Drive power supply for mechanical switch, power supply device, and deterioration diagnosis method

Abstract

The mechanical switch (4) is provided with a mechanical contact (40) and coils (42, 44) that open and close the mechanical contact (40) by receiving the supply of the drive current from the drive power source (30). The drive power supply (30) is provided with 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 in order to turn on / off the mechanical switch (4), whereby a drive current is supplied from the capacitors (C1, C2) to the coils (42, 44). The drive power supply (30) is further provided with: a charging circuit (36) that charges the capacitors (C1, C2) during the OFF period of the switches (320, 340); detection circuits (52, 54) for detecting 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) on the basis of the detected charging current and voltage.

Description

Technical Field

[0001] The present disclosure relates to a driving power supply for a mechanical switch, a power supply device, and a deterioration diagnosis method of a capacitor included in the driving power supply for the mechanical switch. Background Art

[0002] Japanese Patent Application Laid-Open No. 2013-50351 (Patent Document 1) discloses a deterioration diagnosis device for an electric double layer capacitor used in a power supply device such as an instantaneous power failure compensation device.

[0003] The degradation diagnosis device disclosed in Patent Document 1 comprises: a discharge circuit, which connects a sinusoidal wave load circuit to a charged electric double layer capacitor, applies a sinusoidal wave load and discharges the electric double layer capacitor; a current detection circuit, which detects the current flowing through the discharge circuit; a voltage detection circuit, which measures the voltage of the electric double layer capacitor being discharged through the discharge circuit; and a calculation unit, which calculates the impedance of the electric double layer capacitor using the detection current of the current detection circuit and the detection voltage of the voltage detection circuit.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2013-50351 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the above-mentioned degradation diagnosis device, it is necessary to connect a discharge circuit having a sinusoidal wave load circuit to the electric double layer capacitor. In addition, it is necessary to provide a sensor for detecting the current flowing through the discharge circuit and the voltage of the electric double layer capacitor during discharge, and a computing unit for calculating and processing the detection values ​​of these sensors. Therefore, there is a risk that the power supply device will be enlarged due to the degradation diagnosis device being installed in the power supply device. In addition, there is a risk that the cost will also increase due to the enlargement of the power supply device.

[0009] The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide a driving power supply, a power supply device, and a degradation diagnosis method for a mechanical switch that can diagnose the degradation state of a capacitor with a compact structure.

[0010] Means used to solve problems

[0011] A driving power supply in one embodiment of the present disclosure supplies a driving current to a mechanical switch. The mechanical switch includes a mechanical contact and a coil that opens and closes the mechanical contact in response to the supply of the driving current. The driving power supply includes a capacitor and a switch connected between the capacitor and the coil. The switch is configured to be temporarily turned on in order to turn the mechanical switch on or off, thereby supplying a driving current from the capacitor to the coil. The driving power supply also includes: a charging circuit that charges the capacitor while the switch is off; a detection circuit that detects the charging current and voltage of the capacitor; and a diagnostic circuit that diagnoses the deterioration state of the capacitor based on the charging current and voltage detected by the detection circuit.

[0012] A degradation diagnosis method according to one aspect of the present disclosure is a degradation diagnosis method for a capacitor included in a driving power supply that supplies a driving current to a mechanical switch. The mechanical switch includes a mechanical contact and a coil that receives the supply of the driving current and opens and closes the mechanical contact. The driving power supply includes a capacitor and a switch connected between the capacitor and the coil, and is configured to temporarily turn on the switch in order to turn the mechanical switch on or off, thereby supplying the driving current from the capacitor to the coil. The degradation diagnosis method comprises: a step of charging the capacitor during the off period of the switch; a step of detecting the charging current and voltage of the capacitor; and a step of diagnosing the degradation state of the capacitor based on the charging current and voltage.

[0013] Effects of the Invention

[0014] According to the present disclosure, the charging circuit of the capacitor installed in the driving power supply of the mechanical switch can be used to diagnose the degradation state of the capacitor based on the charging current and voltage of the capacitor. Therefore, there is no need to install a dedicated degradation diagnosis device, and the degradation state of the capacitor can be diagnosed with a miniaturized structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a diagram showing the configuration of a power supply device to which the driving power supply of the mechanical switch according to the first embodiment is applied.

[0016] Figure 2 It is a diagram showing an example of the hardware configuration of the control device.

[0017] Figure 3 This is a diagram showing a configuration example of a driving power source according to the first embodiment.

[0018] Figure 4 Yes means Figure 3 A circuit diagram showing an example of a circuit configuration of a drive circuit and a charging circuit.

[0019] Figure 5 It is a diagram for explaining the operation of the driving power supply.

[0020] Figure 6This is a diagram for explaining a first example of capacitor degradation diagnosis processing in a diagnosis circuit.

[0021] Figure 7 1 is a flowchart showing a deterioration diagnosis process of a capacitor in the driving power supply according to the first embodiment.

[0022] Figure 8 1 is a flowchart showing a deterioration diagnosis process of a capacitor in a driving power supply according to the second embodiment.

[0023] Fig. 9 It is a diagram for explaining a second example of the capacitor degradation diagnosis process in the diagnosis circuit. DETAILED DESCRIPTION

[0024] The embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, the same or corresponding parts in the drawings are denoted by the same reference numerals, and their description will not be repeated.

[0025] [Implementation Method 1]

[0026] <Power supply unit configuration>

[0027] Figure 1 FIG. 1 is a diagram showing the configuration of a power supply device to which the driving power supply of the mechanical switch of Embodiment 1 is applied. Figure 1 In the following, a transient voltage drop compensation device is described as an example of a power supply device.

[0028] like Figure 1 As shown, the instantaneous voltage drop compensation device includes an input terminal T1, an output terminal T2, a DC terminal T3, VCBs (Vacuum Circuit Breakers) 1, 5, 6, 21, a high-speed switch 2, a power converter 7, a transformer 20, an operating unit 22, a control device 23, and a drive power supply 30.

[0029] Input terminal T1 receives AC voltage VI of commercial frequency supplied from commercial AC power source 71. The instantaneous value of AC voltage VI is detected by control device 23. When AC voltage VI is lower than the lower limit value, control device 23 determines that an instantaneous voltage drop has occurred.

[0030] The output terminal T2 is connected to a load 72. The load 72 is driven by the AC voltage VO supplied from the output terminal T2. The instantaneous value of the AC voltage VO is detected by the control device 23.

[0031] The DC terminal T3 is connected to a 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 .

