JP6102721B2 - Power storage device and battery device - Google Patents

Description

  The present invention relates to a power storage device and a battery device including a power storage unit that assists the operation of a battery.

  Some conventional vehicles include a power storage unit that assists the operation of the battery in addition to the battery when the voltage of the battery decreases. The power storage unit is also used as an emergency power source that supplies power to the load when the power from the battery is lost in a vehicle collision or the like. A capacitor may be used as the power storage unit. It is known that when a capacitor is left in a charged state, deterioration proceeds. Therefore, when the capacitor is not used, such as when the vehicle is stopped, the capacitor is discharged. Patent Document 1 discloses a circuit that receives a signal for turning on or off a battery, operates a relay switch in accordance with the received signal, and switches between charging and discharging of a capacitor.

JP 2011-159010 A

  When the prior art disclosed in Patent Document 1 is applied to a vehicle, it is impossible to distinguish between a case where the battery is turned off and a case where power from the battery is lost. For this reason, when the electric power from a battery is lost and the electric power feeding from an electrical storage part is required, there exists a problem that an electrical storage part discharges and electric power feeding from an electrical storage part becomes impossible.

  The present invention has been made in view of such circumstances, and the object of the present invention is to distinguish between the case where the connection with the battery is turned off and the case where the power from the battery is lost. It is an object of the present invention to provide a power storage device and a battery device that can supply power from a power storage unit to a load when the power of the power is lost.

A power storage device according to the present invention includes a power storage unit, a charging unit that is supplied with electric power from an external battery and charges the power storage unit, and a discharge unit that discharges the power storage unit, and is connected to the external battery. A connection line, one end of which is connected to the charging unit, the other end of which is connected to the external battery, and a voltage between one end of the switch and the connection line is detected, and the voltage is A discharge control unit that causes the discharge unit to discharge the power storage unit when a predetermined threshold value is exceeded, and prohibits discharging of the power storage unit by the discharge unit when the voltage is equal to or lower than the threshold value. It is characterized by.

Power storage device according to the present invention, the front Symbol discharge unit has an on / off capable discharge circuit for discharging the power storage unit, the discharge controller is connected to one end and the connection line of the switch The discharge circuit is turned on when a voltage exceeding the threshold is applied between one end of the switch and the connection line, and the discharge circuit is applied when a voltage equal to or lower than the threshold is applied. Is configured to be in an off state.

  In the power storage device according to the present invention, the discharge circuit includes a first switching element, and the discharge control unit is applied with a voltage between one end of the switch and the connection line, and the voltage is the threshold value. The second switching element is turned on when the second switching element is exceeded, and the second switching element is turned on so that the first switching element is turned on when the second switching element is turned on. The first switching element is connected.

  The power storage device according to the present invention further includes means for stopping charging when a voltage between terminals of the power storage unit exceeds a predetermined voltage.

  The power storage device according to the present invention further includes means for supplying power from the power storage unit to an external load.

  The power storage device according to the present invention is characterized in that the power storage unit is a capacitor.

  A battery device according to the present invention includes the power storage device according to the present invention and a battery that supplies power to the power storage device.

  In the present invention, the power storage device charged from the battery discharges the power storage unit when the voltage between the connection line connected to the battery and the charging unit is large, and the connection line connected to the battery and the charging unit When the voltage between is low, the power storage unit is not discharged. When the charging is normally stopped, the voltage of the connecting part is low while the voltage of the connecting line is high, and the voltage between the connecting line and the charging part is increased. Therefore, the power storage device discharges the power storage unit when charging is normally stopped. When charging is performed, the connection line and the charging unit are substantially at the same potential. When the power from the battery is lost, both the voltage of the connection line and the charging unit are lowered, and the voltage between the connection line and the charging unit is small. Therefore, the power storage device does not discharge the power storage unit when the voltage between the connection line and the charging unit is small, so that the power storage unit is not discharged when the power from the battery is lost.

