TWI509976B - Power supply system for driving motor and regeneration method using the same - Google Patents

Description

Power supply device for motor drive and retrospective method using the same

The present invention relates to a motor drive power supply device including a regenerative function for restoring regenerative electric power generated by an electric motor to a power source, and a regenerative method using the same.

There is a converter that controls switching of a transistor in which a bridged transistor is controlled by a switching phase of a phase of a three-phase AC power supply, and a motor driver power supply device that restores the regenerative electric power of the motor to a power source. Fig. 3 is a view showing the configuration of such a conventional motor drive power supply device. The motor drive power supply device is composed of an AC reactor ACL and six transistors, six diodes, and a phase detection circuit for detecting the phase of the three-phase AC power supply and a gate control signal generation circuit for driving six transistors. The configuration is disposed between the three-phase AC power source and the motor control device. When the motor is operating in power, the gates of the six transistors are turned off. At this time, the three-phase alternating current input from the three-phase alternating current power source is three-phase full-wave rectification via six diodes connected in parallel to six transistors, and a direct current is supplied to the motor control device. The motor control device includes a converter circuit that converts a direct current into an alternating current during power operation and inversely converts an alternating current generated by the motor M into a direct current at the time of regeneration. At the time of reincarnation, power is restored from the motor M, and when the voltage of the DC portion of the motor control device rises, the phase of the three-phase AC power source detected by the phase detecting circuit is used as a basis, and is sequentially turned on as shown in FIG. The gate of the transistor, and the current flowing in each phase of the three-phase AC power supply returns the power of the DC section to the three-phase AC power source. The interval in which the six transistors are turned on is the upper phase (the phase in which the regenerative voltage is positive), and the power supply voltage of each phase is 120° higher than the power supply voltage of the other phase, and the lower phase is (The regenerative voltage becomes a negative phase), and the power supply voltage of each phase is 120° lower than the power supply voltage of the other phase.

Further, as shown in Japanese Laid-Open Patent Publication No. 2004-154961 (Patent Document 1), when the instantaneous regenerative electric power from the electric motor is large, the power supply is regenerated and the electric resistance is regenerated. Fig. 5 is a view showing a power-regeneration device for regenerative resistance shown in Patent Document 1. In the device of Patent Document 1, as shown in Fig. 5, a resistance regenerative circuit 28 is provided in parallel with the power regeneration circuit 26. Thus, when the motor is decelerating, when the DC voltage of the inverter 34 reaches the first voltage (V1) set in advance, the power regeneration circuit 26 is operated, and when the DC voltage reaches the first voltage set in advance ( When the second voltage (V2) which is higher than V1) is operated, the resistance regenerative circuit 28 is operated. This action is performed by the switch control means 24.

(previous technical literature) (Patent Literature)

Patent Document 1: Japanese Patent Laid-Open Publication No. 2004-154961

When the power supply device for motor drive that regenerates the resistance and the power supply is used as shown in Fig. 5, when an instantaneous power failure occurs during power regeneration, the AC power supply voltage becomes low, so that the power supply regenerative current becomes excessive. Therefore, an alarm indicating an overcurrent occurs depending on the situation, and there is a case where the transistor used in the converter circuit that operates to regenerate the power supply is damaged. Further, in the state where the resistance is regenerated when the instantaneous power failure occurs, when the power supply is restored, the DC voltage of the inverter is high. At this time, if the power is regenerated, the power regeneration current becomes too large, and an alarm indicating an overcurrent occurs, and the transistor is damaged.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a motor drive power supply device that switches to a resistance regenerative without stopping an electric current even when an instantaneous power failure occurs, and uses the device. Regeneration method.

In addition to the above objects, another object of the present invention is to provide a motor drive power supply device that does not become an overcurrent and can be regenerated from a resistance to a power source returning even when recovering from an instantaneous power failure, and a retrospective method using the same.