[0032] VCB1, high-speed switch 2 and VCB5 are connected in series between input terminal T1 and output terminal T2. VCB1 and 5 are connected during normal operation of the instantaneous voltage drop compensation device, and are disconnected during maintenance of the high-speed switch 2 or bypass power supply.

[0033] 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 the 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 (instantaneously low).

[0034] 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 (instantaneously low).

[0035] The semiconductor switch 3 has the characteristics of faster operation speed and lower withstand voltage compared to the mechanical switch 4. The mechanical switch 4 has the characteristics of slower operation speed and higher withstand voltage compared to the semiconductor switch 3. By connecting the semiconductor switch 3 and the mechanical switch 4 in series, a high-speed switch 2 is formed which is instantly disconnected when a momentary low occurs and has a high withstand voltage.

[0036] VCB6 is connected between the input terminal T1 and the output terminal T2. VCB6 is disconnected during normal operation of the instantaneous voltage drop compensation device, and is connected during bypass power supply, for example. When VCB6 is connected, an AC voltage VI is supplied from a commercial AC power source 71 to a load 72 via VCB6, so that the load 72 operates.

[0037] 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 the AC terminal 8b thereof is connected to the primary winding 20a of the transformer 20 via the fuse 9 and the reactor 11. The secondary winding 20b of the transformer 20 is connected to the node N1 between the high-speed switch 2 and VCB5 via VCB21. The instantaneous value of the AC voltage VAC appearing on the primary winding 20a of the transformer 20 is detected by the control device 23.

[0038] The bidirectional converter 8 is a well-known converter including a plurality of semiconductor switching elements and a plurality of diodes, and is controlled by, for example, 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, AC power can be converted into DC power, or vice versa, DC power can be converted into AC power.

[0039] 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 VCB1, the high-speed switch 2, VCB21, the transformer 20, the reactor 1N21 and the fuse 9 into DC power and stores it in the power storage device 73.

[0040] When the AC voltage VI is abnormal, 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. The AC power is supplied to the load 72 via the fuse 9, the reactor 11, the transformer 20, and the VCB 21 and 5.

[0041] Fuse 9 protects bidirectional converter 8 from overcurrent. Current detector 10 detects current IL flowing through reactor 11 and supplies control device 23 with signal ILf indicating the detected value.

[0042] Reactor 11 and capacitor 12 constitute an AC filter. This AC filter is a low-pass filter that allows commercial frequency current to pass and cuts off the switching frequency current generated in bidirectional converter 8. In other words, the AC filter converts the output voltage of bidirectional converter 8 into a sinusoidal AC voltage VAC.

[0043] The transformer 20 exchanges AC power between the node N1 and the power converter 7. The VCB 21 is turned on during normal operation of the instantaneous voltage drop compensation device, and is turned off during maintenance of the high-speed switch 2 or the power converter 7, for example.

[0044] The operation unit 22 includes a plurality of buttons, a plurality of switches, a display, etc. The user of the instantaneous voltage drop compensation device can instruct the start, stop, automatic operation, manual operation, etc. of the instantaneous voltage drop compensation device by operating the operation unit 22, or can set various conditions, etc. The operation unit 22 provides a signal indicating the user's instruction, etc. to the control device 23.

[0045] The control device 23 controls the entire instantaneous voltage drop compensation device based on the signal from the operation unit 22, the AC voltages VI, VO, VAC, the DC voltage VDC, the output signal ILf of the current detector 10, and the like.

[0046] 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 specified reference DC voltage VDCr.

[0047] When the AC voltage VI supplied from the commercial AC power source 71 is abnormal, 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.

[0048] Figure 2 2 is a diagram showing an example of the 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.

[0049] For example, Figure 2 As shown, the control device 23 is configured to include 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. A program is pre-stored in a part of the memory 232, and various functions can be realized by executing the program by the CPU 230.

[0050] Or, with Figure 2 Different from the example, at least a part of the control device 23 can be formed by a circuit such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit). In addition, at least a part of the control device 23 can also be formed by an analog circuit.

[0051] Return to Figure 1 The driving power supply 30 is controlled by the control device 23 to drive the mechanical switch 4. The driving power supply 30 is equipped with a capacitor for storing DC power, and uses the power stored in the capacitor to turn on the mechanical switch 4 when the AC voltage VI is normal, and to turn off the mechanical switch 4 when the AC voltage VI is abnormal.

[0052] The capacitor is required to have high reliability in order to instantly disconnect the mechanical switch 4 when the commercial AC power source 71 drops momentarily and to ensure the power supply to the load 72. Therefore, it is necessary to diagnose the deterioration state of the capacitor and take measures such as replacing the capacitor if the deterioration state is diagnosed to be worse.

[0053] In the present embodiment, the driving power supply 30 is configured to diagnose the degradation state of the capacitor in parallel with the driving of the mechanical switch 4. More specifically, the driving power supply 30 has a charging circuit for charging the capacitor with direct current power, and is configured to diagnose the degradation state of the capacitor during the charging process of the capacitor by the charging circuit. In this way, since the degradation diagnosis of the capacitor is performed using the existing charging circuit, there is no need to install a dedicated degradation diagnosis device in the instantaneous low voltage compensation device. Therefore, the degradation state of the capacitor can be diagnosed with a miniaturized structure.

[0054] <Drive power supply configuration>

[0055] Figure 3 FIG. 2 is a diagram showing a configuration example of the driving power source 30 according to the first embodiment. Figure 3 As shown, the driving power source 30 is configured to supply a driving current to the mechanical switch 4 .

[0056] The mechanical switch 4 includes a mechanical contact 40 and coils 42 and 44 for opening and closing the mechanical contact 40. The mechanical contact 40 is formed using an elastic material such as a spring.

[0057] The coil 42 receives the supply of the driving current Id1 from the driving power source 30, and opens the mechanical contact 40 by converting the electrical energy into mechanical energy. By opening the mechanical contact 40, the mechanical switch 4 is opened, and the energization of the mechanical switch 4 is stopped (opened). In the following description, the coil 42 is also referred to as a "opening coil" for opening the mechanical switch 4.

[0058] The coil 44 receives the supply of the driving current Id2 from the driving power source 30, and converts the electrical energy into mechanical energy to close the mechanical contact 40. By closing the mechanical contact 40, the mechanical switch 4 is turned on, and the power supply to the mechanical switch 4 is started (turned on). In the following description, the coil 42 is also referred to as a "turn-on coil" for turning on the mechanical switch 4.

[0059] The driving power source 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 .

[0060] The drive circuit 32 is a circuit for supplying a drive current Id1 to the opening coil 42. The drive circuit 32 includes a capacitor C1, a drive power switch section 320, a current detector 322, a drive current detection circuit 324, and a drive power control circuit 326.

