Mechanical switch drive power supply, power supply device, and deterioration diagnosis method

Abstract

The mechanical switch (4) includes a mechanical contact (40) and coils (42, 44) that open and close the mechanical contact (40) upon receiving a drive current from the drive power source (30). The drive power source (30) includes capacitors (C1, C2) and switches (320, 340) connected between the capacitors (C1, C2) and the coils (42, 44). The switches (320, 340) are temporarily turned on to turn the mechanical switch (4) on and off, thereby supplying a drive current from the capacitors (C1, C2) to the coils (42, 44). The driving power supply (30) further includes a charging circuit (36) that charges the capacitors (C1, C2) while the switches (320, 340) are off, detection circuits (52, 54) that detect the charging current and voltage of the capacitors (C1, C2), and a diagnosis circuit (58) that diagnoses the deterioration state of the capacitors (C1, C2) from the detected charging current and voltage.

Description

[Technical field]

[0001] The present disclosure relates to a drive power supply for a mechanical switch, a power supply device, and a degradation diagnosis method for a capacitor included in the drive power supply for a mechanical switch. [Background technology]

[0002] JP 2013-50351 A (Patent Document 1) discloses a degradation diagnosis device for an electric double layer capacitor used in a power supply device such as a momentary dip compensation device.

[0003] The degradation diagnosis device disclosed in Patent Document 1 includes a discharge circuit that connects a sine wave load circuit to a charged electric double layer capacitor and applies a sine wave load to discharge the electric double layer capacitor, a current detection circuit that detects the current flowing through the discharge circuit, a voltage detection circuit that measures the voltage of the electric double layer capacitor during discharging via the discharge circuit, and a calculation unit that calculates the impedance of the electric double layer capacitor using the current detected by the current detection circuit and the voltage detected by the voltage detection circuit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-50351 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned degradation diagnosis device, it is necessary to connect a discharge circuit having a sine wave load circuit to the electric double layer capacitor. It is also necessary to install sensors for detecting the current flowing through the discharge circuit and the voltage of the electric double layer capacitor during discharging, and a calculator for processing the detection values ​​of these sensors. Therefore, there is a concern that the power supply device will become larger when the degradation diagnosis device is implemented in the power supply device. There is also a concern that the cost will increase due to the larger size of the power supply device.

[0006] The present disclosure has been made in consideration of the above problems, and has an object to provide a driving power supply for a mechanical switch, a power supply device, and a degradation diagnosis method that are capable of diagnosing the degradation state of a capacitor with a compact configuration. [Means for solving the problem]

[0007] A driving power supply according to an embodiment of the present disclosure supplies a driving current to a mechanical switch. The mechanical switch includes a mechanical contact and a coil that receives the driving current to open and close the mechanical contact. The driving power supply includes a capacitor and a switch connected between the capacitor and the coil. The switch is configured to supply a driving current from the capacitor to the coil by being temporarily turned on to turn the mechanical switch on or off. The driving power supply further includes a charging circuit that charges the capacitor during an off period of the switch, a detection circuit that detects a charging current and a voltage of the capacitor, and a diagnosis circuit that diagnoses a deterioration state of the capacitor from the charging current and the voltage detected by the detection circuit.

[0008] A degradation diagnosis method according to one aspect of the present disclosure is a degradation diagnosis method for a capacitor included in a drive power supply that supplies a drive current to a mechanical switch. The mechanical switch includes a mechanical contact and a coil that receives a drive current and opens and closes the mechanical contact. The drive power supply includes a capacitor and a switch connected between the capacitor and the coil, and is configured to supply the drive current from the capacitor to the coil by temporarily turning on the switch to turn the mechanical switch on or off. The degradation diagnosis method includes the steps of charging the capacitor during an off period of the switch, detecting a charging current and a voltage of the capacitor, and diagnosing a degradation state of the capacitor from the charging current and the voltage. Effect of the Invention

[0009] According to the present disclosure, the deterioration state of a capacitor can be diagnosed from the charging current and voltage of the capacitor by utilizing a capacitor charging circuit mounted on the drive power supply of a mechanical switch. This makes it unnecessary to mount a dedicated deterioration diagnosis device, and makes it possible to diagnose the deterioration state of the capacitor with a compact configuration. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing a configuration of a power supply device to which a drive power supply for a mechanical switch in accordance with a first embodiment is applied; [Diagram 2] FIG. 2 is a diagram illustrating an example of a hardware configuration of a control device. [Diagram 3] FIG. 2 is a diagram showing a configuration example of a driving power supply according to the first embodiment. [Figure 4] 4 is a circuit diagram showing an example of the circuit configuration of a drive circuit and a charging circuit shown in FIG. 3. [Diagram 5] FIG. 4 is a diagram for explaining the operation of a driving power supply. [Figure 6] 5 is a diagram for explaining a first example of a deterioration diagnosis process for a capacitor in a diagnosis circuit. FIG. [Figure 7] 5 is a flowchart showing a degradation diagnosis process for a capacitor in the driving power supply according to the first embodiment. [Figure 8] 10 is a flowchart showing a degradation diagnosis process for a capacitor in a driving power supply according to the second embodiment. [Figure 9] 13 is a diagram for explaining a second example of the degradation diagnosis process of the capacitor in the diagnosis circuit. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals and the description thereof will not be repeated.

[0012] [Embodiment 1] <Power supply configuration> Fig. 1 is a diagram showing the configuration of a power supply device to which a drive power supply for a mechanical switch according to embodiment 1 is applied. In Fig. 1, a momentary sag compensation device will be described as an example of the power supply device.

[0013] As shown in FIG. 1, the instantaneous sag compensation device includes an input terminal T1, an output terminal T2, a DC terminal T3, VCBs (Vacuum Circuit Breakers) 1, 5, 6, and 21, a high-speed switch 2, a power converter 7, a transformer 20, an operation unit 22, a control device 23, and a drive power supply 30.

[0014] The input terminal T1 receives an AC voltage VI of a commercial frequency supplied from a commercial AC power source 71. The instantaneous value of the AC voltage VI is detected by the control device 23. When the AC voltage VI falls below a lower limit value, the control device 23 determines that a momentary sag (momentary voltage drop) has occurred.

[0015] The output terminal T2 is connected to a load 72. The load 72 is driven by an AC voltage VO supplied from the output terminal T2. The instantaneous value of the AC voltage VO is detected by the control device 23.

[0016] The DC terminal T3 is connected to the power storage device 73. The power storage device 73 stores DC power. The power storage device 73 may be a battery or a capacitor. The DC voltage VDC of the DC terminal T3 is detected by the control device 23.

[0017] VCB1, high-speed switch 2, and VCB5 are connected in series between input terminal T1 and output terminal T2. VCB1 and VCB5 are turned on during normal operation of the instantaneous voltage sag compensation device and turned off, for example, during maintenance of high-speed switch 2 or during bypass power supply.

[0018] The high-speed switch 2 includes a semiconductor switch 3 and a mechanical switch 4 connected in series. The semiconductor switch 3 is controlled by a control device 23, and is turned on when the AC voltage VI is normal, and is turned off when the AC voltage VI is abnormal (during a momentary sag).

[0019] The mechanical switch 4 is driven by a driving power supply 30. The driving power supply 30 is controlled by the control device 23, and drives the mechanical switch 4 to the ON state when the AC voltage VI is normal, and drives the mechanical switch 4 to the OFF state when the AC voltage VI is abnormal (during a momentary drop).

[0020] The semiconductor switch 3 has the characteristics of a faster operating speed and a lower withstand voltage than the mechanical switch 4. The mechanical switch 4 has the characteristics of a slower operating speed and a higher withstand voltage than the semiconductor switch 3. By connecting the semiconductor switch 3 and the mechanical switch 4 in series, a high-speed switch 2 that instantly turns off when a voltage sag occurs and has a high withstand voltage is configured.

