JP6444749B2 - Switch device and switch short-circuit determination method - Google Patents

Description

  The present invention relates to a switch device including a pair of switches and a control unit that controls on and off of each of the switches, and a switch short-circuit determination method used in the switch device.

  2. Description of the Related Art In recent years, the use of electric power stored in a battery and using it as a power source has been spreading, including electric vehicles, and the importance of power conversion devices that charge and discharge the battery has increased. In a power converter that charges and discharges at a high voltage and / or a large current, the battery interface is opened and closed by a relay contact for safety.

  On the other hand, when a relay contact opens or closes a circuit to which a high voltage is applied or a circuit through which a large current flows, the contact may be welded by arc discharge, so it is possible to determine whether the relay contact is welded or not. It is very important to keep

  On the other hand, in Patent Document 1, when a pair of main relays provided in a power line connecting a secondary battery and a load composed of an inverter are alternately turned on, a voltage on the load side is detected. A relay welding detection device for determining whether or not a main relay on the opposite side of the main relay that has been turned on is welded is disclosed.

  Further, in Patent Document 2, when the contacts of the first and second main relays inserted in a pair of power supply lines between a direct current power source consisting of a battery and a load circuit are alternately turned off, A method and apparatus for detecting the welding of the main relay on the side opposite to the main relay turned off by detecting whether or not the voltage of the capacitor connected in parallel with the main relay is lowered is disclosed.

JP 2006-310219 A International Publication No. 2004/086696

  However, the techniques disclosed in Patent Documents 1 and 2 have a problem that they cannot be applied when the battery is not connected. Further, when one of the main relays is actually welded, the determination or detection of welding is not performed. Therefore, when the other main relay is turned on, a large current flows from the battery and the other main relay may be welded.

  The present invention has been made in view of such circumstances, and an object of the present invention is to determine whether a pair of switches are short-circuited individually and non-destructively even when a battery is not connected. It is an object of the present invention to provide a switch device and a method for determining a short circuit of a switch that can be determined automatically.

  The switch device according to the present invention is a switch device including a pair of switches and a control unit that controls on and off of each of the switches, a voltage applying unit that applies a voltage between one end of each of the switches, A voltage detection unit that detects a voltage between the one ends, and a circuit including a resistor, a capacitor, a second switch, or a combination thereof connected between the other ends of the switches, and the control And a means for alternately turning on the pair of switches sequentially, and a means for calculating a change amount or rate of change of the voltage detected by the voltage detector before and after turning on. And means for determining whether or not the amount of change or the rate of change calculated by the means is larger than a predetermined threshold value.

The switch device according to the present invention is a switch device including a pair of switches and a control unit that controls on and off of each of the switches, a voltage applying unit that applies a voltage between one end of each of the switches, the voltage detecting section for detecting a voltage between the one ends, or a current detection unit for detecting a current between said one ends, a resistor connected between the other ends of said switch respectively, a capacitor, first A circuit including two switches or a combination thereof, and the control unit alternately turns on the pair of switches sequentially, and the voltage detection unit detects each time the on unit is turned on. whether the voltage is less than a predetermined threshold value, or the current detection unit detects the current it is characterized by having a means for determining whether squid-out predetermined threshold by Redirecting a.
The switch device according to the present invention is characterized in that the voltage application unit limits an output current to a predetermined current or less.

  When the switch device according to the present invention includes the second switch in the circuit, the ON means turns on the second switch simultaneously with each of the pair of switches. To do.

  The switch short-circuit determination method according to the present invention is a method of determining whether or not each switch is short-circuited in a switch device including a pair of switches and a control unit that controls on and off of each of the switches. A voltage applying unit that applies a voltage between one end of each of the switches, a voltage detecting unit that detects a voltage between the one ends, a resistor, a capacitor connected between the other ends of each of the switches, a second A switch or a circuit including a combination thereof, and alternately turning on the pair of switches sequentially, and each time the switch is turned on, the amount of change or rate of change of the voltage detected by the voltage detector before and after turning on. It is calculated, the calculated change amount or change rate is compared with a predetermined threshold value, and it is determined whether or not each of the pair of switches is short-circuited based on the comparison result.

The switch short-circuit determination method according to the present invention is a method of determining whether or not each switch is short-circuited in a switch device including a pair of switches and a control unit that controls on and off of each of the switches. A voltage applying unit that applies a voltage between one end of each of the switches, a detecting unit that detects a voltage or current between the one ends, a resistor, a capacitor connected between the other ends of each of the switches, A circuit including two switches or a combination thereof, and alternately turning on the pair of switches sequentially, each time the switch is turned on, the voltage or current detected by the detection unit is compared with a predetermined threshold, It is characterized by determining whether each of a pair of said switches is short-circuited based on a comparison result.
The switch short-circuit determination method according to the present invention is characterized in that the voltage application unit limits an output current to a predetermined current or less.