[0061] Capacitor C1 is formed by connecting a plurality of electrolytic capacitor elements in series and / or in parallel. A positive terminal of capacitor C1 is connected to DC positive bus PL1, and a negative terminal of capacitor C1 is connected to DC negative bus NL1.

[0062] The driving power switch section 320 uses the power stored in the capacitor C1 to supply the driving current Id1 to the disconnecting coil 42. The driving power switch section 320 has a switch for controlling the supply and stop of the driving current Id1. The switch is turned on and off by the driving power control circuit 326. By turning on the switch, the driving current Id1 is supplied from the capacitor C1 to the disconnecting coil 42. By turning off the switch, the supply of the driving current Id1 to the disconnecting coil 42 is stopped.

[0063] The current detector 322 is provided at the DC positive bus PL1 or the DC negative bus NL1 between the driving power switch section 320 and the disconnecting coil 42 , and detects the driving current Id1 flowing through the disconnecting coil 42 .

[0064] The drive current detection circuit 324 receives a signal Id1 f indicating a detection value of the drive current Id1 from the current detector 322 , and supplies the received signal Id1 f to the charge control circuit 56 .

[0065] The driving power supply control circuit 326 controls the driving power supply switch section 320 based on the 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 of the input terminal T1. The power failure detection signal DET is at an L (logic low) level when the AC voltage VI supplied from the commercial AC power supply 71 is normal, and is at an H (logic high) level when the AC voltage VI is abnormal.

[0066] When the power failure detection signal DET is at L level, that is, when the AC voltage VI supplied from the commercial AC power source 71 is normal, the drive power control circuit 326 maintains the switch included in the drive power switch unit 320 in the off state. By maintaining the switch in the off state, the supply of the drive current Id1 to the disconnection coil 42 is stopped.

[0067] When the commercial AC power source 71 drops momentarily and the power failure detection signal DET changes from the L level to the H level, the driving power control circuit 326 temporarily turns on the switch included in the driving power switch section 320. While the switch is in the on state, the driving current Id1 is supplied to the disconnection coil 42. The disconnection coil 42 disconnects the mechanical contact 40 of the mechanical switch 4 by converting the electric energy based on the driving current Id1 into mechanical energy. By disconnecting the mechanical contact 40, the mechanical switch 4 is disconnected. The on period of the switch in the driving power switch section 320 is preset based on the electric energy required to disconnect the coil 42 in order to disconnect the mechanical contact 40.

[0068] 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 switch section 340, a current detector 342, a drive current detection circuit 344, and a drive power control circuit 346.

[0069] Capacitor C2 is formed by connecting a plurality of electrolytic capacitor elements in series and / or in parallel. The positive terminal of capacitor C2 is connected to DC positive bus PL2, and the negative terminal of capacitor C2 is connected to DC negative bus NL2. DC positive bus PL2 is electrically connected to DC positive bus PL1. DC negative bus NL2 is electrically connected to DC negative bus NL1.

[0070] The driving power switch section 340 uses the power stored in the capacitor C2 to supply the driving current Id2 to the connection coil 44. The driving power switch section 340 has a switch for controlling the supply and stop of the driving current Id2. The switch is turned on and off by the driving power control circuit 346. By turning on the switch, the driving current Id2 is supplied from the capacitor C2 to the connection coil 44. By turning off the switch, the supply of the driving current Id2 to the connection coil 44 is stopped.

[0071] The current detector 342 is provided at the DC positive bus PL2 or the DC negative bus NL2 between the driving power switch section 340 and the closing coil 44 , and detects the driving current Id2 flowing through the closing coil 44 .

[0072] The drive current detection circuit 344 receives a signal Id2 f indicating a detection value of the drive current Id2 from the current detector 342 , and supplies the received signal Id2 f to the charge control circuit 56 .

[0073] The driving power supply control circuit 346 controls the driving power supply switch section 340 based on the power failure detection signal DET from the power failure detection circuit 60 .

[0074] When the power failure detection signal DET is at H level, the drive power control circuit 346 maintains the switch included in the drive power switch unit 340 in the OFF state. By maintaining the switch in the OFF state, the supply of the drive current Id2 to the closing coil 44 is stopped.

[0075] When the power failure detection signal DET changes from the H level to the L level, the driving power supply control circuit 346 temporarily turns on the switch included in the driving power supply switch section 340. While the switch is in the on state, the driving current Id2 is supplied to the on coil 44. The on coil 44 converts the electric energy based on the driving current Id2 into mechanical energy, thereby closing the mechanical contact 40 of the mechanical switch 4. By closing the mechanical contact 40, the mechanical switch 4 is turned on. The on period of the switch in the driving power supply switch section 340 is preset based on the electric energy required to turn on the coil 44 in order to close the mechanical contact 40.

[0076] The charging circuit 36 ​​is a circuit for charging the capacitor C1 of the drive circuit 32 and the capacitor C2 of the drive circuit 34. In order to turn off the mechanical switch 4, the drive current Id1 is supplied from the drive circuit 32 to the disconnection coil 42, thereby reducing the amount of charge stored in the capacitor C1 and reducing the voltage between the terminals of the capacitor C1 (hereinafter referred to as "the voltage of the capacitor C1"). In order to turn on the mechanical switch 4, the drive current Id2 is supplied from the drive circuit 34 to the connection coil 44, thereby reducing the amount of charge stored in the capacitor C2 and reducing the voltage between the terminals of the capacitor C2 (hereinafter referred to as "the voltage of the capacitor C2"). The charging circuit 36 ​​is controlled by the charging control circuit 56 and supplies the charging current Ic to the capacitors C1 and C2. The charging current Ic is a constant current.

[0077] The charging circuit 36 ​​has a first charging mode for supplying a charging current Ic to the capacitor C1 to charge the capacitor C1, a second charging mode for supplying a charging current Ic to the capacitor C2 to charge the capacitor C2, and a third charging mode for supplying a charging current Ic to the capacitors C1 and C2 to charge the capacitors C1 and C2. Switching of the charging modes will be described in detail later.

[0078] 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.

[0079] 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 supplies the received signal Icf to the charging control circuit 56 .

[0080] 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 and V2f representing 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.

[0081] 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 and V2f of the charging voltage detection circuit 54 , the output signals Id1f and Idf of the drive current detection circuits 324 and 344 , and the power failure detection signal DET.

