power supply and the AC terminal of the power module, and the inductance existing between the emitter of the switching element arranged on the positive side of the power module and the AC terminal of the power module. FIG.

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

Here, in the converter 1-1 according to the first embodiment, as described above, the input R-phase voltage VR1 is detected based on the signal generated in the ground VRPGND connected to the wiring 291-2, and the wiring 292- 2, the input S-phase voltage VS1 is detected based on the signal generated at the ground VSPGND connected to the second terminal, and the input T-phase voltage VT1 is further detected based on the signal generated at the ground VTPGND connected to the wiring 293-2. Detected. Therefore, when the power module 22 is viewed from the AC power supply 3, the inductor LR exists in the wiring connecting the terminal 3R of the AC power supply 3 and the AC terminal 11, and the wiring connecting the AC terminal 11 and the switching element S1 is present. Includes an inductor LR1 and an inductance caused by the wiring 291-2. Further, the inductor LS exists in the wiring connecting the terminal 3S of the AC power supply 3 and the AC terminal 12, and the wiring connecting the AC terminal 12 and the switching element S3 is caused by the inductor LS1 and the wiring 292-2. There is an inductance to perform. Further, the inductor LT exists in the wiring connecting the terminal 3T and the AC terminal 13 of the AC power supply 3, and the wiring connecting the AC terminal 13 and the switching element S5 is caused by the inductor LT1 and the wiring 293-2. There is an inductance to perform. Therefore, compared to the technique disclosed in Patent Document 1, the inductance component from the AC power supply 3 to the switching elements S1, S3, S5 is increased. Therefore, for example, when an external device other than the converter 1-1 is connected to the AC power source 3, the voltage from the AC power source 3 applied to the

AC terminals

11, 12, and 13 due to the regenerative operation of the external device is Even when the voltage fluctuates, the voltage fluctuation is reduced by the inductance component.

Although it is possible to take measures to suppress voltage fluctuation using a filter capacitor or the like, using a filter capacitor is not desirable because a voltage phase delay occurs. In converter 1-1 according to the first embodiment, fluctuations in input R-phase voltage VR1 and the like detected by voltage phase detection unit 24 are suppressed without using a filter capacitor. Even when the power of the converter 1-1 is turned on in the operating state, the fluctuation of the signal generated in the ground VRPGND connected to the wiring 291-2 is suppressed, and the input R-phase voltage VR1 in the voltage phase detection unit 24 is suppressed. Detection accuracy is improved.

Further, as the electric power supplied to the motor drive device 4 shown in FIG. 1 increases, the current flowing through the

AC terminals

11, 12, 13 of the converter 1-1 increases, so that the

AC terminals

11, 12, 13 increase in size. The

AC terminals

11, 12 and 13 are directly connected to the printed circuit board on which the voltage phase detection unit 24, the base drive signal generation unit 26, the regeneration control unit 28, the base drive circuit 27 and the control power supply unit 29 are mounted by screwing or the like. It becomes difficult to do. Therefore, it is necessary to connect the

AC terminals

11, 12, 13 and the printed circuit board using a bus bar, a harness, or the like, and the configuration for detecting the voltage phase of the AC power source 3 is complicated. According to the converter 1-1 according to the first embodiment, the input R-phase voltage VR1 and the like are detected using a signal generated in the ground connected to the wiring 291-2 that is the pattern wiring on the printed circuit board, Since the voltage phase of the AC power source 3 can be detected, even when the

AC terminals

11, 12, 13 are enlarged, a bus bar, a harness, and the like are not required, the manufacturing cost of the converter 1-1 is reduced, and the AC power source 3 is further reduced. It is possible to prevent the configuration for detecting the voltage phase from becoming complicated.

Further, according to the converter 1-1 according to the first embodiment, since a signal generated at the ground connected to the wiring 291-2 or the like can be used, it is possible to design a pattern that can be easily arranged on a printed circuit board, thereby saving space. Can be achieved.

Embodiment 2.
FIG. 14 is a diagram illustrating a configuration of a converter and a motor control device according to the second embodiment. Converter 1-2 according to the second embodiment includes voltage phase detector 24A instead of voltage phase detector 24 shown in FIG. In the following, first, in the voltage phase detector 24 of the first embodiment, the spike voltage generated in the line voltage and the phase voltage generated during the regenerative operation based on the input R phase voltage VR1, the input S phase voltage VS1, and the input T phase voltage VT1. The variation will be described, and then the configuration of the voltage phase detection unit 24A according to the second embodiment will be described.

FIG. 15 is a diagram illustrating waveforms such as a line voltage, a base drive signal, and a phase detection signal that are generated during the regenerative operation of the converter according to the first embodiment. FIG. 15 shows, in order from the top, 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 regenerative operation, and the R phase generated during the regenerative operation. The waveform of the phase detection signal RSD is shown. As shown in FIG. 15, when the STN is switched between the high level and the low level from the base drive signal SRP, when the on / off operation of the switching elements S1 to S6 shown in FIG. A spike-like voltage fluctuation occurs in the inter-voltages VR-S, VS-T, and VT-R. When such voltage fluctuation occurs, for example, at the zero cross point of the line voltage VR-S, the potential of the phase detection signal RSD changes in the order of High level, Low level, and High level in a short period of time.

FIG. 16 is a diagram illustrating waveforms of a phase voltage, a base drive signal, a phase detection signal, and the like generated during the regenerative operation of the converter according to the first embodiment. In FIG. 16, in order from the top, the waveforms of the base drive signals SRP to STN during the regenerative operation, the waveforms of the phase voltages VR2, VS2, and VT2 during the regenerative operation, and the phase detection signals RD and SD generated during the regenerative operation are shown. , TD waveforms. As shown in FIG. 16, when the STN is switched between the high level and the low level from the base drive signal SRP, the switching elements S1 to S6 shown in FIG. Spike-like voltage fluctuations occur in the voltages VR2, VS2, and VT2. When such voltage fluctuation occurs, for example, at the zero cross point of the phase voltage VR2, the potential of the phase detection signal RD changes in the order of High level, Low level, and High level in a short period of time. The potentials of the phase detection signals SD and TD change similarly.

As described in the first embodiment, for example, the input R-phase voltage VR1 or the like is input to the voltage phase detection unit 24. However, the wiring 291 is provided between the AC terminal 11 of the power module 22 and the switching element S1. Inductance due to -2 exists. Although this inductance can reduce the influence of voltage fluctuation caused by the regenerative operation of the external device connected to the AC power supply 3, the switching elements S1 to S6 are connected to the wiring 291-2 connected to the switching elements S1 to S6. Spike-like voltage fluctuations resulting from the on / off operation of the first and second signals are superimposed. The voltage fluctuation shown in FIG. 15 and FIG. 16 is caused by the fact that the phases of the switching elements S1 to S6 are switched from on to off or from off to on, and the phase is conducted through the rectifier elements D1 to D6. This is because the voltage is divided by the inductance and the inductance of the

AC terminals

11, 12, and 13. That is, during the regenerative operation of the power module 22, the line voltage and the phase voltage generated based on the input R-phase voltage VR1, the input S-phase voltage VS1, and the input T-phase voltage VT1 are spike-like generated by the regenerative operation. It becomes more susceptible to voltage fluctuations.

In addition, the voltage phase detection unit 24 transmits signals such as a wiring 291-2 connected to the switching element S1, a wiring 292-2 connected to the switching element S3, a wiring 293-2 connected to the switching element S5, That is, since the input R-phase voltage VR1, the input S-phase voltage VS1, and the input T-phase voltage VT1 are detected, it is also affected by voltage fluctuations caused by ringing that occurs during the on / off operation of the switching elements S1, S3, and S5. 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 reactor 2 and the

AC terminals

11, 12, 13 of the power module 22, the voltage There are many factors of fluctuation. That is, the voltage phase detection unit 24 shown in the first embodiment can reduce the influence of voltage fluctuation caused by the regenerative operation of the external device connected to the AC power supply 3, but the converter 1 in which the voltage phase detection unit 24 is mounted. There is a problem that it is easily affected by voltage fluctuations caused by the regenerative operation 1. In order to solve such problems, a method of removing voltage fluctuations by filtering the detected line voltage or phase voltage waveform with a filter capacitor or the like, and suppressing the ringing by slowing the switching speed of the switching element. A method etc. can be considered. However, when filtering is performed, a delay occurs from the original voltage phase of the AC power supply 3, and correction to match the original voltage phase is required. Further, when the switching speed is slowed, there is a problem that the switching loss of the power module 22 increases.

