JP7047499B2 - Power converter - Google Patents

Description

The present invention relates to a power converter.

Conventionally, a power conversion device is known (see, for example, Patent Document 1).

Patent Document 1 includes a drive unit that includes a semiconductor switching element and converts electric power, an arithmetic processing unit that generates a control signal for controlling the semiconductor switching element, and a drive unit when a stop command is input. A power conversion device including a safety unit for stopping the driving of the power supply unit and a control power supply unit for supplying electric power to the arithmetic processing unit and the safety unit is disclosed. The power conversion device of Patent Document 1 is configured to diagnose the control power supply unit at the time of startup.

In addition, conventionally, electric motors are often used for fans, pumps, elevators, machine rooms of buildings, drive parts of manufacturing equipment, etc. installed in factories, etc., and these electric motors are used for power of inverter devices, servo amplifiers, etc. It is driven by a power converter that uses electronics. If a failure or the like occurs in this type of power conversion device, the power conversion device, the electric motor, or the like may be damaged in some cases. Against this background, it is required that a motor drive system using a power conversion device be provided with a stop function based on an international standard. This stop function must be ensured even when, for example, the control power supply unit of the power converter fails and an abnormality such as overvoltage occurs, and the required level of safety against the failure differs depending on the application. There is. Therefore, in order to further improve the safety of the motor drive system, the failure diagnosis function for the control power supply unit, the main power supply is cut off, the operation of the drive unit is stopped promptly when a failure occurs, and the device is surely stopped. It is important to have a stop function.

Japanese Unexamined Patent Publication No. 2016-178739

However, in the conventional power conversion device as described in Patent Document 1, the failure diagnosis of the control power supply circuit for operating the stop circuit is performed only by the initialization process at the time of starting the device power supply. In the failure diagnosis of this control power supply circuit, it is diagnosed whether or not the control power supply output can be cut off correctly. When the control power output is cut off, the safety unit stops the output of the control signal to the power conversion unit and puts the power conversion unit (drive unit) in the stopped state. Can't. Here, some machines and manufacturing appliances are always energized and the frequency of power restart is low. In such a device, the frequency of failure diagnosis of the control power supply circuit decreases, so that the rate of operation without diagnosing the stop function or the diagnostic function increases. As a result, there is a problem that the reliability of stopping the power conversion unit is lowered.

The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a power conversion device capable of improving the reliability of stopping a power conversion unit. Is.

In order to achieve the above object, the power conversion device according to one aspect of the present invention includes a semiconductor switching element, a power conversion unit that converts power, and an operation for generating a control signal for controlling the semiconductor switching element. It includes a processing unit, a stop unit that stops the drive of the power conversion unit when a stop command is input, and a power supply unit that supplies power to the arithmetic processing unit and the stop unit. Whether or not it is possible to diagnose a failure of the cutoff circuit of the power supply unit or detect an abnormality in the output voltage from the power supply unit while the drive of the power conversion unit is stopped based on the stop signal from the stop unit when input. It is configured to perform circuit diagnosis of the power supply unit, which is the diagnosis, and the stop unit is connected to the power conversion unit based on the command input unit to which the stop command is input and the stop command signal from the command input unit. The stop signal includes a cutoff unit that cuts off the supply of power, and the stop signal feeds back a stop command signal from the command input unit and a signal transmitted from the cutoff unit to the power conversion unit based on the stop command signal to the cutoff unit. Includes a feedback signal from the unit .

In the power conversion device according to one aspect of the present invention, by configuring as described above, a stop command is input not only when the power conversion device is started but also when the emergency stop button is pressed. Even when the input of the stop command changes, such as in a case, the circuit diagnosis of the power supply unit can be performed, so that the frequency of the circuit diagnosis of the power supply unit can be increased. As a result, it is possible to easily detect a circuit failure of the power supply unit, and thus it is possible to improve the reliability of stopping the power conversion unit.

Further , the arithmetic processing unit is configured to perform circuit diagnosis of the power supply unit based on the stop signal from the stop unit when a stop command is input. As a result , the change in the input of the stop command can be reliably acquired by the arithmetic processing unit, so that the circuit diagnosis can be reliably performed when the stop command is input.