  In the present invention, the power storage device turns on the discharge circuit when a large voltage is applied between the switch that connects the charging unit to the battery and the connection line. Thus, the power storage device can discharge the power storage unit when the voltage between the connection line and the charging unit is large. Further, the power storage device turns off the discharge circuit when the voltage applied between the switch and the connection line is small. Thus, the power storage device cannot discharge the power storage unit when the voltage between the connection line and the charging unit is small.

  In the present invention, the power storage device includes a first switching element that turns on / off the discharge circuit and a second switching element that turns on / off the first switching element. When the voltage between the connection line connected to the battery and the switch is large, the second switching element is turned on, the first switching element is turned on, and the power storage unit is discharged.

  In the present invention, the power storage device stops charging the power storage unit when the voltage between the terminals of the power storage unit exceeds a predetermined voltage. This prevents overcharging of the power storage unit.

  In the present invention, the power storage device can supply power from the power storage unit to an external load. For this reason, when the power from the battery is lost, the power storage unit can supply power to an external load.

  In the present invention, the power storage unit is a capacitor and can be repeatedly charged and discharged.

  In the present invention, the power storage unit does not discharge when power from the battery is lost, such as when a vehicle collides. For this reason, when the power from the battery is lost, the power storage device can supply power from the power storage unit to the load.

It is a block diagram which shows the internal structure of a battery apparatus. It is a partial circuit diagram which shows the circuit structural example of an electrical storage apparatus. It is a typical timing chart which shows the timing of operation of an electrical storage device.

Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.
FIG. 1 is a block diagram showing an internal configuration of the battery device. The battery 3 is a vehicle-mounted battery mounted on a vehicle and supplies power to a load 4 disposed in the vehicle. The power storage device 1 of the present invention is connected between a battery 3 and a load 4. The battery 3 and the power storage device 1 constitute the battery device of the present invention. A power line (connection line) 21 is connected to the battery 3, and the load 4 is connected to the battery 3 via the power line 21. Electric power is supplied from the battery 3 to the load 4 through the electric power line 21.

  The power storage device 1 includes an IG (ignition) relay 22 that is turned on when an engine (not shown) mounted on the vehicle operates. When the engine is stopped, the IG relay 22 is turned off. The IG relay 22 corresponds to the switch in the present invention. One end of the IG relay 22 is connected to the emitter of the pnp-type first transistor 13. The other end of the IG relay 22 is connected to the battery 3 in parallel with the power line 21. Hereinafter, one end of the IG relay 22 is referred to as an internal end. The collector of the first transistor 13 is connected to one end of the resistor 113.

  The power storage device 1 includes a capacitor 111 corresponding to the power storage unit in the present invention. Since the capacitor 111 is used as the power storage unit, the power storage device 1 can be easily charged and discharged and has high stability. The capacitor 111 has a ground end and a non-ground end. The other end of the resistor 113 is connected to the non-grounded end of the capacitor 111. When the IG relay 22 and the first transistor 13 are on, the power from the battery 3 is supplied to the capacitor 111 and the capacitor 111 is charged. The first transistor 13 and the resistor 113 are included in the charging unit in the present invention. That is, the IG relay 22 is connected to the charging unit and serves as a switch for turning on / off the power supply to the charging unit. When the IG relay 22 is in the off state, power from the battery 3 is not supplied. Hereinafter, one end of the IG relay 22 connected to the first transistor 13 is referred to as an internal end.

  A power supply unit 14 for supplying power charged in the capacitor 111 to the load 4 is connected to the non-grounded end of the capacitor 111. The power feeding unit 14 is connected to the load 4 and can supply power from the capacitor 111 to the load 4.

  The power storage device 1 includes a discharge circuit 11 including a capacitor 111 and a resistor 113. One end of the resistor 113 is connected to the drain of an N-type channel first FET (Field effect transistor) 112. The source of the first FET 112 is grounded. When the first FET 112 is in the on state, the discharge circuit 11 is closed, and a current using the capacitor 111 as a power source flows through the resistor 113 and the first FET 112, and the capacitor 111 is discharged. The first FET 112 corresponds to the first switching element in the present invention.