[0082] In one aspect, the charging control circuit 56 controls the charging circuit 36 ​​to charge the capacitor C1 in response to the stop of the supply of the driving current Id1 to the disconnection coil 42, that is, in response to the switch included in the driving power switch unit 320 being turned off. Specifically, the charging control circuit 56 controls the charging circuit 36 ​​to execute the first charging mode in response to the elapse of the switch on period from the moment when the power failure detection signal DET changes from the L level to the H level. The charging current Ic is supplied to the capacitor C1 to accumulate charge, and when the voltage V1 of the capacitor C1 reaches a predetermined upper limit value VH, the charging control circuit 56 controls the charging circuit 36 ​​to stop supplying the charging current Ic to the capacitor C1.

[0083] On the other hand, the charging control circuit 56 controls the charging circuit 36 ​​to charge the capacitor C2 according to the situation that the supply of the driving current Id2 to the closing coil 44 is stopped, that is, according to the situation that the switch included in the driving power switch unit 340 is turned off. Specifically, the charging control circuit 56 controls the charging circuit 36 ​​to execute the second charging mode according to the situation that the switch-on period has passed since the power failure detection signal DET changes from the H level to the L level. When the voltage V2 of the capacitor C2 reaches the upper limit value VH, the charging control circuit 56 controls the charging circuit 36 ​​to stop supplying the charging current Ic to the capacitor C2.

[0084] In addition, when the voltage V1 of the capacitor C1 and the voltage V2 of the capacitor C2 have not reached the upper limit value VH, the charging control circuit 56 controls the charging circuit 36 ​​to execute the third charging mode. The charging current Ic is supplied to store charges in the capacitors C1 and C2, and when the voltages V1 and V2 of the capacitors C1 and C2 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.

[0085] The charging control circuit 56 includes a diagnostic circuit 58 for diagnosing the degradation state of the capacitors C1 and C2. The diagnostic circuit 58 diagnoses the degradation state 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.

[0086] in addition, Figure 3The functions of the driving current detection circuit 324 and the driving power control circuit 326 in the driving circuit 32, the driving current detection circuit 344 and the driving power control circuit 346 in the driving circuit 34, the charging current detection circuit 52, the charging voltage detection circuit 54 and the charging control circuit 56 are determined by the control device 23 ( Figure 1 ) is implemented by at least one of software processing and hardware processing.

[0087] Figure 4 Yes means Figure 3 2 is a circuit diagram showing an example of the circuit configuration of the drive circuits 32 and 34 and the charging circuit 36.

[0088] like Figure 4 As shown, the drive circuit 32 is configured to include 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 freewheeling circuit 320a and a switch 320b.

[0089] 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 opening coil 42 is connected between the positive output terminal 32c and the negative output terminal 32d.

[0090] The diode D1 is connected between the positive input terminal 32a and the positive terminal of the capacitor C1. The diode D1 is a diode for backflow prevention.

[0091] The capacitor C1 can be represented by a series circuit of an electrostatic capacitance C and an ESR (equivalent series resistance) as a resistance component. In addition, an electrolytic capacitor has a characteristic that the electrostatic capacitance C decreases and the ESR increases as the deterioration progresses.

[0092] The discharge resistor R1 is connected between the positive terminal and the negative terminal 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 disconnection coil 42 and the charging circuit 36 ​​.

[0093] The freewheeling circuit 320a and the switch 320b are connected in series between the positive terminal and the negative terminal of the capacitor C1. Figure 3 The driving power supply switch section 320 is shown. A node N2 between the freewheeling circuit 320a and the switch 320b is connected to the negative output terminal 32d.

[0094] The switch 320b is a switch for controlling the supply and stop of the driving current Id1. The switch 320b is turned on and off by the driving power supply control circuit 326. By turning on the switch 320b, the driving current Id1 is supplied from the capacitor C1 to the disconnecting coil 42. The current detector 322 is inserted between the negative side output terminal 32d and the node N2 to detect the driving current Id1. By turning off the switch 320b, the supply of the driving current Id1 to the disconnecting coil 42 is stopped.

[0095] The freewheeling circuit 320a is a circuit for protecting the drive circuit 32 from the surge voltage generated when the switch 320b is turned off to stop supplying the drive current Id1 to the off coil 42. The freewheeling 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.

[0096] The drive circuit 34 has the same configuration as 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 freewheeling circuit 340a, and a switch 340b.

[0097] The positive input terminal 34a is connected to the DC positive bus PL2, and the negative input terminal 34b is connected to the DC negative bus NL2. A closing coil 44 is connected between the positive output terminal 34c and the negative output terminal 34d.

[0098] The diode D2 is connected between the positive input terminal 34a and the positive terminal of the capacitor C2. The diode D2 is a diode for backflow prevention.

[0099] The discharge resistor R2 is connected between the positive terminal and the negative terminal of the capacitor C2. The discharge resistor R2 is provided to discharge the charge stored in the capacitor C2 when the drive circuit 34, the closing coil 44, and the charging circuit 36 ​​are electrically disconnected.

[0100] The freewheeling circuit 340a and the switch 340b are connected in series between the positive terminal and the negative terminal of the capacitor C2. Figure 3 The driving power supply switch section 340 is shown. A node N3 between the freewheeling circuit 340a and the switch 340b is connected to the negative output terminal 34d.

[0101] The switch 340b is a switch for controlling the supply and stop of the driving current Id2. The switch 340b is turned on and off by the driving power supply control circuit 346. By turning on the switch 340b, the driving current Id2 is supplied from the capacitor C2 to the connection coil 44. The current detector 342 is inserted between the negative side output terminal 34d and the node N3 to detect the driving current Id2. By turning off the switch 340b, the supply of the driving current Id2 to the connection coil 44 is stopped.

[0102] The freewheeling circuit 340a is a circuit for protecting the drive circuit 34 from the surge voltage generated when the switch 340b is turned off to stop supplying the drive current Id2 to the connection coil 44. The freewheeling 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.

[0103] The charging circuit 36 ​​includes a battery 36a and a DC / DC converter 36b. The DC / DC converter 36b is controlled by a 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 that matches the lower voltage of the voltages V1 and V2. Since diodes D1 and D2 for reverse current blocking are provided in the drive circuits 32 and 34, the charging current Ic is supplied only to the capacitor with the lower voltage. In addition, 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 becomes approximately half of the charging current Ic supplied only to a single capacitor.

[0104] By controlling the output voltage of the DC / DC converter 36 b and the diodes D1 and D2 for backflow prevention, the charging circuit 36 ​​can automatically switch between the first charging mode, the second charging mode, and the third charging mode according to the voltages V1 and V2 .

[0105] The DC reactor L1 is inserted in the DC positive bus PL1 between the DC / DC converter 36 b and the drive circuit 32 , and smoothes the DC current supplied from the DC / DC converter 36 b .