In the present invention, the voltage application unit is connected between one ends of each of the pair of switches, and a circuit including a resistor, a capacitor, a second switch, or a combination thereof is connected between the other ends. Has been. In this state, the control unit turns on the voltage application by the voltage application unit and sequentially turns on one and the other of the pair of switches, and the voltage detected by the voltage detection unit before and after each turn-on. The change amount or change rate is calculated, and it is determined whether or not the calculation result is larger than a predetermined threshold value.
Thus, when one of the pair of switches is turned on and the other switch is short-circuited, a current flows from the voltage application unit to the circuit via the pair of switches, and the voltage detected by the voltage detection unit On the other hand, when the other switch is not short-circuited, the voltage detected by the voltage detector does not decrease. For this reason, when the amount of change or rate of change of the voltage detected by the voltage detector before and after the controller turns on one (or the other) of the pair of switches is greater than a predetermined threshold, the other (or the other) of the pair of switches (or Is determined to be short-circuited.

In the present invention, the voltage application unit is connected between one ends of each of the pair of switches, and a circuit including a resistor, a capacitor, a second switch, or a combination thereof is connected between the other ends. Has been. In this state, the control unit turns on the voltage application by the voltage application unit and sequentially turns on one and the other of the pair of switches. Each time the control unit turns on, the voltage detected by the detection unit is smaller than a predetermined threshold value. Or whether the current detected by the detection unit is larger than a predetermined threshold value.
Thus, when one of the pair of switches is turned on and the other switch is short-circuited, a current flows from the voltage application unit to the circuit via the pair of switches, and the applied voltage from the voltage application unit. Decreases. In this case, when the detection unit detects a voltage smaller than the predetermined threshold or a current larger than the predetermined threshold, when the other switch is not short-circuited, the voltage that the detection unit is not smaller than the predetermined threshold or a predetermined A current that is not greater than a threshold is detected. For this reason, when the control unit turns on one (or the other) of the pair of switches and the detection unit detects a voltage or a large current smaller than a predetermined threshold, the other (or one) of the pair of switches is short-circuited. It is determined that

In the present invention, when the circuit includes the second switch, the control unit simultaneously turns on the second switch when sequentially turning on one and the other of the pair of switches.
Thereby, when it is not necessary to determine the presence or absence of a short circuit about a pair of switch, a part or all of the said circuit is cut off from between the other ends of each of a pair of switch.

According to the present invention, the voltage detected by the voltage detection unit before and after the control unit turns on one (or the other) of the pair of switches, when the change amount or change rate is greater than the predetermined threshold, or the control unit is a pair. When one (or the other) of the switches is turned on and the current detected by the current detection unit is greater than a predetermined threshold, it is determined that the other (or one) of the pair of switches is short-circuited.
Therefore, even when the battery is not connected, it can be determined individually and nondestructively whether or not the pair of switches are short-circuited.

It is a block diagram which shows the structural example of the switch apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the process sequence of CPU which determines the presence or absence of the short circuit of a relay contact in the switch apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the process sequence of CPU which determines the presence or absence of the short circuit of a relay contact in the switch apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structural example of the switch apparatus which concerns on Embodiment 2 of this invention. It is a part of flowchart which shows the process sequence of CPU which determines the presence or absence of the short circuit of a relay contact in the switch apparatus which concerns on Embodiment 2 of this invention. It is a block diagram which shows the structural example of the switch apparatus which concerns on Embodiment 3 of this invention. It is a part of flowchart which shows the process sequence of CPU which determines the presence or absence of the short circuit of a relay contact in the switch apparatus which concerns on Embodiment 3 of this invention.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.
(Embodiment 1)
FIG. 1 is a block diagram showing a configuration example of a switch device according to Embodiment 1 of the present invention. In the figure, 1a is a switch device, and the switch device 1a is a pair of on / off switches between an external voltage converter 2 that converts AC voltage into DC voltage and an external power storage device 3 that stores DC power. Relays (corresponding to a pair of switches) RLY1 and RLY2 and a control unit 10 that controls on and off of each of the relays RLY1 and RLY2. The pair of relays is, for example, an electromagnetic switch, an electromagnetic contactor, a general-purpose electromagnetic relay, or a semiconductor relay, but may be a switching element such as a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor).

  The power storage device 3 includes a battery 31 and a relay RLYb having two circuit relay contacts for turning on / off the connection between the battery 31 and the switch device 1a, but is not limited thereto. For example, the switch device 1a may be detachably connected to the battery 31 of the power storage device 3 by a charge / discharge cable. The relay RLYb is turned on / off by a control circuit (not shown) or a user, for example.

  In the first embodiment, the voltage converter 2 and / or the power storage device 3 may not be connected to the switch device 1a. The voltage converter 2 may have a function of an inverter that converts a DC voltage from the battery 31 into an AC voltage.