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

A method for detecting the maximum value or the minimum value of the phase voltage by the voltage phase detector 24A will be described with reference to FIG. FIG. 17 is a diagram illustrating a configuration example of the voltage phase detection unit illustrated in FIG. 14.

The voltage phase detector 24A includes a neutral point 40, a resistor 41A, a resistor 41B, a resistor 41C, and a phase detector 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 detector 42.

The other end of the resistor 41A receives an input R-phase voltage VR1 that is the potential of the emitter of the switching element S1. The input R-phase voltage VR1 is input to the resistor 41A and to the phase detector 42. An input S-phase voltage VS1, which is the potential of the emitter of the switching element S3, is input to the other end of the resistor 41B. The input S-phase voltage VS1 is input to the resistor 41B and to the phase detector 42. An input T-phase voltage VT1, which is the potential of the emitter of the switching element S5, is input to the other end of the resistor 41C. The input T-phase voltage VT1 is input to the resistor 41C and to the phase detector 42.

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

Next, a method for detecting the minimum value of the phase voltage will be described with reference to FIG. FIG. 18 is a diagram illustrating a waveform of an R-phase phase detection signal generated by the voltage phase detection unit according to the second embodiment and a waveform of an R-phase phase voltage generated based on the phase detection signal.

FIG. 18 shows the phase detection threshold voltage, the waveform of the neutral phase reference phase voltage VR3 generated during the regeneration operation of the converter 1-2, and the voltage phase detection unit 24A during the regeneration operation of the converter 1-2. The waveform of the generated phase detection signal RD3 is shown. The value of the phase detection threshold voltage is set to such a value that the potential of the phase detection signal RD3 becomes High level when the phase of the neutral point reference phase voltage VR3 is between 60 ° and 120 °. The threshold voltage for phase detection is set in the voltage phase detector 24A. The neutral point reference phase voltage VR3 is calculated by the phase detector 42, for example, with VR3 = VR1-NG using the potential NG of the neutral point 40 as a reference.

When the phase of the neutral point reference phase voltage VR3 reaches 60 °, the potential of the phase detection signal RD3 changes from Low level to High level. When the phase of the neutral point reference phase voltage VR3 reaches 90 °, the potential of the phase detection signal RD3 changes in the order of High level, Low level, and High level in a short period of time. 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. In the interval from the phase of the neutral point reference phase voltage VR3 to 120 ° to the phase 60 ° after one cycle, 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 the Low level to the High level. The center of the section from the phase 120 ° to 420 ° of the neutral point reference phase voltage VR3 corresponds to the phase 270 ° of the neutral point reference phase voltage VR3, and the phase of the neutral point reference phase voltage VR3 is 270 °. In this case, the potential of the neutral point reference phase voltage VR3 is minimum.

Although not shown in FIG. 18, it is generated based on the waveform of the S-phase detection signal generated by the voltage phase detector 24A during the regeneration operation of the converter 1-2 and the S-phase detection signal. The waveform of the phase voltage of the S phase changes with the same tendency as the waveform shown in FIG. The waveform of the T-phase detection signal generated by the voltage phase detector 24A during the regeneration operation of the converter 1-2 and the waveform of the T-phase voltage generated based on the T-phase detection signal are shown in FIG. It changes with the same tendency as the waveform shown.

As shown in FIG. 18, the phase of the neutral point reference phase voltage VR3 is changed from 60 ° by setting the value of the phase detection threshold voltage near the value at which the potential of the neutral point reference phase voltage VR3 becomes maximum. Up to 120 °, the potential of the phase detection signal RD3 changes once. That is, the number of times affected by the on / off operation of the switching element can be set only when the phase of the neutral reference phase voltage VR3 is 90 °.

In the vicinity of the phase of 90 ° of the neutral point reference phase voltage VR3, the potential of the phase detection signal RD3 changes in the order of High level, Low level, and High level. In this manner, the potential of the phase detection signal RD3 varies. The width is shorter than the width of the section where the phase of the neutral point reference phase voltage VR3 is 120 ° to 420 °, that is, the width of the section where the potential of the phase detection signal RD3 is maintained at the low level. Therefore, when the period during which the low-level phase detection signal RD3 continues to be output does not exceed the specific period, the low-level phase detection signal RD3 is determined to be noise, thereby reducing the influence of voltage fluctuation. be able to.

In the voltage phase detection unit 24A according to the second embodiment, the potential of the phase detection signal RD3 changes from the High level to the Low level in the interval where the phase of the neutral point reference phase voltage VR3 is 120 ° to 420 °. The minimum value of the neutral point reference phase voltage VR3 can be calculated by calculating the time from the time point to the time point when the level changes from the Low level to the High level. This time is assumed to be longer than the specific period used for the noise determination. By utilizing 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 converter 1-2 according to the second embodiment, the phase detection signal is generated based on the signals generated at grounds VRPGND, VSPGND, and VTPGND provided in control power supply unit 29. Even in this case, the voltage phase of the AC power supply 3 can be detected without being affected by the on / off operation of the switching element.

In the second embodiment, the voltage phase is detected using the minimum value of the phase voltage. However, the converter 1-2 according to the second embodiment has not only the minimum value of the phase voltage but also the maximum value. By detecting, voltage phase detection can be performed in a shorter time. For example, by adding a phase detection threshold voltage such that the phase detection signal RD3 is at a high level while the phase of the neutral point reference phase voltage VR3 is between 240 ° and 300 °, The maximum value of the phase voltage VR3 can be calculated. 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.

In the second embodiment, the phase of the neutral point reference phase voltage VR3 is between 60 ° and 120 °, and the phase of the neutral point reference phase voltage VR3 is between 240 ° and 300 °. A phase detection threshold voltage is set such that the potential of the detection signal RD3 is at a high level. The phase where the switching element is turned on and off as viewed from the neutral reference phase voltage VR3 is 30 °, 90 °. 150.degree., 210.degree., 270.degree., 330.degree., Etc., for example, the threshold voltage for phase detection is set between the phase of the neutral reference phase voltage VR3 from 45.degree. A phase detection threshold voltage may be set so that the potential of the phase detection signal RD3 is at a high level until the angle.

Further, in the second embodiment, the voltage phase is detected by calculating the phase voltage, but the converter 1-2 of the second embodiment calculates the voltage phase by calculating the line voltage. It is also possible to perform detection. For example, when the phase of the line voltage is between 45 ° and 135 °, a phase detection threshold voltage may be set such that the potential of the phase detection signal is at a high level. In this case, when the phase of the line voltage is between 135 ° and 405 °, the potential of the phase detection signal is at a low level, and the center point of the phase of the line voltage from 135 ° to 405 ° is the phase 270 °. The line voltage corresponding to is the minimum value.

The voltage phase detection unit 24 and the regeneration control unit 28 according to the first embodiment, and the voltage phase detection unit 24A and the regeneration control unit 28 according to the second embodiment are hardware using a photocoupler, a logic IC, and the like. For example, a single circuit, a composite circuit, a programmed processor, a processor programmed in parallel, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof It may be configured by software.

Further, according to converter 1-1 according to the first embodiment and converter 1-2 according to the second embodiment, a line-to-line voltage that is a line-to-line voltage is obtained by using a signal transmitted to the pattern wiring on the printed board. The voltage VR-S, the line voltage VS-T, the line voltage VT-R, and the input R phase voltage VR1, the input S phase voltage VS1, and the input T phase voltage VT1, which are phase voltages, can be calculated. For this reason, these voltages can be used for the detection of a power failure. The detection of a power failure is to detect a state where power from the AC power source 3 is not supplied to the converter. The detection of a power failure will be further described in detail in a third embodiment to be described later.

Further, according to converter 1-1 according to the first embodiment and converter 1-2 according to the second embodiment, the line voltage VR-S calculated based on the signal transmitted to the pattern wiring on the printed circuit board, At least one of the line voltage VS-T, the line voltage VT-R, the input R phase voltage VR1, the input S phase voltage VS1, and the input T phase voltage VT1 is used as the reference voltage Vref of the regeneration control unit 28 described above. It can be used for setting.

Embodiment 3 FIG.
FIG. 19 is a diagram illustrating a configuration of a converter and a motor control device according to the third embodiment. Converter 1-3 according to Embodiment 3 has the same configuration as converter 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 in 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. FIG. 20 has the same configuration as FIG. 11, and an input voltage detection unit 43 is illustrated instead of the voltage phase detection unit 24. The input voltage detection unit 43 includes a signal VR1 generated in the ground VRPGND connected to the wiring 291-2 and a signal generated in the ground VSPGND connected to the wiring 292-2 as described in the first embodiment. VS1 and VT1 which is a signal generated in the ground VTPGND connected to the wiring 293-2 are input. The input voltage detector 43 detects the line voltage or phase voltage of the AC power supply 3 based on these signals.