Further, the stop unit includes a command input unit to which a stop command is input and a cutoff unit that cuts off the supply of power to the power conversion unit based on the stop command signal from the command input unit, and the stop signal is a command. It includes a stop command signal from the input unit and a feedback signal from the cutoff unit. As a result , the circuit diagnosis of the power supply unit can be started based on both the stop command signal and the feedback signal, so that the circuit diagnosis of the power supply unit is performed with the drive of the power conversion unit reliably stopped. be able to.

In the power conversion device according to the above one aspect, preferably, the arithmetic processing unit is configured to perform circuit diagnosis of the power supply unit when the input of the stop command is canceled, and then restart the drive of the power conversion unit. ing. With this configuration, it is possible to detect a circuit failure of the power supply unit before restarting the drive of the power conversion unit, so that it is possible to suppress the restart of the drive of the power conversion unit in the state of having a circuit failure. can.

In the power conversion device according to the above one aspect, preferably, when a stop command is input, the arithmetic processing unit is configured to perform a diagnosis of the stop unit in addition to the circuit diagnosis of the power supply unit. With this configuration, it is possible to diagnose whether or not the stop unit operates normally in response to the input of the stop command together with the circuit diagnosis of the power supply unit.

According to the present invention, as described above, it is possible to provide a power conversion device capable of improving the reliability of stopping the power conversion unit.

It is a block diagram which showed the outline of the power conversion apparatus by one Embodiment of this invention. It is a circuit diagram which showed the power conversion part of the power conversion apparatus by one Embodiment of this invention. It is a circuit diagram which showed the power supply diagnosis part of the power conversion apparatus by one Embodiment of this invention. It is a table which showed the truth value of the stop part of the power conversion apparatus by one Embodiment of this invention. It is a table which showed the truth value of the power supply diagnosis part of the power conversion apparatus by one Embodiment of this invention. It is a figure which showed the operation sequence of the stop part of the power conversion apparatus by one Embodiment of this invention. It is a figure which showed the example in the normal state of the power supply diagnosis sequence of the power conversion apparatus by one Embodiment of this invention. It is a figure which showed the example at the time of the diagnosis abnormality of the power supply diagnosis sequence of the power conversion apparatus by one Embodiment of this invention. It is a figure which showed the power supply diagnosis timing of the power conversion apparatus by one Embodiment of this invention.

Hereinafter, embodiments embodying the present invention will be described with reference to the drawings.

The configuration of the power conversion device 100 according to the embodiment of the present invention will be described with reference to FIGS. 1 to 9.

(Configuration of power converter)
As shown in FIG. 1, the power conversion device 100 is configured to convert an input DC or AC power into a set AC power and output the power. The power conversion device 100 is configured to convert electric power and supply electric power to the load unit 200. The load unit 200 includes an electric motor such as a motor.

The power conversion device 100 includes a power conversion unit 10, an arithmetic processing unit 20, a stop unit 30, a power supply diagnosis unit 40, and a control power supply unit 50. An emergency stop button 300 is connected to the power conversion device 100. The stop unit 30 includes two stop circuits. Specifically, the stop unit 30 includes a command input unit 311 and a gate cutoff control unit 321 as the first system. Further, the stop unit 30 includes a command input unit 312 and a gate cutoff control unit 322 as a second system. The power supply diagnosis unit 40 and the control power supply unit 50 are examples of the "power supply unit" within the scope of the claims. Further, the gate cutoff control units 321 and 322 are examples of "blocking units" within the scope of the claims.

The power conversion unit 10 includes semiconductor switching elements Sa, Sb, Sc, Sd, Se, and Sf (see FIG. 2), and is configured to perform power conversion. Specifically, the power conversion unit 10 is configured to supply electric power from the outside, convert the electric power, and supply the electric power to the external load unit 200. In the example shown in FIG. 2, the power conversion unit 10 is supplied with three-phase (L1 phase, L2 phase, and L3 phase) AC power from the outside, and the load unit 200 is supplied with three phases (a phase, b phase, and c phase). It is configured to supply AC power.