[0021] The VCB6 is connected between the input terminal T1 and the output terminal T2. The VCB6 is turned off during normal operation of the instantaneous sag compensation device, and turned on during, for example, bypass power supply. When the VCB6 is turned on, an AC voltage VI is supplied from the commercial AC power supply 71 to the load 72 via the VCB6, and the load 72 is operated.

[0022] The power converter 7 includes a bidirectional converter 8, a fuse 9, a current detector 10, a reactor 11, and a capacitor 12. The DC terminal 8a of the bidirectional converter 8 is connected to the DC terminal T3, and its AC terminal 8b is connected to a primary winding 20a of a transformer 20 via the fuse 9 and the reactor 11. The secondary winding 20b of the transformer 20 is connected to a node N1 between the high-speed switch 2 and the VCB 5 via a VCB 21. The instantaneous value of the AC voltage VAC appearing in the primary winding 20a of the transformer 20 is detected by a control device 23.

[0023] The bidirectional converter 8 is a well-known device including a plurality of semiconductor switching elements and a plurality of diodes, and is controlled, for example, by PWM (Pulse Width Modulation) by the control device 23. By turning on and off each semiconductor switching element included in the bidirectional converter 8 at a predetermined frequency, it becomes possible to convert AC power to DC power, and conversely, to convert DC power to AC power.

[0024] When the AC voltage VI supplied from the commercial AC power supply 71 is normal, the bidirectional converter 8 converts the AC power supplied from the commercial AC power supply 71 via the VCB 1, the high-speed switch 2, the VCB 21, the transformer 20, the reactor 1N21, and the fuse 9 into DC power and stores it in the power storage device 73.

[0025] Moreover, when the AC voltage VI is not normal, the bidirectional converter 8 converts the DC power of the power storage device 73 into AC power and outputs it to the AC terminal 8b. This AC power is supplied to the load 72 via the fuse 9, the reactor 11, the transformer 20, and the VCBs 21 and 5.

[0026] The fuse 9 protects the bidirectional converter 8 from an overcurrent. The current detector 10 detects a current IL flowing through the reactor 11, and provides the control device 23 with a signal ILf indicating the detected value.

[0027] The reactor 11 and the capacitor 12 constitute an AC filter. This AC filter is a low-pass filter that passes a commercial frequency current and blocks a switching frequency current generated in the bidirectional converter 8. In other words, the AC filter converts the output voltage of the bidirectional converter 8 into a sinusoidal AC voltage VAC.

[0028] The transformer 20 transmits and receives AC power between the node N1 and the power converter 7. The VCB 21 is turned on during normal operation of the instantaneous sag compensation device, and is turned off, for example, during maintenance of the high-speed switch 2 or the power converter 7.

[0029] The operation unit 22 includes a plurality of buttons, a plurality of switches, a display, etc. A user of the voltage sag compensation device can operate the operation unit 22 to give instructions for starting, stopping, automatic operation, manual operation, etc. of the voltage sag compensation device, and to set various conditions, etc. The operation unit 22 provides a signal indicating the user's instructions, etc. to the control device 23.

[0030] The control device 23 controls the entire instantaneous sag compensation device based on signals from the operation unit 22, AC voltages VI, VO, and VAC, DC voltage VDC, output signal ILf of the current detector 10, and the like.

[0031] When the AC voltage VI supplied from the commercial AC power supply 71 is normal, the control device 23 controls the bidirectional converter 8 based on the AC voltage VAC, the DC voltage VDC, and the output signal ILf of the current detector 10, so that the DC voltage VDC at the DC terminal T3 becomes a predetermined reference DC voltage VDCr.

[0032] When the AC voltage VI supplied from the commercial AC power supply 71 is not normal, the control device 23 controls the bidirectional converter 8 so that the AC voltage VO at the output terminal T2 becomes a predetermined reference AC voltage VOr.

[0033] 2 is a diagram showing an example of a hardware configuration of the control device 23. Typically, the control device 23 can be configured by a microcomputer in which a predetermined program is stored in advance.

[0034] 2, the control device 23 includes a CPU (Central Processing Unit) 230, a memory 232, and an input / output (I / O) circuit 234. The CPU 230, the memory 232, and the I / O circuit 234 can exchange data with each other via a bus 236. Programs are stored in advance in a partial area of ​​the memory 232, and various functions can be realized by the CPU 230 executing the programs.

[0035] Alternatively, unlike the example of Fig. 2, at least a part of the control device 23 can be configured using a circuit such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit). Also, at least a part of the control device 23 can be configured using an analog circuit.

[0036] Returning to Fig. 1, the driving power supply 30 is controlled by the control device 23 and drives the mechanical switch 4. The driving power supply 30 is equipped with a capacitor that stores DC power, and uses the power stored in the capacitor to turn on the mechanical switch 4 when the AC voltage is VI and to turn off the mechanical switch 4 when the AC voltage VI is not normal.

[0037] High reliability is required for the capacitor in order to instantly turn off the mechanical switch 4 when a momentary drop occurs in the commercial AC power supply 71 and ensure the power supply to the load 72. Therefore, it is necessary to diagnose the deterioration state of the capacitor, and if it is diagnosed that the deterioration state is progressing, it is necessary to take measures such as replacing the capacitor.

[0038] In this embodiment, the driving power supply 30 is configured to diagnose the deterioration state of the capacitor in parallel with driving the mechanical switch 4. More specifically, the driving power supply 30 has a charging circuit for charging the capacitor with DC power, and is configured to diagnose the deterioration state of the capacitor while the capacitor is being charged by this charging circuit. Since the deterioration diagnosis of the capacitor is performed using an existing charging circuit in this way, there is no need to mount a dedicated deterioration diagnosis device on the instantaneous dip compensation device. Therefore, it is possible to diagnose the deterioration state of the capacitor with a compact configuration.

[0039] <Drive power supply configuration> 3 is a diagram showing an example of the configuration of the driving power supply 30 according to embodiment 1. As shown in FIG.

[0040] The mechanical switch 4 includes a mechanical contact 40, and coils 42 and 44 that open and close the mechanical contact 40. The mechanical contact 40 is formed using an elastic material such as a spring.

[0041] The coil 42 receives a drive current Id1 from the drive power supply 30 and converts electrical energy into mechanical energy to open the mechanical contact 40. When the mechanical contact 40 is opened, the mechanical switch 4 is turned off and the current flow through the mechanical switch 4 is stopped (opened). In the following description, the coil 42 is also referred to as an “open coil” for turning off the mechanical switch 4.

[0042] The coil 44 receives a drive current Id2 from the drive power supply 30 and converts electrical energy into mechanical energy to close the mechanical contact 40. Closing the mechanical contact 40 turns on the mechanical switch 4, and starts (closes) the passage of electricity through the mechanical switch 4. In the following description, the coil 42 is also referred to as a "closing coil" for turning on the mechanical switch 4.

[0043] The driving power supply 30 includes driving circuits 32 and 34, a charging circuit 36, a current detector 50, a charging current detection circuit 52, a charging voltage detection circuit 54, a charging control circuit 56, and a power failure detection circuit 60.

[0044] The drive circuit 32 is a circuit for supplying a drive current Id1 to the open coil 42. The drive circuit 32 includes a capacitor C1, a drive power supply switch unit 320, a current detector 322, a drive current detection circuit 324, and a drive power supply control circuit 326.

[0045] The capacitor C1 is configured by connecting a plurality of electrolytic capacitor elements in series and / or parallel. The positive terminal of the capacitor C1 is connected to the DC positive bus PL1, and the negative terminal of the capacitor C1 is connected to the DC negative bus NL1.