  The power storage device 1 includes a discharge control unit 12. The discharge control unit 12 is connected to the middle of the power line 21 and the internal end of the IG relay 22, and is further connected to the gate of the first FET 112. The discharge controller 12 switches the first FET 112 on and off according to the voltage between the power line 21 and the internal end of the IG relay 22. Thereby, the discharge controller 12 controls whether or not the capacitor 111 is discharged by the discharge circuit 11.

  The power storage device 1 further includes a comparison circuit 15 that compares the voltage between both terminals of the capacitor 111 and the output voltage of the battery 3. The comparison circuit 15 is connected to the base of the first transistor 13 and switches the first transistor 13 on and off according to the voltage comparison result.

  FIG. 2 is a partial circuit diagram illustrating a circuit configuration example of the power storage device 1. The power feeding unit 14 is configured by a DC (Direct Current) DC converter. The discharge control unit 12 includes a P-type channel second FET 121 and a resistor 122. The second FET 121 corresponds to the second switching element in the present invention. The source of the second FET 121 is connected in the middle of the power line 21, and the gate of the second FET 121 is connected to the inner end of the IG relay 22. The drain of the second FET 121 is grounded via a resistor 122. The gate of the first FET 112 is connected to the drain of the second FET 121. When the IG relay 22 is in the ON state, the power line 21 and the internal ends of the IG relay 22 have the same potential, the source voltage of the second FET 121 is high, and the gate voltage is also high. The gate-source voltage is less than the threshold voltage for turning on the second FET 121, and the second FET 121 is off. For this reason, the voltage of the gate of the first FET 112 becomes low, the first FET 112 is in an off state, and the discharge circuit 11 cannot discharge the capacitor 111. In this way, the discharge control unit 12 prohibits the capacitor 111 from discharging.

  When the IG relay 22 is turned off, the voltage of the power line 21 continues to be high, while the voltage at the inner end of the IG relay 22 becomes low. The source voltage of the second FET 121 is high, the gate voltage is low, the gate-source voltage exceeds the threshold voltage, and the second FET 121 is turned on. The voltage of the gate of the first FET 112 becomes high, the first FET 112 is turned on, the discharge circuit 11 becomes a closed circuit, and the discharge circuit 11 discharges the capacitor 111. In this way, the discharge control unit 12 causes the discharge circuit 11 to discharge the capacitor 111.

  The comparison circuit 15 is composed of a regulator using a comparator 151. The cathode of the Zener diode 153 is connected to the non-inverting input (+ IN) terminal of the comparator 151. The cathode of the Zener diode 153 is further connected to the internal end of the IG relay 22 via the resistor 156, and the anode of the Zener diode 153 is grounded. As a result, the non-inverting input (+ IN) of the comparator 151 becomes a constant voltage determined by the Zener diode 153. One end of a resistor 157 is connected to the non-grounded end of the capacitor 111, and a grounded resistor 158 is connected to the other end of the resistor 157. Further, the other end of the resistor 157 is connected to the inverting input (−IN) terminal of the comparator 151. Therefore, the voltage between both terminals of the capacitor 111 is divided by the resistors 157 and 158 and becomes an inverting input (−IN) of the comparator 151.

  The output terminal of the comparator 151 is connected to the base of the npn-type second transistor 152. The emitter of the second transistor 152 is grounded, and the collector is connected to the base of the first transistor 13 via a resistor 154. A resistor 155 is connected between the base and emitter of the first transistor 13.

