JP2019161702A - Circuit protection device and power supply monitoring device - Google Patents

Abstract

Provided are a circuit protection device and a power supply monitoring device capable of improving maintainability as compared with the related art. A circuit protection device is provided between a DC power supply and a protection target circuit to which a positive voltage and a negative voltage of the DC power supply are input, wherein the circuit protection device includes a DC power supply and a first terminal of the protection target circuit. A relay provided between the input terminal and between the negative terminal of the DC power supply and the second input terminal of the circuit to be protected, and changes from a non-conductive state to a conductive state when a positive voltage and / or a negative voltage becomes an abnormal voltage. And a conduction circuit that changes the state of the relay from the closed state to the open state. [Selection diagram] FIG.

Description

  The present invention relates to a circuit protection device and a power supply monitoring device.

  Patent Document 1 listed below discloses a circuit protection device that appropriately protects a monitoring circuit that monitors an assembled battery. The circuit protection device includes a plurality of fuses provided between terminals of a plurality of battery cells constituting the assembled battery and input terminals of the monitoring circuit, and of the fuses adjacent to each other among the plurality of fuses. A plurality of Zener diodes (constant voltage diodes) inserted on the output side (monitoring circuit). In this circuit protection device, when an overvoltage is input from the assembled battery, the Zener diode changes its state from a non-conductive state (OFF state) to a conductive state (ON state), and a current flows through a plurality of fuses. The monitoring circuit is protected by fusing.

JP 2014-7883 A

  By the way, although the circuit protection device can protect the monitoring circuit, it is necessary to replace at least the blown fuse when the monitoring circuit is to be reused. Since this fuse is provided with the number of battery cells plus one, and in the assembled battery used for vehicles, the number of battery cells reaches several tens to several hundreds, so that the number of fuses blown increases. Therefore, the replacement of the fuse is an extremely complicated operation, and there is a problem that the maintainability of the circuit protection device is poor.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a circuit protection device and a power supply monitoring device capable of improving maintainability as compared with the related art.

  In order to achieve the above object, according to the present invention, as a first solution means for a circuit protection device, a DC power supply and a protection target circuit to which a positive voltage and a negative voltage of the DC power supply are input are provided. A circuit protection device provided between a positive terminal of the DC power supply and a first input terminal of the circuit to be protected and between a negative terminal of the DC power supply and a second input terminal of the circuit to be protected. And a conduction circuit that changes the state of the relay from a closed state to an open state by changing from a non-conductive state to a conductive state when the positive voltage or / and the negative voltage becomes an abnormal voltage. Is adopted.

  In the present invention, as a second solving means relating to the circuit protection device, in the first solving means, the conduction circuit includes a cathode terminal provided between the plus terminal and the first input terminal. A constant voltage diode connected to one excitation terminal of one of the relays and having an anode terminal connected to one excitation terminal of the second relay provided between the minus terminal and the second input terminal In the first relay, the other excitation terminal is connected to the contact on the protection target circuit side, and in the second relay, the other excitation terminal is connected to the contact on the protection target circuit side. Adopt the means that.

  According to the present invention, as a third solving means relating to the circuit protection device, in the first solving means, the conduction circuit has a cathode terminal provided between the plus terminal and the first input terminal. A first constant voltage diode that is connected to one excitation terminal of the first relay and whose anode terminal is grounded, and a second terminal that is provided between the negative terminal and the second input terminal. A second constant voltage diode connected to one excitation terminal of the relay and having an anode terminal grounded, and the first relay has the other excitation terminal connected to a contact on the protection target circuit side. The second relay employs means in which the other excitation terminal is connected to the contact on the protection target circuit side.

  In the present invention, as a fourth solving means related to the circuit protection device, in any one of the first to third solving means, the relay and the conduction circuit connect the DC power source and the protection target circuit. A means of being mounted inside the connector member is employed.

  In the present invention, as a fifth solving means related to the circuit protection device, in the first to fourth solving means, the means that the relay is a mechanical relay is adopted.

  In the present invention, as means for solving the power supply monitoring device, the circuit protection device according to any one of the first to fifth solutions, the protection target circuit, and the DC power supply via the circuit protection device. A monitoring circuit for monitoring the above is adopted.

 ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the circuit protection apparatus and power supply monitoring apparatus which can improve maintenance property conventionally.