[0046] The drive power switch unit 320 uses the power stored in the capacitor C1 to supply a drive current Id1 to the open coil 42. The drive power switch unit 320 has a switch for controlling the supply and stop of the drive current Id1. The on and off of this switch is controlled by a drive power control circuit 326. When the switch is turned on, the drive current Id1 is supplied from the capacitor C1 to the open coil 42. When the switch is turned off, the supply of the drive current Id1 to the open coil 42 is stopped.

[0047] The current detector 322 is provided on the DC positive bus PL1 or the DC negative bus NL1 between the drive power supply switch unit 320 and the open coil , and detects the drive current Id1 flowing through the open coil .

[0048] The drive current detection circuit 324 receives a signal Id1f indicating a detection value of the drive current Id1 from the current detector 322, and provides the received signal Id1f to the charge control circuit 56.

[0049] The drive power supply control circuit 326 controls the drive power supply switch unit 320 based on a power failure detection signal DET from the power failure detection circuit 60. The power failure detection circuit 60 generates the power failure detection signal DET based on the AC voltage VI at the input terminal T1. The power failure detection signal DET is set to an L (logical low) level when the AC voltage VI supplied from the commercial AC power supply 71 is normal, and is set to an H (logical high) level when the AC voltage VI is abnormal.

[0050] When the power failure detection signal DET is at an L level, that is, when the AC voltage VI supplied from the commercial AC power supply 71 is normal, the drive power supply control circuit 326 maintains the switch included in the drive power supply switch unit 320 in the OFF state. By maintaining the switch in the OFF state, the supply of the drive current Id1 to the open coil 42 is stopped.

[0051] When a momentary drop occurs in the commercial AC power supply 71 and the power failure detection signal DET transitions from L level to H level, the drive power supply control circuit 326 temporarily turns on a switch included in the drive power supply switch unit 320. During the period in which the switch is in the ON state, a drive current Id1 is supplied to the opening coil 42. The opening coil 42 converts electrical energy based on the drive current Id1 into mechanical energy, thereby opening the mechanical contact 40 of the mechanical switch 4. The mechanical switch 4 is turned off by opening the mechanical contact 40. The ON period of the switch in the drive power supply switch unit 320 is preset based on the electrical energy required by the opening coil 42 to open the mechanical contact 40.

[0052] The drive circuit 34 is a circuit for supplying a drive current Id2 to the closing coil 44. The drive circuit 34 includes a capacitor C2, a drive power supply switch unit 340, a current detector 342, a drive current detection circuit 344, and a drive power supply control circuit 346.

[0053] The capacitor C2 is configured by connecting a plurality of electrolytic capacitor elements in series and / or parallel. The positive terminal of the capacitor C2 is connected to the DC positive bus PL2, and the negative terminal of the capacitor C2 is connected to the DC negative bus NL2. The DC positive bus PL2 is electrically connected to the DC positive bus PL1. The DC negative bus NL2 is electrically connected to the DC negative bus NL1.

[0054] The drive power switch unit 340 uses the power stored in the capacitor C2 to supply a drive current Id2 to the closing coil 44. The drive power switch unit 340 has a switch for controlling the supply and stop of the drive current Id2. The on and off of this switch is controlled by a drive power control circuit 346. When the switch is turned on, the drive current Id2 is supplied from the capacitor C2 to the closing coil 44. When the switch is turned off, the supply of the drive current Id2 to the closing coil 44 is stopped.

[0055] The current detector 342 is provided on the DC positive bus PL2 or the DC negative bus NL2 between the drive power supply switch unit 340 and the closing coil 44, and detects the drive current Id2 flowing through the closing coil 44.

[0056] The drive current detection circuit 344 receives a signal Id2f indicating a detection value of the drive current Id2 from the current detector 342, and provides the received signal Id2f to the charge control circuit 56.

[0057] The drive power supply control circuit 346 controls the drive power supply switch section 340 based on a power failure detection signal DET from the power failure detection circuit 60 .

[0058] When the power failure detection signal DET is at H level, the drive power control circuit 346 maintains in the OFF state the switch included in the drive power switch unit 340. By maintaining the switch in the OFF state, the supply of the drive current Id2 to the closing coil 44 is stopped.

[0059] When the power failure detection signal DET transitions from H level to L level, the drive power supply control circuit 346 temporarily turns on a switch included in the drive power supply switch unit 340. During the period in which the switch is in the on state, a drive current Id2 is supplied to the closing coil 44. The closing coil 44 closes the mechanical contact 40 of the mechanical switch 4 by converting electrical energy based on the drive current Id2 into mechanical energy. Closing the mechanical contact 40 turns on the mechanical switch 4. The on period of the switch in the drive power supply switch unit 340 is preset based on the electrical energy required by the closing coil 44 to close the mechanical contact 40.

[0060] The charging circuit 36 ​​is a circuit for charging the capacitor C1 of the driving circuit 32 and the capacitor C2 of the driving circuit 34. By supplying a driving current Id1 from the driving circuit 32 to the opening coil 42 to turn off the mechanical switch 4, the amount of charge accumulated in the capacitor C1 decreases, and the terminal voltage of the capacitor C1 (hereinafter simply referred to as the "voltage of the capacitor C1") drops. By supplying a driving current Id2 from the driving circuit 34 to the closing coil 44 to turn on the mechanical switch 4, the amount of charge accumulated in the capacitor C2 decreases, and the terminal voltage of the capacitor C2 (hereinafter simply referred to as the "voltage of the capacitor C2") drops. The charging circuit 36 ​​is controlled by a charging control circuit 56 and supplies a charging current Ic to the capacitors C1 and C2. The charging current Ic is a constant current.

[0061] The charging circuit 36 ​​has a first charging mode in which the charging current Ic is supplied to the capacitor C1 to charge the capacitor C1, a second charging mode in which the charging current Ic is supplied to the capacitor C2 to charge the capacitor C2, and a third charging mode in which the charging current Ic is supplied to the capacitors C1 and C2 to charge the capacitors C1 and C2. The switching of the charging modes will be described in detail later.

[0062] The current detector 50 detects the charging current Ic flowing from the charging circuit 36 ​​to the corresponding capacitor in each of the first to third charging modes.

[0063] The charging current detection circuit 52 receives a signal Icf indicating a detection value of the charging current Ic from the current detector 50 , and provides the received signal Icf to a charging control circuit 56 .

[0064] The charging voltage detection circuit 54 detects instantaneous values ​​of the DC voltage V1 of the DC positive bus PL1 and the DC voltage V2 of the DC positive bus PL2, and provides signals V1f, V2f indicating the detected values ​​to the charging control circuit 56. The DC voltage V1 of the DC positive bus PL1 corresponds to the voltage of the capacitor C1. The DC voltage V2 of the DC positive bus PL2 corresponds to the voltage of the capacitor C2.

[0065] The charging control circuit 56 controls the charging circuit 36 ​​based on the output signal Icf of the charging current detection circuit 52, the output signals V1f, V2f of the charging voltage detection circuit 54, the output signals Id1f, Idf of the drive current detection circuits 324, 344, and the power failure detection signal DET.

[0066] In one aspect, the charge control circuit 56 controls the charge circuit 36 ​​to charge the capacitor C1 in response to the supply of the drive current Id1 to the open coil 42 being stopped, that is, in response to the switch included in the drive power switch unit 320 being turned off. Specifically, the charge control circuit 56 controls the charge circuit 36 ​​to execute the first charge mode in response to the elapse of the switch on period from the time point when the power failure detection signal DET transitions from the L level to the H level. When the charge current Ic is supplied to the capacitor C1 and the voltage V1 of the capacitor C1 reaches a predetermined upper limit value VH, the charge control circuit 56 controls the charge circuit 36 ​​to stop the supply of the charge current Ic to the capacitor C1.