[0106] <Drive power supply operation>

[0107] Next, the operation of the driving power source 30 according to the first embodiment will be described.

[0108] Figure 5 3 is a diagram for explaining the operation of the driving power supply 30. Figure 5 , waveforms showing time changes of the power failure detection signal DET, the switches 320 b and 340 b , the drive currents Id1 and Id2 , the voltages V1 and V2 of the capacitors C1 and C2 , and the charging current Ic are shown.

[0109] like Figure 5 As shown in FIG. 1 , at time t1, the commercial AC power source 71 is momentarily disconnected, so the power failure detection signal DET changes from the L level to the H level. In the drive circuit 32, the drive power control circuit 326 temporarily turns on the switch 320b according to the power failure detection signal DET changing from the L level to the H level. Figure 5 In the period from time t1 to time t2, the switch 320b is in the on state.

[0110] While the switch 320b is on, the drive current Id1 is supplied from the drive circuit 32 to the opening coil 42. The opening coil 42 converts the electric energy based on the drive current Id1 into mechanical energy to open the mechanical contact 40 of the mechanical switch 4. By opening the mechanical contact 40, the mechanical switch 4 is opened.

[0111] Before time t1, the voltage V1 of the capacitor C1 is maintained at a predetermined upper limit value VH. The voltage V1 of the capacitor C1 is proportional to the amount of charge stored in the capacitor C1. The upper limit value VH is set based on the amount of charge required to supply the drive current Id1 to the off coil 42 during the on period of the switch 320b.

[0112] During the period from time t1 to t2, the amount of charge stored in the capacitor C1 decreases as the drive current Id1 is supplied, so the voltage V1 of the capacitor C1 decreases. In response to the fact that the switch 320b is disconnected 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 that matches the voltage V1, which is the lower of the voltages V1 and V2, thereby supplying the charging current Ic to the capacitor C1. As a result, after time t2, charge is stored in the capacitor C1 and the voltage V1 gradually increases. In addition, since the charging current Ic is a constant current (current value I1), the voltage V1 increases linearly.

[0113] At time t3, the commercial AC power source 71 is restored, and the power failure detection signal DET changes from the L level to the H level. In the drive circuit 34, the drive power control circuit 346 temporarily turns on the switch 340b in response to the power failure detection signal DET changing from the H level to the L level. Figure 5 In the embodiment, during the period from time t3 to time t4, the switch 340b is in the on state. During the on period of the switch 340b, the drive current Id2 is supplied from the drive circuit 34 to the on coil 44. The on coil 44 converts the electrical energy based on the drive current Id2 into mechanical energy, thereby closing the mechanical contact 40 of the mechanical switch 4. By closing the mechanical contact 40, the mechanical switch 4 is turned on.

[0114] 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 the voltage V2 of the capacitor C2 decreases. In response to the switch 340b being turned off at time t4, the charging control circuit 56 controls the charging circuit 36 ​​to charge the capacitor C2.

[0115] exist Figure 5 In the example, at time t4, both voltages V1 and V2 have not reached the upper limit value VH, so 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 that matches the lower voltage of the voltages V1 and V2. Since the voltage V2 is lower than the voltage V1, after time t4, only the charging current Ic is supplied to the capacitor C2. As a result, charge is accumulated in the capacitor C2, and the voltage V2 increases linearly. On the other hand, after time t4, the supply of the charging current Ic to the capacitor C1 is stopped, so the voltage V1 maintains the value at time t4.

[0116] 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, charges are accumulated in the capacitors C1 and C2, so that the voltages V1 and V2 gradually increase. When the voltages V1 and V2 reach the upper limit value VH, the charging control circuit 56 stops the supply of the charging current Ic by stopping the charging circuit 36.

[0117] As described above, the driving power supply 30 supplies the driving currents Id1 and Id2 from the capacitors C1 and C2 to the coils 42 and 44, respectively, to open and close the mechanical contact 40, thereby turning on or off the mechanical switch 4. Then, after turning on or off the mechanical switch 4, the driving power supply 30 supplies the charging current Ic from the charging circuit 36 ​​to the capacitors C1 and C2 to charge the capacitors C1 and C2, so that the capacitors C1 and C2 store the power for driving the mechanical switch 4 next time.

[0118] During the charging process of the capacitors C1 and C2 , the diagnosis circuit 58 diagnoses the degradation state of the capacitors C1 and C2 based on 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 .

[0119] (Capacitor Deterioration Diagnosis)

[0120] Figure 6 1 is a diagram for explaining a first example of the capacitor degradation diagnosis process in the diagnosis circuit 58. Figure 6 Extract Figure 5The voltage V1 of the capacitor C1 and the charging current Ic are partially shown in FIG. Figure 6 , the degradation diagnosis process of the capacitor C1 is described.

[0121] like Figure 6 As shown in FIG. 1 , before time t2, the amount of charge stored in capacitor C1 decreases with the supply of drive current Id1, so the voltage V1 of capacitor C1 decreases. At time t2, charging circuit 36 ​​starts to supply 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.

[0122] The voltage V1 of the capacitor C1 changes by an amount ΔV2 at time t2 when the charging current Ic starts to be supplied. The amount of change ΔV2 is caused by a change in the magnitude of the current flowing through the ESR of the capacitor C1.

[0123] During the period from time t2 to time 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 measurement start time for diagnosis. VA corresponds to the voltage V1 of the capacitor C1 at the measurement start time (hereinafter also referred to as "measurement start voltage"). In addition, the time difference between time t2 and time ta is about several milliseconds, which is set so as not to include the change of the voltage V1 caused by ESR in the measurement result.

[0124] The diagnostic circuit 58 adds a predetermined amount ΔV1 to VA, and sets VB, which is the addition result, as 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 because the measurement result does not include the change in the voltage V1 caused by the ESR when the supply of the charging current Ic is stopped. The predetermined amount ΔV1 corresponds to an embodiment of the "first amount".

[0125] The diagnosis circuit 58 detects the time tb when 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 time.

[0126] 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. Then, the diagnostic circuit 58 calculates the charge amount Q accumulated in the capacitor C1 during the measurement period by integrating the charging current Ic during the measurement period. Figure 6In the example of , since the charging current Ic is a constant value I1, the charge amount Q is Q=I1×(tb-ta). The charge amount 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.