According to the third embodiment, since a signal generated in the ground connected to the wiring 291-2 and the like can be used, the configuration for detecting the phase voltage or the line voltage of the AC power supply 3 as in the first embodiment. Can be prevented from becoming complicated. Further, according to the third embodiment, since a signal generated in the ground connected to the wiring 291-2 can be used, it is possible to design a pattern that can be easily arranged on a printed circuit board, and to save space. .

Further, according to the third embodiment, it is possible to add a power failure detection unit that determines whether or not a power failure of the AC power supply 3 has occurred based on the output signal of the input voltage detection unit 43. The power failure detection unit may be a display device or an audio device that simply notifies whether or not a power failure has occurred, or may be a control device or a controller having a control function. When a power failure detection unit is provided, control such as how to operate the motor 5 controlled by the motor driving device 4 using the DC power of the converter 1-3 when a power failure occurs in the AC power source 3 or It is possible to give instructions promptly.

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

Converter 1-4 according to Embodiment 4 includes an RST-dq coordinate conversion unit 44, which is 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 is the output signal of the voltage phase detection unit 24, so that d is a current corresponding to active power. An axis current Id and a q-axis current Iq that is a current corresponding to reactive power are calculated. The regeneration control unit 28A performs a regeneration start operation and a 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. However, the voltage phase detection unit 24A 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, each voltage phase detection unit has been described as detecting the line voltage of the AC power supply 3 or the voltage phase of the phase voltage. However, the present invention is not limited to this. 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, the R phase voltage phase θr, the S phase voltage phase θs, and the T phase voltage phase θt of the AC power supply 3 is calculated. It is also possible. Hereinafter, the R phase voltage phase may be referred to as a first voltage phase, the S phase voltage phase may be referred to as a second voltage phase, and the T phase voltage phase may be referred to as a third voltage phase.

Next, the RST-dq coordinate conversion unit 44 in the fourth embodiment will be described. The RST-dq coordinate conversion unit 44 has a function of converting an RST axis that is a fixed coordinate axis into a dq axis that is a rotation coordinate axis. The voltage phase detector 24 calculates the power source angular frequency ω and the R phase voltage phase θr of the AC power source 3, and converts the RST axis signal into a dq axis signal based on the power source angular frequency ω and the R phase voltage phase θr.

Here, the phase voltages VR, VS, and VT of the AC power source 3 are represented by balanced three-phase voltages of time t, effective value Ea, power source angular frequency ω, and initial phase α. Then, the phase voltages VR, VS, and VT of the AC power supply 3 are expressed by the following formula (1). Note that the initial phase α is the phase of the phase voltage VR when t = 0.

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 indicating the R phase, S phase, and T phase of the AC power supply 3. The dq axis is a rotational coordinate axis that rotates clockwise at the power source angular frequency ω. Here, when the phase of the d-axis with respect to the R-phase axis is θ, the following equation (2) is established between the two coordinate axes.

The following equation (3) can be derived by calculating the voltages Vd and Vq of the dq axis which is the rotation coordinate axis using the above equations (1) and (2).

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

Consider the case where θ = π / 2 in the above formula (3). Substituting θ = π / 2 into equation (3), the following equation (5) can be derived.

As can be seen from the equations (4) and (5), the equation (4) can be derived from any value of θ in the equation (3). That is, the d-axis voltage is equivalent to the power supply voltage vector. Accordingly, the d-axis corresponds to the active power direction, and the q-axis corresponds to the reactive power direction.

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

For example, θr = 0 when the R-phase voltage VR is 0, and θr = π / 2 when the R-phase voltage VR is √2Ea which is the maximum value. 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).

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

As described above, since the d-axis is active power and the q-axis is reactive power, the d-axis current indicates current corresponding to active power and the q-axis indicates current corresponding to reactive power. Accordingly, the d-axis current Id becomes a positive value signal in a power running operation such as during motor acceleration. On the other hand, the d-axis current Id becomes a negative value signal in a regenerative operation such as during motor deceleration.

Generally, in a converter, when input currents Ir, Is, It are detected and control such as start and stop of a regenerative operation is performed, it is necessary to convert an RST axis that is a fixed coordinate axis into a dq axis that is a rotational coordinate axis. For the coordinate conversion, information on the voltage phase of the AC power supply 3 is required. As described above, the voltage phase of the AC power supply 3 is detected by using the signal generated in the ground connected to the wiring 291-2 that is the pattern wiring on the printed circuit board by using the method of the present embodiment. Therefore, the configuration for detecting the voltage phase of the AC power supply 3 can be simplified. Therefore, if the voltage phase detector 24 or the voltage phase detector 24A shown in the present embodiment is used, it can contribute to cost reduction of the converter.

Next, the regeneration control unit 28A according to the fourth embodiment will be described. Based on the d-axis current Id and the bus voltage VPN, the regeneration control unit 28A continues to transmit the STN to the base drive circuit 27 from the base drive signal SRP output from the base drive signal generation unit 26 or performs base drive. It is determined whether to stop transmission of the STN to the base drive circuit 27 from the base drive signal SRP output from the signal generation unit 26. When the regeneration control unit 28A determines that the transmission of the STN from the base drive signal SRP to the base drive circuit 27 is continued, the STN is continuously input to the base drive circuit 27 from the base drive signal SRP. When the regeneration control unit 28A determines to stop transmission of the STN from the base drive signal SRP to the base drive circuit 27, the input of the STN from the base drive signal SRP to the base drive circuit 27 is stopped.

FIG. 23 is a diagram illustrating a configuration example of the regeneration control unit 28A illustrated in FIG. The regeneration control unit 28A shown in FIG. 23 is different 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 those of the regeneration control unit 28 shown in the first embodiment. In addition, the same code | symbol is attached | subjected to the component which is the same as that of FIG. 3, or equivalent. In the regeneration stop determination unit 61, the d-axis current Id is input to the negative input terminal of the comparator 66. When the d-axis current Id is larger than the threshold current Iref, a Low level signal is output, and when the d-axis current Id becomes less than the threshold current Iref, a High level signal is output.

As described above, the voltage phase of the AC power supply 3 can be detected even in the converter that detects the input current instead of the bus current. Thereby, it can contribute to the cost reduction of a converter.

Embodiment 5 FIG.
FIG. 24 is a diagram illustrating a configuration of a converter and a motor control device according to the fifth embodiment. Converter 1-5 according to the fifth embodiment has the same or equivalent configuration as converter 1-4 shown in FIG. 21, and an overload detection unit 45 is further added. In addition, the same code | symbol is used for the same or equivalent component, and the overlapping description is abbreviate | omitted suitably.

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

FIG. 25 is a waveform diagram showing the behavior when the motor driving device 4 shown in FIG. 24 operates the motor 5. Time is taken on the horizontal axis, and the motor speed N, motor torque Tout, motor output Pout, bus voltage VPN, and d-axis current Id are shown from the top.

First, the t00 to t01 interval in FIG. 25 will be described. This section is a section where the motor is accelerating and is a motor power running section. 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 speed N and the motor output Pout increase due to the motor torque Tout. As the motor output Pout increases, the d-axis current Id increases in the positive direction. As the motor torque Tout decreases, the motor output Pout becomes constant and the peak value of the d-axis current Id also becomes constant.

The section t01 to t02 in FIG. 25 will be described. This section is a section in which the motor speed N is a constant speed. Unlike the period from time t00 to t01, since the motor output Pout is a low value, the d-axis current Id hardly flows.

The section t02 to t03 in FIG. 25 will be described. This section is a section where the motor is decelerating and is a motor regeneration section. Time t02 is the time when the motor starts to decelerate, and time t03 is the time when the motor stops. When the motor starts to decelerate, the regenerative power of the motor flows into the smoothing capacitor 21 and the bus voltage VPN increases. When the bus voltage VPN exceeds a predetermined value based on the above-described regeneration control unit 28A, converter 1-5 starts a power regeneration operation. Due to the power regeneration operation of converter 1-5, d-axis current Id flows in the negative direction, and bus voltage VPN decreases. At time t02, the motor output Pout at the time of motor deceleration, that is, the absolute value of the regenerative electric power of the motor is large and a large current flows. However, as the motor speed N decreases, the absolute value of the motor output Pout also decreases. The absolute value of the flowing d-axis current Id is also reduced.

25 that the magnitude of the d-axis current Id is determined by the motor output Pout. That is, a proportional relationship is established between the motor output Pout and the d-axis current Id. The d-axis current Id is obtained based on the input currents Ir, Is, It. Therefore, increasing the d-axis current Id is equivalent to increasing the absolute values of the input currents Ir, Is, It.

