JP6643153B2 - Power supply - Google Patents

Description

  The present invention relates to a power supply device including a relay between a secondary battery and a transformer circuit.

  2. Description of the Related Art Conventionally, electric vehicles, hybrid vehicles, and the like having an electric motor as a power source of a vehicle are known. These vehicles are equipped with a power supply device for supplying AC power to the electric motor. This power supply device includes, for example, a battery (secondary battery), a DC-DC converter (transformer circuit) for boosting the voltage of the battery, an inverter for converting the boosted DC power to AC power, a battery and DC-DC. A relay for switching between a connected state and a disconnected state with the converter.

JP-A-7-169380

  By the way, it is known that abnormal noise is generated when the above-mentioned relay is switched on (connected state) / off (disconnected state). However, abnormal noise also occurs while the relay is on (connected state). In particular, the switching of the relay on / off is limited to the time when the ignition switch is turned on / off, but the relay is kept on while the ignition switch is turned on. Therefore, the driver of the vehicle or the like may feel discomfort due to the abnormal noise generated while the relay is on.

  As a countermeasure against the sound of the relay, there is a method of providing a sound absorbing material (for example, cotton) around the relay. For example, Patent Literature 1 discloses a method of filling the entire area between a relay cover and an outer cover with an insulating material in order to improve the soundproofing of the relay.

  However, if a member such as a sound absorbing material is separately provided as a measure against the sound of the relay, cost and weight increase. By the way, if a member for noise suppression is provided so as to cover the relay, the relay is likely to be broken down due to heat or the like. Therefore, if the noise control members are provided in the entire surrounding area at some distance from the relay, a large amount of noise control members are required, and the cost and weight increase according to the amount.

  The present invention has been made in order to solve the above problems, and a power supply device capable of suppressing abnormal noise caused by a relay in a connected state without separately providing a member for sound suppression. The purpose is to provide.

  A power supply device according to the present invention is a power supply device including a secondary battery, a transformer circuit, and a relay for switching the secondary battery and the transformer circuit between a connected state and a disconnected state, wherein the relay is connected to a coil. When the movable contact moves in accordance with energization / de-energization, the movable contact comes into contact with the fixed contact in the connected state, and the movable contact separates from the fixed contact in the cut-off state. When an electric current flows, an electromagnetic force in a direction from the movable contact side to the fixed contact side is generated.

  The inventors of the present application have conducted intensive studies on the above-described problems. As a result, when the connection state is established, the movable contact that is in contact with the fixed contact vibrates due to the ripple current generated in the transformer circuit. (Abnormal noise) was obtained.

  Therefore, the power supply device according to the present invention is configured such that an electromagnetic force in a direction from the movable contact side to the fixed contact side is generated when the secondary battery is discharged, so that the ripple current generated in the movable contact by the transformer circuit is generated. Flows, the electromagnetic force in the direction from the movable contact to the fixed contact changes (increases or decreases) due to the ripple current. Therefore, when the secondary battery is discharged, the ripple current causes the electromagnetic force to change in the direction in which the movable contact is pressed against the fixed contact. When charging the secondary battery, the current flowing through the movable contact is smaller than when discharging the secondary battery, so that the vibration noise generated by the ripple current is small. As described above, according to the power supply device of the present invention, it is possible to suppress the vibration noise (abnormal noise) generated in the relay due to the ripple current in the connected state without separately providing a member for noise suppression. Becomes

  In the power supply device according to the present invention, the relay includes the pair of permanent magnets, and the pair of permanent magnets is arranged such that the N pole of one permanent magnet and the S pole of the other permanent magnet face each other with the movable contact therebetween. It is preferable to generate an electromagnetic force when a current flows through the movable contact in a magnetic field generated between the N pole of one permanent magnet and the S pole of the other permanent magnet. By doing so, the direction in which the electromagnetic force acts when the secondary battery is discharged can be set by the connection destination of the fixed contact and the arrangement of the pair of permanent magnets.