  The switching device 1a also applies an inspection voltage for inspecting the presence or absence of a short circuit of the relay contacts between one end of the relay contacts of the relays RLY1 and RLY2 (hereinafter referred to as a first terminal pair) T1 and T1. The voltage application unit 18 includes a test circuit including a capacitor C1 connected between the other ends of the relay contacts of the relays RLY1 and RLY2 (hereinafter referred to as a second terminal pair) T2 and T2, and a relay RLY3. The relay contact of the relay RLY3 is connected in series with the resistor R3, and this series circuit is connected in parallel with the relay contact of the relay RLY1.

  The capacitor C1 is for smoothing the output voltage of the voltage converter 2, for example. The inspection circuit may be a resistor or a circuit in which one or a plurality of resistors and / or capacitors are connected in combination. However, the inspection circuit needs to lower the inspection voltage when it becomes a load of the voltage application unit 18 via the relay contacts of the relays RLY1 and RLY2.

  The relay RLY3 is for preventing an inrush current flowing through the relay contact of the relay RLY1, and a small capacity electromagnetic relay or the like is applied. For example, when the relays RLY1 and RLY2 are simultaneously turned on, an inrush current may flow from the battery 31 to the output capacitor C1 of the voltage converter 2 via the relay contacts of the relays RLY1 and RLY2. In order to prevent this, by temporarily turning on relays RLY2 and RLY3 in advance, capacitor C1 is slowly charged from battery 31 via resistor R3. In the first embodiment, relay RLY3 is used for a purpose other than the above.

  The control unit 10 includes a CPU 11, which includes a ROM 12 that stores information such as a control program, a RAM 13 that stores temporarily generated information, a relay drive circuit 14 that drives each of the relays RLY1, RLY2, and RLY3, and voltage application. The I / O (input / output interface) 15 for controlling on / off of the unit 18 and an A / D converter 16 for converting an analog voltage into a digital voltage value are bus-connected.

  The relay drive circuit 14 is connected to each relay coil of the relays RLY1, RLY2, and RLY3. The relay drive circuit 14 applies excitation current to these relay coils to drive each of them, whereby the relays RLY1, RLY2, and RLY3 are turned on.

  The A / D converter 16 is connected between the first terminal pair T1 and T1, and the voltage application unit 18 converts the voltage applied between the first terminal pair T1 and T1 to convert the digital voltage value. It comes to detect. Here, the input impedance of the A / D converter 16 is sufficiently larger than the output impedance of the voltage application unit 18 and the resistance value of the resistor R3, and substantially A between the first terminal pair T1 and T1. It can be ignored that the / D converter 16 is connected.

  The voltage application unit 18 includes a constant voltage power source 181 having a so-called U-shaped characteristic and a diode D1 having an anode connected to an output terminal on the plus side of the constant voltage power source 181. The constant voltage power supply 181 is supplied with a low-voltage DC voltage from the power supply PW1, and the constant voltage power supply 181 boosts the DC voltage to generate a test voltage of, for example, 450V to 500V. The inspection voltage applied between the first terminal pair T1 and T1 by the voltage application unit 18 is supplied from the cathode of the diode D1 and the negative output terminal of the constant voltage power supply 181.

  For example, when the switch device 1a and the power storage device 3 are connected by a charge / discharge cable, a voltage application circuit for applying an inspection voltage for inspecting whether the charge / discharge cable is short-circuited is provided. In some cases, the voltage application circuit may also serve as the voltage application unit 18.

  The inspection voltage supplied by the voltage application unit 18 is a DC voltage, but is not limited thereto. For example, when the voltage between the first terminal pair T1 and T1 is rectified and applied to the A / D converter 16, the inspection voltage may be an AC voltage. However, when the above-described inspection circuit includes a capacitor, the inspection voltage is preferably a DC voltage.

  In the above-described configuration, the control unit 10 is configured such that a DC voltage is not previously applied between the voltage converter 2 and the second terminal pair T2, T2, and between the power storage device 3 and the first terminal pair T1, T1. Make sure that no DC voltage is applied. Thereafter, the control unit 10 applies a voltage between the first terminal pair T1 and T1 by the voltage application unit 18, and sequentially turns on and off one of the relays RLY1 and RLY2, and before and after turning on the first terminal pair T1. , T1 based on the voltage change between the relays RLY1 and RLY2, whether or not the relay contacts are short-circuited is determined separately.

  For example, when only the relay RLY1 is turned on and the relay contact of the relay RLY2 is short-circuited, the capacitor C1 is connected from the constant voltage power supply 181 of the voltage application unit 18 through the diode D1 and the relay contacts of the relays RLY1 and RLY2. The charging current flows through the constant voltage power supply 181 and the inspection voltage from the constant voltage power supply 181 is lowered due to the U-shaped characteristic. For this reason, a change occurs in the voltage between the first terminal pair T1 and T1 before and after the relay RLY1 is turned on. When the change amount or change rate of the voltage is larger than a predetermined threshold value, it is determined that the relay contact of the relay RLY2 is short-circuited.