A power supply device for driving a motor according to the present invention includes a power supply circuit, a regenerative resistance circuit, and an on-signal generating circuit. The power supply circuit includes a rectification function that converts an alternating current from an alternating current power source into a direct current and supplies a direct current power to the motor control device, and a regenerative power that is returned from the motor control device side, using a converter having a plurality of semiconductor switching elements. The circuit is back and forth in the regenerative function of the AC power supply. The regenerative resistor circuit is configured by a series circuit of a regenerative resistor and a switching circuit, and is disposed between the DC output terminals of the power supply circuit, and uses the switching circuit to be in an on state, and consumes the regenerative electric power by the regenerative resistor. The on-signal generating circuit is a second on-signal that controls the first on-signal of the converter circuit when the power is regenerated at the time of regenerative control, and controls the conduction of the switching circuit when the resistance is regenerated.

In the present invention, the on-signal generating circuit is a differential voltage between the DC voltage between the DC input portions of the motor control device and the power supply voltage of the AC power source at the time of regeneration, and is determined in advance based on the instantaneous power failure. When the voltage is larger, the output of the first ON signal is stopped, and the converter circuit is in a non-operating state, and the second ON signal is output while the output of the first ON signal is stopped. When the on-signal generating circuit outputs the first on-signal and the second on-signal in such a manner, when the instantaneous power-off occurs, the power-back is stopped and the resistor is regenerated to perform the return. Therefore, with the instantaneous power failure, even if the DC voltage on the input side of the motor control device rises, there is no case where an overcurrent flows to the semiconductor switching element of the converter circuit that performs the power regeneration. Further, since the resistance is regenerated in the event of an instantaneous power failure, it is possible to provide a motor drive power supply device having a highly reliable regenerative function.

The reference voltage may be determined in such a manner as to prevent an overcurrent current from flowing through the semiconductor switching element used in the converter circuit. Specifically, the reference voltage may be determined depending on the performance of the semiconductor switching element to be used and the specifications of the power supply.

The configuration of the on-signal generating circuit can be arbitrarily performed by the above-mentioned actor. For example, the ON signal generating circuit may be: a DC voltage detecting unit that detects a DC voltage; a phase detecting unit that detects a phase of a power source voltage of the AC power source; and a power source voltage wave height value that detects a power source voltage wave height value of the AC power source. And a phase difference voltage calculation unit that obtains a phase difference voltage between the power source voltage peak value and the DC voltage; and a command generation unit; and a first conduction signal generation unit and a second conduction signal generation unit. The command generation unit compares the phase difference voltage with the reference voltage, and outputs an output command for outputting the command of the first ON signal when the phase difference voltage is equal to or lower than the reference voltage. Further, when the phase difference voltage is larger than the reference voltage, an output stop command for instructing the output of the first ON signal to be stopped is output. Further, the first ON signal generating unit generates the first ON command in accordance with the phase of the power supply voltage detected by the phase detecting unit, and when the output command is input, the first ON signal is output to the converter circuit, and the output is stopped. When the command is input, the first conduction signal is output to the converter circuit. In addition, when the DC voltage is equal to or higher than the first reference DC voltage determined in advance, the second ON signal generating unit outputs the second ON signal, and the DC voltage is determined to be lower than the first reference DC voltage. When the second reference DC voltage is equal to or lower than the second reference DC voltage, the output of the second ON signal is stopped. The on-signal generating circuit has the above-described configuration, and the second on-signal that controls the power-on return and the second-on-conduction signal that controls the regenerative resistance can be generated with a relatively simple configuration.

The present invention can be used as a method of regenerating the above-described motor drive device. In the method of the present invention, when an instantaneous power failure occurs at the time of regeneration, the operation of the converter circuit is stopped, and during the stop operation of the converter circuit, only the regenerative resistance circuit is used for regeneration. Therefore, even when an instantaneous power failure occurs, the protection and control of the semiconductor switching elements constituting the converter circuit can be simultaneously performed.

Even after the instantaneous power failure is resumed, there is a case where the DC voltage is high. Therefore, even after the instantaneous power failure is restored, the voltage difference between the DC voltage between the DC input portions of the motor control device and the power supply voltage of the AC power source is larger than the reference voltage determined in advance by the instantaneous power failure. The action of the converter circuit will be re-opened, and only the regenerative resistor circuit will be used for regeneration. In this way, it is possible to surely prevent an overcurrent from flowing in the case of the semiconductor switching element of the converter circuit.