  In the power supply device according to the present invention, when the relay is a positive-side relay that switches the positive side of the secondary battery and the transformer circuit between the connected state and the cutoff state, the direction of the current flowing through the movable contact when the secondary battery is discharged is A pair of permanent magnets are arranged so that a current flows from the secondary battery to the transformer circuit, and the direction of the electromagnetic force is from the movable contact to the fixed contact according to the direction of the current flowing to the movable contact. Configuration. With such a configuration, in the relay on the positive electrode side, the electromagnetic force acts in the direction of pressing the movable contact against the fixed contact when the secondary battery is discharged.

  In the power supply device according to the present invention, when the relay is a negative-side relay that switches the negative side of the secondary battery and the transformer circuit between a connected state and a cut-off state, the direction of the current flowing through the movable contact when the secondary battery is discharged is A pair of permanent magnets are arranged so that current flows from the transformer circuit to the secondary battery, and the direction of the electromagnetic force is from the movable contact side to the fixed contact side according to the direction of the current flowing through the movable contact. Configuration. With this configuration, in the negative electrode side relay, the electromagnetic force acts in the direction of pressing the movable contact against the fixed contact when the secondary battery is discharged.

  The power supply device according to the present invention may be mounted on a vehicle having an electric motor as a power source, and the transformer circuit may increase the voltage of the secondary battery when the secondary battery is discharged. In the case of this configuration, the current flowing through the movable contact of the relay is large (particularly, the current (maximum value) that flows when the secondary battery is discharged to drive the electric motor is larger than when the secondary battery is charged), so that the ripple current also becomes large. . ADVANTAGE OF THE INVENTION According to the power supply device which concerns on this invention, even when a large electric current flows into a movable contact at the time of discharge of a secondary battery, etc., the vibration noise which generate | occur | produces in a relay by ripple current can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to suppress the abnormal noise resulting from a relay at the time of a connection state, without providing the member for sound measures separately.

FIG. 2 is a block diagram illustrating a configuration of a power supply device according to the embodiment. It is a sectional view showing an example of a relay (OFF state) of a power supply device concerning an embodiment. It is a sectional view showing an example of a relay (ON state) of a power supply device concerning an embodiment. FIG. 4 is a plan view showing an arrangement of fixed contacts, movable contacts, and permanent magnets of the relay shown in FIGS. 2 and 3. It is a figure which shows the relationship between the electric current which flows through a relay at the time of discharge and charge, and the magnitude of a vibration sound, (a) is the case of the power supply device which concerns on embodiment, (b) is the case of the conventional power supply device. .

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts have the same reference characters allotted. In the respective drawings, the same elements are denoted by the same reference numerals, and redundant description will be omitted.

  A power supply device 1 according to the embodiment will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of a power supply device 1 according to the embodiment. In the present embodiment, the present invention is applied to a power supply device 1 mounted on a vehicle having an electric motor as a drive source. The vehicle may be an electric vehicle (EV [Electric Vehicle]) including only an electric motor as a drive source, or a hybrid vehicle (HEV [Hybrid Electric Vehicle]) including an electric motor and an engine as a drive source.

  The power supply device 1 converts the DC power of the battery 10 into AC power and supplies it to the electric motor 2 when the vehicle is accelerating. In addition, when the vehicle decelerates, power supply device 1 converts AC power generated by electric motor 2 by regenerative braking into DC power to charge battery 10. The electric motor 2 functions as an electric motor, and is, for example, a three-phase AC type AC synchronous motor. The electric motor 2 is a motor generator that also functions as a generator.

  The power supply device 1 includes a battery 10 (corresponding to a secondary battery described in the appended claims), a DC-DC converter 11 (corresponding to a transformer circuit described in the appended claims), an inverter 12, a relay 13, 14 is provided. The power supply device 1 is controlled by an ECU [Electronic Control Unit] 15.

  The battery 10 is a chargeable / dischargeable secondary battery, and includes, for example, a lithium ion battery and a nickel hydride battery. The battery 10 is a high-voltage battery, for example, a battery of several hundred volts. The battery 10 is configured to have a predetermined voltage by connecting a plurality of secondary batteries in series, for example, and the plurality of serially connected secondary batteries are stored in a battery box. The battery 10 is discharged when the electric motor 2 is energized, and charged when the electric motor 2 is regenerated.