  Similarly, when only the relay RLY2 is turned on, the relay contact of the relay RLY1 when the amount of change or rate of change in voltage between the first terminal pair T1 and T1 before and after the relay RLY2 is turned on is larger than a predetermined threshold value. Is determined to be short-circuited. The first cause of short-circuiting of the relay contact is welding, but the cause of short-circuiting is not limited to welding.

  On the other hand, when the relay contacts of the relays RLY1 and RLY2 are both short-circuited, the relay contact short-circuit is not detected by the above-described method. However, when a test voltage is applied between the first terminal pair T1 and T1 by the voltage application unit 18, the voltage between the first terminal pair T1 and T1 is lower than a certain voltage due to the charging current to the capacitor C1. Therefore, it is determined that the relay contacts of relays RLY1 and RLY2 are both short-circuited. Even if it is determined that the relay contact of the relay RLY1 or the relay RLY3 is short-circuited when the voltage between the first terminal pair T1 and T1 decreases when the inspection voltage is applied and only the relay RLY2 is turned on. Good.

Below, operation | movement of the control part 10 mentioned above is demonstrated using the flowchart which shows it. The processing shown below is executed by the CPU 11 in accordance with a control program stored in advance in the ROM 12.
2 and 3 are flowcharts showing the processing procedure of the CPU 11 for determining whether or not the relay contact is short-circuited in the switch device 1a according to the first embodiment of the present invention. The processes in FIGS. 2 and 3 are started as appropriate as one of the self-diagnosis programs in the switch device 1a.

  When the processing of FIG. 2 is started, the CPU 11 turns off all the relays including the relays RLY1 and RLY2 by the relay drive circuit 14 (S10) and turns off the application of the inspection voltage by the voltage application unit 18 (S11). ). Thereafter, the CPU 11 waits for a predetermined time longer than the operation time of all the relays and the off time of the constant voltage power supply 181 (S12), and then detects the voltage between the first terminal pair T1, T1 (S13). In order for the CPU 11 to wait for a predetermined time, for example, the CPU 11 may wait until a predetermined time is counted after a timer (not shown) starts timing.

  Next, the CPU 11 determines whether or not there is a voltage application from the battery 31 to the first terminal pair T1 and T1 depending on whether or not a voltage that is not substantially zero is detected (S14). When there is voltage application from the battery 31 (S14: YES), the CPU 11 shifts the processing to step S12 in order to wait until the voltage application is stopped.

  When no voltage is applied from the battery 31 (S14: NO), the CPU 11 turns on the relays RLY2 and RLY3 (S15) and waits for a predetermined time longer than the operation time of each of the relays RLY2 and RLY3 (S16). A voltage between one terminal pair T1, T1 is detected (S17). The predetermined time here may be different from the predetermined time in step S12 (the same applies hereinafter). As described above, since the input impedance of the A / D converter 16 is sufficiently larger than the resistance value of the resistor R3, the voltage applied to the second terminal pair T2 and T2 is substantially detected in step S17. .

  Next, the CPU 11 determines whether or not there is a voltage application from the voltage converter 2 to the second terminal pair T2 and T2 depending on whether or not a substantially non-zero voltage is detected (S18). When there is voltage application from the voltage converter 2 (S18: YES), the CPU 11 shifts the processing to step S16 in order to stand by until no voltage application occurs. On the other hand, when no voltage is applied from the voltage converter 2 (S18: NO), the CPU 11 turns off the relays RLY2 and RLY3 (S19).

  Moving to FIG. 3, the CPU 11 turns on the application of the inspection voltage by the voltage application unit 18 using the I / O 15 (S20). Thereafter, the CPU 11 waits for a predetermined time longer than the operation time of the relays RLY2 and RLY3 and the ON time of the constant voltage power supply 181 (S21), and then detects the voltage between the first terminal pair T1, T1 (S22). The voltage thus stored is stored in the RAM 13 (S23).

  Next, the CPU 11 turns on the relay RLY1 (S24), waits for a predetermined time longer than the operation time of the relay RLY1 (S25), and then detects the voltage between the first terminal pair T1, T1 (S26). Thereafter, the CPU 11 calculates the detected voltage change amount or change rate with respect to the voltage stored in the RAM 13 for the voltage between the first terminal pair T1 and T1 (S27), and whether or not the calculation result is larger than a predetermined threshold value. Is determined (S28).

  When the calculation result is larger than the predetermined threshold value (S28: YES), the CPU 11 stores in the RAM 13 that the relay contact of the relay RLY2 (simply indicated as relay RLY2 in the figure: the same applies hereinafter) is short-circuited (S29). Thereafter, the process proceeds to step S40 described later. In step S29, an alarm may be output to a display unit and / or an audio output unit (not shown), for example, without storing the short circuit in the RAM 13.

  When the calculation result is not greater than the predetermined threshold (S28: NO), the CPU 11 turns off the relay RLY1 (S30), and waits for a predetermined time longer than the operation time of the relay RLY1 (S31). The following processing from step S32 to S38 is obtained by replacing the relay RLY1 in the processing from the above-described steps S22 to S28 with the relay RLY2. Specifically, the relay RLY2 is turned on in step S34, and the process waits for a predetermined time longer than the operation time of the relay RLY2 in step S35. Description of other steps is omitted.