The arithmetic processing unit 20 is configured to generate a control signal for controlling the semiconductor switching elements Sa to Sf. Specifically, the arithmetic processing unit 20 is configured to transmit a PWM (Pulse Width Modulation) output signal to the power conversion unit 10 to control switching of the semiconductor switching elements Sa to Sf. The arithmetic processing unit 20 includes, for example, a CPU (central processing unit), a memory, and the like. The arithmetic processing unit 20 is configured to be supplied with electric power from the control power supply unit 50. Further, the arithmetic processing unit 20 is configured to control the diagnosis of the power supply diagnosis unit 40. Further, the arithmetic processing unit 20 is configured to perform diagnostic processing and status monitoring processing of the stop unit 30.

The stop unit 30 is configured to stop driving the power conversion unit 10 when a stop command is input. Specifically, when the emergency stop button 300 is operated and a stop command is input, the stop unit 30 cuts off the power supplied to the gate of the power conversion unit 10 to drive the power conversion unit 10. Is configured to stop. The stop unit 30 is configured to be supplied with electric power from the control power supply unit 50. Specifically, the stop unit 30 is supplied with electric power from the control power supply unit 50 via the power supply diagnosis unit 40.

The command input units 311 and 312 of the stop unit 30 are configured to input a stop command. Specifically, the command input units 311 and 312 are configured to receive the signal from the emergency stop button 300 and transmit the signal to the gate cutoff control units 321 and 322. The command input unit 311 receives the IN1 signal from the emergency stop button 300, and outputs the IN1a signal to the arithmetic processing unit 20 and the gate cutoff control unit 321. Specifically, the command input unit 311 receives the H level IN1 signal and outputs the H level IN1a signal. Further, the command input unit 311 receives the L level IN1 signal and outputs the L level IN1a signal. The command input unit 312 receives the IN2 signal from the emergency stop button 300, and outputs the IN2a signal to the arithmetic processing unit 20 and the gate cutoff control unit 322. Specifically, the command input unit 312 receives the H level IN2 signal and outputs the H level IN2a signal. Further, the command input unit 312 receives the L level IN2 signal and outputs the L level IN2a signal. The IN1 signal and IN2 signal from the emergency stop button 300 are H level when the emergency stop button 300 is ON, and L level when the emergency stop button 300 is OFF. The command input units 311 and 312 and the emergency stop button 300 are connected by an insulating circuit. For example, the command input units 311 and 312 and the emergency stop button 300 are connected via a photocoupler.

The gate cutoff control units 321 and 322 of the stop unit 30 are configured to cut off the supply of electric power to the power conversion unit 10 based on the stop command signal from the command input units 311 and 312. The gate cutoff control unit 321 receives the IN1a signal from the command input unit 311 and outputs the FB1 signal to the arithmetic processing unit 20 and the power conversion unit 10. Specifically, the gate cutoff control unit 321 receives the H level IN1a signal and supplies electric power to the power conversion unit 10. Further, the gate cutoff control unit 321 receives the L level IN1a signal and cuts off the supply of electric power to the power conversion unit 10. The gate cutoff control unit 322 receives the IN2a signal from the command input unit 312, and outputs the FB2 signal to the arithmetic processing unit 20 and the power conversion unit 10. Specifically, the gate cutoff control unit 322 receives the H level IN2a signal and supplies power to the power conversion unit 10. Further, the gate cutoff control unit 322 receives the L level IN2a signal and cuts off the supply of electric power to the power conversion unit 10. Further, when the power supply from the control power supply unit 50 is stopped, the power supply from the gate cutoff control unit 321 and 322 to the power conversion unit 10 is stopped. As a result, when the emergency stop button 300 is ON and when there is no power supply from the control power supply unit 50 to the gate cutoff control units 321 and 322, the drive of the power conversion unit 10 is stopped. The circuit of the stop unit 30 is duplicated because even if one circuit fails, if both IN1 and IN2 signals reach the L level (emergency stop button 300 is ON), the load unit is duplicated. This is to ensure that the 200 is stopped.