If an excessive current continues to flow through the power module 22 mounted on the converter 1-5, the converter 1-5 enters an overload state. At this time, since the same current as the input currents Ir, Is, It flows through the power module 22, the power is indirectly monitored by monitoring the d-axis current Id calculated based on the input currents Ir, Is, It. The current flowing through the module 22 can be detected. Since the input currents Ir, Is, and It are alternating currents, they flow in both positive and negative directions regardless of motor power running or motor regeneration. On the other hand, in the case of the d-axis current Id, a current flows in a positive direction during motor power running, and a current flows in a negative direction during motor regeneration.

Next, the overload detection unit 45 in the fifth embodiment will be described. FIG. 26 is a diagram illustrating a configuration example of the overload detection unit 45 illustrated in FIG. The overload detection unit 45 includes a comparator 190, a comparator 191 and an OR circuit 192. The d-axis current upper limit value Idmax is input to the minus input terminal of the comparator 190, and the d-axis current Id is input to the plus input terminal of the comparator 190. Further, the d-axis current lower limit value Idmin is input to the plus input terminal of the comparator 191, and the d-axis current Id is input to the minus input terminal of the comparator 191. The output signals of the comparator 190 and the comparator 191 are input to the input terminal of the OR circuit 192, and the output signal of the OR circuit 192 is handled as the output signal of the overload detection unit 45. Here, when the overload detection unit 45 outputs a high level signal, the converter 1-5 is determined to be in an overload state, and when the overload detection unit 45 outputs a low level signal, the converter 1-5 5 is determined not to be overloaded.

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 converter 1-5. The d-axis current upper limit value Idmax is a current limit value during powering operation, and the d-axis current lower limit value Idmin is a current limit value during regenerative operation.

According to the above configuration, when the d-axis current Id becomes equal to or higher than the d-axis current upper limit value Idmax, the comparator 190 outputs a high level signal, and the logical sum circuit 192 receives a high level signal. As a result, the OR circuit 192 outputs a high level signal, and the overload detection unit 45 outputs a high level signal. 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 High level signal, and the OR circuit 192 receives a High level signal. As a result, the OR circuit 192 outputs a high level signal, and the overload detector 45 outputs a high level signal. The signal output from the overload detection unit 45 is notified to the motor drive device 4 or the host control device 100 via a communication line (not shown).

As described above, in converter 1-5 according to the fifth embodiment, the load state of converter 1-5 during motor power running and motor regeneration is monitored based on d-axis current Id, and based on the monitoring result. Thus, it is determined whether converter 1-5 is in an instantaneous overload state.

With the configuration of the fifth embodiment, the cost of the power supply phase detector can be reduced, and a simple configuration of monitoring the converter overload state with the d-axis current Id can be realized. It can contribute to the conversion.

In the fifth embodiment, whether or not the instantaneous overload state is determined only by the d-axis current Id that is proportional to the motor output Pout, but whether or not the instantaneous overload state is also determined using the q-axis current Iq. It may be determined. By using both the d-axis current Id and the q-axis current Iq, both the effective current and the reactive current can be monitored. As a result, the energization state of converter 1-5 can be more accurately determined, and therefore it is possible to more accurately determine whether or not it is an instantaneous overload state.

Embodiment 6 FIG.
FIG. 27 is a diagram illustrating a configuration of a converter and a motor control device according to the sixth embodiment. Converter 1-6 according to the sixth embodiment has the same or equivalent configuration as converter 1-5 shown in FIG. 24, and overload detector 45 in FIG. 24 is replaced with overload detector 45A in FIG. ing. In addition, the same code | symbol is used for the same or equivalent component, and the overlapping description is abbreviate | omitted suitably.

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

In general, steady-state overload protection for power converters such as converters and inverters estimates the temperature of components mounted on the power converter, and when the estimated temperature exceeds the temperature to be protected, The power converter is protected by determining that it is in an overload state and stopping the operation of the power converter. Examples of components mounted on the power converter include a power element group and a capacitor related to power supply to the motor.

As a specific example of steady state overload protection, an overload protection curve as shown in FIG. 28 is known. FIG. 28 is a waveform diagram for explaining steady-state overload protection in the sixth embodiment. In FIG. 28, the horizontal axis is the energization current I of the power converter, and the vertical axis is the allowable energization time Ta, and these relationships are shown as overload protection characteristics. This overload protection characteristic is used when obtaining the time until the temperature rise due to the energization reaches the temperature to be protected when the power conversion device is energized continuously with a certain energization current I. Specifically, the value on the vertical axis at the intersection of the straight line drawn in parallel to the vertical axis from the point on the horizontal axis representing the value of a certain energization current I and the overload protection curve shown is set as the temperature to be protected. .

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

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

As can be seen from both of FIGS. 30 and 31, the change characteristic of the temperature rise is close to the characteristic of the delay filter of several orders. Therefore, the temperature rise estimation unit 194 calculates the temperature rise estimated value Kc of the power module 22 and the smoothing capacitor 21 by using the d-axis current absolute value | Id | corresponding to the absolute value of the d-axis current Id as an input signal. be able to. Examples of several-order delay filters are IIR filters and moving average filters.

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

As described above, in converter 1-6 according to the sixth embodiment, the load state of converter 1-6 is monitored based on d-axis current Id, and based on the monitoring result, converter 1-6 performs overload during normal operation. It is determined whether or not it is in a state.

With the configuration of the sixth embodiment, the cost of the power supply phase detector can be reduced, and a simple configuration in which the overload state of the converter is monitored with the d-axis current Id can be realized. It can contribute to the conversion.

In Embodiment 6, it is determined whether or not the steady-state overload state is based only on the d-axis current Id that is proportional to the motor output Pout, but the steady-state overload state is also determined using the q-axis current Iq. It may be determined whether or not. By using both the d-axis current Id and the q-axis current Iq, both the effective current and the reactive current can be monitored. As a result, the energization state of converter 1-6 can be determined more accurately, and therefore it can be determined more accurately whether or not the steady-state overload state is present.

Embodiment 7 FIG.
FIG. 32 is a diagram illustrating a configuration of a converter and a motor control device according to the seventh embodiment. Converter 1-7 according to the seventh embodiment shown in FIG. 32 is identical to converter 1-5 according to the fifth embodiment shown in FIG. 24 in the configuration of bus voltage detector 23, base drive signal generator 26, and regeneration controller. While the illustration of 28A is omitted, a motor control unit 4A is added inside the motor driving device 4. Other configurations are the same as or equivalent to those in FIG. 24, and the same or equivalent components are denoted by the same reference numerals.

The motor control unit 4A has a function of supplying arbitrary AC power to the motor 5 and controlling the motor 5 at a variable speed. The output of the overload detection unit 45 in the converter 1-7 is configured to be input to the motor control unit 4A via the communication path 46. In FIG. 32, the overload detection unit 45 described in the fifth embodiment, that is, the overload detection unit 45 having a function of determining the instantaneous overload state is used. However, the overload detection unit 45 described in the sixth embodiment is used. It may be replaced with a load detection unit 45A, that is, an overload detection unit 45A having a function of determining a steady-state overload state, or it has both an instantaneous overload state determination function and a steady-state overload state determination function. An overload detection unit may be used.

The input current detection unit 25A detects the 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 based on the R-phase phase θr and the power supply angular frequency ω of the AC power supply 3 detected by the voltage phase detection unit 24, and d The shaft current Id is input to the overload detection unit 45. Overload detection unit 45 determines whether converter 1-7 is in an overload state based on d-axis current Id. When it is determined that converter 1-7 is in an overload state and overload detection unit 45 outputs a high level signal, motor control unit 4A controls AC power so as to reduce the output of motor 5.

The following method is illustrated as a method for reducing the output of the motor 5.
(I) Control is performed so that the motor 5 is operated with a torque command that is more limited than the torque command previously determined by the motor operation command.
(Ii) Control the motor 5 so that it operates with a rotation command that is more limited than the rotation command previously determined by the motor operation command.
(Iii) Control the motor 5 to free run. Specifically, the switching operation for on / off control of a switching element (not shown) provided in the motor driving device 4 is stopped, and the motor 5 is brought into a free state.

Next, operations of converter 1-7 and motor drive device 4 according to the seventh embodiment will be described with reference to FIGS. FIG. 33 is a flowchart showing operations of the converter and the motor control unit according to the seventh embodiment. In FIG. 33, the notation of the reference numerals is omitted.