  When the calculation result is larger than the predetermined threshold value in step S38 (S38: YES), the CPU 11 stores in the RAM 13 that the relay contact of the relay RLY1 is short-circuited (S39). Here, an alarm may be output without storing the short circuit in the RAM 13. The predetermined threshold value may be different between steps S28 and S38. When the calculation result is not larger than the predetermined threshold value (S38: NO) or when the process of step S39 is finished, the CPU 11 turns off all the relays including the relays RLY1 and RLY2 (S40) and the voltage application unit 18 The application of the inspection voltage is turned off (S41), and the processing shown in FIGS.

  In the above-described flowchart, it is determined whether or not the relay contacts are short-circuited in the order of relays RLY1 and RLY2 in the processing from step S20 to S40. However, the relay contact of relay RLY2 is first determined whether or not there is a short circuit. You may make it perform. Also, the relays RLY1 and RLY2 are turned on after the voltage application unit 18 is turned on, but the voltage application unit 18 may be turned on after turning on the relays RLY1 and RLY2 (also in other embodiments described later) The same).

As described above, according to the first embodiment, the voltage application unit 18 is connected between one end of each relay contact of the relays RLY1 and RLY2, that is, between the first terminal pair T1, T1, and the other ends. That is, a test circuit including a resistor R1, a capacitor, or a combination thereof is connected between the second terminal pair T2 and T2. In this state, the control unit 10 turns on the application of the test voltage by the voltage application unit 18, and sequentially turns on one and the other of the relays RLY1 and RLY2, and each time it is turned on, the A / D before and after turning on The change amount or change rate of the voltage detected by the converter 16 is calculated, and it is determined whether or not the calculation result is larger than a predetermined threshold value.
As a result, when one of the relays RLY1 and RLY2 is turned on and the other relay contact is short-circuited, current is supplied from the voltage application unit 18 to the inspection circuit via the relay contacts of the relays RLY1 and RLY2. The voltage detected by the A / D converter 16 decreases, whereas the voltage detected by the A / D converter 16 does not decrease when the other relay contact is not short-circuited. For this reason, when the change amount or change rate of the voltage detected by the A / D converter 16 before and after the controller 10 turns on one (or the other) of the relays RLY1 and RLY2 is larger than a predetermined threshold, the relay RLY1 And the other (or one) relay contact of RLY2 is determined to be short-circuited.
Therefore, even when the battery 31 is not connected, it can be determined individually and nondestructively whether the relay contacts of the relays RLY1 and RLY2 are short-circuited.

(Embodiment 2)
The first embodiment is a mode in which the presence or absence of a relay contact short circuit is determined based on a comparison result between a change amount or a change rate of an inspection voltage applied between the second terminal pair T2 and T2 and a predetermined threshold value. On the other hand, the second embodiment is a form in which the presence or absence of a short circuit of the relay contact is determined based on the comparison result between the inspection voltage applied between the second terminal pair T2 and T2 and a predetermined threshold value.

  FIG. 4 is a block diagram showing a configuration example of the switch device according to Embodiment 2 of the present invention. In the figure, reference numeral 1b denotes a switch device, and the switch device 1b includes a test circuit including a relay (corresponding to a second switch) RLY4 having a relay contact connected between the second terminal pair T2 and T2. The relay coil of the relay RLY4 is connected to the relay drive circuit 14. The relay drive circuit 14 is driven by applying an exciting current to the relay coil, whereby the relay RLY4 is turned on.

  Since the other configuration of the switch device 1b is the same as that of the switch device 1a in the first embodiment, portions corresponding to those of the first embodiment are denoted by the same reference numerals and description thereof is omitted. In the second embodiment, the A / D converter 16 that detects the voltage between the first terminal pair T1 and T1 corresponds to a detection unit.

  The inspection circuit may be a circuit in which a relay contact of the relay RLY4 and one or a plurality of resistors and / or capacitors are connected in combination (this inspection circuit or the inspection circuit in the first embodiment, Equivalent to a resistor, a capacitor, a second switch or a combination of these). When the relay RLY4 is turned on, the current flowing through the relay contact flows from the constant voltage power source 181 having a U-shaped characteristic. Therefore, a small capacity electromagnetic relay or the like can be applied to the relay RLY4.

  In the above-described configuration, the control unit 10 applies the voltage between the first terminal pair T1 and T1 by the voltage application unit 18, and then sequentially turns on one and the other of the relays RLY1 and RLY2, Based on the voltage between the terminal pair T1 and T1, whether or not the relay contacts of the relays RLY1 and RLY2 are short-circuited is determined separately.