[0067] In another aspect, the charge control circuit 56 controls the charge circuit 36 ​​to charge the capacitor C2 in response to the supply of the drive current Id2 to the closing coil 44 being stopped, that is, in response to the switch included in the drive power switch unit 340 being turned off. Specifically, the charge control circuit 56 controls the charge circuit 36 ​​to execute the second charge mode in response to the elapse of the switch on period from the time point when the power failure detection signal DET transitions from H level to L level. When the charge current Ic is received and the voltage V2 of the capacitor C2 reaches the upper limit value VH, the charge control circuit 56 controls the charge circuit 36 ​​to stop the supply of the charge current Ic to the capacitor C2.

[0068] If neither the voltage V1 of the capacitor C1 nor the voltage V2 of the capacitor C2 has reached the upper limit value VH, the charging control circuit 56 controls the charging circuit 36 ​​to execute the third charging mode. When the charging current Ic is supplied to the capacitors C1 and C2 and electric charge is accumulated in the capacitors C1 and C2, causing the voltages V1 and V2 of the capacitors C1 and C2 to reach the upper limit value VH, the charging control circuit 56 controls the charging circuit 36 ​​to stop supplying the charging current Ic to the capacitors C1 and C2.

[0069] The charging control circuit 56 includes a diagnostic circuit 58 for diagnosing the deterioration states of the capacitors C1 and C2. The diagnostic circuit 58 diagnoses the deterioration states of the capacitors C1 and C2 based on the output signal Icf of the charging current detection circuit 52 and the output signals V1f and V2f of the charging voltage detection circuit 54. The diagnostic circuit 58 will be described in detail later.

[0070] The functions of each block of the drive current detection circuit 324 and the drive power supply control circuit 326 in the drive circuit 32, the drive current detection circuit 344 and the drive power supply control circuit 346 in the drive circuit 34, the charging current detection circuit 52, the charging voltage detection circuit 54, and the charging control circuit 56 shown in FIG. 3 can be realized by at least one of software processing and hardware processing by the control device 23 (FIG. 1).

[0071] FIG. 4 is a circuit diagram showing an example of the circuit configuration of the drive circuits 32 and 34 and the charging circuit 36 ​​shown in FIG.

[0072] As shown in FIG. 4, the drive circuit 32 includes a positive input terminal 32a, a negative input terminal 32b, a positive output terminal 32c, a negative output terminal 32d, a diode D1, a capacitor C1, a discharge resistor R1, a freewheel circuit 320a, and a switch 320b.

[0073] The positive input terminal 32a is connected to the DC positive bus PL1, and the negative input terminal 32b is connected to the DC negative bus NL1. An open coil 42 is connected between the positive output terminal 32c and the negative output terminal 32d.

[0074] The diode D1 is connected between the positive input terminal 32a and the positive terminal of the capacitor C1. The diode D1 is a reverse current blocking diode.

[0075] Capacitor C1 can be represented as a series circuit of capacitance C and ESR (Equivalent Series Resistance), which is a resistance component. Note that electrolytic capacitors have the characteristic that as degradation progresses, the capacitance C decreases and the ESR increases.

[0076] The discharge resistor R1 is connected between the positive and negative terminals of the capacitor C1 and is provided to discharge the charge stored in the capacitor C1 when the drive circuit 32 is electrically disconnected from the open coil 42 and the charging circuit 36.

[0077] The freewheel circuit 320a and the switch 320b are connected in series between the positive terminal and the negative terminal of the capacitor C1. The freewheel circuit 320a and the switch 320b constitute the drive power switch unit 320 shown in Fig. 3. A node N2 between the freewheel circuit 320a and the switch 320b is connected to the negative output terminal 32d.

[0078] The switch 320b is a switch for controlling the supply and stop of the drive current Id1. The on and off of the switch 320b is controlled by the drive power supply control circuit 326. When the switch 320b is turned on, the drive current Id1 is supplied from the capacitor C1 to the open coil 42. The current detector 322 is interposed between the negative output terminal 32d and the node N2, and detects the drive current Id1. When the switch 320b is turned off, the supply of the drive current Id1 to the open coil 42 is stopped.

[0079] The freewheel circuit 320a is a circuit for protecting the drive circuit 32 from a surge voltage that occurs when the switch 320b is turned off to stop the supply of the drive current Id1 to the open coil 42. The freewheel circuit 320a is, for example, a diode having a cathode electrically connected to the positive output terminal 32c and an anode electrically connected to the negative output terminal 32d.

[0080] The drive circuit 34 has a similar configuration to the drive circuit 32. Specifically, the drive circuit 34 includes a positive input terminal 34a, a negative input terminal 34b, a positive output terminal 34c, a negative output terminal 34d, a diode D2, a capacitor C2, a discharge resistor R2, a freewheel circuit 340a, and a switch 340b.

[0081] The positive input terminal 34a is connected to a DC positive bus PL2, and the negative input terminal 34b is connected to a DC negative bus NL2. A closing coil 44 is connected between the positive output terminal 34c and the negative output terminal 34d.

[0082] The diode D2 is connected between the positive input terminal 34a and the positive terminal of the capacitor C2. The diode D2 is a reverse current blocking diode.

[0083] The discharge resistor R2 is connected between the positive and negative terminals of the capacitor C2 and is provided to discharge the charge stored in the capacitor C2 when the drive circuit 34 is electrically disconnected from the closing coil 44 and the charging circuit 36.

[0084] The freewheel circuit 340a and the switch 340b are connected in series between the positive terminal and the negative terminal of the capacitor C2. The freewheel circuit 340a and the switch 340b constitute the drive power switch unit 340 shown in Fig. 3. A node N3 between the freewheel circuit 340a and the switch 340b is connected to the negative output terminal 34d.

[0085] The switch 340b is a switch for controlling the supply and stop of the drive current Id2. The on and off of the switch 340b is controlled by the drive power supply control circuit 346. When the switch 340b is turned on, the drive current Id2 is supplied from the capacitor C2 to the closing coil 44. The current detector 342 is interposed between the negative output terminal 34d and the node N3, and detects the drive current Id2. When the switch 340b is turned off, the supply of the drive current Id2 to the closing coil 44 is stopped.

[0086] The free-wheel circuit 340a is a circuit for protecting the drive circuit 34 from a surge voltage that occurs when the switch 340b is turned off to stop the supply of the drive current Id2 to the closing coil 44. The free-wheel circuit 340a is, for example, a diode having a cathode electrically connected to the positive output terminal 34c and an anode electrically connected to the negative output terminal 34d.

[0087] The charging circuit 36 ​​includes a battery 36a and a DC / DC converter 36b. The DC / DC converter 36b is controlled by the charging control circuit 56 and generates a charging current Ic based on the DC power of the battery 36a. The DC / DC converter 36b outputs an output voltage according to the lower of the voltages V1 and V2. Since the drive circuits 32 and 34 are provided with reverse current blocking diodes D1 and D2, the charging current Ic is supplied only to the capacitor with the lower voltage. When the voltages V1 and V2 are equal to each other, the charging current Ic is supplied to the capacitors C1 and C2. In this case, the charging current Ic supplied to each capacitor is approximately half of the charging current Ic supplied to only a single capacitor.

[0088] By controlling the output voltage in this manner in the DC / DC converter 36b and by using the reverse current blocking diodes D1 and D2, the charging circuit 36 ​​is able to automatically switch between the first charging mode, the second charging mode, and the third charging mode according to the voltages V1 and V2.