Further, after the instantaneous power failure is restored, the voltage difference between the DC voltage between the DC input portions of the motor control device and the power supply voltage of the AC power source is smaller than the reference voltage determined in advance by the instantaneous power failure.回 Regenerate with power.

Fig. 1 is a view showing a schematic configuration of an example of an embodiment of a power supply device for driving a motor according to the present invention. The AC reactor ACL is connected to the three-phase AC power supply AC, and the transistor Tr1 to Tr6, which are six semiconductor switching elements, are bridged at the output thereof to constitute the converter circuit CV. Further, six diodes D1 to D6 are connected in parallel to the six transistors Tr1 to Tr6. The six diodes D1 to D6 constitute a three-phase rectifier circuit that bridges. The power supply regenerative circuit PR is constructed by the bridged transistors Tr1 to Tr6 and the diodes D1 to D6.

A series circuit of a regenerative resistor R and a parallel circuit of a transistor Tr7 and a diode D7 constituting the switch circuit is connected in parallel between the DC output terminals of the converter circuit CV. This series circuit constitutes a resistance regenerative circuit RR. The resistance regenerative circuit RR is configured to discharge the regenerative electric power by the regenerative resistor R by turning on the transistor Tr7 (switching circuit).

Further, a smoothing capacitor C is connected in parallel between the DC output terminals of the converter circuit CV. At both ends of the smoothing capacitor C, a motor control device MC including an inverter circuit is connected. The inverter circuit converts direct current into alternating current and the three-phase alternating current motor M supplies a three-phase alternating current of a predetermined frequency as a motor current. When the motor M is decelerated to be in a regenerative state, the inverter circuit operates as a converter that converts an alternating current generated by the electric motor M into a direct current.

The phase detecting unit PD and the power supply voltage wave height detecting unit VHD are connected to the output side of the AC reactor ACL connected to the R phase, the S phase, and the T phase. Further, a DC voltage detecting unit VD is provided for measuring the voltage across the smoothing capacitor C, that is, the DC voltage on the input side of the motor control device MC.

The outputs of the DC voltage detecting unit VD, the phase detecting unit PD, and the power source voltage high value detecting unit VHD are input to the ON signal generating circuit SG. The on-signal generation circuit SG generates a plurality of first conduction signals S for turning on the six transistors Tr1 to Tr6 constituting the converter in the power regeneration circuit PR during power operation and regenerative operation of the motor M, and A second conduction signal S' for causing the transistor Tr7 in the resistance regeneration circuit RR to be in an on state occurs at the time of regeneration. In the present embodiment, the on-signal generating circuit SG is in a momentary power failure when the DC voltage Vdc between the DC input portions of the motor control device MC and the power supply voltage peak value Vp of the AC power source AC are different from each other at the time of the return. When the reference voltage Vr determined in advance as the reference is larger, the output of the first ON signal S is stopped, and the converter circuit in the power regeneration circuit PR is brought into a non-operating state, and the first conduction signal S is stopped. During the output period, the second conduction signal S' is output. In the on-signal generating circuit SG, the first on-signal S is generated by the first on-signal generating unit CS1 and output, and the second on-signal S' is generated in the second on-signal generating unit CS2. And is output. The first ON signal generating unit CS1 is the same as the gate signal (on signal) used in the existing power source regenerative circuit shown in FIG. 4, for example. Further, in order to obtain a specific effect, it is needless to say that the first ON signal S which is slightly different in phase from the gate signal (on signal) shown in FIG. 4 can be generated by the first ON signal generating unit CS1. .