  For example, when only the relay RLY1 is turned on and the relay contact of the relay RLY2 is short-circuited, the relay RLY4 is connected from the constant voltage power supply 181 of the voltage application unit 18 through the diode D1 and the relay contacts of the relays RLY1 and RLY2. A current flows through the relay contact, and the inspection voltage from the constant voltage power source 181 decreases due to the U-shaped characteristic. For this reason, the voltage between the first terminal pair T1, T1 decreases after the relay RLY1 is turned on. When this voltage is smaller than a predetermined threshold value, it is determined that the relay contact of relay RLY2 is short-circuited.

  Similarly, when only the relay RLY2 is turned on, the relay contact of the relay RLY1 is short-circuited when the voltage between the first terminal pair T1, T1 after the relay RLY2 is turned on is smaller than a predetermined threshold value. It is determined. If the voltage between the first terminal pair T1 and T1 before turning on the relays RLY1 and RLY2 is smaller than a predetermined threshold, it is determined that the relay contacts of the relays RLY1 and RLY2 are both short-circuited. In this case, when a charge / discharge cable is connected to the power storage device 3, determination including a short circuit of the charge / discharge cable is possible.

Below, operation | movement of the control part 10 mentioned above is demonstrated using the flowchart which shows it.
FIG. 5 is a part of a flowchart showing a processing procedure of the CPU 11 for determining whether or not the relay contact is short-circuited in the switch device 1b according to the second embodiment of the present invention. The process of FIG. 5 is executed as a process subsequent to the process shown in FIG. 2 of the first embodiment. However, the relay turned off in step S10 includes the relay RLY4.

  Moving from step S19 in FIG. 2 to FIG. 5, the CPU 11 turns on the application of the inspection voltage by the voltage application unit 18 using the I / O 15 (S50). Thereafter, the CPU 11 turns on the relays RLY1 and RLY4 (S54), and waits for a predetermined time longer than the operation time of the relays from the relays RLY1 to RLY4 and the on-time of the constant voltage power source 181 (S55), and then the first terminal pair The voltage between T1 and T1 is detected (S56).

  Next, the CPU 11 determines whether or not the voltage detection result is smaller than a predetermined threshold (S58). If the voltage is smaller than the predetermined threshold (S58: YES), the RAM 13 indicates that the relay contact of the relay RLY2 is short-circuited. (S59) and the process proceeds to step S70.

  On the other hand, when the detection result is not smaller than the predetermined threshold value in step S58 (S58: NO), the CPU 11 turns off the relay RLY1 (S60). Thereafter, the CPU 11 turns on the relay RLY2 (S64), waits for a predetermined time longer than the operation time of the relays RLY1 and RLY2 (S65), and then detects the voltage between the first terminal pair T1, T1 (S66). .

  Next, the CPU 11 determines whether or not the voltage detection result is smaller than a predetermined threshold (S68). If the voltage detection result is smaller than the predetermined threshold (S68: YES), the RAM 13 indicates that the relay contact of the relay RLY1 is short-circuited. (S69). Here, an alarm may be output without storing the short circuit in the RAM 13. The predetermined threshold value may be different between steps S58 and S68.

  When the calculation result is not smaller than the predetermined threshold value (S68: NO) or when the process of step S69 is finished, the CPU 11 turns off all the relays including the relays RLY1, RLY2, and RLY4 (S70), and the voltage application unit. 18 is turned off (S71), and the process of FIG.

As described above, according to the second embodiment, the voltage application unit 18 is connected between one end of each relay contact of the relays RLY1 and RLY2, that is, between the first terminal pair T1, T1, and the other ends. That is, a test circuit including a resistor R1, a capacitor, or a combination thereof is connected between the second terminal pair T2 and T2. In this state, the control unit 10 turns on the application of the test voltage by the voltage application unit 18 and sequentially turns on and off one of the relays RLY1 and RLY2, and the current detected by the A / D converter 16 each time it is turned on. Is smaller than a predetermined threshold value.
As a result, when one of the relays RLY1 and RLY2 is turned on and the other relay contact is short-circuited, current is supplied from the voltage application unit 18 to the inspection circuit via the relay contacts of the relays RLY1 and RLY2. When the applied voltage from the voltage application unit 18 decreases and the A / D converter 16 detects a voltage smaller than a predetermined threshold, the other relay contact is not short-circuited, and the A / D conversion is performed. The detector 16 detects a voltage that is not less than a predetermined threshold. Therefore, when the control unit 10 turns on one (or the other) of the relays RLY1 and RLY2, when the A / D converter 16 detects a voltage smaller than a predetermined threshold, the other (or the other) of the relays RLY1 and RLY2 (or On the other hand, it is determined that the relay contact is short-circuited.
Therefore, even when the battery 31 is not connected, it can be determined individually and nondestructively whether the relay contacts of the relays RLY1 and RLY2 are short-circuited.

Further, according to the second embodiment, the control unit 10 simultaneously turns on the relay RLY4 when the relays RLY1 and RLY2 of the relays RLY1 and RLY2 are sequentially turned on.
Therefore, when it is not necessary to determine whether the relay contacts of the relays RLY1 and RLY2 are short-circuited, part or all of the inspection circuit including the relay RLY4 can be disconnected from the second terminal pair T2, T2.