  The DC-DC converter 11 boosts the DC voltage of the battery 10 to a desired voltage. Further, the DC-DC converter 11 reduces the high-voltage DC current converted by the inverter 12 to a voltage at which the battery 10 can be charged. The DC-DC converter 11 includes, for example, a reactor (power inductor), a switching element (for example, IGBT), and the like, and accumulates and discharges electric energy in the reactor in accordance with ON / OFF of the switching element, so that the voltage is increased. change.

  In the DC-DC converter 11, a ripple current is generated with switching by the switching element. The frequency of the ripple current is the same as the switching frequency of the switching element. The switching frequency is, for example, several kHz to several tens kHz.

  The inverter 12 converts the high-voltage DC current boosted by the DC-DC converter 11 into a three-phase AC current, and supplies the AC current to the electric motor 2. The inverter 12 converts the three-phase alternating current generated by the electric motor 2 into a direct current. The inverter 12 includes, for example, two switching elements and two diodes corresponding to each phase of the electric motor 2, and the switching elements of each phase are turned on / off. The inverter 12 and the DC-DC converter 11 constitute, for example, a power control unit (PCU).

  The relay 13 is a relay on the positive electrode side, and is provided on a power supply line 16 on the positive electrode side for connecting the battery 10 and the DC-DC converter 11. The relay 14 is a negative-side relay, and is provided on a negative-side energizing line 17 for connecting the battery 10 and the DC-DC converter 11. The relays 13 and 14 are stored in, for example, the battery box described above.

  Relays 13 and 14 switch battery 10 and DC-DC converter 11 between a connected state and a disconnected state. In the connected state, battery 10 and DC-DC converter 11 are electrically connected via relays 13 and 14. In the cutoff state, the battery 10 and the DC-DC converter 11 are cut off electrically. The relays 13 and 14 are switched to a connected state when a predetermined condition at the time of turning on is satisfied after an ignition switch (not shown) is turned on, and cut off when a predetermined condition at the time of turning off is satisfied after the ignition switch is turned off. State.

  The relays 13 and 14 are electromagnetic relays. An example of the configuration of the electromagnetic relays 13 and 14 will be described with reference to FIGS. FIG. 2 is a cross-sectional view illustrating an example of the relays 13 and 14 (OFF state) of the power supply device 1 according to the embodiment. The relay 13 and the relay 14 have the same configuration. FIG. 3 is a cross-sectional view illustrating an example of the relays 13 and 14 (ON state) of the power supply device 1 according to the embodiment. The relay 13 and the relay 14 have the same configuration. 2 and 3 are cross-sectional views taken along a line connecting the center of the fixed contact 21 and the center of the fixed contact 22.

  The relays 13 and 14 include a coil 20, a pair of fixed contacts 21 and 22, a movable contact 23, a fixed iron core 24, a movable iron core 25, a return spring 26, a rod 27, a contact pressure spring 28, And the permanent magnets 29 and 30 of FIG.

  One fixed contact 21 of the relay 13 is connected to one end of an energizing line 16a. The other end of the power supply line 16a is connected to a positive terminal (plus terminal) of the battery 10. One end of an energizing line 16b is connected to the other fixed contact 22 of the relay 13. The other end of the energizing line 16b is connected to the DC-DC converter 11. The energizing line 16 includes the energizing line 16a and the energizing line 16b.

  One fixed contact 21 of the relay 14 is connected to one end of an energizing line 17b. The other end of the energizing line 17b is connected to the DC-DC converter 11. One end of an energizing line 17a is connected to the other fixed contact 22 of the relay 14. The other end of the power supply line 17a is connected to a negative terminal (negative terminal) of the battery 10. The energizing line 17 includes the energizing line 17a and the energizing line 17b.

  The fixed contact 21 and the fixed contact 22 are arranged in parallel at a predetermined interval. One end face of the fixed contacts 21 and 22 on the movable contact 23 side is a flat end face, for example, a circular flat end face. One end face of the fixed contact 21 and one end face of the fixed contact 22 are arranged at the same height position.

  The movable contact 23 is arranged on one end face side of the fixed contacts 21 and 22 so as to face the one end face. The movable contact 23 is movable from a position separated by a predetermined distance from the fixed contacts 21 and 22 to a position in contact with each end face of the fixed contacts 21 and 22. The movable contact 23 has, for example, a flat plate shape.