In the present embodiment, the on-signal generating circuit SG further includes a phase difference voltage calculating unit DV and a command generating unit CG. The phase difference voltage calculation unit DV obtains a phase difference voltage ΔV between the power source voltage wave height value Vp detected by the power source voltage wave height value detecting unit VHD and the DC voltage Vdc detected by the DC voltage detecting unit VD. The command generation unit CG compares the phase difference voltage ΔV with the reference voltage Vr, and outputs an output command for instructing the output of the first ON signal S when the phase difference voltage ΔV is equal to or lower than the reference voltage Vr, and the phase difference voltage ΔV is compared with the reference. When the voltage Vr is larger, an output stop command for instructing the output of the first ON signal S to stop is generated. The first conduction signal generating unit CS1 generates the first conduction command S based on the phase of the power supply voltage detected by the phase detecting unit PD, and outputs the first conduction signal S to the converter circuit when the output command is input. On the other hand, when the output stop command is input, the configuration in which the first ON signal S is output to the converter circuit is stopped. In addition, when the DC voltage Vdc is equal to or greater than the first reference DC voltage Vr1 determined in advance, the second conduction command generating unit CS2 outputs the second conduction signal S', and the DC voltage Vdc is greater than the first reference DC voltage Vr1. When the second predetermined reference DC voltage Vr2 is lower than the predetermined value, the output of the second conduction signal S' is stopped.

When the ON signal generation circuit SG outputs the first ON signal S and the second ON signal S' in the event of an instantaneous power failure, the operation of the power supply regenerative circuit PR is stopped and the return is performed by the resistance regenerative circuit RR. Therefore, even if the DC voltage Vdc on the input side of the motor control device MC rises by the instantaneous power failure, there is no case where the overcurrent flows to the transistors Tr1 to Tr6 of the converter circuit CV in the power supply circuit PR. Further, in the event of an instantaneous power failure, the resistance regenerative circuit RR performs a regenerative operation, thereby maintaining high-reliability regenerative control.

After the instantaneous power failure recovery, there is also a situation in which the DC voltage is high. Therefore, the command generation unit CG is a phase difference voltage between the DC voltage between the DC input portions of the motor control device and the power source voltage of the AC power source after the instantaneous power failure recovery, and is a reference voltage determined in advance based on the instantaneous power failure. If it is too large, the operation of the converter circuit CV will not be restarted, and the return command may be continuously issued only by the regenerative resistance circuit. In this way, it is possible to surely prevent the case where an overcurrent flows in the semiconductor switching element of the converter circuit. Further, after the instantaneous power failure is restored, the voltage difference between the DC voltage between the DC input portions of the motor control device and the power supply voltage of the AC power source is smaller than the reference voltage determined in advance based on the instantaneous power failure, and of course, it is also possible to use The power is restored. In this case, for example, when the phase difference voltage ΔV between the power supply voltage wave height value Vp and the DC voltage Vdc detected by the DC voltage detecting unit VD is lower than the reference voltage Vr, the command generation unit CG outputs an output command. And the action of re-opening the converter circuit CV can be made.

The operation of the embodiment of Fig. 1 will be briefly described below using Fig. 2 . Fig. 2 is an operation waveform diagram assuming that an instantaneous power failure occurs in the middle of the rapid reduction motor. When the motor M is operated in power, the gates of the transistors Tr1 to Tr6 are turned off. Further, three-phase full-wave rectification is performed from the three-phase AC power supply AC via the diodes D1 to D6 connected in parallel to the transistors Tr1 to Tr6, and electric power is supplied to the motor control device MC. When the electric motor M is in the decelerating state, the regenerative state is returned to the power source side from the electric motor M, and the voltage of the DC portion of the motor control device MC is increased. Further, the transistors Tr1 to Tr6 are turned on in the conduction period designated by the conduction signals S1 to S6 in accordance with the phase of the three-phase AC voltage detected by the phase detecting unit PD. As a result, the regenerative current flows in each phase to restore the regenerative electric power of the rising DC voltage to the power source AC. If there is no instantaneous power failure, by regenerative, when the DC voltage Vdc rises, the power regeneration operation is repeated. Therefore, in the present embodiment, power supply is usually returned to operate.