[0127] The diagnostic circuit 58 obtains the electrostatic 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 degradation state of the capacitor C1 based on the obtained electrostatic capacitance C. Electrolytic capacitors generally have a characteristic that the electrostatic capacitance C decreases due to degradation. The diagnostic circuit 58 diagnoses the degradation state of the capacitor C1 based on, for example, the change amount of the current electrostatic capacitance C relative to the electrostatic capacitance C when the capacitor C1 is in the initial state.

[0128] Figure 7 1 is a flowchart showing a deterioration diagnosis process of the capacitor in the driving power supply 30 according to the first embodiment. Figure 7 The flowchart is repeatedly executed by the charging control circuit 56 in the control device 23 at a predetermined control cycle when the driving power supply 30 is in operation. Figure 7 The steps of the deterioration diagnosis process of capacitor C1 are shown in FIG. Figure 7 The same steps are also performed in parallel with the degradation diagnosis process of the capacitor C2.

[0129] like Figure 7 As shown, the charging control circuit 56 determines whether the switch 320b included in the driving power switch section 320 of the driving circuit 32 has been turned off through step (hereinafter simply referred to as "S") 01. In S01, if the on-period of the switch 320b has passed since the power failure detection signal DET changed from the L level to the H level, S01 determines yes. If the power failure detection signal DET is at the L level or the H level, or if the on-period has not passed, S01 determines no.

[0130] When it is determined that the switch 320b is turned off (YES in S01), the charging control circuit 56 proceeds to S02 to control 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 that matches the lower voltage V1 of the voltages V1 and V2, thereby supplying a charging current Ic to the capacitor C1.

[0131] During the charging process 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 S03 .

[0132] In S04, the diagnosis circuit 58 detects the voltage V1 at the measurement start time ta after the charging start time of the capacitor C1, and sets the detected value as the measurement start voltage VA. Next, in S05, the diagnosis circuit 58 adds a predetermined amount ΔV1 to the measurement start voltage VA, thereby setting the measurement end voltage VB.

[0133] In S06, the diagnosis circuit 58 detects the measurement end time tb when the voltage V1 reaches the measurement end voltage VB. In S07, the diagnosis circuit 58 integrates the charging current Ic during the period from the measurement start time ta to the measurement end time tb, thereby calculating the charge amount Q accumulated in the capacitor C1 during this period.

[0134] In S08, the diagnostic circuit 58 divides the calculated charge amount Q by a predetermined amount ΔV1 to obtain the capacitance C of the capacitor C1 (C=Q / ΔV1). In S09, the diagnostic circuit 58 diagnoses the discharge degradation state of the capacitors C1 and C2 based on the capacitance C obtained in S07.

[0135] In S10, the charge control circuit 56 determines whether the voltage V1 of the capacitor C1 is equal to or greater than the upper limit value VH. If V1<VH (No determination in S10), the charge control circuit 56 continues to charge the capacitor C1.

[0136] When V1 ≥ VH (YES determination in S10 ), the charging control circuit 56 controls the charging circuit 36 ​​in S11 to stop supplying the charging current Ic to the capacitor C1 , thereby completing the charging of the capacitor C1 .

[0137] As described above, in the driving power supply 30 of the first embodiment, during the charging process of the capacitors C1 and C2 included in the driving power supply 30 of the mechanical switch 4, the degradation state of the capacitors C1 and C2 is diagnosed based on 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. Thus, the degradation state of the capacitors C1 and C2 can be diagnosed by using the charging circuit 36 ​​and the charging control circuit 56 already provided in the driving power supply 30, so there is no need to install a dedicated degradation diagnosis device in the instantaneous voltage drop compensation device. Therefore, the degradation state of the capacitors C1 and C2 can be diagnosed with a compact structure.

[0138] [Implementation Method 2]

[0139] In the first embodiment described above, when charging capacitors C1 and C2 in preparation for the next drive of mechanical switch 4 by drive power source 30 , the deterioration state of capacitors C1 and C2 is diagnosed based on charging current Ic and voltages V1 and V2 of capacitors C1 and C2 .

[0140] In the above configuration, since a relatively large charging current Ic is supplied to each capacitor, the voltage of each capacitor changes greatly in response to the charging current Ic. Therefore, the influence of the charging current detection circuit 52 and the charging voltage detection circuit 54 on the detection error is reduced, and as a result, the electrostatic capacitance of each capacitor can be calculated with high accuracy. In addition, since the degradation diagnosis is performed each time the capacitors C1 and C2 are charged, the rapid degradation of the capacitors C1 and C2 caused by the spark generated when the capacitors C1 and C2 are discharged can be detected.

[0141] However, on the other hand, when the frequency of the instantaneous drop of the commercial AC power source 71 is low, the frequency of the driving power source 30 driving the mechanical switch 4 becomes low. Therefore, in the configuration described in Embodiment 1, the frequency of performing the degradation diagnosis of the capacitors C1 and C2 also becomes low. In this case, there is a risk that it is difficult to detect the time-dependent degradation of the capacitors C1 and C2. Even when the frequency of the instantaneous drop of the commercial AC power source 71 is low, in order to ensure the charge storage capacity of the capacitors C1 and C2 to prevent the occurrence of the instantaneous drop, it is also required to regularly diagnose the degradation state of the capacitors C1 and C2.

[0142] Therefore, in the second embodiment, a configuration for periodically diagnosing the degradation state of the capacitors C1 and C2 in the standby state of the driving power supply 30 will be described. In addition, the configuration of the driving power supply 30 of the second embodiment is similar to that of the first embodiment except for the configuration of the diagnosis circuit 58. Figure 3 and Figure 4 The configuration of the driving power source 30 shown is the same, and therefore the description thereof will be omitted.

[0143] Figure 8 1 is a flowchart showing a deterioration diagnosis process of the capacitor in driving power supply 30 according to the second embodiment. Figure 8 The flowchart is in Figure 1 During normal operation of the instantaneous voltage drop compensation device shown, the charging control circuit 56 in the control device 23 repeatedly executes the control cycle in a predetermined manner. Figure 8 The steps of the deterioration diagnosis process of capacitor C1 are shown in FIG. Figure 8 The same steps are also performed in parallel with the degradation diagnosis process of the capacitor C2.

[0144] like Figure 8 As shown, the charging control circuit 56 is connected with Figure 7 Similarly, at S01 , it is determined whether the switch 320 b included in the driving power switch section 320 of the driving circuit 32 is turned off.

[0145] When it is determined that the switch 320b is turned off (YES in S01), the charging control circuit 56 enters the Figure 7In the same S02, the charging circuit 36 ​​is controlled to charge the capacitor C1. During the charging process of the capacitor C1, the charging control circuit 56 controls the charging control circuit 56 by Figure 7 Similarly, at S03 , the charging current Ic and the voltage V1 of the capacitor C1 are detected based on the output signals of the charging current detection circuit 52 and the charging voltage detection circuit 54 .