  The fixed core 24 and the movable core 25 are arranged at the center of the cylindrical coil 20. The movable iron core 25 is arranged on one end face side of the fixed iron core 24 so as to face this one end face. The return spring 26 is arranged between the fixed iron core 24 and the movable iron core 25. One end of the rod 27 is fixed to the center of the movable iron core 25. The other end of the rod 27 passes through the center of the fixed iron core 24. The contact pressure spring 28 is arranged between the flange-shaped other end of the rod 27 and the movable contact 23.

  The pair of permanent magnets 29 and 30 are permanent magnets for extinguishing arc discharge. As shown in FIG. 4, the pair of permanent magnets 29 and 30 are opposed to each other across the fixed contacts 21 and 22 and the movable contact 23 (particularly, the contact points between the fixed contacts 21 and 22 and the movable contact 23). Have been. In particular, the N pole of one permanent magnet 29 and the S pole of the other permanent magnet 30 face each other. The permanent magnets 29 and 30 have, for example, a flat plate shape.

  When the coil 20 is energized and excited, a magnetic flux is generated and a magnetic field is generated. This magnetic field magnetizes the fixed core 24 and the movable core 25 and attracts each other. Thereby, the movable core 25 moves to the fixed core 24 side, and the rod 27 moves with the movement of the movable core 25. With the movement of the rod 27, the movable contact 23 moves toward the fixed contacts 21 and 22, and the movable contact 23 contacts one end face of the fixed contact 21 and one end face of the fixed contact 22 as shown in FIG. I do. As a result, the relays 13 and 14 are connected (on), and the fixed contact 21 and the fixed contact 22 are electrically connected via the movable contact 23.

  When the current supply to the coil 20 is stopped, the coil 20 is demagnetized. Due to this demagnetization, the magnetization of the fixed iron core 24 and the movable iron core 25 is eliminated. Thereby, the movable iron core 25 moves to the opposite side (the side away from the fixed iron core 24) by the return spring 26, and the rod 27 moves with the movement of the movable iron core 25. With the movement of the rod 27, the movable contact 23 moves to a side opposite to the fixed contacts 21 and 22 (a side away from the fixed contacts 21 and 22), and as shown in FIG. Move away from As a result, the relays 13 and 14 are turned off (off).

  The ECU 15 that controls the relays 13 and 14 will be described. The ECU 15 includes a microprocessor for performing calculations, a ROM for storing a program for causing the microprocessor to execute each process, a RAM for storing various data such as calculation results, a backup RAM for storing the stored contents, and an input / output device. It has an I / F and the like. The ECU 15 performs energization / stop of energization of the relays 13 and 14 (coil 20), switching control of the switching element of the DC-DC converter 11, switching control of the switching element of the inverter 12, and the like. The ECU 15 may be, for example, a motor control ECU, a hybrid control ECU, or a plurality of ECUs. In the case of a configuration including a plurality of ECUs, for example, the energization / de-energization of the relays 13 and 14 is performed by a battery ECU, and the switching control of the DC-DC converter 11 and the inverter 12 is performed by a motor control ECU.

  In addition, between the pair of permanent magnets 29, 30, a magnetic flux is generated from the N pole of one permanent magnet 29 to the S pole of the other permanent magnet 30, and a magnetic field is generated. When a current flows through the movable contact 23 in this magnetic field, an electromagnetic force is generated. Therefore, in the relays 13 and 14, the electromagnetic force acts on the movable contact 23 in the connected state. According to Fleming's left-hand rule, the direction in which the electromagnetic force acts depends on the direction of the current flowing through the movable contact 23 and the arrangement of the pair of permanent magnets 29 and 30 with respect to the movable contact 23 (the magnetic field generated between the permanent magnets 29 and 30). Direction).