The power supply diagnosis unit 40 is configured to perform circuit diagnosis of the power conversion device 100. The power supply diagnosis unit 40 is configured such that the power P is supplied from the control power supply unit 50 and the power PS is supplied to the stop unit 30. Further, the power supply diagnosis unit 40 is configured to change the power PS based on the diagnosis signal S1 from the calculation processing unit 20 and output it to the calculation processing unit 20.

The control power supply unit 50 is configured to supply electric power to the arithmetic processing unit 20 and the stop unit 30. The control power supply unit 50 is configured to be supplied with electric power from the outside.

(Circuit configuration of power converter)
The circuit configuration of the power conversion unit 10 will be described with reference to FIG. The power conversion unit 10 is configured to convert the input AC power into the set AC power and output it. The power conversion unit 10 converts the AC power input from the AC power supply (not shown) via the input terminals L1, L2 and L3 into three-phase (a-phase, b-phase and c-phase) AC power. It is configured. Further, the power conversion unit 10 is configured to output the converted AC power of the a-phase, b-phase, and c-phase to the external load unit 200 via the output terminals a, b, and c.

The power conversion unit 10 includes a capacitor C, semiconductor switching elements Sa, Sb, Sc, Sd, Se, Sf, diodes Da, Db, Dc, Dd, De, Df, and diodes Dg, Dh, Di, Dj, Dk. , Dl and gate drive circuits Ga, Gb, Gc, Gd, Ge, Gf.

The gate drive circuits Ga, Gc, and Ge are configured to be supplied with electric power from the gate cutoff control unit 321. Further, the gate drive circuits Gb, Gd and Gf are configured to be supplied with electric power from the gate cutoff control unit 322. Further, the gate drive circuits Ga, Gb, Gc, Gd, Ge, and Gf insulate and connect the circuit including the semiconductor switching elements Sa, Sb, Sc, Sd, Se, and Sf to the arithmetic processing unit 20 and the stop unit 30. Therefore, it contains a photocoupler. Further, the gate drive circuits Ga, Gb, Gc, Gd, Ge, and Gf are configured to perform switching control of the semiconductor switching elements Sa, Sb, Sc, Sd, Se, and Sf under the control of the arithmetic processing unit 20. There is. In the gate drive circuits Ga, Gb, Gc, Gd, Ge, and Gf, when the power supply from the stop unit 30 (gate cutoff control unit 321 or 322) is stopped, or the PWM output signal from the arithmetic processing unit 20 When is stopped, the drive is stopped. Then, in this case, the driving of the power conversion unit 10 is stopped.

The gate drive circuit Ga performs switching control of the semiconductor switching element Sa by the PWM output signal of the U phase. The gate drive circuit Gb controls the switching of the semiconductor switching element Sb by the X-phase PWM output signal. The gate drive circuit Gc controls the switching of the semiconductor switching element Sc by the PWM output signal of the V phase. The gate drive circuit Gd controls the switching of the semiconductor switching element Sd by the PWM output signal of the Y phase. The gate drive circuit Ge performs switching control of the semiconductor switching element Se by the PWM output signal of the W phase. The gate drive circuit Gf controls the switching of the semiconductor switching element Sf by the Z-phase PWM output signal.

(Circuit configuration of power supply diagnostic unit)
The circuit configuration of the power supply diagnosis unit 40 will be described with reference to FIG. The power supply diagnosis unit 40 includes a cutoff switch 41, a comparator 42, and a transistor 43.

The cutoff switch 41 is configured to output the electric power supplied from the control power supply unit 50 to the stop unit 30. Further, the cutoff switch 41 is configured to cut off the supply of electric power from the control power supply unit 50 to the stop unit 30.

The comparator 42 is configured to switch ON / OFF of the cutoff switch 41. Specifically, the comparator 42 compares the power supply PS to be monitored with the reference voltage (overvoltage detection threshold value). Further, the comparator 42 outputs an H level when the power supply PS rises to an overvoltage level, and outputs an L level in a normal state. The output of the comparator 42 is connected to the base terminal of the cutoff switch 41, and cuts off the power supply PS when overvoltage is detected.