[0089] The DC reactor L1 is inserted in the DC positive bus PL1 between the DC / DC converter 36b and the drive circuit 32, and smoothes the DC current supplied from the DC / DC converter 36b.

[0090] <Operation of the driving power supply> Next, the operation of the driving power supply 30 according to the first embodiment will be described.

[0091] Fig. 5 is a diagram for explaining the operation of the driving power supply 30. Fig. 5 shows waveforms representing the time changes of each of the power failure detection signal DET, the switches 320b and 340b, the driving currents Id1 and Id2, the voltages V1 and V2 of the capacitors C1 and C2, and the charging current Ic.

[0092] As shown in Fig. 5, at time t1, a momentary drop occurs in the commercial AC power supply 71, causing the power failure detection signal DET to transition from L level to H level. In the drive circuit 32, the drive power supply control circuit 326 temporarily turns on the switch 320b in response to the power failure detection signal DET transitioning from L level to H level. In Fig. 5, the switch 320b is in the ON state during the period from time t1 to t2.

[0093] During the on-period of this switch 320b, a drive current Id1 is supplied from the drive circuit 32 to the opening coil 42. The opening coil 42 converts electrical energy based on the drive current Id1 into mechanical energy, thereby opening the mechanical contact 40 of the mechanical switch 4. When the mechanical contact 40 is opened, the mechanical switch 4 is turned off.

[0094] Before time t1, the voltage V1 of the capacitor C1 is maintained at a predetermined upper limit VH. The voltage V1 of the capacitor C1 is proportional to the amount of charge stored in the capacitor C1. The upper limit VH is set based on the amount of charge required to supply the drive current Id1 to the open coil 42 during the ON period of the switch 320b.

[0095] During the period from time t1 to t2, the amount of charge stored in the capacitor C1 decreases with the supply of the drive current Id1, so that the voltage V1 of the capacitor C1 drops. In response to the switch 320b being turned off at time t2, the charging control circuit 56 controls the charging circuit 36 ​​to charge the capacitor C1. The DC / DC converter 36b included in the charging circuit 36 ​​outputs an output voltage in accordance with the lower voltage V1 of the voltages V1 and V2, so that the charging current Ic is supplied to the capacitor C1. As a result, after time t2, charge is accumulated in the capacitor C1 and the voltage V1 gradually increases. Note that since the charging current Ic is a constant current (current value I1), the voltage V1 increases linearly.

[0096] At time t3, the commercial AC power supply 71 is restored, and the power failure detection signal DET transitions from L level to H level. In the drive circuit 34, the drive power supply control circuit 346 temporarily turns on the switch 340b in response to the transition of the power failure detection signal DET from H level to L level. In FIG. 5, the switch 340b is in the ON state during the period from time t3 to t4. During the ON period of the switch 340b, a drive current Id2 is supplied from the drive circuit 34 to the closing coil 44. The closing coil 44 closes the mechanical contact 40 of the mechanical switch 4 by converting electrical energy based on the drive current Id2 into mechanical energy. Closing the mechanical contact 40 turns on the mechanical switch 4.

[0097] Before time t3, the voltage V2 of the capacitor C2 is maintained at the upper limit value VH. During the period from time t3 to t4, the amount of charge stored in the capacitor C2 decreases with the supply of the drive current Id2, so that the voltage V2 of the capacitor C2 drops. In response to the switch 340b being turned off at time t4, the charge control circuit 56 controls the charging circuit 36 ​​to charge the capacitor C2.

[0098] In the example of FIG. 5, since both of the voltages V1 and V2 have not reached the upper limit value VH at time t4, the charging control circuit 56 controls the charging circuit 36 ​​to charge the capacitors C1 and C2. Specifically, the DC / DC converter 36b included in the charging circuit 36 ​​outputs an output voltage according to the lower of the voltages V1 and V2. Since the voltage V2 is lower than the voltage V1, the charging current Ic is supplied only to the capacitor C2 after time t4. As a result, charge is accumulated in the capacitor C2, and the voltage V2 increases linearly. On the other hand, since the supply of the charging current Ic to the capacitor C1 is stopped after time t4, the voltage V1 maintains the value at time t4.

[0099] When the voltage V2 increases and becomes equal to the voltage V1 (time t5), the charging circuit 36 ​​supplies the charging current Ic to the capacitors C1 and C2. After time t5, the voltages V1 and V2 gradually increase as electric charge accumulates in the capacitors C1 and C2. When the voltages V1 and V2 reach the upper limit value VH, the charging control circuit 56 stops the charging circuit 36, thereby stopping the supply of the charging current Ic.

[0100] As described above, the driving power supply 30 supplies driving currents Id1, Id2 from the capacitors C1, C2 to the coils 42, 44, respectively, to open and close the mechanical contact 40, thereby turning on or off the mechanical switch 4. After turning on or off the mechanical switch 4, the driving power supply 30 supplies a charging current Ic from the charging circuit 36 ​​to the capacitors C1, C2 to charge the capacitors C1, C2 so that the capacitors C1, C2 store power for driving the mechanical switch 4 the next time.

[0101] While the capacitors C1, C2 are being charged, the diagnostic circuit 58 diagnoses the deterioration state of the capacitors C1, C2 based on the charging current Ic detected by the charging current detection circuit 52 and the voltages V1, V2 of the capacitors C1, C2 detected by the charging voltage detection circuit .

[0102] (Capacitor Deterioration Diagnosis) Fig. 6 is a diagram for explaining a first example of the deterioration diagnosis process of the capacitor in the diagnosis circuit 58. Fig. 6 shows a part of the waveform of the voltage V1 and the charging current Ic of the capacitor C1 shown in Fig. 5. The deterioration diagnosis process of the capacitor C1 will be explained with reference to Fig. 6.

[0103] 6, before time t2, the amount of charge stored in the capacitor C1 decreases with the supply of the drive current Id1, so that the voltage V1 of the capacitor C1 drops. At time t2, the charging circuit 36 ​​starts to supply the charging current Ic to the capacitor C1. After time t2, the charging circuit 36 ​​is controlled by the charging control circuit 56 to supply the charging current Ic having a constant value I1 to the capacitor C1.

[0104] The voltage V1 of the capacitor C1 changes by ΔV2 at time t2 when the supply of the charging current Ic starts. This change ΔV2 occurs due to a change in the magnitude of the current flowing through the ESR of the capacitor C1.

[0105] During the period from time t2 to t4, the voltage V1 increases linearly. The diagnostic circuit 58 detects the value VA of the voltage V1 at time ta after time t2 based on the output signal V1f of the charging voltage detection circuit 54. Time ta corresponds to the start time of measurement for diagnosis. VA corresponds to the voltage V1 of the capacitor C1 at the start time of measurement (hereinafter also referred to as the "measurement start voltage"). The time difference between time t2 and time ta is about several milliseconds, which is set so that fluctuations in the voltage V1 caused by ESR are not included in the measurement result.

[0106] The diagnostic circuit 58 adds a predetermined amount ΔV1 to VA, and sets the sum VB to the voltage V1 of the capacitor C1 at the end of the measurement (hereinafter also referred to as the "measurement end voltage") (VB=VA+ΔV1). The predetermined amount ΔV1 is set to, for example, about 1 / 2 to 1 / 3 of the rated voltage of the capacitor C1. This is to prevent fluctuations in the voltage V1 caused by the ESR when the supply of the charging current Ic is stopped from being included in the measurement result. The predetermined amount ΔV1 corresponds to one example of the "first amount".

[0107] The diagnostic circuit 58 detects the time tb at which the voltage V1 reaches the measurement end voltage VB, based on the output signal V1f of the charging voltage detection circuit 54. This time tb corresponds to the measurement end point.