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

The motor control unit 4A receives the determination result of the overload detection unit 45 (step S104). Based on the received determination result, motor control unit 4A determines whether converter 1-7 is in an overload state (step S105). In the case of a signal indicating that the received determination result is an overload state (High level signal in the example of Embodiment 5) (Yes in Step S105), the motor driving device is configured so that the output of the motor 5 is limited. The motor output from 4 is limited (step S106), and the AC power with the output of the motor 5 limited is output to the motor 5 (step S107). In the case where the received determination result is a signal indicating that it is not in an overload state (a low level signal in the example of Embodiment 5) (No in step S105), the process proceeds to step S107 without performing the process in step S106. Transition. That is, when the received determination result is not an overload state, the AC power in the normal control operation is output to the motor 5 without limiting the output of the motor 5 (step S107). The processes of steps S104 to S107 described above are the 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 if the operation of the motor 5 exceeds the expected value and the converter 1-7 is in an overload state, the AC power is applied so that the motor driving device 4 reduces the output of the motor 5. Therefore, the overload state of the converter 1-7 can be eliminated, and adverse effects such as deterioration and damage of the converter 1-7 can be eliminated without stopping the system. Therefore, a converter having a small capacity can be selected, which can contribute to cost reduction of the industrial machine.

Embodiment 8 FIG.
FIG. 34 is a diagram illustrating a configuration of a converter and a motor control device according to the eighth embodiment. 34, in the configuration of converter 1-7 according to the seventh embodiment shown in FIG. 32, a host controller 100, a motor drive device 400, and a motor 500 instead of the motor 5 are added. The host controller 100 has a function of outputting a motor operation command to each of the

motor drive devices

4 and 400 via the communication paths 47a and 47b, and outputs a motor operation command to each of the

motor drive devices

4 and 400. . The output of the overload detection unit 45 in the converter 1-8 is input to the host controller 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 connected to the smoothing capacitor 21 in the converter 1-8. Connected. The motor control unit 400A supplies variable AC power to the motor 500 to perform variable speed control. In FIG. 34, the overload detection unit 45 suitable for instantaneous overload detection is shown. However, the overload detection unit 45 may be replaced with an overload detection unit 45A suitable for steady-state overload detection. You may comprise using the overload detection part provided with the function of both load detection and a steady-time overload detection.

The input current detection unit 25A detects the 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 based on the R-phase phase θr and the power supply angular frequency ω of the AC power supply 3 detected by the voltage phase detection unit 24, and d The shaft current Id is input to the overload detection unit 45. Overload detection unit 45 determines whether converter 1-8 is in an overload state based on d-axis current Id. When it is determined that converter 1-8 is in an overload state, a signal indicating that the converter is in an overload state (high level signal) is notified to host control device 100 via communication path 46. The host controller 100 uses at least one of the communication paths 47a and 47b corresponding to at least one of the motor controller 4A of the motor driver 4 and the motor controller 400A of the motor driver 400, An instruction is given to generate a motor operation command that limits the output of the motor to be controlled. At least one of the motor control unit 4A and the motor control unit 400A controls the AC power so as to decrease the output of the motor 5 or the motor 500 based on the received motor operation command.

Hereinafter, a specific example will be described. Here, a machine tool including a spindle motor and a servo motor is taken as an example, and it is assumed that the motor 5 is a spindle motor and the motor 500 is a servo motor. The host control device 100 may be provided on the machine tool or may not be provided on the machine tool.

(I) The host control device 100 outputs a motor operation command for reducing the output of the motor 5 that is a spindle motor to the motor control unit 4A.
(Ii) In order not to lengthen the cycle time, the host controller 100 limits the output of the motor 500 that is a servo motor having a shorter acceleration time and deceleration time than the motor 5 that is a spindle motor. decide. The host controller 100 maintains the output of the motor 5 that is a spindle motor, and outputs a motor operation command for limiting the output of the motor 500 that is a servo motor to the motor control unit 4A and the motor control unit 400A.

Next, operations of the converter and the motor drive device according to the eighth embodiment will be described with reference to FIGS. FIG. 35 is a flowchart showing operations of the converter and the motor drive device according to the eighth embodiment. In FIG. 35, the notation of symbols is omitted.

The RST-dq coordinate conversion unit 44 generates a d-axis current based on the input currents Ir, Is, It detected by the input current detection unit 25A, the R phase phase θr calculated by the voltage phase detection unit 24, and the power source angular frequency ω. Id is calculated (step S201). Overload detection unit 45 determines whether converter 1-8 is in an overload state based on d-axis current Id (step S202). The overload detection unit 45 notifies the host controller 100 of the determination result through the communication path 46 (step S203). The processes in steps S201 to S203 described above are the processes of converter 1-8, and converter 1-8 repeatedly executes the processes in steps S201 to S203.

The host control device 100 receives the determination result of the overload detection unit 45 (step S204). Based on the received determination result, host controller 100 determines whether converter 1-8 is in an overload state (step S205). In the case of a signal indicating that the received determination result is an overload state (High level signal in the example of Embodiment 5) (Yes in Step S205), the output of at least one of the motor 5 and the motor 500 is limited. (Step S206), and outputs a motor operation command that restricts the output of the motor to the motor drive device that drives the motor to be controlled (step S207). In the case where the received determination result is a signal indicating that it is not in an overload state (in the example of Embodiment 5, a low level signal) (No in step S205), the process proceeds to step S207 without performing the process in step S206. Transition. That is, when the received determination result is not an overload state, the output restriction on the motor 5 and the motor 500 is not performed, and a normal motor operation command is output (step S207). The above steps S204 to S207 are the processes of the host control apparatus 100, and the host control apparatus 100 repeatedly executes the processes of steps S204 to 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 the motor operation command from the host control device 100 (step S208), and AC power is supplied to the motor according to the received motor operation command. 5 and the motor 500 so as to be output (step S209). The processes of steps S208 and S209 described 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 when the operations of the motor 5 and the motor 500 perform an operation that exceeds the assumption, and the converter 1-8 is in an overload state, the host control device 100 performs at least one of the motor 5 and the motor 500. A motor operation command that restricts one output is output to the corresponding motor drive device, and the motor drive device controls the AC power so as to decrease the motor output to be controlled. It is possible to eliminate the adverse effects such as deterioration and damage of the converter 1-8 without stopping the system. Further, in an industrial machine using a plurality of motors such as machine tools, by outputting a motor operation command so as to prevent the cycle time from becoming long, the cycle time can be maintained while maintaining the cycle time. An overload condition can be eliminated. Therefore, a converter having a small capacity can be selected, which can contribute to cost reduction of the industrial machine.

Embodiment 9 FIG.
FIG. 36 is a diagram illustrating a configuration of a converter and a motor control device according to the ninth embodiment. In FIG. 36, the configuration is the same as or equivalent to the configuration of converter 1-8 according to the eighth embodiment shown in FIG. 34, but converter control unit 1A is added inside converter 1-9, and inside converter control unit 1A. An overload detection unit 45B is provided. 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. The host control device 100, the motor driving device 400, the motor driving device 4, and the converter 1-9 are daisy chain connected via a communication path. Specifically, converter control unit 1A of converter 1-9 and motor control unit 4A of motor drive device 4 are connected via communication path 46, and motor control unit 4A of motor drive device 4 and motor control of motor drive device 400 are controlled. The unit 400A is connected via a communication path 48a, and the motor control unit 400A of the motor driving device 400 and the host control apparatus 100 are connected via a communication path 48b. In the above-described configuration, for example, a motor operation command output from the host 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. Will be.

In an industrial machine such as that described above, in the instantaneous overload state, a plurality of motors are generally operated at a high output. Here, a machine tool including a plurality of servo motors and spindle motors is taken as an example. Here, it is assumed that the spindle motor is the motor 5 and the servo motor is the motor 500. In a machine tool, there are operations in which a plurality of servo motors and a spindle motor perform simultaneous acceleration operation or simultaneous deceleration operation. For this reason, when the servo motor and the spindle motor operate at their maximum outputs, the maximum outputs of the motors overlap in the simultaneous acceleration / deceleration operation as described above, and the power supplied by the converter increases.

In machine tools, the output of a spindle motor is generally larger than that of a servo motor. For this reason, the ratio of the electric power supplied from the converter to each motor driving device is increased by the spindle motor driving device. In the case of the simultaneous acceleration / deceleration operation as described above, the power supplied to the converter can be quickly reduced by reducing the output of the motor 5 that is a spindle motor without using the host controller 100.