[0146] Through Figure 7 Similarly, in S10, the charge control circuit 56 determines whether the voltage V1 of the capacitor C1 is equal to or greater than the upper limit value VH. If V1<VH (No determination in S10), the charge control circuit 56 continues to charge the capacitor C1.

[0147] When V1 ≥ VH (“YES” in S10), the charging control circuit 56 Figure 7 The same S11 controls the charging circuit 36 ​​to stop supplying the charging current Ic to the capacitor C1, thereby terminating the charging of the capacitor C1.

[0148] Returning to S01, when the switch 320b is not turned off (when S01 is determined as "No"), the charging control circuit 56 enters S21 to determine whether the drive circuit 32 is in the standby state. In S21, based on the output signal V1f of the charging voltage detection circuit 54, if the voltage V1 of the capacitor C1 is greater than the upper limit value VH, S21 determines "Yes". If the voltage V1 is less than the upper limit value VH, S21 determines "No".

[0149] When the drive circuit 32 is in the standby state (when the determination of "yes" in S21), the charging control circuit 56 determines whether a predetermined period has passed since the last time the degradation of the capacitor C1 was diagnosed through S22. In S22, the charging control circuit 56 has a timing function and measures the elapsed time since the last time the degradation diagnosis was performed. If the elapsed time has not reached the predetermined period (for example, 1 month), S22 determines "no". If the elapsed time has reached the predetermined period, S22 determines "yes".

[0150] When a predetermined period has passed since the last time the degradation diagnosis of the capacitor C1 was performed (when the judgment of "yes" is made in S22), the charging control circuit 56 enters S23 and controls the charging circuit 36 ​​to charge the capacitor C1. In S23, the charging control circuit 56 charges the capacitor C1 in such a way that the voltage V1 of the capacitor C1 increases by a predetermined amount ΔV3. When the drive circuit 32 is in the standby state, the voltage V1 of the capacitor C1 is above the upper limit value VH. Therefore, the capacitor C1 may become overcharged by the charging in S23. Since the capacitor C1 becomes overcharged, an excessive driving current Id1 is supplied to the disconnection coil 42 when the drive circuit 32 is actuated, and there is a risk of the mechanical contact 40 rebounding. From the viewpoint of avoiding such a situation, the predetermined amount ΔV3 is set to a small voltage that does not affect the operation of the drive circuit 32. The predetermined amount ΔV3 corresponds to an embodiment of the "second amount".

[0151] During the charging process 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 .

[0152] Through Figure 7 Similarly, at S04, the diagnosis circuit 58 detects the voltage V1 at the measurement start time ta after the charging start time of the capacitor C1, and sets the detected value as the measurement start voltage VA. Figure 7 Similarly, at S05 , the diagnosis circuit 58 adds a predetermined amount ΔV3 to the measurement start voltage VA to thereby set the measurement end voltage VB.

[0153] Through Figure 7 Similarly, in S06, the diagnosis circuit 58 detects the measurement end time tb when the voltage V1 reaches the measurement end voltage VB. Figure 7 Similarly, at S07 , the diagnosis circuit 58 integrates the charging current Ic during the period from the measurement start time ta to the measurement end time tb, thereby calculating the charge amount Q accumulated in the capacitor C1 during the period.

[0154] Through Figure 7 Similarly, at S08, the diagnostic circuit 58 divides the calculated charge amount Q by a predetermined amount ΔV3, thereby obtaining the electrostatic capacitance C of the capacitor C1 (C = Q / ΔV3). Figure 7 Similarly, in S09 , the diagnosis circuit 58 diagnoses the discharge degradation state of the capacitors C1 , C2 based on the electrostatic capacitance C obtained in S07 .

[0155] In addition, the degradation diagnosis process of the capacitors C1 and C2 in the second embodiment may be implemented in combination with the degradation diagnosis process of the capacitors C1 and C2 in the first embodiment. That is, when the driving power supply 30 is in the operating state of driving the mechanical switch 4, the degradation diagnosis process of the first embodiment is implemented when the capacitors C1 and C2 are charged, and when the driving power supply 30 is in the standby state, the degradation diagnosis process of the second embodiment is implemented.

[0156] In this way, the deterioration state of the capacitors C1 and C2 can be appropriately diagnosed without depending on the frequency of occurrence of the instantaneous drop of the commercial AC power source 71. That is, when the frequency of occurrence of the commercial AC power source 71 is high, the rapid deterioration of the capacitors C1 and C2 caused by sparks during repeated discharge can be detected. In addition, when the frequency of occurrence of the instantaneous drop of the commercial AC power source 71 is low, the time-dependent deterioration of the capacitors C1 and C2 can be detected.

[0157] [Implementation method 3]

[0158] In the above-mentioned first and second embodiments, the configuration for calculating the electrostatic capacitance C of each capacitor in order to diagnose the degradation state of the capacitors C1 and C2 is described. In the third embodiment, the configuration for calculating the ESR of each capacitor is described.

[0159] Fig. 9 4 is a diagram for explaining a second example of the capacitor degradation diagnosis process in the diagnosis circuit 58. Fig. 9 Extract Figure 5 The voltage V1 of the capacitor C1, the drive current Id1, and the charging current Ic are partially shown. Fig. 9 , the degradation diagnosis process of the capacitor C1 is described.

[0160] like Fig. 9 As shown in FIG. 1 , before time t2, the amount of charge stored in capacitor C1 decreases with the supply of drive current Id1, so the voltage V1 of capacitor C1 decreases. At time t2, charging circuit 36 ​​starts to supply 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.

[0161] The voltage V1 of the capacitor C1 changes by ΔV2 at time t2. The change ΔV2 is caused by a change in the magnitude of the current flowing through the ESR of the capacitor C1 due to the stop of the supply of the drive current Id1 from the capacitor C1 and the start of the supply of the charging current Ic to the capacitor C1.

[0162] That is, the change ΔV2 is the sum of the change ΔV21 caused by stopping the supply of the drive current Id1 and the 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 is equivalent to the decrease in the voltage V1, and ΔV22 is equivalent to the increase in the voltage V1.

[0163] The diagnosis circuit 58 detects the change ΔV2 based on the output signal of the charging voltage detection circuit 54, and obtains the ESR by dividing the detected change ΔV2 by the sum of the drive current Id1 and the charging current Ic. The drive current Id1 has a negative value, and the charging current Ic has a positive value.