[0108] Next, the diagnostic circuit 58 detects the charging current Ic during the measurement period from the measurement start time ta to the measurement end time tb based on the output signal Icf of the charging current detection circuit 52. The diagnostic circuit 58 then integrates the charging current Ic during the measurement period to calculate the amount of charge Q accumulated in the capacitor C1 during the measurement period. In the example of FIG. 6, since the charging current Ic is a constant value I1, the amount of charge Q is Q=I1×(tb−ta). Note that this amount of charge Q corresponds to the area of ​​the portion surrounded by the time ta and the time tb in the waveform of the charging current Ic.

[0109] The diagnostic circuit 58 obtains the capacitance C of the capacitor C1 by dividing the calculated charge amount Q by the change amount (predetermined amount ΔV1) of the voltage V1 during the measurement period (C=Q / ΔV1). Then, the diagnostic circuit 58 diagnoses the deterioration state of the capacitor C1 based on the obtained capacitance C. Electrolytic capacitors generally have a characteristic that the capacitance C decreases due to deterioration. The diagnostic circuit 58 diagnoses the deterioration state of the capacitor C1 based on, for example, the amount of change in the current capacitance C relative to the capacitance C when the capacitor C1 is in an initial state.

[0110] Fig. 7 is a flowchart showing deterioration diagnosis processing of the capacitor in the driving power supply 30 according to the first embodiment. The flowchart in Fig. 7 is repeatedly executed at a predetermined control period by the charge control circuit 56 in the control device 23 during operation of the driving power supply 30. Fig. 7 shows the procedure of deterioration diagnosis processing of the capacitor C1. The charge control circuit 56 also executes deterioration diagnosis processing of the capacitor C2 in parallel according to the same procedure as in Fig. 7.

[0111] 7, the charge control circuit 56 determines whether or not the switch 320b included in the drive power switch unit 320 of the drive circuit 32 has been turned off in step (hereinafter simply referred to as "S") 01. In S01, if the ON period of the switch 320b has elapsed since the power failure detection signal DET transitioned from L level to H level, a YES determination is made in S01. If the power failure detection signal DET is at L level or H level, or if the ON period has not elapsed, a NO determination is made in S01.

[0112] If it is determined that the switch 320b is turned off (YES in S01), the charging control circuit 56 proceeds to S02 and controls the charging circuit 36 ​​to charge the capacitor C1. In S02, the DC / DC converter 36b included in the charging circuit 36 ​​outputs an output voltage in accordance with the lower voltage V1 of the voltages V1 and V2, thereby supplying a charging current Ic to the capacitor C1.

[0113] During charging of the capacitor C1, the charging control circuit 56 detects the charging current Ic and the voltage V1 of the capacitor C1 based on the output signals of the charging current detection circuit 52 and the charging voltage detection circuit 54 by S03.

[0114] In step S04, diagnostic circuit 58 detects voltage V1 at measurement start time ta after the charging start time of capacitor C1, and sets the detected value as measurement start voltage VA. Next, in step S05, diagnostic circuit 58 adds a predetermined amount ΔV1 to measurement start voltage VA to set measurement end voltage VB.

[0115] In step S06, the diagnostic circuit 58 detects the measurement end time tb at which the voltage V1 reaches the measurement end voltage VB. In step S07, the diagnostic circuit 58 integrates the charging current Ic during the period from the measurement start time ta to the measurement end time tb to calculate the amount of charge Q stored in the capacitor C1 during that period.

[0116] In S08, the diagnostic circuit 58 obtains the capacitance C of the capacitor C1 by dividing the calculated charge amount Q by a predetermined amount ΔV1 (C = Q / ΔV1). In S09, the diagnostic circuit 58 diagnoses the deterioration state of the discharge of the capacitors C1 and C2 based on the capacitance C obtained in S07.

[0117] In S10, the charge control circuit 56 determines whether the voltage V1 of the capacitor C1 is equal to or higher than the upper limit value VH. When V1 < VH (when the determination in S10 is NO), the charge control circuit 56 continues to charge the capacitor C1.

[0118] When V1 ≥ VH (when the determination in S10 is YES), the charge control circuit 56 terminates the charging of the capacitor C1 by controlling the charging circuit 36 so as to stop the supply of the charging current Ic to the capacitor C1 in S11.

[0119] As described above, in the drive power source 30 according to the first embodiment, during the charging of the capacitors C1 and C2 included in the drive power source 30 of the mechanical switch 4, the deterioration state of the capacitors C1 and C2 is diagnosed from the charging current Ic detected by the charging current detection circuit 52 and the voltages V1 and V2 of the capacitors C1 and C2 detected by the charging voltage detection circuit 54. According to this, since the deterioration state of the capacitors C1 and C2 can be diagnosed by using the charging circuit 36 and the charge control circuit 56 already provided in the drive power source 30, it is not necessary to mount a dedicated deterioration diagnosis device on the transient voltage compensation device. Therefore, it is possible to diagnose the deterioration state of the capacitors C1 and C2 with a downsized configuration.

[0120] [Second Embodiment] In the above-described first embodiment, the configuration for diagnosing the deterioration state of the capacitors C1 and C2 from the charging current Ic and the voltages V1 and V2 of the capacitors C1 and C2 when charging the capacitors C1 and C2 in preparation for the next drive of the mechanical switch 4 by the drive power source 30 has been described.

[0121] In the above configuration, a relatively large charging current Ic is supplied to each capacitor, and the voltage of each capacitor changes significantly in response to this charging current Ic. This reduces the effect of detection errors by the charging current detection circuit 52 and the charging voltage detection circuit 54, and as a result, the capacitance of each capacitor can be calculated with high accuracy. In addition, deterioration diagnosis is performed every time the capacitors C1 and C2 are charged, making it possible to detect rapid deterioration of the capacitors C1 and C2 due to sparks that occur when the capacitors C1 and C2 are discharged.

[0122] However, on the other hand, in a situation where the frequency of occurrence of a momentary dip in the commercial AC power supply 71 is low, the driving power supply 30 drives the mechanical switch 4 less frequently. Therefore, in the configuration described in the first embodiment, the frequency of execution of the deterioration diagnosis of the capacitors C1 and C2 is also low. In such a case, there is a concern that it may become difficult to detect the deterioration over time of the capacitors C1 and C2. Even in a situation where the frequency of occurrence of a momentary dip in the commercial AC power supply 71 is low, in order to guarantee the charge storage capacity of the capacitors C1 and C2 in preparation for the occurrence of a momentary dip, it is required to periodically diagnose the deterioration state of the capacitors C1 and C2.

[0123] Therefore, in the second embodiment, a configuration will be described in which the deterioration states of the capacitors C1 and C2 are periodically diagnosed in the standby state of the driving power source 30. Note that the configuration of the driving power source 30 according to the second embodiment is the same as that of the driving power source 30 shown in Figs. 3 and 4 except for the configuration of the diagnostic circuit 58, and therefore a description thereof will be omitted.

[0124] Fig. 8 is a flowchart showing deterioration diagnosis processing of the capacitor in the driving power supply 30 according to the second embodiment. The flowchart in Fig. 8 is repeatedly executed at a predetermined control period by the charge control circuit 56 in the control device 23 during normal operation of the instantaneous sag compensation device shown in Fig. 1. Fig. 8 shows the procedure of deterioration diagnosis processing of the capacitor C1. The charge control circuit 56 also executes deterioration diagnosis processing of the capacitor C2 in parallel according to the same procedure as in Fig. 8.

[0125] As shown in FIG. 8, the charge control circuit 56 determines, by the same S01 as in FIG. 7, whether or not the switch 320b included in the drive power switch section 320 of the drive circuit 32 is turned off.