  As described above, in the DC-DC converter 11, a ripple current occurs. This ripple current is superimposed on the DC current and flows to the relays 13 and 14 (movable contacts 23). Since the magnitude of the ripple current changes periodically, the current flowing through the movable contact 23 changes periodically, and the electromagnetic force acting on the movable contact 23 changes (increases or decreases). The change in the electromagnetic force causes the movable contact 23 in contact with the fixed contacts 21 and 22 to vibrate, thereby generating a vibration sound. In particular, in the power supply device 1 using the high-voltage battery 10 to drive the electric motor 2, the DC current flowing through the movable contacts 23 of the relays 13 and 14 is large (particularly, the charging is performed to drive the electric motor 2 during discharging. Since the current (maximum value) flowing is larger than at the time, the ripple current also increases, and the vibration noise increases. The power supply device 1 has a configuration for suppressing this vibration sound.

  A method for connecting the fixed contacts 21 and 22 and a method for arranging the permanent magnets 29 and 30 for suppressing the vibration noise will be described with reference to FIG. FIG. 4 is a plan view showing the arrangement of the fixed contacts 21 and 22, the movable contacts 23 and the permanent magnets 29 and 30 of the relays 13 and 14 shown in FIGS. 2 and 3. FIG. 4 shows the arrangement of the fixed contacts 21 and 22, the movable contact 23, and the permanent magnets 29 and 30 when the movable contact 23 is viewed from the fixed contacts 21 and 22.

  In the relay 13, the fixed contact 21 is connected to the positive terminal of the battery 10 via the power supply line 16a, and the fixed contact 22 is connected to the DC-DC converter 11 via the power supply line 16b. On the other hand, in the relay 14, the fixed contact 21 is connected to the DC-DC converter 11 via the power supply line 17b, and the fixed contact 22 is connected to the negative terminal of the battery 10 via the power supply line 17a. Therefore, in both the relays 13 and 14, a current flows from the fixed contact 21 to the fixed contact 22 when the battery 10 is discharged, and a current flows from the fixed contact 22 to the fixed contact 21 when the battery 10 is charged.

  Further, in the relays 13 and 14, a pair of permanent magnets 29 and 30 are arranged at respective positions sandwiching the movable contact 23 so as to be parallel to the longitudinal direction of the movable contact 23. In particular, when a current flows from the fixed contact 21 to the fixed contact 22 at the movable contact 23 when the battery 10 is discharged, the pair of permanent magnets 29 and 30 generate electromagnetic force in the direction from the movable contact 23 to the fixed contacts 21 and 22. It is arranged to generate a magnetic field in a direction to generate a force. For example, as shown in FIG. 4, when it is assumed that the fixed contact 21 side is the rear side and the fixed contact 22 is the front side, the N pole is the permanent magnet 29 on the movable contact 23 side and the S pole is the right side of the movable contact 23. The permanent magnet 30 on the movable contact 23 side is on the left side of the movable contact 23.

  When the battery 10 is discharged, a DC current flows from the fixed contact 21 to the fixed contact 22 through the movable contacts 23 of the relays 13 and 14. In the relays 13 and 14, a magnetic flux is generated from the N pole of the permanent magnet 29 to the S pole of the permanent magnet 30, and a magnetic field in the direction of arrow D shown in FIG. 4 is generated. In the case of the current flowing direction and the magnetic field direction D, an electromagnetic force is generated from the movable contact 23 to the fixed contacts 21 and 22 according to Fleming's left-hand rule. This electromagnetic force acts in a direction to press the movable contact 23 against the fixed contacts 21 and 22. In particular, when the ripple current generated by the DC-DC converter 11 is superimposed on the DC current and flows through the movable contact 23, the movable contact 23 is pressed against the fixed contacts 21 and 22 in accordance with the periodic change of the ripple current. The acting electromagnetic force changes (increases or decreases).

  By the way, since the electric motor 2 is driven at the time of discharging, the maximum value of the DC current flowing through the relays 13 and 14 (movable contact 23) is larger than at the time of charging. As the DC current increases, the ripple current also increases, and the change in the electromagnetic force accompanying the change in the ripple current also increases. As described above, the electromagnetic force acts in the direction of pressing the movable contact 23 against the fixed contacts 21 and 22 during discharging. Even if the electromagnetic force in this direction changes due to the ripple current, the movable contact 23 that is in contact with the fixed contacts 21 and 22 is always pressed against the fixed contacts 21 and 22 by the electromagnetic force. hard.