  In a state where the capacitor 111 is not charged, the voltage between both terminals of the capacitor 111 is 0V, and the inverting input (−IN) of the comparator 151 is also 0V. When the IG relay 22 is turned on when the capacitor 111 is not charged, the non-inverting input (+ IN) of the comparator 151 is a constant voltage and the inverting input (−IN) is 0 V. + IN)> inverting input (−IN), and the output of the comparator 151 becomes high. A positive voltage is applied between the base and emitter of the second transistor 152, and the second transistor 152 is turned on. When the second transistor 152 is turned on, a negative voltage is applied between the base and the emitter of the first transistor 13, the first transistor 13 is turned on, and charging of the capacitor 111 is started. By charging, the voltage between both terminals of the capacitor 111 rises, and the inverting input (−IN) of the comparator 151 also rises. When the inverting input (−IN) of the comparator 151 rises and becomes non-inverting input (+ IN) <inverting input (−IN), the output of the comparator 151 becomes low. The second transistor 152 is turned off, the first transistor 13 is also turned off, and charging of the capacitor 111 is stopped. That is, the capacitor 111 is charged until the voltage between both terminals reaches a predetermined voltage, and charging is stopped when the voltage between both terminals exceeds the predetermined voltage. Here, the predetermined voltage is a voltage between both terminals such that the voltage divided by the resistors 157 and 158 has the same value as the non-inverting input (+ IN) of the comparator 151. In this way, the comparison circuit 15 stops charging the capacitor 111, thereby preventing the capacitor 111 from being overcharged.

  FIG. 3 is a schematic timing chart showing the operation timing of the power storage device 1. In the figure, the horizontal axis represents time, and the vertical axis represents the output voltage of the battery 3, the voltage at the internal end of the IG relay 22, the voltage at the non-grounded end of the capacitor 111, and the voltages at the discharge circuit 11 and the power supply unit 14. Yes. The output voltage of the battery 3 is the voltage of the source of the second FET 121, and the voltage at the inner end of the IG relay 22 is the voltage of the gate of the second FET 121. The voltage of the discharge circuit 11 is the voltage of the gate of the first FET 112, and the voltage of the power feeding unit 14 is the output voltage of the power feeding unit 14. Usually, the output voltage of the battery 3 is high. When the IG relay 22 changes from the off state to the on state, the voltage at the inner end of the IG relay 22 changes from low to high. As described above, the second FET 121 is turned off, the voltage of the discharge circuit 11 is low, the first FET 112 is turned off, and the discharge circuit 11 does not discharge the capacitor 111. The capacitor 111 is charged, and the voltage at the non-grounded end of the capacitor 111 increases with charging and becomes high.

  When the IG relay 22 changes from the on state to the off state, the voltage at the internal end of the IG relay 22 changes from high to low. The power from the battery 3 is not supplied, and the capacitor 111 is not charged. As described above, the second FET 121 is turned on, the voltage of the discharge circuit 11 is high, the first FET 112 is turned on, and the discharge circuit 11 discharges the capacitor 111. The capacitor 111 is discharged, and the voltage at the non-grounded end of the capacitor 111 decreases with the discharge and becomes low. The power supply unit 14 does not supply power to the load 4, and the output voltage of the power supply unit 14 is low.

  There is a case where power from the battery 3 is lost, for example, when a car equipped with the battery device causes a collision accident and the battery 3 is damaged or the cable is broken. When the power from the battery 3 is lost, the power supply from the battery 3 is stopped even if the IG relay 22 is turned on. Both the output voltage of the battery 3 and the voltage at the internal end of the IG relay 22 are low. The source potential of the second FET 121 is low, the gate potential is also low, the gate-source voltage is less than the threshold voltage, and the second FET 121 is turned off. For this reason, the voltage of the discharge circuit 11 becomes low, the first FET 112 is turned off, and the discharge circuit 11 does not discharge the capacitor 111. In this manner, the discharge control unit 12 prohibits the discharge of the capacitor 111 when the power supply from the battery 3 is stopped while the IG relay 22 is in the on state. When power from the battery 3 is lost, power supply from the battery 3 to the load 4 through the power line 21 is stopped. Instead, the power feeding unit 14 starts supplying the power charged in the capacitor 111 to the load 4, and the output voltage of the power feeding unit 14 becomes high. The voltage at the non-grounded end of the capacitor 111 gradually decreases as power is supplied. The power supply from the power supply unit 14 enables the load 4 such as a mechanism for releasing the door lock to operate even after the power from the battery 3 is lost.