The transistor 43 has a function of lowering the reference voltage level when the diagnostic signal S1 from the arithmetic processing unit 20 reaches the H level. That is, when the diagnostic signal is at H level, the output of the comparator 42 is at H level, and the cutoff switch 41 is turned off. As a result, the power supply PS to the stop unit 30 is cut off. When the diagnostic signal is at L level, the output of the comparator 42 is at L level and the cutoff switch 41 is turned on. The arithmetic processing unit 20 can diagnose the failure of the cutoff switch 41 and the comparator 42 by monitoring the voltage level of the power supply PS.

(Operation of the stop part)
The operation of the stop unit 30 will be described with reference to FIG. When the power of the control power supply unit 50 is ON, when the INx signal (where x is 1 or 2) is H level, the INxa signal (where x is 1 or 2) becomes H level and the FBx output (where x is 1 or 2). However, for x, 1 or 2) is PSa (power output). In this case, the emergency stop button 300 is OFF, which is the case of normal operation. Further, when the power supply of the control power supply unit 50 is ON and the INx signal is L level, the INxa signal becomes L level and the FBx output becomes 0V (power cutoff state). In this case, the emergency stop button 300 is turned on. When the power supply of the control power supply unit 50 is OFF, the INx signal is not output, the INxa signal becomes the L level, and the FBx output becomes 0V (power cutoff state). In this case, the stop power supply is OFF.

The operation sequence of the stop unit 30 will be described with reference to FIG. When the power supply of the control power supply unit 50 is turned on (PS power supply ON), the IN1 signal and the IN2 signal become H level. In this case, the emergency stop button 300 is OFF. As a result, the IN1a signal and the IN2a signal become H level. As a result, the FB1 output and the FB2 output are turned on, and the PSa power is output to the power conversion unit 10. As a result, the state of the power conversion unit 10 changes from the output OFF state to the operable state.

After that, when the emergency stop button 300 is operated and turned ON, the IN1 signal and the IN2 signal become L level. As a result, the IN1a signal and the IN2a signal become L level. As a result, the FB1 output and the FB2 output are turned off, and the power supply to the power conversion unit 10 is cut off. As a result, the state of the power conversion unit 10 changes from the operable state to the output OFF (gate cutoff) state.

After that, when the emergency stop button 300 is operated to be turned off (released), the IN1 signal and the IN2 signal become H level. As a result, the IN1a signal and the IN2a signal become H level. As a result, the FB1 output and the FB2 output are turned on, and the PSa power is output to the power conversion unit 10. As a result, the state of the power conversion unit 10 changes from the output OFF state to the operable state.

(Operation of power supply diagnostic unit)
The operation of the power supply diagnosis unit 40 will be described with reference to FIG. In the state C1, when the diagnostic signal S1 from the arithmetic processing unit 20 is H level, the voltage level of the power supply PS is L level. In this case, it is judged to be normal. The state C1 is a state at the time of diagnosis. In the state C2, when the diagnostic signal S1 from the arithmetic processing unit 20 is the L level, the voltage level of the power supply PS is the H level. In this case, it is judged to be normal. The state C2 is a state during normal operation. In the state C3, when the diagnostic signal S1 from the arithmetic processing unit 20 is H level, the voltage level of the power supply PS is H level. In this case, it is determined to be a failure. In this case, the loss of the function of the cutoff switch 41 may be considered as the cause of the failure. In the state C4, when the diagnostic signal S1 from the arithmetic processing unit 20 is the L level, the voltage level of the power supply PS is the L level. In this case, it is determined to be a failure. In this case, the cause of the failure may be the loss of the function of the cutoff switch 41 or the detection of overvoltage.

The operation sequence of the power supply diagnosis unit 40 will be described with reference to FIGS. 7 and 8.