It is a block diagram which shows the function structure of the circuit protection apparatus and power supply monitoring apparatus which concern on one Embodiment of this invention. It is a circuit diagram which shows the detailed structure of the circuit protection apparatus which concerns on one Embodiment of this invention. It is a circuit diagram which shows the detailed structure of the circuit protection apparatus which concerns on the modification of one Embodiment of this invention. It is a block diagram which shows the function structure of the power supply monitoring apparatus which concerns on the modification of one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
A power supply monitoring apparatus A according to the present embodiment is a monitoring apparatus that monitors an assembled battery X (DC power supply) as shown in FIG. 1 and includes a monitoring circuit 1 and a connector 2 with a protective function. Of the components constituting such a power supply monitoring device, the connector 2 with a protective function corresponds to the circuit protection device in the present invention.

  First, the assembled battery X is a battery mounted on a vehicle such as an electric vehicle or a hybrid vehicle, and is a secondary battery such as a lithium ion battery or a nickel metal hydride battery. The assembled battery X includes a plurality of battery cells b1 to bn (n is a natural number of 2 or more) each having a plus terminal and a minus terminal and connected in series to each other. That is, in the assembled battery X, the battery cells b2 to bn-1 are connected in series between the battery cell b1 located on the highest potential side and the battery cell bn located on the lowest potential side.

  Such an assembled battery X supplies DC power to an inverter that drives, for example, a traveling motor that generates traveling power of the vehicle. That is, the plus terminal P1 of the assembled battery X is connected to one input terminal (high potential side input terminal) of the inverter, and the minus terminal P2 of the assembled battery X is connected to the other input terminal (low potential side input terminal) of the inverter. Has been.

  The assembled battery X includes a CID (Current Interrupt Device) as illustrated. This CID is provided on the positive terminal side of each battery cell b1 to bn corresponding to each battery cell b1 to bn constituting the assembled battery X, and the internal pressure of the battery cell is excessive due to abnormality of the corresponding battery cell. It is a shut-off element (disconnect element) that mechanically releases the positive terminals of the battery cells b1 to bn by operating when it rises to.

  The monitoring circuit 1 is a circuit that monitors the assembled battery X based on the output voltage of the assembled battery X. That is, the monitoring circuit 1 includes a plurality of pairs of input terminals respectively corresponding to the output terminals (plus terminal and minus terminal) of each of the battery cells b1 to bn. Further, the output terminals (plus terminal and minus terminal) of each of the battery cells b1 to bn and the plural pairs of input terminals of the monitoring circuit 1 are connected to each other by connection lines L1 to Ln + 1.

  An output voltage (plus voltage or minus voltage) is input to the monitoring circuit 1 from the output terminals (plus terminal and minus terminal) of each of the battery cells b1 to bn via the protective function connector 2 (connector member). The The monitoring circuit 1 detects the voltage between the terminals of each battery cell b1 to bn (the difference voltage between the plus voltage and the minus voltage) as the cell voltage V1 to Vn based on the output voltage of each of the battery cells b1 to bn. The state of the assembled battery X is monitored based on the cell voltages V1 to Vn. The monitoring circuit 1 outputs the monitoring result of the assembled battery X to a battery control device (battery ECU) that controls charging / discharging of the assembled battery X.

  The protective function connector 2 is an electronic component mounted on the circuit board together with the monitoring circuit 1, and electrically and mechanically connects the circuit board and the connection lines L1 to Ln + 1. In addition to the connection function between the circuit board and each of the connection lines L1 to Ln + 1, the connector 2 with a protective function is connected to each connection line when the output voltage of the assembled battery X reaches an abnormal high voltage (abnormal voltage). A circuit protection function for protecting the monitoring circuit 1 by separating the connection between L1 to Ln + 1 and the monitoring circuit 1 is provided.

  That is, when the output voltage of the assembled battery X is in a normal voltage range, the connector 2 with a protective function connects the battery cells b1 to bn and the monitoring circuit 1, and the assembled battery X is operated by the operation of the CID described above. When the output voltage becomes an abnormal voltage, the connection between the battery cells b1 to bn and the monitoring circuit 1 is cut off.

  FIG. 2 shows a detailed configuration of the protective function-equipped connector 2 corresponding to the battery cell b1 as a representative. That is, the protective function connector 2 includes the mechanical relay 2a (first relay) provided between the connection line L1 and the first input terminal of the monitoring circuit 1, the connection line L2 and the second of the monitoring circuit 1. A mechanical relay 2b (second relay) provided between the input terminal and a constant voltage diode 2c provided between the pair of mechanical relays 2a and 2b is mounted inside. In addition, the connector 2 with a protection function corresponding to battery cells b2-bn other than such battery cell b1 is also equipped with the structure similar to FIG.