(Embodiment 3)
In the first embodiment, the relay contacts of the relays RLY1 and RLY2 are based on the comparison result between the change amount or change rate of the test voltage applied between the first terminal pair T1 and T1 by the voltage application unit 18 and a predetermined threshold value. In contrast to the configuration in which the presence or absence of a short circuit is determined, the third embodiment is a relay based on a comparison result between a current flowing from the voltage application unit 18 between the first terminal pair T1 and T1 and a predetermined threshold value. This is a form in which the presence or absence of a short circuit of the relay contacts of RLY1 and RLY2 is determined.

  FIG. 6 is a block diagram illustrating a configuration example of the switch device according to the third embodiment of the present invention. In the figure, reference numeral 1c denotes a switch device. The switch device 1c includes a current detection unit (equivalent to a detection unit) 19 that detects a current flowing between the voltage application unit 18 and the first terminal pair T1, T1, and a second terminal pair. And an inspection circuit including a resistor R1 connected between T2 and T2.

  The current detection unit 19 includes a resistor R4 and a differential amplifier 191 that amplifies a voltage drop due to a current flowing through the resistor R4. The resistor R4 is connected between the cathode of the diode D1 and one end of the relay contact of the relay RLY1. The output of the differential amplifier 191 is connected to the A / D converter 16. Thereby, the A / D converter 16 converts the current flowing through the resistor R4 into a digital current value and detects it.

  Since the other configuration of the switch device 1c is the same as that of the switch device 1a in the first embodiment, portions corresponding to those of the first embodiment are denoted by the same reference numerals and description thereof is omitted. The inspection circuit may be a circuit in which the relay contact of the relay RLY4 in the second embodiment and one or a plurality of resistors and / or capacitors are connected in combination.

  In the above-described configuration, the control unit 10 applies the voltage between the first terminal pair T1 and T1 by the voltage application unit 18, and then sequentially turns on and turns on one and the other of the relays RLY1 and RLY2. Whether or not the relay contacts of the relays RLY1 and RLY2 are short-circuited is individually determined based on the current flowing between the terminal pair T1 and T1.

  For example, when only the relay RLY1 is turned on and the relay contact of the relay RLY2 is short-circuited, the diode D1, the resistor R4, and the relay contacts of the relays RLY1 and RLY2 are connected from the constant voltage power supply 181 of the voltage application unit 18. Current flows through the resistor R1. In this case, when the current flowing through the resistor R4 is larger than a predetermined threshold, it is determined that the relay contact of the relay RLY2 is short-circuited. Similarly, when only relay RLY2 is turned on, it is determined that the relay contact of relay RLY1 is short-circuited when the current flowing through resistor R4 is greater than a predetermined threshold.

Below, operation | movement of the control part 10 mentioned above is demonstrated using the flowchart which shows it.
FIG. 7 is a part of a flowchart showing a processing procedure of the CPU 11 for determining whether or not the relay contact is short-circuited in the switch device 1c according to the third embodiment of the present invention. The process of FIG. 7 is executed as a process subsequent to the process shown in FIG. 2 of the first embodiment.

  Of the processes from steps S80 to S101 shown in FIG. 7, the processes and contents from steps S50 to S71 shown in FIG. 5 of the second embodiment are substantially the same for the processes excluding steps S84, S86, S88, S96 and S98. Part of the description is omitted.

  2, the CPU 11 turns on the application of the inspection voltage by the voltage application unit 18 (S80), turns on the relay RLY1 (S84), and operates the relays from the relays RLY1 to RLY3. After waiting for a predetermined time longer than the time and the on-time of the constant voltage power source 181 (S85), the current detection unit 19 is used to detect the current flowing between the first terminal pair T1, T1 (S86).

  Next, the CPU 11 determines whether or not the current detection result is larger than a predetermined threshold (S88). If the current detection result is larger than the predetermined threshold (S88: YES), the RAM 13 indicates that the relay contact of the relay RLY2 is short-circuited. (S89) and the process proceeds to step S100.

  On the other hand, when the detection result is not greater than the predetermined threshold value in step S88 (S88: NO), the CPU 11 turns off the relay RLY1 (S90). Thereafter, the CPU 11 turns on the relay RLY2 (S94) and waits for a predetermined time longer than the operation time of the relays RLY1 and RLY2 (S95), and then uses the current detection unit 19 between the first terminal pair T1, T1. The flowing current is detected (S96).

  Next, the CPU 11 determines whether or not the current detection result is greater than a predetermined threshold (S98). If the current detection result is greater than the predetermined threshold (S98: YES), the RAM 13 indicates that the relay contact of the relay RLY1 is short-circuited. (S99), all the relays are turned off (S100), and the application of the inspection voltage by the voltage application unit 18 is turned off (S101), and the process of FIG. The predetermined threshold value may be different between steps S88 and S98.