[0126] When it is determined that the switch 320b has been turned off (when YES is determined in S01), the charge control circuit 56 proceeds to S02, which is the same as in FIG. 7, and controls the charge circuit 36 to charge the capacitor C1. During the charging of the capacitor C1, the charge control circuit 56 detects the charge current Ic and the voltage V1 of the capacitor C1 based on the output signals of the charge current detection circuit 52 and the charge voltage detection circuit 54 by the same S03 as in FIG. 7.

[0127] By the same S10 as in FIG. 7, the charge control circuit 56 determines whether or not the voltage V1 of the capacitor C1 is equal to or higher than the upper limit value VH. When V1 < VH (when NO is determined in S10), the charge control circuit 56 continues to charge the capacitor C1.

[0128] When V1 ≥ VH (when YES is determined in S10), the charge control circuit 56 controls the charge circuit 36 to stop supplying the charge current Ic to the capacitor C1 by the same S11 as in FIG. 7, thereby ending the charging of the capacitor C1.

[0129] Returning to S01, when the switch 320b is not turned off (when NO is determined in S01), the charge control circuit 56 proceeds to S21 and determines whether or not the drive circuit 32 is in a standby state. In S21, when the voltage V1 of the capacitor C1 is equal to or higher than the upper limit value VH based on the output signal V1f of the charge voltage detection circuit 54, S21 is determined as YES. When the voltage V1 is less than the upper limit value VH, S21 is determined as NO.

[0130] When the drive circuit 32 is in a standby state (YES in S21), the charge control circuit 56 determines in S22 whether a predetermined period has passed since the capacitor C1 was last diagnosed for deterioration. In S22, the charge control circuit 56 has a clocking function and measures the time elapsed since the last deterioration diagnosis was performed. If the elapsed time has not reached the predetermined period (e.g., one month), NO is determined in S22. If the elapsed time has reached the predetermined period, YES is determined in S22.

[0131] If a predetermined period has elapsed since the previous degradation diagnosis of the capacitor C1 was performed (YES in S22), the charging control circuit 56 proceeds to S23 and controls the charging circuit 36 ​​to charge the capacitor C1. In S23, the charging control circuit 56 charges the capacitor C1 so as to increase the voltage V1 of the capacitor C1 by a predetermined amount ΔV3. When the drive circuit 32 is in a standby state, the voltage V1 of the capacitor C1 is equal to or higher than the upper limit value VH, so that the capacitor C1 may be overcharged by the charging in S23. If the capacitor C1 is overcharged, an excessive drive current Id1 is supplied to the open coil 42 during the operation of the drive circuit 32, and the mechanical contact 40 may rebound. In order to avoid such a situation, the predetermined amount ΔV3 is set to a minute voltage that does not affect the operation of the drive circuit 32. The predetermined amount ΔV3 corresponds to one embodiment of the "second amount".

[0132] During charging of the capacitor C1, the charging control circuit 56 detects the charging current Ic and the voltage V1 of the capacitor C1 based on the output signals of the charging current detection circuit 52 and the charging voltage detection circuit 54 at S24.

[0133] 7, diagnostic circuit 58 detects voltage V1 at measurement start time ta after charging of capacitor C1 starts, and sets the detected value as measurement start voltage VA. Next, diagnostic circuit 58 adds a predetermined amount ΔV3 to measurement start voltage VA, thereby setting measurement end voltage VB.

[0134] In S06, which is the same as in Fig. 7, the diagnostic circuit 58 detects the measurement end time tb at which the voltage V1 reaches the measurement end voltage VB. In S07, which is the same as in Fig. 7, the diagnostic circuit 58 integrates the charging current Ic during the period from the measurement start time ta to the measurement end time tb to calculate the amount of charge Q stored in the capacitor C1 during that period.

[0135] 7, the diagnostic circuit 58 calculates the capacitance C of the capacitor C1 by dividing the calculated charge amount Q by a predetermined amount ΔV3 (C=Q / ΔV3). In S09, the diagnostic circuit 58 diagnoses the deterioration state of the discharge of the capacitors C1 and C2 based on the capacitance C calculated in S07.

[0136] The degradation diagnosis process for the capacitors C1, C2 according to the second embodiment can be performed in combination with the degradation diagnosis process for the capacitors C1, C2 according to the first embodiment. That is, when the driving power source 30 is in an operating state for driving the mechanical switch 4, the degradation diagnosis process for the capacitors C1, C2 according to the first embodiment is performed during charging of the capacitors C1, C2, and when the driving power source 30 is in a standby state, the degradation diagnosis process for the second embodiment can be performed.

[0137] In this way, the deterioration state of the capacitors C1 and C2 can be appropriately diagnosed regardless of the frequency of occurrence of the momentary dip in the commercial AC power supply 71. That is, in a situation where the frequency of occurrence of the momentary dip in the commercial AC power supply 71 is high, it is possible to detect rapid deterioration of the capacitors C1 and C2 due to repeated sparks during discharge. Also, in a situation where the frequency of occurrence of the momentary dip in the commercial AC power supply 71 is low, it is possible to detect deterioration over time of the capacitors C1 and C2.

[0138] [Embodiment 3] In the above-mentioned first and second embodiments, the configuration for calculating the capacitance C of each capacitor in order to diagnose the degradation state of the capacitors C1 and C2 has been described. In the third embodiment, a configuration for calculating the ESR of each capacitor will be described.

[0139] Fig. 9 is a diagram for explaining a second example of the deterioration diagnosis process of the capacitor in the diagnosis circuit 58. Fig. 9 shows a part of the waveforms of the voltage V1, the drive current Id1, and the charging current Ic of the capacitor C1 shown in Fig. 5. The deterioration diagnosis process of the capacitor C1 will be explained with reference to Fig. 9.

[0140] 9, before time t2, the amount of charge stored in capacitor C1 decreases with the supply of drive current Id1, so that the voltage V1 of capacitor C1 drops. At time t2, charging circuit 36 ​​starts supplying charging current Ic to capacitor C1. After time t2, charging circuit 36 ​​is controlled by charging control circuit 56 to supply charging current Ic having a constant value I1 to capacitor C1.

[0141] At time t2, the voltage V1 of the capacitor C1 changes by ΔV2. This change ΔV2 occurs because the supply of the drive current Id1 from the capacitor C1 is stopped and the supply of the charging current Ic to the capacitor C1 is started, causing a change in the magnitude of the current flowing through the ESR of the capacitor C1.

[0142] That is, the amount of change ΔV2 is the sum of the amount of change ΔV21 caused by stopping the supply of the drive current Id1 and the amount of change ΔV22 caused by starting the supply of the charging current Ic (ΔV2=ΔV21+ΔV22). ΔV21 has a magnitude equal to the product of the ESR and the value of the drive current Id1 (ESR×Id1). ΔV22 has a magnitude equal to the product of the ESR and the value I1 of the charging current Ic (ESR×I1). ΔV21 corresponds to the amount of decrease by which the voltage V1 is decreased, and ΔV22 corresponds to the amount of increase by which the voltage V1 is increased.

[0143] The diagnostic circuit 58 detects the amount of change ΔV2 based on the output signal of the charging voltage detection circuit 54, and obtains the ESR by dividing the detected amount of change ΔV2 by the sum of the driving current Id1 and the charging current Ic. Note that the driving current Id1 has a negative value, and the charging current Ic has a positive value.

[0144] The diagnostic circuit 58 diagnoses the degradation state of the capacitor C1 based on the obtained capacitance C. An electrolytic capacitor generally has a characteristic that the ESR increases with degradation. The diagnostic circuit 58 diagnoses the degradation state of the capacitor C1 based on, for example, the amount of change in the current ESR with respect to the ESR when the capacitor C1 is in the initial state.