  In the mechanical relay 2a, one contact is connected to the connection line L1, the other contact (contact on the monitoring circuit 1 side) is connected to the first input terminal of the monitoring circuit 1, and one excitation terminal Ta1 is a constant voltage diode. 2c is connected to the cathode terminal, and one excitation terminal Ta2 is connected to the other contact (contact on the monitoring circuit 1 side).

  The mechanical relay 2b has one contact point connected to the connection line L2, the other contact point connected to the second input terminal of the monitoring circuit 1, and one excitation terminal Tb1 connected to the anode terminal of the constant voltage diode 2c. One excitation terminal Tb2 is connected to its other contact (the contact on the monitoring circuit 1 side).

  As described above, the constant voltage diode 2c has a cathode terminal connected to one excitation terminal Ta1 of the mechanical relay 2a and an anode terminal connected to one excitation terminal Tb1 of the mechanical relay 2b. The constant voltage diode 2c includes a cathode voltage, that is, a voltage at the other contact of one mechanical relay 2a (positive voltage of the battery cell b1) and an anode voltage, that is, a voltage at the other contact of the other mechanical relay 2b (negative of the battery cell b1) This is a conduction circuit that is in a non-conducting state when a difference voltage with respect to (voltage) is in a normal voltage range and changes from a non-conducting state to a conducting state when the difference voltage reaches a predetermined breakdown voltage (abnormal voltage).

  That is, in this connector 2 with a protective function, one mechanical relay 2a is inserted between the positive terminal of the battery cell b1 and the first input terminal of the monitoring circuit 1, and the negative terminal of the battery cell b1 and the monitoring circuit 1 The other mechanical relay 2b is inserted between the second input terminal. Moreover, in this connector 2 with a protective function, the constant voltage diode 2c is inserted between the other contact located on the output side of one mechanical relay 2a and the other contact located on the output side of the other mechanical relay 2b. ing.

  Next, the operation of the power supply monitoring apparatus A configured as described above, particularly the operation of the protective function connector 2 which is a characteristic component of the power supply monitoring apparatus will be described in detail.

  In this power supply monitoring device A, the monitoring circuit 1 detects the cell voltages V1 to Vn of the battery cells b1 to bn respectively input from the assembled battery X via the connector 2 with a protective function, thereby operating the assembled battery X. To monitor. The monitoring circuit 1 confirms that the assembled battery X is in an overvoltage state when the cell voltages V1 to Vn of the battery cells b1 to bn deviate from the normal voltage range, for example, reach an overvoltage range due to overcharging. Notify the battery ECU. As a result, the charging process of the assembled battery X by the battery ECU ends.

  In the battery pack X, the internal pressure of the battery cell may be abnormally increased due to an abnormality in one of the battery cells, and the CID may be activated. When one of the n battery cells b1 to bn is activated, an abnormal voltage is applied to the monitoring circuit 1 from the assembled battery X. For example, when the CID of the battery cell b1 is activated, the first and second input terminals of the monitoring circuit 1 corresponding to the battery cell b1 are connected via a pair of connection lines L1 and L2 and a pair of mechanical relays 2a and 2b. There is a risk that an abnormal voltage may be applied.

  With respect to such an abnormal voltage, in the protective function connector 2, since the abnormal voltage (breakdown voltage) is applied between the cathode terminal and the anode terminal of the constant voltage diode 2c, the constant voltage diode 2c is non-conductive. The state changes from the state (normal state) to the conductive state (abnormal state). As a result, the pair of mechanical relays 2 a and 2 b change from the closed state to the open state, and prevents the abnormal voltage from being input to the monitoring circuit 1.

  According to such a power supply monitoring device A, when the output voltage (cell voltage) of each of the battery cells b1 to bn in the assembled battery X becomes an abnormal voltage, the constant voltage diode 2c becomes conductive and the pair of mechanical relays 2a, When 2b changes to the open state to protect the monitoring circuit 1 (protection target circuit) and the cell voltage returns to the normal voltage, the constant voltage diode 2c becomes non-conductive and the pair of mechanical relays 2a and 2b open. Return from the state to the closed state. Therefore, according to the present embodiment, the maintainability can be improved as compared with the case of using the conventional fuse.