  On the other hand, when the battery 10 is charged, a DC current flows from the fixed contact 22 to the fixed contact 21 through the movable contacts 23 of the relays 13 and 14. As in the case of charging, a magnetic field in the direction of arrow D shown in FIG. In the case of the current flowing direction and the magnetic field direction D, an electromagnetic force is generated from the fixed contacts 21 and 22 to the movable contact 23 according to Fleming's left-hand rule. This electromagnetic force acts in a direction to separate the movable contact 23 from the fixed contacts 21 and 22. In particular, when the ripple current generated by the DC-DC converter 11 is superimposed on the DC current and flows through the movable contact 23, the movable contact 23 is separated from the fixed contacts 21 and 22 in accordance with the periodic change of the ripple current. The acting electromagnetic force changes (increases or decreases). The change in the electromagnetic force in this direction causes the movable contact 23 that is in contact with the fixed contacts 21 and 22 to vibrate away from the fixed contacts 21 and 22, so that a vibration sound is easily generated.

  However, at the time of charging, the maximum value of the DC current flowing through the relays 13 and 14 (the movable contact 23) is smaller than at the time of discharging, so that the ripple current is also smaller. Therefore, the change in the electromagnetic force due to the change in the ripple current is small, and the magnitude (sound pressure) of the vibration sound can be suppressed.

  Finally, an example of the magnitude of the vibration sound at the time of discharging and charging of the battery 10 will be described with reference to FIG. FIGS. 5A and 5B are diagrams showing the relationship between the current flowing through the relays 13 and 14 at the time of discharging and charging and the magnitude of the vibration sound. FIG. 5A shows the case of the power supply device 1 according to the embodiment, and FIG. This is the case of a conventional power supply device. In addition, the conventional power supply device generates an electromagnetic force in the direction from the fixed contact side to the movable contact side during discharging (compared to the power supply device 1 according to the embodiment) (in the direction from the movable contact side to the fixed contact side during charging). A different point is that the relay is configured to generate electromagnetic force).

  5A and 5B, the horizontal axis is the current (A), and the vertical axis is the magnitude (dB) of the vibration sound. In the example shown in FIG. 5, the maximum value of the DC current flowing through the relays 13 and 14 (movable contacts 23) is approximately 200 A during discharging and approximately 100 A during charging. The amplitude of the ripple current is several A. In FIG. 5A, an example of the relationship between the current at the time of discharging and the magnitude of the vibration sound is indicated by a line indicated by reference symbol DR, and the relationship between the current during charging and the magnitude of the oscillation sound is indicated by the line indicated by reference symbol CR. An example is shown. In FIG. 5B, an example of the relationship between the current at the time of discharging and the magnitude of the vibration sound is indicated by a line indicated by reference symbol DR ′, and the current during charging and the magnitude of the vibration sound are indicated by the line indicated by reference sign CR ′. Is shown as an example.

  The case of the power supply device 1 will be described with reference to FIG. At the time of discharge, the vibration noise is hardly generated in the relays 13 and 14, and therefore, as the current flowing through the movable contact 23 increases, the vibration noise decreases as indicated by the line DR. On the other hand, at the time of charging, the relays 13 and 14 tend to generate a vibration sound. Therefore, the vibration sound increases as the current flowing through the movable contact 23 increases as indicated by the line CR. However, at the time of charging, the maximum value of the current flowing through the movable contact 23 is smaller than at the time of discharging, so that the vibration noise is suppressed from increasing.

  Referring to FIG. 5B, a case of a conventional power supply device will be described as a comparative example. At the time of discharging, a vibration sound is easily generated in the relay. Therefore, as the current flowing through the movable contact increases, the vibration sound increases as indicated by the line DR '. In particular, at the time of discharging, the maximum value of the current flowing through the movable contact is larger than at the time of charging, so that the vibration noise is increased. The driver and the like in the vehicle feel discomfort due to the loud vibration sound. On the other hand, at the time of charging, the relay does not easily generate vibration noise, and therefore, the vibration noise decreases as the current flowing through the movable contact increases, as indicated by the line CR '.

  According to the power supply device 1 according to the embodiment, the electromagnetic force acts in the direction of pressing the movable contact 23 against the fixed contacts 21 and 22 when the battery 10 is discharged. Without this, it is possible to suppress the vibration noise (abnormal noise) generated in the relays 13 and 14 due to the ripple current in the connected state. Since it is not necessary to provide a member for sound countermeasures to suppress vibration noise, cost and weight do not increase.