[0145] 9, an example of a configuration is described in which the ESR is calculated from the increase ΔV3 in the voltage V1 at time t2 when the supply of the charging current Ic to the capacitor C1 is started, but the ESR may be calculated from the change ΔV4 in the voltage V1 at time t4 when the supply of the charging current Ic to the capacitor C1 is stopped. ΔV4 has a magnitude equal to the product (ESR×I1) of the ESR and the value I1 of the charging current Ic. ΔV4 corresponds to the amount of reduction in the voltage V1.

[0146] In the above-mentioned first to third embodiments, the configuration example of the driving power supply that supplies a driving current to the mechanical switch included in the power supply device has been described, but the driving power supply according to the present disclosure is not limited to the power supply device and can be applied to devices that include a mechanical switch. When applied to any device, it is possible to diagnose the deterioration state of the capacitor included in the driving power supply without increasing the size of the device.

[0147] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the scope of the claims, and it is intended to include all modifications within the scope and meaning equivalent to the scope of the claims. [Explanation of symbols]

[0148] 1,5,6,21 VCB, 2 high-speed switch, 3 semiconductor switch, 4 mechanical switch, 7 power converter, 8 bidirectional converter, 9 fuse, 10,50,322,342 current detector, 11 reactor, 12,C1,C2 capacitor, 20 transformer, 20a primary winding, 20b secondary winding, 22 operation unit, 23 control device, 30 drive power supply, 32,34 drive circuit, 32a,34b positive input terminal, 32b,34b negative input terminal, 32c,34c positive output terminal, 32d,34d negative output terminal, 36 charging circuit, 36a battery, 36b DC / DC converter, 40 mechanical contact, 42 open coil, 44 closing coil, 52 charging current detection circuit, 54 charging voltage detection circuit, 56 charging control circuit, 58 diagnostic circuit, 60 Power failure detection circuit, 71 commercial AC power supply, 72 load, 73 power storage device, 230 CPU, 232 memory, 234 I / O circuit, 236 bus, 320, 340 drive power switch unit, 320a, 340a return circuit, 320b, 340b switch, 324, 344 drive current detection circuit, 326, 346 drive power control circuit, T1 input terminal, T2 output terminal, T3 DC terminal, PL1, PL2 DC positive bus, NL1, NL2 DC negative bus, L1 DC reactor, R1, R2 discharge resistor, D1, D2 diode, Id1, Id2 drive current, Ic charge current, DET power failure detection signal.

Claims

1. A drive power supply for supplying a drive current to a mechanical switch, the mechanical switch includes a mechanical contact and a coil that opens and closes the mechanical contact when supplied with the drive current; The driving power supply is A capacitor; a switch connected between the capacitor and the coil, the switch being configured to supply the drive current from the capacitor to the coil by being temporarily turned on to turn on or off the mechanical switch; The driving power supply is a charging circuit that charges the capacitor during an off period of the switch; a detection circuit for detecting a charging current and a voltage of the capacitor; a diagnosis circuit for diagnosing a deterioration state of the capacitor from the charging current and the voltage detected by the detection circuit, the charging circuit charges the capacitor so as to increase the voltage of the capacitor by a second amount when a predetermined period has elapsed since a previous diagnosis while the switch is off; During charging of the capacitor, the diagnostic circuit Integrating the charging current during the time period in which the voltage on the capacitor increases by the second amount. By doing so, the amount of charge stored in the capacitor during the period is calculated, Calculating the capacitance of the capacitor by dividing the calculated charge amount by the second amount; A drive power supply for a mechanical switch that diagnoses a deterioration state of the capacitor based on the calculated capacitance.

2. the charging circuit charges the capacitor during the off period after the switch is temporarily turned on, During charging of the capacitor, the diagnostic circuit calculating an amount of charge stored in the capacitor during a period in which the voltage of the capacitor increases by a first amount by integrating the charging current during that period; Calculating the capacitance of the capacitor by dividing the calculated amount of charge by the first amount; The drive power supply for a mechanical switch according to claim 1 , wherein a deterioration state of the capacitor is diagnosed based on the calculated capacitance.

3. The diagnostic circuitry includes: calculating an equivalent series resistance of the capacitor from an amount of change in the voltage based on the charging current at the start or end of charging of the capacitor; 2. The drive power supply for a mechanical switch according to claim 1, wherein a deterioration state of the capacitor is diagnosed based on the calculated equivalent series resistance.

4. a mechanical switch having a first terminal receiving an AC voltage supplied from an AC power source and a second terminal connected to a load; a power converter connected between the second terminal of the mechanical switch and a power storage device; a control device configured to turn on the mechanical switch when the AC power supply is normal and to turn off the mechanical switch when the AC power supply is abnormal; a drive power supply that receives an instruction from the control device and supplies a drive current to the mechanical switch; the mechanical switch includes a mechanical contact and a coil that opens and closes the mechanical contact when supplied with the drive current; The driving power supply is A capacitor; a switch connected between the capacitor and the coil, the switch being configured to supply the drive current from the capacitor to the coil by being temporarily turned on to turn on or off the mechanical switch; The driving power supply is a charging circuit that charges the capacitor during an off period of the switch; a detection circuit for detecting a charging current and a voltage of the capacitor; a diagnosis circuit for diagnosing deterioration of the capacitor based on the charging current and the voltage detected by the detection circuit, the charging circuit charges the capacitor so as to increase the voltage of the capacitor by a second amount when a predetermined period has elapsed since a previous diagnosis while the switch is off; During charging of the capacitor, the diagnostic circuit Integrating the charging current during the time period in which the voltage on the capacitor increases by the second amount. By doing so, the amount of charge stored in the capacitor during the period is calculated, Calculating the capacitance of the capacitor by dividing the calculated charge amount by the second amount; The power supply device diagnoses a deterioration state of the capacitor based on the calculated capacitance.

5. A method for diagnosing deterioration of a capacitor included in a drive power supply that supplies a drive current to a mechanical switch, comprising the steps of: the mechanical switch includes a mechanical contact and a coil that opens and closes the mechanical contact when supplied with the drive current; the drive power supply includes a capacitor and a switch connected between the capacitor and the coil, and is configured to supply the drive current from the capacitor to the coil by temporarily turning on the switch to turn on or off the mechanical switch; charging the capacitor during an off period of the switch; detecting a charging current and a voltage of the capacitor; diagnosing a deterioration state of the capacitor from the charging current and the voltage; the charging step includes the step of charging the capacitor so as to increase the voltage of the capacitor by a second amount when a predetermined period has elapsed since a previous diagnosis during an off period of the switch; The diagnosing step includes: calculating an amount of charge stored in the capacitor during a period in which the voltage of the capacitor increases by the second amount by integrating the charging current during that period; calculating the capacitance of the capacitor by dividing the calculated amount of charge by the second amount; and diagnosing a deterioration state of the capacitor based on the calculated capacitance.

6. the charging step includes the step of charging the capacitor during the off period after the switch is temporarily turned on, The diagnosing step includes: During charging of the capacitor, the charging current is integrated during a period in which the voltage of the capacitor increases by a first amount to calculate an amount of charge stored on the capacitor during that period. The step of issuing; calculating a capacitance of the capacitor by dividing the calculated amount of charge by the first amount; The degradation diagnosis method according to claim 5 , further comprising the step of diagnosing a degradation state of the capacitor based on the calculated capacitance.

7. The diagnosing step includes: calculating an equivalent series resistance of the capacitor from a change in the voltage based on the charging current at the start or end of charging of the capacitor; 6. The degradation diagnosis method according to claim 5, further comprising the step of diagnosing a degradation state of the capacitor based on the calculated equivalent series resistance.

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