On the other hand, the steady-state overload state is not a state in which the converter supplies excessive power, but the operating cycle of industrial machinery is severe, and the temperature rises in components such as power modules and smoothing capacitors mounted on the converter due to long-term operation. Is a case where the temperature exceeds the allowable temperature. In such a case, it is necessary to review the operation cycle. By reviewing the motor operation command for the motor 5 that is the spindle motor or the motor 500 that is the servo motor, or the motor operation command for both via the host controller 100, the operation cycle is reviewed. It is suitable to reduce the sum of the average output of the motor in operation.

Next, operations of the converter, the motor drive device, and the host control device according to the ninth embodiment will be described with reference to FIGS. 36 and 37. FIG. FIG. 37 is a flowchart illustrating operations of the converter, the motor drive device, and the host control device according to the ninth embodiment.

The RST-dq coordinate conversion unit 44 generates a d-axis current based on the input currents Ir, Is, It detected by the input current detection unit 25A, the R phase phase θr calculated by the voltage phase detection unit 24, and the power source angular frequency ω. Id is calculated (step S301). Based on the d-axis current Id, 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, that is, an overload of the converter 1-9. The load state is determined (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 in steps S301 to S303 described above is the processing of converter 1-9, and converter 1-9 repeatedly executes the processing in steps S301 to S303.

The motor control unit 4A receives the determination result of the overload detection unit 45B (step S304). Based on the received determination result, motor control unit 4A determines whether converter 1-9 is in an instantaneous overload state (step S305). When the received determination result is a signal indicating that the instantaneous overload state is present (step S305, Yes), the motor output from the motor driving device 4 is limited so that the output of the motor 5 is limited (step S306). The AC power whose motor output is limited is output to the motor 5 (step S307). In addition, when the received determination result is not an instantaneous overload state (step S305, No), it transfers to step S307, without performing the process of step S306. That is, when the received determination result is not in the instantaneous overload state, the AC power in the normal control operation is output to the motor 5 without limiting the output of the motor 5 (step S307). Further, the motor control unit 4A notifies the determination result of the overload detection unit 45B to the motor control unit 400A (step S308). The processes of steps S304 to S308 described above are the 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 determination result to the host controller 100 via the communication path 48b (step S309). S310). The processes of steps S309 and S310 described above are the processes of the motor control unit 400A, and the motor control unit 400A repeatedly executes the processes of steps S309 and S310.

The host control device 100 receives the determination result of the overload detection unit 45B from the motor control unit 400A (step S311). Based on the received determination result, host controller 100 determines whether converter 1-9 is in an instantaneous overload state (step S312). When the received determination result is a signal indicating that the instantaneous overload state is present (step S312, Yes), it is determined to limit the output of the motor 500 (step S313), and the motor control unit 400A that controls the motor 500 is determined. On the other hand, a motor operation command that limits the motor output is output (step S316). On the other hand, if the received determination result is a signal indicating that the instantaneous overload state is not present (step S312, No), it is further determined whether or not the converter 1-9 is in a steady state overload state (step S314). If the received determination result is a signal indicating that the steady-state overload state is present (step S314, Yes), the change of the operation cycle of each axis operated by the servo motor is determined (step S315), and the motor 500 is controlled. The motor operation command changed so as to suppress the average output of the motor 500 is output to the motor control unit 400A (step S316). When the received determination result is a signal indicating that the steady-state overload state is not present (step S314, No), the process proceeds to step S316 without performing the process of step S315. The processes of steps S311 to S316 described above are the processes of the host controller 100, and the host controller 100 repeatedly executes the processes of steps S311 to S316.

The above control is summarized as follows. First, when it is determined as an instantaneous overload state, AC power is output to the motor 5 so that the motor control unit 4 A limits the motor output without going through the host controller 100. In parallel with this control, the motor control unit 400A and the host control device 100 are notified of the instantaneous overload state. Based on the determination result, the host controller 100 generates a motor operation command for the motor 500 so as to limit the output of the motor operation of the motor 500 and outputs the motor operation command to the motor drive device 400. In the motor drive device 4, the output of the motor 5 is once limited to avoid an instantaneous overload state, and thereafter, the host control device 100 reviews the motor operation command again.

On the other hand, when it is determined that the steady state overload state, the motor control unit 4A continues the operation command based on the motor operation command output from the host control device 100, and in parallel with this, the motor control unit 400A and the host control unit The control device 100 is notified that it is in a steady state overload state. Based on the determination result, host controller 100 generates a motor operation command so as to limit the average output in the motor operation of motor 500 and outputs the motor operation command to motor drive device 400.

In the above description, the output limit for the motor 5 is limited when it is determined as an instantaneous overload state, and the output limit for the motor 500 is limited when it is determined as a steady state overload state. When it is determined that the state is an overload state, the output of both the motor 5 and the motor 500 may be limited. Further, when it is determined that the state is an overload state at the steady state, output restriction may be performed on both the motor 5 and the motor 500.

The overload detection unit 45B can detect an instantaneous overload state and a steady-state overload state, respectively. For the overload state notification method, a dedicated communication line for overload detection is provided. It may be provided, or a method of notifying an overload state by serial communication or the like may be used.

According to the ninth embodiment, when the converter 1-9 is in an instantaneous overload state, the motor output can be quickly reduced. In addition, when converter 1-9 is in an overload state during normal operation, the severe operation cycle is improved by reviewing the motor operation command output from host controller 100 to each motor drive device, and installed in converter 1-9. The temperature rise of the power module 22 and the smoothing capacitor 21 can be reduced. With these controls, adverse effects such as deterioration and damage of the converter 1-9 can be solved without stopping the system. Further, in an industrial machine using a plurality of motors such as machine tools, by outputting a motor operation command so as to prevent the cycle time from becoming long, the cycle time can be maintained while maintaining the cycle time. An overload condition can be eliminated. Therefore, a converter having a small capacity can be selected, which can contribute to cost reduction of the industrial machine.

Embodiment 10 FIG.
FIG. 38 is a diagram illustrating a configuration of a converter and a motor control device according to the tenth embodiment. The converter 1-10 according to the tenth embodiment has the same configuration 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, the bus current detection While the illustration of the unit 25, the base drive signal generation unit 26, and the regeneration control unit 28 is omitted, a power failure detection unit 50 is added inside the converter 1-10. In the configuration of FIG. 38, a motor drive device 400, a motor 500, and a host control device 100 are added as in the eighth and ninth embodiments. Further, in the configuration of FIG. 38, a DC voltage detector 82 for detecting the voltage between the DC terminals 17-18 is arranged inside the motor driving device 4, and the DC terminal is provided inside the motor driving device 400. A DC voltage detector 83 for detecting a voltage between terminals 19-20 is arranged. Further, the host control device 100, the motor drive device 400, the motor drive device 4, and the converter 1-10 are daisy chain connected via a communication path. Specifically, the power failure detection unit 50 of the converter 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 of the motor drive device 400 are controlled. The unit 400A is connected by a communication path 86a, and the motor control unit 400A of the motor driving device 400 and the host control apparatus 100 are connected by a communication path 86b. In the above-described configuration, for example, a motor operation command output from the host 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. Will be.

As described in the third embodiment, the power failure detection unit 50 detects a power failure of the AC power source 3 based on the output signal of the input voltage detection unit 43, and drives the motor via the

communication paths

85, 86a, 86b. A function of notifying the power failure information to the device 4, the motor drive device 400, and the host control device 100 is provided.

The motor control unit 4A has a function of controlling the motor 5 at a variable speed by supplying arbitrary AC power to the motor 5, and a function of receiving a detection signal of the DC voltage detection unit 82. The motor control unit 400A has a function of controlling the motor 500 at a variable speed by supplying arbitrary AC power to the motor 500, and a function of receiving a detection signal of the DC voltage detection unit 83. Note that 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 voltage across the smoothing capacitor 21, that is, the detection value of the bus voltage detection unit 23.

When a power failure occurs in the AC power supply 3, the motor driving device 4 and the motor driving device 400 cannot continue normal operation of each motor. At this time, if the converter 1-10 performs the power regeneration operation, the voltage difference between the bus voltage VPN and the AC power supply 3 is large, so that an excessive current flows and the power module 22 is damaged. There is a fear. Therefore, the power regeneration operation cannot be performed when a power failure occurs.

If the

motor

5 or 500 is operating when a power failure occurs, it is necessary to stop the operating motor. On the other hand, when the motor is decelerated, the regenerative power of the motor is accumulated in the smoothing capacitor 21 of the converter 1-10, and the bus voltage VPN increases. Originally, when the bus voltage VPN rises, the power supply regeneration operation may be performed by operating the switching elements S1 to S6 of the power module 22, but the power regeneration operation cannot be performed for the above-described reason. As a result, the bus voltage VPN further increases. Therefore, when the bus voltage VPN exceeds a certain value, it is determined that the voltage is an overvoltage, and the control of each motor must be stopped. In this case, it takes time until each motor stops, and for example, the feed shaft of the machine tool may collide with the shaft end.