As described above, according to the third embodiment, the voltage application unit 18 is connected between one ends of the relay contacts of the relays RLY1 and RLY2, that is, between the first terminal pair T1 and T1, and the other ends. That is, a test circuit including a resistor R1, a capacitor, or a combination thereof is connected between the second terminal pair T2 and T2. In this state, the control unit 10 turns on the application of the test voltage by the voltage application unit 18 and sequentially turns on and off one of the relays RLY1 and RLY2, and each time the control unit 10 turns on, the current detected by the current detection unit 19 is predetermined. It is determined whether it is larger than the threshold value.
Thereby, when one of the relays RLY1 and RLY2 is turned on, when the other relay contact is short-circuited, the voltage application unit 18 through the current detection unit 19 and the relay contacts of the relays RLY1 and RLY2 respectively. When a current flows through the inspection circuit and the current detection unit 19 detects a current greater than a predetermined threshold, the current detection unit 19 generates a current that is not greater than the predetermined threshold when the other relay contact is not short-circuited. To detect. Therefore, when the control unit 10 turns on one (or the other) of the relays RLY1 and RLY2, if the current detected by the current detection unit 19 is greater than a predetermined threshold, the other (or one) of the relays RLY1 and RLY2 It is determined that the relay contact is short-circuited.
Therefore, even when the battery 31 is not connected, it can be determined individually and nondestructively whether the relay contacts of the relays RLY1 and RLY2 are short-circuited.

  The embodiment disclosed this time is to be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims. In addition, the technical features described in each embodiment can be combined with each other.

DESCRIPTION OF SYMBOLS 1a, 1b, 1c Switch apparatus 10 Control part 11 CPU
12 ROM
13 RAM
16 A / D converter 18 Voltage application unit 19 Current detection unit RLY1, RLY2, RLY4 Relay R1 Resistor C1 Capacitor 2 Voltage converter 3 Power storage device 31 Battery

Claims (7)

In a switch device comprising a pair of switches and a control unit that controls on and off of each of the switches,
A voltage applying unit for applying a voltage between one end of each of the switches;
A voltage detector for detecting a voltage between the one ends;
A resistor, a capacitor, a second switch, or a circuit including a combination thereof connected between the other ends of each of the switches,
The controller is
An ON means for alternately turning on the pair of switches sequentially;
Means for calculating the amount of change or rate of change of the voltage detected by the voltage detector before and after being turned on each time the turning-on means is turned on;
And a means for determining whether or not the amount of change or the rate of change calculated by the means is greater than a predetermined threshold value. In a switch device comprising a pair of switches and a control unit that controls on and off of each of the switches,
A voltage applying unit for applying a voltage between one end of each of the switches;
Voltage detecting unit for detecting a voltage between said one ends, or a current detection unit for detecting a current between said one ends,
A resistor, a capacitor, a second switch, or a circuit including a combination thereof connected between the other ends of each of the switches,
The controller is
An ON means for alternately turning on the pair of switches sequentially;
Each time the on means is turned on, whether the voltage of the voltage detecting unit has detected is smaller than a predetermined threshold value, or the current detection unit detects the current is equal to or squid-out predetermined threshold by Redirecting a And a switching device. The switch device according to claim 1 , wherein the voltage application unit limits an output current to a predetermined current or less . If it contains the second switch in the circuit, the on means any of claims 1 to 3, characterized in that said second switch are such that they are turned on simultaneously and s the pair of switches husband The switch device according to claim 1 . In a method of determining the presence or absence of a short circuit of each of the switches in a switch device comprising a pair of switches and a control unit that controls on and off of each of the switches,
A voltage applying unit for applying a voltage between one end of each of the switches;
A voltage detector for detecting a voltage between the one ends;
A resistor, a capacitor, a second switch, or a circuit including a combination thereof connected between the other ends of each of the switches;
Alternately turn on the pair of switches sequentially,
Every time it turns on, it calculates the amount of change or rate of change of the voltage detected by the voltage detector before and after turning on,
Compare the calculated amount of change or rate of change with a predetermined threshold,
It is determined whether each of a pair of said switch is short-circuited based on a comparison result. The short circuit determination method of the switch characterized by the above-mentioned. In a method of determining the presence or absence of a short circuit of each of the switches in a switch device comprising a pair of switches and a control unit that controls on and off of each of the switches,
A voltage applying unit for applying a voltage between one end of each of the switches;
A detection unit for detecting a voltage or current between the one ends;
A resistor, a capacitor, a second switch, or a circuit including a combination thereof connected between the other ends of each of the switches;
Alternately turn on the pair of switches sequentially,
Each time it is turned on, the voltage or current detected by the detection unit is compared with a predetermined threshold value,
It is determined whether each of a pair of said switch is short-circuited based on a comparison result. The short circuit determination method of the switch characterized by the above-mentioned. 7. The switch short-circuit determination method according to claim 5, wherein the voltage application unit limits an output current to a predetermined current or less.

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