When the instantaneous power failure occurs during power regeneration, as shown in the second (B) diagram, the power supply voltage peak value Vp is lowered. As shown in the second (C) diagram, the DC voltage Vdc of the DC portion of the motor control device MC is rise. When the difference between the DC voltage Vdc and the power supply voltage wave height value Vp is equal to or greater than the reference voltage Vr, the supply of the gate control signal (on signal) of the transistors Tr1 to Tr6 constituting the converter circuit in the power supply circuit PR is stopped. (The period of the stop is called interlocking). The second (D) diagram shows the period of the interlock. When the DC voltage Vdc of the DC portion of the motor control device MC exceeds the resistance regenerative operation voltage Vr1, the resistance regeneration circuit RR is operated. The second conduction signal S' of the transistor Tr7 in the resistance regenerative circuit RR is controlled to conduct the transistor Tr7 when the DC voltage Vdc becomes the first reference voltage Vr1, and the DC voltage Vdc is greater than the second reference voltage Vr2. Small, the transistor Tr7 is made non-conductive. Since this operation is repeated, the DC voltage Vdc of the motor control device of the second (C) diagram fluctuates during the interlocking period. Even when the instantaneous power failure is resumed, the power supply return circuit PR is interlocked with respect to the supply of the first conduction signal S of the converter circuit CV while the phase difference between the power supply voltage peak value Vp and the direct current voltage Vdc is large. When the motor speed is lowered, the regenerative electric power from the electric motor becomes smaller, and the DC voltage Vdc is lowered so that the difference from the power supply voltage wave high value Vp becomes smaller, the command generating portion CG outputs the output first output signal S to the power regeneration circuit PR. The output instruction of the instruction. At this time, since the difference between the DC voltage Vdc and the power supply voltage wave height value Vp is small, there is no possibility of an overcurrent.

In the present embodiment, the AC reactor ACL may be disposed rearward of the connection point of the phase detecting unit PD (on the power regeneration circuit PR side).

According to the above embodiment, when the DC voltage Vdc of the motor control device and the power supply voltage peak value Vp are larger than each other by ΔV in the power supply device for the resistor regenerative and power supply regenerative, the ON signal of the power regeneration circuit PR is applied. Interlocking, when the phase difference ΔV becomes smaller, the interlock is made. As a result, even if an instantaneous power failure occurs, the power supply current of the power supply device is not excessively large, and an alarm indicating an overcurrent or a failure of the transistors Tr1 to Tr6 is generated, and a highly reliable power supply retrograding device can be realized.

(industrial availability)

According to the invention, the conduction signal generating circuit is a voltage difference between the DC voltage between the DC input portions of the motor control device and the power supply voltage of the AC power source at the time of regeneration, and is determined in advance based on the instantaneous power failure. When the voltage is larger, the output of the first ON signal is stopped, and the converter circuit is in a non-operating state. When the output of the first ON signal is stopped, only the second ON signal is output. In the event of an instantaneous power outage, the power regeneration is stopped and only the resistor is used to regenerate. Therefore, with the instantaneous power failure, even if the DC voltage on the input side of the motor control device rises, there is no case where an overcurrent flows to the semiconductor switching element of the converter circuit that performs the power regeneration. Further, since the resistance is regenerated at the time of instantaneous power failure, it is possible to provide a motor drive power supply device having a highly reliable regenerative function.

Tr1 to Tr7. . . Transistor

D1～D7. . . Dipole

CV. . . Converter circuit

MC. . . Motor control unit

M. . . electric motor

AC. . . Three-phase AC power supply

VD. . . DC voltage detection unit

PD. . . Phase detection unit

SG. . . On signal generation circuit

RR. . . Resistance return circuit

PR. . . Power return circuit

Fig. 1 is a view showing a schematic configuration of an example of an embodiment of a power supply device for driving a motor according to the present invention.

The second (A) to (2)th drawings are operation waveforms for explaining the operation of the embodiment of Fig. 1.

Fig. 3 is a view showing a schematic configuration of an example of a conventional motor drive power supply device.

Fig. 4 is a view showing an operation waveform of a conventional power supply device for driving a motor.

Fig. 5 is a view showing a schematic configuration of another conventional motor drive power supply device.