In the case of the example shown in FIG. 7, when the diagnostic signal S1 is set to the H level (pulse ON) as the diagnosis 1 in the state where the control power supply P is turned on, the voltage level of the power source PS is set to the L level (power OFF). Become. In this case, it is determined to be normal (state C1 in FIG. 5). Further, as the diagnosis 2, when the diagnostic signal S1 is set to the L level (pulse OFF), the voltage level of the power supply PS is set to the H level (power ON). In this case, it is determined to be normal (state C2 in FIG. 5). After that, the power conversion unit 10 can be operated. Here, in the diagnosis 1, since the power supply PS is turned off, the power to the power conversion unit 10 is cut off. Therefore, it is necessary to perform a diagnosis when the drive of the power conversion unit 10 is stopped.

In the case of the example shown in FIG. 8, when the diagnostic signal S1 is set to the H level (pulse ON) as the diagnosis 1 in the state where the control power supply P is the power ON, the voltage level of the power supply PS is the H level (power ON). I'll wait. In this case, it is determined to be abnormal case 1 (state C3 in FIG. 5). Further, as the diagnosis 2, when the diagnostic signal S1 is set to the L level (pulse OFF), the voltage level of the power supply PS is set to the L level (power OFF). In this case, it is determined to be an abnormal case 2 (state C4 in FIG. 5). In this case, the operation of the power conversion unit 10 is stopped.

(Processing of arithmetic processing unit)
Here, the arithmetic processing unit 20 is configured to perform circuit diagnosis of the control power supply unit 50 (power supply diagnosis unit 40) with the drive of the power conversion unit 10 stopped when the input of the stop command changes. Has been done. Specifically, the arithmetic processing unit 20 has the control power supply unit 50 in at least one of the cases where the input of the stop command is changed, the stop command is input, and the stop command input is canceled. It is configured to perform circuit diagnosis of (power supply diagnosis unit 40). That is, the arithmetic processing unit 20 has at least one of the case where the emergency stop button 300 is turned on (when the emergency stop is stopped) and the case where the emergency stop button 300 is turned off (when the emergency stop is released). Is configured to perform circuit diagnosis of the control power supply unit 50 (power supply diagnosis unit 40).

Further, the arithmetic processing unit 20 is configured to perform circuit diagnosis of the control power supply unit 50 (power supply diagnosis unit 40) based on the stop signal from the stop unit 30 when a stop command is input. The stop signal includes a stop command signal (IN1a signal, IN2a signal) from the command input units 311 and 312, and a feedback signal (FB1, FB2) from the gate cutoff control units 321 and 322.

Further, the arithmetic processing unit 20 is configured to perform circuit diagnosis of the control power supply unit 50 (power supply diagnosis unit 40) when the input of the stop command is canceled, and then restart the drive of the power conversion unit 10. There is. Further, the arithmetic processing unit 20 is configured to perform a diagnosis of the stop unit 30 in addition to the circuit diagnosis of the control power supply unit 50 (power supply diagnosis unit 40) when a stop command is input. That is, the stop command becomes valid (when the emergency stop button 300 or the like is pressed), and after the gate is normally shut off by the gate cutoff control units 321 and 322, the control power supply unit 50 (power supply diagnosis unit 40) is diagnosed. .. Further, after the stop command is changed from valid to invalid (when the emergency stop button 300 is released from the pressed state), the gate cutoff control units 321 and 322 are normally in the gate driveable state, and then the control power supply unit 50 (power supply). The diagnosis of the diagnosis unit 40) is performed.

Further, the arithmetic processing unit 20 monitors the IN1a signal and IN2a signal of the command input units 311 and 312 and the outputs FB1 and FB2 of the gate cutoff control units 321 and 322, and controls the gate cutoff according to the input state of the stop command. It is diagnosed that the blocking process by the units 321 and 322 is correctly performed. This is a diagnosis of the operation of the stop unit 30 shown in FIG. Further, the arithmetic processing unit 20 diagnoses that the two stop circuits are operating in the same manner. This is a diagnosis of duplex circuit operation. When the diagnosis is abnormal, the arithmetic processing unit 20 stops the PWM signal output and stops the output of the power conversion unit 10. As a state monitoring function of the stop unit 30, the arithmetic processing unit 20 detects that the input state of the stop command has changed and the stop unit 30 has operated normally based on the diagnostic function of the stop unit 30, and that state. Is configured to hold.