[0164] The diagnosis circuit 58 diagnoses the degradation state of the capacitor C1 based on the obtained electrostatic capacitance C. Electrolytic capacitors generally have a characteristic that ESR increases due to degradation. The diagnosis circuit 58 diagnoses the degradation state of the capacitor C1 based on, for example, the amount of change in the current ESR relative to the ESR when the capacitor C1 is in the initial state.

[0165] In addition, Fig. 9 In the above, an example of calculating the ESR based on the increase ΔV3 of the voltage V1 at time t2 when the charging current Ic starts to be supplied to the capacitor C1 is described, but the ESR may be calculated based on the change ΔV4 of the voltage V1 at time t4 when the charging current Ic stops being supplied to the capacitor C1. ΔV4 has a magnitude equal to the product of the ESR and the value I1 of the charging current Ic (ESR×I1). ΔV4 corresponds to the amount of reduction by which the voltage V1 is reduced.

[0166] In addition, in the above-mentioned embodiments 1 to 3, the configuration example of the driving power supply for supplying driving current to the mechanical switch included in the power supply device is described, but the driving power supply disclosed in the present invention is not limited to the power supply device, and can also be applied to a device including a mechanical switch. When applied to any device, the deterioration state of the capacitor included in the driving power supply can be diagnosed without enlarging the device.

[0167] The embodiments disclosed herein should be considered to be illustrative in all aspects and not restrictive. The scope of the present disclosure is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0168] Description of Reference Numerals

[0169] 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 operating unit, 23 control device, 30 driving power supply, 32, 34 driving 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 disconnect coil, 44 connect 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 freewheeling 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 inductor, R1, R2 discharge resistors, D1, D2 diodes, Id1, Id2 drive current, Ic charging current, DET power failure detection signal.

Claims

1. A driving power supply for a mechanical switch, supplying a driving current to the mechanical switch, wherein: The mechanical switch includes a mechanical contact and a coil, and the coil receives the drive current to open and close the mechanical contact. The driving power supply comprises: Capacitors; as well as a switch connected between the capacitor and the coil, the switch being configured to be temporarily turned on in order to turn the mechanical switch on or off, thereby supplying the drive current from the capacitor to the coil, The driving power supply also has: a charging circuit, for charging the capacitor during the off period of the switch; A detection circuit, detecting the charging current and voltage of the capacitor; as well as The diagnosis circuit diagnoses a deterioration state of the capacitor based on the charging current and the voltage detected by the detection circuit.

2. The driving power supply of the mechanical switch according to claim 1, wherein: The charging circuit charges the capacitor during the off period after the switch is temporarily turned on. During the charging process of the capacitor, the diagnostic circuit, By integrating the charging current during a period in which the voltage of the capacitor increases by a first amount, the amount of charge accumulated in the capacitor during the period is calculated, calculating the electrostatic capacitance of the capacitor by dividing the calculated charge amount by the first amount, Based on the calculated electrostatic capacitance, a deterioration state of the capacitor is diagnosed.

3. The driving power supply of the mechanical switch according to claim 1 or 2, wherein: The charging circuit charges the capacitor so that the voltage of the capacitor increases by a second amount when the switch is off and a predetermined period has elapsed since the last diagnosis. During the charging process of the capacitor, the diagnostic circuit, By integrating the charging current during a period in which the voltage of the capacitor increases by the second amount, the amount of charge accumulated in the capacitor during the period is calculated, calculating the electrostatic capacitance of the capacitor by dividing the calculated charge amount by the second amount, Based on the calculated electrostatic capacitance, a deterioration state of the capacitor is diagnosed.

4. The driving power supply of the mechanical switch according to claim 1, wherein: The diagnostic circuit, calculating an equivalent series resistance of the capacitor based on the amount of change in the voltage due to the charging current at the start or end of charging of the capacitor, Based on the calculated equivalent series resistance, a degradation state of the capacitor is diagnosed.

5. A power supply device comprising: 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; as well as a driving power supply, receiving an instruction from the control device, and supplying a driving current to the mechanical switch; The mechanical switch includes a mechanical contact and a coil, and the coil receives the drive current to open and close the mechanical contact. The driving power supply comprises: capacitors; and a switch connected between the capacitor and the coil, the switch being configured to be temporarily turned on in order to turn the mechanical switch on or off, thereby supplying the drive current from the capacitor to the coil, The driving power supply also includes: a charging circuit for charging the capacitor during the off period of the switch; A detection circuit for detecting the charging current and voltage of the capacitor; and The diagnosis circuit diagnoses degradation of the capacitor based on the charging current and the voltage detected by the detection circuit.

6. A degradation diagnosis method for a capacitor included in a driving power supply for supplying a driving current to a mechanical switch, wherein: The mechanical switch includes a mechanical contact and a coil, and the coil receives the drive current to open and close the mechanical contact. The driving power source includes a capacitor and a switch connected between the capacitor and the coil, and is configured to temporarily turn on the switch in order to turn on or off the mechanical switch, thereby supplying the driving current from the capacitor to the coil. The degradation diagnosis method comprises the following steps: charging the capacitor during an off period of the switch; detecting the charging current and voltage of the capacitor; and A deterioration state of the capacitor is diagnosed based on the charging current and the voltage.

7. The degradation diagnosis method according to claim 6, wherein: The charging step includes: during the off period after the switch is temporarily turned on, charging the capacitor; The diagnostic steps include the following steps: In a charging process of the capacitor, by integrating the charging current during a period in which the voltage of the capacitor increases by a first amount, an amount of charge accumulated in the capacitor during the period is calculated; calculating the electrostatic capacitance of the capacitor by dividing the calculated charge amount by the first amount; and Based on the calculated electrostatic capacitance, a deterioration state of the capacitor is diagnosed.

8. The degradation diagnosis method according to claim 6 or 7, wherein: The charging step includes: when the switch is off and a predetermined period has passed since the last diagnosis, the capacitor is charged so that the voltage of the capacitor is increased by a second amount; The diagnostic steps include the following steps: In a charging process of the capacitor, by integrating the charging current during a period in which the voltage of the capacitor increases by the second amount, an amount of charge accumulated in the capacitor during the period is calculated; calculating the electrostatic capacitance of the capacitor by dividing the calculated charge amount by the second amount; and Based on the calculated electrostatic capacitance, a deterioration state of the capacitor is diagnosed.

9. The degradation diagnosis method according to claim 6, wherein: The diagnostic steps include the following steps: calculating an equivalent series resistance of the capacitor based on an amount of change in the voltage due to the charging current at the start or end of charging of the capacitor; and Based on the calculated equivalent series resistance, a degradation state of the capacitor is diagnosed.

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