Tr1 to Tr7. . . Transistor

D1～D7. . . Dipole

CV. . . Converter circuit

MC. . . Motor control unit

M. . . electric motor

AC. . . Three-phase AC power supply

VD. . . DC voltage detection unit

PD. . . Phase detection unit

SG. . . On signal generation circuit

RR. . . Resistance return circuit

PR. . . Power return circuit

S. . . First conduction signal

S’. . . Second conduction signal

T. . . phase

ACL. . . AC reactor

CS ₁ . . . First conduction signal generating unit

CS ₂ . . . Second conduction signal generating unit

CG. . . Command generation department

DV. . . Phase difference voltage calculation department

VHD. . . Power supply voltage wave height detection unit

R. . . Regenerative resistance

C. . . Rectifier capacitor

Claims (3)

A power supply device for driving a motor, comprising: a power supply circuit having a rectifying function for converting an alternating current from an alternating current power source into a direct current and supplying a direct current power to the motor control device; and being provided from the motor control device side The retrograded regenerative power uses a converter circuit having a plurality of semiconductor switching elements to regenerate the regenerative function of the alternating current power source; the regenerative resistance circuit is composed of a series circuit of a regenerative resistor and a switching circuit, and is disposed in the power supply circuit Between the DC output terminals, the switching circuit is turned on, the regenerative power is consumed by the regenerative resistor, and the turn-on signal generating circuit is generated to control the converter circuit when power is restored during the regenerative period. a conduction signal and a second conduction signal for controlling conduction of the switching circuit when the resistor is regenerated, the motor driving power supply device is characterized in that the conduction signal generating circuit is configured as follows: a DC voltage a detecting unit that detects the motor control device a DC voltage between the stream input units; a phase detecting unit that detects a phase of a power source voltage of the AC power source; a power source voltage wave height detecting unit that detects a power source voltage wave height value of the AC power source; and a phase difference voltage calculation unit Find the above power supply voltage wave height value and And a command generating unit that compares the phase difference voltage with a reference voltage determined in advance based on an instantaneous power failure, and outputs a command to command the first conduction signal when the phase difference voltage is equal to or less than the reference voltage. The output command of the output is an output stop command for instructing the output of the first conduction signal to stop when the phase difference voltage is greater than the reference voltage; and the first conduction signal generation unit is based on the phase detection unit The first conduction command is generated by the detected phase of the power supply voltage, and when the output command is input, the first ON signal is output to the converter circuit, and when the output stop command is input, the operation is stopped. The first on-signal is output to the converter circuit, and the second on-signal generating unit outputs the second on-signal when the DC voltage is equal to or greater than a predetermined first reference DC voltage. When the DC voltage is equal to or lower than a predetermined second reference DC voltage that is lower than the first reference DC voltage, the DC voltage is stopped. In the output of the second ON signal, the ON signal generating circuit stops the first ON signal when the voltage difference between the DC voltage and the power supply voltage peak value is greater than the reference voltage when regenerating. The converter circuit is outputted in a non-operating state, and the second ON signal is outputted while the output of the first ON signal is stopped. The power supply device for driving a motor according to claim 1, wherein the reference voltage is a current that prevents an overcurrent from flowing in the converter circuit The mode of the semiconductor switching element used is determined. A regenerative method using a regenerative method of a motor drive power supply device including: a power supply circuit that converts an alternating current from an alternating current power source into a direct current and supplies a direct current power to the motor control device a rectification function; and a regenerative power that is regenerated from the motor control device side, using a converter circuit having a plurality of semiconductor switching elements to regenerate the regenerative function of the AC power source; and a regenerative resistance circuit, which is a regenerative resistor and a switch a circuit of a series circuit, which is disposed between the DC output terminals of the power supply circuit, and uses the switching circuit to be in an ON state, and consumes the regenerative electric power by the regenerative resistor. The regenerative method is characterized in that: when reborn, the motor When the voltage difference between the DC voltage between the DC input portions of the control device and the power supply voltage peak value of the AC power supply is larger than a reference voltage determined in advance based on the instantaneous power failure, the operation of the converter circuit is stopped. In the above converter circuit The period of the stop operation is regenerated by the regenerative resistor circuit, and after the instantaneous power failure is restored, the voltage difference between the DC voltage between the DC input portions of the motor control device and the power source voltage of the AC power source is a ratio of instantaneous power failure. When the reference voltage determined in advance as the reference is larger, the operation of the converter circuit is not re-executed, and only the regenerative resistor circuit is regenerated, and after the instantaneous power failure recovery, the motor control device described above The phase difference voltage between the DC voltage between the DC input unit and the power source voltage of the AC power source is smaller than the reference voltage determined in advance by the instantaneous power failure, and the operation of the converter circuit is performed again.