Also, depending on the characteristics of the motor or the state of friction driven by the motor, for example, the gravitational axis, it is necessary to continue supplying AC power from the motor driving device to the motor even when the motor is decelerated. That is, in this case, since the regenerative power is not generated in the motor even when the motor is decelerated, the DC power stored in the smoothing capacitor 21 is used. In such a situation, when a power failure occurs in the AC power supply 3 and the motor is stopped, the bus voltage VPN rapidly decreases. Normally, when the bus voltage VPN is too low, the motor drive device cannot supply AC power for driving the motor, and therefore determines that the voltage is low and stops control of the motor. Also in this case, it takes time until the motor stops, and there is a possibility that the motor collides with the shaft end or the like.

In order to solve the above-described problem, in the tenth embodiment, the determination result of the power failure detection unit 50 of the converter 1-10 is transmitted to the motor control unit 4A, the motor control unit 400A, and the host control via the

communication paths

85, 86a, 86b. Notify the device 100. When the notified determination result is a signal indicating that a power failure has occurred in the AC power supply 3, the motor control unit 4 A controls the AC power supplied to the motor 5 based on the detection value of the DC voltage detection unit 82. Further, 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, it is necessary to give priority to quickly stopping the servo motor that operates the feed shaft when a power failure occurs in the AC power supply 3. is there. Therefore, the operation of the motor 5 corresponding to the spindle motor is controlled to keep the bus voltage VPN at an appropriate value so that the motor 500 corresponding to the servo motor can be safely decelerated and stopped.

As described above, the DC voltage detector 82 is the same as the bus voltage VPN detected by the bus voltage detector 23. For this reason, the detection value of the DC voltage detection unit 82 is handled as the bus voltage VPN. A bus voltage determination circuit that determines the bus voltage VPN is configured inside the motor control unit 4A. 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 illustrating a configuration example of the bus voltage determination circuit according to the tenth embodiment. In FIG. 39, the bus voltage determination circuit includes

comparators

196 and 197. The bus voltage upper limit value VPNmax is input to the negative input terminal of the comparator 196, and the detection value VPN of the DC voltage detection unit 82 is input to the positive input terminal of the comparator 196. The detected value VPN of the DC voltage detector 82 is input to the minus input terminal of the comparator 197, and the bus voltage lower limit value VPNmin is input to the plus input terminal of the comparator 197. Comparator 196 determines whether or not bus voltage VPN is equal to or higher than a predetermined bus voltage upper limit value VPNmax. The comparator 197 determines whether or not the bus voltage VPN is equal to or lower than a predetermined bus voltage lower limit value VPNmin.

When the comparator 196 outputs a high level signal and the comparator 197 outputs a low level signal, the bus voltage VPN is larger than an appropriate value, and the bus voltage VPN needs to be lowered. . In this case, if the motor 5 corresponding to the spindle motor is accelerated, the motor 5 becomes a power running operation, and the bus voltage VPN can be lowered. 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 of being lower than an appropriate value, and the bus voltage VPN needs to be raised. There is. In this case, if the motor 5 corresponding to the spindle motor is decelerated, the motor 5 performs a regenerative operation, and the bus voltage VPN can be increased.

Next, operations of the converter, the motor drive device, and the host control device according to Embodiment 10 will be described with reference to FIGS. 40, 41, and 42 in addition to FIG. FIG. 40 is a flowchart showing an operation of converter 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 illustrating the operation of the motor control unit 400A according to the tenth embodiment. 40 to 42, the respective flowcharts are individually shown. However, it is also possible to show them in one figure as shown in FIG.

First, the operation of converter 1-10 in the tenth embodiment will be described with reference to FIG. 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 or not a power failure has occurred in the AC power supply 3 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 processes in steps S401 to S403 described above are the processes of converter 1-10, and converter 1-10 repeatedly executes the processes in steps S401 to S403.

Next, the operation of the motor control unit 4A in the tenth embodiment will be described with reference to FIG. 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 or not a power failure has occurred in the AC power supply 3 based on the received determination result (step S503). When the received determination result is a signal indicating that a power failure has occurred (step S503, Yes), the motor control unit 4A determines whether the bus voltage VPN detected by the DC voltage detection unit 82 is equal to or higher than the bus voltage upper limit value VPNmax. It is determined whether or not (step S504).

When the bus voltage VPN is equal to or higher than the bus voltage upper limit value VPNmax (in the tenth embodiment, when 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 is less than the bus voltage upper limit value VPNmax (in the tenth embodiment, when the output signal of the comparator 196 is at the low level) (step S504, No), the motor control unit 4A determines that the bus voltage VPN is the bus voltage. It is determined whether it is below the lower limit value VPNmin (step S505). The bus voltage VPN is equal to or lower than the bus voltage lower limit value VPNmin (in the tenth embodiment, when 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 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 larger than the bus voltage lower limit value 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 In the case of low level) (step S505, No), the motor control unit 4A stops the power supply to the motor 5 and free-runs the motor 5 (step S506), and the motor 5 is generated based on step S506. AC power is output (step S509). In this control, since the motor 5 is free running, the power supply is stopped.

If it is determined in step S501 that the determination result is a signal indicating that a power failure has not occurred, the processing in steps S504 to S508 is skipped, and the processing in step S509 is performed. That is, the motor control unit 4A outputs alternating current power to operate the motor 5 in accordance with the motor operation command transmitted from the host control device 100. The above steps S501 to S509 are the processes of the motor control unit 4A, and the motor control unit 4A repeatedly executes the processes of steps S501 to S509. In the control in step S506, the motor control unit 4A stops the power supply to the motor 5 and free-runs the motor 5. However, the motor 5 may be controlled to maintain a constant speed.

Next, the operation of the motor control unit 400A according to the tenth embodiment will be described with reference to FIG. The motor control unit 400A receives a determination result regarding the presence or absence of a power failure from the motor control unit 4A via the communication path 86a (step S601). The motor control unit 400A notifies the determination result regarding the presence or absence of a power failure to the host control device 100 via the communication path 86b (step S602). The motor control unit 400A determines whether or not a power failure has occurred in the AC power supply 3 based on the determination result received in step S601 (step S603). When the received determination result is a signal indicating that a power failure has occurred (step S603, Yes), the motor control unit 400A changes the motor operation command to decelerate the motor 500 (step S604), and AC power based on the changed motor operation command is output (step S605). On the other hand, when the received determination result is a signal indicating that a power failure has not occurred (No in step S603), the motor control unit 400A skips the process in step S604 and performs the process in step S605. That is, the motor control unit 400A outputs AC power for operating the motor 500 in accordance with the motor operation command transmitted from the host control device 100 (step S605). The above steps S601 to S605 are the processing of the motor control unit 400A, and the motor control unit 400A repeatedly executes the processing of steps S601 to S605.

In the tenth embodiment, when a power failure occurs in the AC power source 3, the motor driving device 4 and the motor driving device 400, for example, drive the motor 500 that drives the feed shaft without passing through the host control device 100 that outputs a motor operation command. It can be stopped immediately. For example, when the motor control unit 400A receives a power failure detection signal, the motor 500 is decelerated. At this time, when the deceleration energy during this deceleration is accumulated in the smoothing capacitor 21, the bus voltage VPN increases. By increasing or decreasing the bus voltage VPN by the motor 5, the bus voltage VPN becomes an overvoltage or low voltage. In addition, the motor 500 can be 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.

Note that some of the control functions in the converter and the motor driving device described in the first to tenth embodiments may be configured by hardware using a photocoupler, a logic IC, or the like. A circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, a combination of these, or a software may be used.

Further, the configuration shown in the above embodiment shows an example of the content of the present invention, and can be combined with another known technique, and can be combined without departing from the gist of the present invention. It is also possible to omit or change a part of.