In addition, this invention is not limited to the said embodiment, For example, the following modifications can be considered.
(1) In the above embodiment, as shown in FIG. 2, the connector 2 with protective function (mechanical relay 2a (first relay), mechanical relay 2b (second relay), and constant voltage diode 2c (conduction circuit)) Although the circuit protection device is configured, the present invention is not limited to this. For example, as shown in FIG. 3, a protective function connector 2A (circuit protection device) using a pair of constant voltage diodes 2d and 2e instead of the constant voltage diode 2c may be employed.

  That is, of the pair of constant voltage diodes 2d and 2e, one constant voltage diode 2d (first constant voltage diode) has a cathode terminal connected to one excitation terminal Ta1 of the mechanical relay 2a (first relay). The anode terminal is grounded. The other constant voltage diode 2e (second constant voltage diode) has a cathode terminal connected to one excitation terminal Tb1 of the mechanical relay 2b (second relay) and an anode terminal grounded.

  In such a protective function-equipped connector 2A, when the terminal voltage of each of the battery cells b1 to bn in the assembled battery X becomes an abnormal voltage, one or both of the pair of constant voltage diodes 2d and 2e change to a conductive state. As a result, one or both of the pair of mechanical relays 2a and 2b are changed to the open state to protect the monitoring circuit 1 (protection target circuit). When the terminal voltage of each battery cell b1 to bn returns to the normal voltage, one or both of the pair of mechanical relays 2a and 2b change to the closed state, and the cell voltage of each battery cell b1 to bn is normal. Detection is possible.

(2) In the above embodiment, the circuit protection function of the monitoring circuit 1 is added to the connector 2 with a protection function whose main function is the connector function, but the present invention is not limited to this. For example, as shown in FIG. 4, these two functions may be separated into a connector 2A and a protection circuit 2B. That is, the circuit protection device according to the present invention may be configured as a single protection circuit 2B separated from the connector function.

(3) In the above embodiment, the mechanical relays 2a and 2b are used as the first and second relays, but the present invention is not limited to this. Instead of the mechanical relays 2a and 2b, that is, the contact relays, non-contact relays such as semiconductor relays may be employed.

(4) In the said embodiment, although each battery cell b1-bn demonstrated each assembled battery X provided with CID, this invention is not limited to this. In addition to the CID that operates based on the abnormal internal pressure of the battery cell, various elements can be considered as the interruption element provided in the assembled battery for safety measures.

X battery pack (DC power supply)
b1 to bn Battery cells L1 to Ln Connection line 1 Monitoring circuit 2 Connector with protection function (connector member)
2A Connector 2B Protection circuit 2a Mechanical relay (first relay)
2b Mechanical relay (second relay)
2c constant voltage diode 2d first constant voltage diode 2e second constant voltage diode

Claims (6)

A circuit protection device provided between a DC power supply and a protection target circuit to which a positive voltage and a negative voltage of the DC power supply are input,
A relay provided between the positive terminal of the DC power source and the first input terminal of the circuit to be protected and between the negative terminal of the DC power source and the second input terminal of the circuit to be protected;
And a conduction circuit that changes the state of the relay from a closed state to an open state by changing from a non-conductive state to a conductive state when the positive voltage and / or the negative voltage becomes an abnormal voltage. apparatus. In the conduction circuit, a cathode terminal is connected to one excitation terminal of the first relay provided between the plus terminal and the first input terminal, and an anode terminal is connected to the minus terminal and the second terminal. A constant voltage diode connected to one excitation terminal of the second relay provided between the input terminal and the input terminal;
In the first relay, the other excitation terminal is connected to a contact on the protection target circuit side,
2. The circuit protection device according to claim 1, wherein in the second relay, the other excitation terminal is connected to a contact on the protection target circuit side. The conduction circuit includes a first constant voltage in which a cathode terminal is connected to one excitation terminal of the first relay provided between the plus terminal and the first input terminal, and an anode terminal is grounded. A diode, a cathode terminal connected to one excitation terminal of the second relay provided between the minus terminal and the second input terminal, and a second constant voltage diode having an anode terminal grounded With
In the first relay, the other excitation terminal is connected to a contact on the protection target circuit side,
2. The circuit protection device according to claim 1, wherein in the second relay, the other excitation terminal is connected to a contact on the protection target circuit side.   The circuit protection device according to claim 1, wherein the relay and the conduction circuit are mounted inside a connector member that connects the DC power source and the circuit to be protected. .   The circuit protection device according to claim 1, wherein the relay is a mechanical relay. A circuit protection device according to any one of claims 1 to 5;
A power monitoring apparatus comprising: a monitoring circuit that is the protection target circuit and that monitors the DC power supply via the circuit protection apparatus.

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