  According to the power supply device 1 according to the embodiment, the connection destination of the fixed contacts 21 and 22 (the direction of the current that can flow through the movable contact 23) and the arrangement of the pair of permanent magnets 29 and 30 (generated between the permanent magnets 29 and 30). The direction in which the electromagnetic force acts when the battery 10 is discharged can be set by the direction of the magnetic field.

  As described above, the embodiments of the present invention have been described. However, the present invention is not limited to the above embodiments, and various modifications are possible. For example, in the above-described embodiment, the present invention is applied to a vehicle including the electric motor 2 as a driving source. However, any power supply device including a relay between a secondary battery and a transformer circuit may be applied to a vehicle other than the vehicle.

  In the above embodiment, the relays 13 and 14 are provided on both sides of the positive electrode side and the negative electrode side. However, the present invention can be applied to a case where relays are provided only on one side such as the positive electrode side.

Reference Signs List 1 power supply device 2 electric motor 10 battery (secondary battery)
11 DC-DC converter (Transformer circuit)
12 Inverter 13,14 Relay 20 Coil 21,22 Fixed contact 23 Movable contact 29,30 Permanent magnet

Claims (3)

A power supply device comprising: a secondary battery, a transformer circuit, and a relay that switches the secondary battery and the transformer circuit between a connected state and a disconnected state,
In the relay, the movable contact moves in accordance with energization / de-energization of the coil, so that the movable contact comes into contact with a fixed contact in the connection state, and the movable contact moves from the fixed contact in the cutoff state. Away,
When discharging the secondary battery, it is configured to generate an electromagnetic force in a direction from the movable contact side to the fixed contact side when a current flows through the movable contact ,
Further, the relay includes a pair of permanent magnets,
The pair of permanent magnets are disposed so that the N pole of one permanent magnet and the S pole of the other permanent magnet face each other with the movable contact therebetween.
When a current flows through the movable contact in a magnetic field generated between the N pole of the one permanent magnet and the S pole of the other permanent magnet, the electromagnetic force is generated,
When the relay is a positive-side relay that switches the positive side of the secondary battery and the transformer circuit between a connected state and a disconnected state, the direction of current flowing through the movable contact when the secondary battery is discharged is the secondary direction. A direction in which current flows from the battery to the transformer circuit, and the pair of permanent magnets is arranged such that the direction of the electromagnetic force is in the direction from the movable contact side to the fixed contact side in accordance with the direction of the current flowing through the movable contact. A power supply device, wherein a magnet is arranged . A power supply device comprising: a secondary battery, a transformer circuit, and a relay that switches the secondary battery and the transformer circuit between a connected state and a disconnected state,
In the relay, the movable contact moves in accordance with energization / de-energization of the coil, so that the movable contact comes into contact with a fixed contact in the connection state, and the movable contact moves from the fixed contact in the cutoff state. Away,
When discharging the secondary battery, it is configured to generate an electromagnetic force in a direction from the movable contact side to the fixed contact side when a current flows through the movable contact ,
Further, the relay includes a pair of permanent magnets,
The pair of permanent magnets are disposed so that the N pole of one permanent magnet and the S pole of the other permanent magnet face each other with the movable contact therebetween.
When a current flows through the movable contact in a magnetic field generated between the N pole of the one permanent magnet and the S pole of the other permanent magnet, the electromagnetic force is generated,
When the relay is a negative-side relay that switches the negative side of the secondary battery and the transformer circuit between a connected state and a disconnected state, the direction of current flowing through the movable contact when the secondary battery is discharged is the direction of the transformer circuit. From the movable contact to the fixed contact side so that the direction of the electromagnetic force is in the direction from the movable contact side to the fixed contact side according to the direction of the current flowing to the movable contact. A power supply device, wherein a magnet is arranged . Installed in vehicles equipped with an electric motor as a power source,
The transformer circuit includes a power supply device according to claim 1 or 2, characterized in that characterized in that boosts the voltage of the secondary battery during discharging of the secondary battery.

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