1-1, 1-2, 1-3, 1-4, 1-5, 1-6, 1-7, 1-8, 1-9, 1-10 converter, 1A converter control unit, 2,2- 1, 2-2, 2-3 reactor, 3 AC power supply, 3R, 3S, 3T, 21a, 21b terminal, 4,400 motor drive unit, 4A, 400A motor control unit, 5,500 motor, 6-1, 6 -2 output terminal, 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 terminal, 21 smoothing capacitor, 22 power module, 23 bus voltage detector, 24, 2 A voltage phase detector, 25 bus current detector, 25A input current detector, 26 base drive signal generator, 27 base drive circuit, 28, 28A regeneration controller, 29 control power supply, 30 insulation transformer, 31 main power, 32 IC for power supply control, 33 switching element, 34 feedback unit, 35 base control circuit, 35A, 35B, 35C, 35D, 35E, 35F control circuit, 36 voltage application unit, 36A first voltage application unit, 36B second voltage application Part, 36C third voltage applying part, 36D fourth voltage applying part, 36E fifth voltage applying part, 36F sixth voltage applying part, 37, 63 NPN transistor, 38 PNP transistor, 39 base resistance, 40 neutral point, 41A , 41B, 41C resistance, 42 phase detector, 43 input voltage detector 44 RST-dq coordinate conversion unit, 45, 45A, 45B overload detection unit, 46, 47a, 47b, 48a, 48b, 85, 86a, 86b communication path, 50 power failure detection unit, 51, 52, 53, 91, 92 , 93 AC wiring, 60 regeneration start determination unit, 61 regeneration stop determination unit, 62 OR circuit, 64 subtractor, 65, 66, 190, 191, 195, 196, 197 comparator, 70N, 71N negative bus, 70P, 71P positive bus, 80N, 80P, 501, 502, 503 connection point, 82, 83 DC voltage detection unit, 192 OR circuit, 193 absolute value calculation unit, 194 temperature rise estimation unit, 100 host controller, C21, C22, C23, C24 capacitors, D1, D2, D3, D4, D5, D6, D21, D22, D23, D24 Flow element, S1, S2, S3, S4, S5, S6 switching element.

Claims

A power regeneration function that is arranged between an AC power source that is an input power source and a motor driving device that controls the motor at a variable speed, supplies DC power to the motor driving device, and returns regenerative power when the motor decelerates to the AC power source In a converter comprising:
An AC terminal connected to the AC power source, a first terminal to which a high potential side DC wiring is connected, a second terminal to which a low potential side DC wiring is connected, and a plurality of switching elements A power module;
A drive circuit for driving each of the plurality of switching elements;
A control power supply unit that generates power supplied to the plurality of switching elements and power supplied to the drive circuit;
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 serving as a reference potential of the control power supply unit, the voltage phase of the AC voltage is detected, and the detected A voltage phase detector that generates and outputs a phase detection signal indicating the voltage phase; and
A drive signal generator that generates a drive signal for controlling on / off operations of the plurality of switching elements based on the phase detection signal;
A converter comprising:
The voltage phase detection unit calculates a phase voltage of the AC voltage, and generates the phase detection signal using at least one of a maximum value and a minimum value of the phase voltage. The listed converter.
The converter according to claim 2, wherein the phase voltage is used for detection of a power failure of the AC power supply.
A signal control unit that continues transmission of the drive signal output from the drive signal generation unit to the drive circuit or stops transmission of the drive signal output from the drive signal generation unit to the drive circuit; Prepared,
The converter according to claim 2, wherein the phase voltage is used as a reference voltage of the signal control unit.
The voltage phase detection unit calculates a line voltage of the AC voltage, and generates the phase detection signal using at least one of a maximum value and a minimum value of the line voltage. The converter according to 1.
The converter according to claim 5, wherein the line voltage is used for detection of a power failure of the AC power supply.
A signal control unit that continues transmission of the drive signal output from the drive signal generation unit to the drive circuit or stops transmission of the drive signal output from the drive signal generation unit to the drive circuit; Prepared,
The converter according to claim 5, wherein the line voltage is used as a reference voltage of the signal control unit.
A phase voltage or a line voltage of the AC power supply is detected based on a signal flowing through the emitters of the plurality of switching elements connected to the first terminal or a signal flowing through a ground serving as a reference potential of the control power supply unit. The converter according to claim 1, further comprising an input voltage detection unit that performs the operation.
The converter according to claim 8, further comprising a power failure detection unit that uses the line voltage detected by the input voltage detection unit to detect a power failure of the AC power supply.
The converter according to claim 8, further comprising a power failure detection unit that uses the phase voltage detected by the input voltage detection unit to detect a power failure of the AC power supply.
The AC power supply is a three-phase AC power supply, and the voltage phase detector is a first voltage phase that is a voltage phase of a first phase of the three-phase AC power supply, and a second voltage that is a voltage phase of a second phase. The converter according to claim 1, wherein at least one of a phase, a third voltage phase that is a voltage phase of a third phase, and a power supply angular frequency is calculated.
An input current detection unit for detecting a current input to the AC terminal of the power module;
The three-phase input current detected by the input current detection unit is coordinate-transformed based on the phase detection signal, so that the d-axis current is a current corresponding to active power and the q-axis current is a current corresponding to reactive power. A current value conversion unit for calculating
The converter according to claim 11, comprising:
The overload detection unit for detecting whether or not the converter is in an instantaneous overload state based on at least one of the d-axis current and the q-axis current. The listed converter.
In addition to determining whether or not the converter is in the instantaneous overload state, the overload detection unit is based on at least one of the d-axis current and the q-axis current when the converter is in a steady state. It is determined whether or not an overload state occurs, and the determination result of the overload detection unit is output to the motor drive device or a host control device that outputs a motor operation command to the motor drive device. Item 14. The converter according to Item 13.
When the d-axis current is greater than a predetermined allowable d-axis current lower limit value and smaller than an allowable d-axis current upper limit value, the overload detection unit determines that the converter is not operating in an instantaneous overload state. And when the d-axis current is equal to or lower than the allowable d-axis current lower limit value or higher than the allowable d-axis current upper limit value, it is determined that the converter is operating in an instantaneous overload state. The converter according to claim 13 or 14.
The overload detection unit calculates an absolute value based on at least one of the d-axis current and the q-axis current; and
A filter unit for inputting and averaging the calculation result of the absolute value calculation unit;
16. The method according to claim 13, wherein when the output result of the filter unit is equal to or greater than a predetermined allowable absolute value, it is determined that the converter is operating in a steady-state overload state. A converter according to claim 1.
A motor control device comprising: the converter according to any one of claims 13 to 16; and a motor driving device that receives a direct current from the converter and controls the motor at a variable speed.
When the determination result of the overload detection unit is determined to be an overload, the motor drive device performs a motor operation that restricts the output of the motor from a motor operation command output from a host control device. The motor control device according to claim 17, wherein variable speed control of the motor is performed.
When it is determined that the determination result of the overload detection unit is an overload, a motor operation command is changed so that a motor operation that restricts the output of the motor is performed, and the motor drive device is connected via a host controller. The motor control device according to claim 17, wherein the motor control device is controlled to output to the motor.
The communication path is daisy chained in the order of the host controller, the motor drive device, and the converter, the overload detection unit detects an instantaneous overload state, and the determination result from the overload detection unit to the motor drive device Is notified, the motor drive device performs variable speed control of the motor so that the motor operation restricts the output of the motor from the motor operation command output from the host control device, and The host controller is notified of the determination result of the overload detection unit, and the host controller receives the determination result, and when it is in an instantaneous overload state, the motor operation is performed to limit the output of the motor. The motor control device according to claim 18 or 19, wherein a motor operation command is changed to be output to the motor drive device.
The communication path is daisy chained in the order of the host controller, the motor drive device, and the converter, and the overload detection unit detects a steady state overload state, and the overload detection unit determines the motor drive device. When the result is notified, the motor drive device performs variable speed control of the motor based on the motor operation command output from the host controller, and sends the determination result of the overload detector to the host controller. The higher-level control device receives the determination result, and changes the operation cycle so as to suppress the average output of the motor and outputs it to the motor drive device when it is in a steady-state overload state. The motor control device according to claim 18, wherein the motor control device is controlled.
The variable speed control is performed so as to decelerate at least one of the motors driven by the plurality of motor driving devices when a power failure of the AC power supply is detected. The motor control device according to item 1.
The motor driving device includes a DC voltage detection unit that is connected between the first terminal and the second terminal and detects a voltage of a smoothing capacitor that stores DC power,
The motor driving device is
When the detected value of the DC voltage detection unit is equal to or higher than the DC voltage upper limit value, variable speed control is performed so as to accelerate a motor different from the motor that performs the deceleration,
When the detection value of the DC voltage detection unit is less than or equal to the DC voltage lower limit value, variable speed control is performed so as to decelerate a motor different from the motor that performs the deceleration,
When the detection value of the DC voltage detection unit is larger than the DC voltage lower limit value and smaller than the DC voltage upper limit value, a motor other than the motor that performs the deceleration is free-run or variable speed so as to maintain a constant speed. The motor control device according to claim 22, wherein control is performed.