(Power supply diagnosis timing)
The power supply diagnosis timing will be described with reference to FIG. When the power supply P of the control power supply unit 50 is energized, the initialization process of the arithmetic processing unit 20 is started. In this initialization process, power supply diagnosis 1 (power supply start) is performed. Further, the power supply of the control power supply unit 50 is turned on (P power supply ON), and the IN1 signal and the IN2 signal become H level. In this case, the emergency stop button 300 is OFF. As a result, the IN1a signal and the IN2a signal become H level. As a result, the FB1 output and the FB2 output are turned on, and the PSa power is output to the power conversion unit 10. As a result, the control power supply unit 50 (power supply diagnosis unit 40) is diagnosed. When the diagnosis result is normal, the state of the power conversion unit 10 changes from the output OFF state to the operable state.

After that, when the emergency stop button 300 is operated and turned ON, the IN1 signal and the IN2 signal become L level. As a result, the IN1a signal and the IN2a signal become L level. As a result, the FB1 output and the FB2 output are turned off, and the power supply to the power conversion unit 10 is cut off. As a result, the state of the power conversion unit 10 changes from the operable state to the output OFF (gate cutoff) state. In this case, power supply diagnosis 2 (stop input) is performed. Further, the change between the IN1a signal and the output FB1 is detected, and the gate cutoff control unit 321 is diagnosed. In this case, since the state of change is normal, it is determined that the system 1 is normal. Further, the gate cutoff control unit 322 is diagnosed by detecting the change between the IN2a signal and the output FB2. In this case, since the state of change is normal, it is determined that the system 2 is normal. Further, since the change in the system 1 and the change in the system 2 are the same, it is determined that the operation of the duplex circuit is normal.

After that, when the emergency stop button 300 is operated to be turned off (released), the IN1 signal and the IN2 signal become H level. As a result, the IN1a signal and the IN2a signal become H level. As a result, the FB1 output and the FB2 output are turned on. Then, the power supply diagnosis 3 (stop input) is performed. Further, the change between the IN1a signal and the output FB1 is detected, and the gate cutoff control unit 321 is diagnosed. In this case, since the state of change is normal, it is determined that the system 1 is normal. Further, the gate cutoff control unit 322 is diagnosed by detecting the change between the IN2a signal and the output FB2. In this case, since the state of change is normal, it is determined that the system 2 is normal. Further, since the change in the system 1 and the change in the system 2 are the same, it is determined that the operation of the duplex circuit is normal. After the diagnosis is completed, the state of the power conversion unit 10 changes from the output OFF state to the operable state.

(Effect of this embodiment)
In this embodiment, the following effects can be obtained.

In the present embodiment, as described above, the control power supply unit 50 (power supply diagnosis unit 40) has the arithmetic processing unit 20 in a state where the drive of the power conversion unit 10 is stopped when the input of the stop command changes. It is configured to perform circuit diagnosis. As a result, the control power supply is used not only when the power conversion device 100 is started, but also when the input of the stop command is changed, such as when the stop command is input based on the fact that the emergency stop button 300 is pressed. Since the circuit diagnosis of the unit 50 (power supply diagnosis unit 40) can be performed, the frequency of the circuit diagnosis of the control power supply unit 50 (power supply diagnosis unit 40) can be increased. As a result, it is possible to easily find a circuit failure of the control power supply unit 50 (power supply diagnosis unit 40), so that the reliability of stopping the power conversion unit 10 can be improved.

Further, in the present embodiment, as described above, the arithmetic processing unit 20 is at least when the input of the stop command is changed, when the stop command is input, and when the input of the stop command is canceled. On the other hand, it is configured to perform circuit diagnosis of the control power supply unit 50 (power supply diagnosis unit 40). As a result, after the stop command is input and the drive of the power conversion unit 10 is stopped, or before the input of the stop command is canceled and the drive of the power conversion unit 10 is restarted, the control power supply unit 50 ( The circuit diagnosis of the power supply diagnosis unit 40) can be performed.