  Even when the output voltage of the battery 3 decreases during the operation of the battery device, the power storage device 1 performs the same process as when the power from the battery 3 is lost. Since the IG relay 22 is in the ON state, the connection line 21 and the inner end of the IG relay 22 are substantially at the same potential, the second FET 121 and the first FET 112 are in the OFF state, and the discharge circuit 11 does not discharge the capacitor 111. The output voltage from the battery 3 to the load 4 decreases, and instead, the power supply unit 14 supplies the power charged in the capacitor 111 to the load 4.

  As described above in detail, in the present embodiment, power storage device 1 discharges capacitor 111 when IG relay 22 is turned off and power supply from battery 3 is stopped, and IG relay 22 is turned on. When the power supply from the battery 3 is stopped, discharging of the capacitor 111 is prohibited. The capacitor 111 is discharged when the voltage between the internal end of the IG relay 22 and the power line 21 is large, so that the capacitor 111 is discharged when the power supply from the battery 3 is stopped by turning off the IG relay 22. be able to. The capacitor 111 is discharged in a state where the power storage device 1 is not used, and the deterioration of the capacitor 111 is prevented. Further, by prohibiting the discharge of the capacitor 111 when the voltage between the inner end of the IG relay 22 and the power line 21 is small, the discharge of the capacitor 111 can be prohibited when the IG relay 22 is in the ON state. Discharging is prohibited when the capacitor 111 is charged, and discharging is also prohibited when power supply from the battery 3 is stopped while the IG relay 22 is on. Therefore, when the power from the battery 3 is lost during a car crash or the like, the capacitor 111 is not discharged, and the power storage device 1 can supply the power charged in the capacitor 111 to the load 4.

  Note that the above embodiments are merely examples and should not be considered as restrictive. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims. The circuit configuration of the power storage device 1 described in this embodiment is an example, and the power storage device 1 can be configured with other circuits. For example, the power storage device 1 may have a form using a power storage unit other than a capacitor, or a form using a switching element other than an FET. Moreover, the form mounted in vehicles other than a motor vehicle may be sufficient as the battery apparatus 1. FIG. Further, the battery device 1 may be a device other than a vehicle-mounted device.

1 Power Storage Device 11 Discharge Circuit 111 Capacitor (Power Storage Unit)
112 1st FET (1st switching element)
12 Discharge Control Unit 121 Second FET (Second Switching Element)
14 Power Supply Unit 15 Comparison Circuit 21 Power Line (Connection Line)
22 IG relay (switch)
3 Battery 4 Load

Claims (7)

In a power storage device comprising: a power storage unit; a charging unit that is supplied with power from an external battery to charge the power storage unit; and a discharge unit that discharges the power storage unit.
A connection line connected to the external battery;
A switch having one end connected to the charging unit and the other end connected to the external battery;
When a voltage between one end of the switch and the connection line is detected, and the voltage exceeds a predetermined threshold value, the discharge unit is caused to discharge the power storage unit, and the voltage is equal to or lower than the threshold value. And a discharge control unit that prohibits discharge of the power storage unit by the discharge unit. Before Symbol discharge unit has an on / off capable discharge circuit for discharging the power storage unit,
The discharge controller is
The discharge circuit is connected to one end of the switch and the connection line, and when a voltage exceeding the threshold is applied between the one end of the switch and the connection line, the discharge circuit is turned on, and is equal to or lower than the threshold. The power storage device according to claim 1, wherein the discharge circuit is configured to be turned off when a voltage is applied. The discharge circuit includes a first switching element,
The discharge controller is
A second switching element that is turned on when a voltage between one end of the switch and the connection line is applied and the voltage exceeds the threshold;
The first switching element is connected to the second switching element so that the first switching element is turned on when the second switching element is on. Power storage device. The power storage device according to any one of claims 1 to 3, further comprising means for stopping charging when a voltage between terminals of the power storage unit exceeds a predetermined voltage. The power storage device according to any one of claims 1 to 4, further comprising means for supplying power from the power storage unit to an external load. The power storage device according to any one of claims 1 to 5, wherein the power storage unit is a capacitor. The power storage device according to any one of claims 1 to 6,
A battery device comprising: a battery that supplies electric power to the power storage device.

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