Further, in the present embodiment, as described above, when a stop command is input to the arithmetic processing unit 20, the circuit diagnosis of the control power supply unit 50 (power supply diagnosis unit 40) is performed based on the stop signal from the stop unit 30. Is configured to do. As a result, the change in the input of the stop command can be reliably acquired by the arithmetic processing unit 20, so that the circuit diagnosis can be reliably performed when the stop command is input.

Further, in the present embodiment, as described above, the stop signal includes a stop command signal from the command input units 311 and 312 and a feedback signal from the gate cutoff control units 321 and 322. As a result, the circuit diagnosis of the control power supply unit 50 (power supply diagnosis unit 40) can be started based on both the stop command signal and the feedback signal, so that the drive of the power conversion unit 10 is reliably stopped. Therefore, the circuit diagnosis of the control power supply unit 50 (power supply diagnosis unit 40) can be performed.

Further, in the present embodiment, as described above, when the input of the stop command is canceled, the arithmetic processing unit 20 performs the circuit diagnosis of the control power supply unit 50 (power supply diagnosis unit 40), and then the power conversion unit 10 It is configured to restart the drive of. As a result, the circuit failure of the control power supply unit 50 (power supply diagnosis unit 40) can be detected before the drive of the power conversion unit 10 is restarted, so that the drive of the power conversion unit 10 is restarted with the circuit failure. Can be suppressed.

Further, in the present embodiment, as described above, when the stop command is input, the arithmetic processing unit 20 diagnoses the stop unit 30 in addition to the circuit diagnosis of the control power supply unit 50 (power supply diagnosis unit 40). Configure to do. Thereby, whether or not the stop unit 30 operates normally with respect to the input of the stop command can be diagnosed together with the circuit diagnosis of the control power supply unit 50 (power supply diagnosis unit 40).

(Modification example)
It should be noted that the embodiments disclosed this time are exemplary in all respects and are not considered to be restrictive. The scope of the present invention is shown by the scope of claims rather than the description of the above-described embodiment, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims.

For example, in the above embodiment, an example of the configuration in which the input of the stop command is changed by the operation of the emergency stop button is shown, but the present invention is not limited to this. In the present invention, the input of the stop command may be changed by other than the operation of the emergency stop button.

Further, in the above embodiment, an example of the configuration in which the power conversion device converts electric power into three-phase alternating current is shown, but the present invention is not limited to this. In the present invention, for example, the power conversion device may be configured to convert electric power into single-phase alternating current. Further, the circuit configuration of the power conversion device is not limited to the circuit configuration of the embodiment.

10 Power conversion unit 20 Arithmetic processing unit 30 Stop unit 50 Control power supply unit (power supply unit)
100 Power converter 311, 312 Command input unit 321, 322 Gate cutoff control unit Sa, Sb, Sc, Sd, Se, Sf Semiconductor switching element

Claims (3)

A power conversion unit that includes a semiconductor switching element and converts power,
An arithmetic processing unit that generates a control signal for controlling the semiconductor switching element, and
A stop unit that stops the drive of the power conversion unit when a stop command is input, and a stop unit.
A power supply unit that supplies electric power to the arithmetic processing unit and the stop unit is provided.
The arithmetic processing unit diagnoses a failure of the cutoff circuit of the power supply unit in a state where the drive of the power conversion unit is stopped based on the stop signal from the stop unit when the stop command is input. It is configured to perform circuit diagnosis of the power supply unit, which is a diagnosis of whether or not an abnormality in the output voltage from the power supply unit can be detected .
The stop unit includes a command input unit to which the stop command is input and a cutoff unit that cuts off the supply of electric power to the power conversion unit based on the stop command signal from the command input unit.
The stop signal is feedback from the cutoff unit that feeds back the stop command signal from the command input unit and the signal transmitted from the cutoff unit to the power conversion unit based on the stop command signal to the cutoff unit. A power converter , including a signal . The first aspect of the present invention, wherein the arithmetic processing unit performs circuit diagnosis of the power supply unit when the input of the stop command is canceled, and then restarts the drive of the power conversion unit. Power converter. The power conversion according to claim 1 or 2 , wherein the arithmetic processing unit is configured to perform diagnosis of the stop unit in addition to circuit diagnosis of the power supply unit when the stop command is input. Device.

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