JP2015171254A - auxiliary capacitor charge control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an auxiliary capacitor charge control device for a vehicle, capable of continuously performing the variable control of charging voltage of an auxiliary capacitor according to an ambient temperature, to suppress the deterioration of the auxiliary capacitor without causing wasteful component cost.SOLUTION: The auxiliary capacitor charge control device for controlling to charge an auxiliary capacitor C is provided on a vehicle power supply in which a generator 8, interlocked with an engine 9, generates electricity to charge a main capacitor B and the auxiliary capacitor C and feeds power to a plurality of load 3 from the generator 8, the main capacitor B, and the auxiliary capacitor C. The auxiliary capacitor charge control device includes: a switch T1 provided among the generator 8, the main capacitor B, and the auxiliary capacitor C; voltage division circuits R1, R2 for dividing a charge voltage to the auxiliary capacitor C; temperature correction circuits Rt, R3 for correcting each charge voltage value obtained by the division by the voltage division circuits R1, R2, according to the ambient temperature of the auxiliary capacitor C; and a switch on/off control circuit 5 for controlling the switch T1 to switch on/off when the charge voltage value corrected by the temperature correction circuits Rt, R3 is lower/higher than a predetermined voltage value.

Description

  The present invention provides a power supply device for a vehicle that generates power from a generator mounted on a vehicle, charges the main capacitor and the auxiliary capacitor, and supplies power to the plurality of loads from the generator, the main capacitor, and the auxiliary capacitor. The present invention relates to an auxiliary capacitor charge control device that controls the charging of the battery.

In recent years, in order to improve fuel efficiency, development of hybrid cars and electric cars has been promoted, and fuel efficiency has been improved by performing idling stop and the like in gasoline engine cars.
However, in the idling stop, when the engine is ignited again after the engine is once stopped, the battery voltage rapidly decreases with the cranking of the engine due to the inrush current to the starter.

When the battery voltage rapidly decreases, for example, a body ECU (Electronic Control Unit) or the like may erroneously perform a low voltage reset. Therefore, in an idling stop vehicle, an auxiliary capacitor such as a large-capacitance capacitor is provided in addition to the battery (main capacitor), and a method of dealing with a sudden drop in battery voltage due to cranking is taken.
The auxiliary capacitor is also used as a power source for unlocking the door when the battery is lost due to a vehicle collision or the like.

Capacitors deteriorate over time if they are used for many years, and the capacitance decreases or the internal resistance increases. The degree of progress of this deterioration generally conforms to the 10 ° C. double rule of the “Arrhenius rule”.
In addition, “charging voltage” can also be mentioned as an influence on how the deterioration of the capacitor proceeds. Assuming that the environmental temperature is constant, the lower the charging voltage, the more difficult the deterioration proceeds.
Therefore, there has been proposed a power supply device that supplies necessary power in response to a change in environmental temperature while suppressing deterioration of the capacitor in an auxiliary capacitor circuit using a large-capacity capacitor.

  Patent Document 1 includes a capacitor unit including a plurality of capacitors, a bypass switch that is connected to at least one of the plurality of capacitors and shorts both ends of the capacitor, and a temperature sensor that measures the temperature in the vicinity of the capacitor unit. A power supply device is disclosed. When charging the capacitor unit, if the detected temperature of the temperature sensor is equal to or lower than the predetermined temperature, the controller turns on the bypass switch and does not charge the capacitor to which the bypass switch is connected. If it exceeds, the bypass switch is turned off and the capacitor including the bypass switch is charged.

Japanese Patent Laid-Open No. 2008-5562

  Since the power supply device disclosed in Patent Document 1 described above can be controlled only in two stages of ON / OFF of the bypass switch, it is difficult to set the temperature threshold roughly, and there are capacitors that are not used depending on the environmental temperature. Therefore, there is a problem that it is wasteful and disadvantageous in terms of component costs.

  The present invention has been made in view of the above-described circumstances, and can continuously and variably control the charging voltage to the auxiliary capacitor according to the ambient temperature to suppress the deterioration of the auxiliary capacitor. It is an object of the present invention to provide an auxiliary capacitor charging control device for a vehicle power supply device that does not cause waste.

  An auxiliary capacitor charging control device according to a first aspect of the present invention is a vehicle power supply that generates power from a generator linked to an engine and charges the main capacitor and the auxiliary capacitor, and supplies power to a plurality of loads from the generator, the main capacitor, and the auxiliary capacitor. In the auxiliary capacitor charging control device that is provided in the device and controls charging to the auxiliary capacitor, a switch provided between the generator, the main capacitor, and the auxiliary capacitor, and a voltage dividing voltage for charging the auxiliary capacitor A circuit, a temperature correction circuit that corrects the charging voltage value divided by the voltage dividing circuit according to the ambient temperature of the auxiliary capacitor, and the charging voltage value corrected by the temperature correction circuit is lower / higher than a predetermined voltage value And an on / off control circuit for controlling the switch on / off.

  In this auxiliary storage battery charging control device, a generator linked to the engine generates power and charges the main storage battery and the auxiliary storage battery, and is provided in a vehicle power supply device that supplies power to a plurality of loads from the generator, the main storage battery and the auxiliary storage battery, Controls charging to the auxiliary capacitor. A switch is provided between the generator, the main capacitor, and the auxiliary capacitor, and a voltage dividing circuit divides the charging voltage to the auxiliary capacitor. When the temperature correction circuit corrects the charging voltage value divided by the voltage dividing circuit according to the ambient temperature, and the on / off control circuit corrects the charging voltage value corrected by the temperature correction circuit to be lower / higher than the predetermined voltage value In addition, the switch is controlled to be turned on / off.

  In the auxiliary storage battery charging control device according to the second aspect of the invention, the voltage dividing circuit divides the voltage by a high-voltage side resistor and a low-voltage side resistor, and the temperature correction circuit uses a series circuit of an NTC thermistor and a resistor as the high-voltage side resistor. It is connected in parallel.

  In this auxiliary capacitor charging control device, the voltage dividing circuit divides the charging voltage to the auxiliary capacitor by the high-voltage side resistor and the low-voltage side resistor, and the temperature correction circuit converts the series circuit of the NTC thermistor and the resistor to the voltage dividing circuit. It is connected in parallel to the high-voltage side resistor.

  According to a third aspect of the present invention, there is provided an auxiliary storage battery charge control device, wherein a power generator for a vehicle that generates power from a generator linked to an engine and charges the main storage battery and the auxiliary storage battery and supplies power to a plurality of loads from the generator, the main storage battery, and the auxiliary storage battery. In the auxiliary capacitor charging control device that is provided in the device and controls charging to the auxiliary capacitor, a switch provided between the generator, the main capacitor, and the auxiliary capacitor, and a voltage dividing voltage for charging the auxiliary capacitor A reference voltage circuit that corrects and outputs a predetermined reference voltage value according to the ambient temperature of the auxiliary capacitor, and a charging voltage value divided by the voltage dividing circuit is a reference voltage output by the reference voltage circuit. And an on / off control circuit for controlling the switch on / off when the value is lower / higher than the value.

  In this auxiliary storage battery charging control device, a generator linked to the engine generates power and charges the main storage battery and the auxiliary storage battery, and is provided in a vehicle power supply device that supplies power to a plurality of loads from the generator, the main storage battery and the auxiliary storage battery, Controls charging to the auxiliary capacitor. A switch is provided between the generator, the main capacitor, and the auxiliary capacitor, and a voltage dividing circuit divides the charging voltage to the auxiliary capacitor. The reference voltage circuit corrects and outputs a predetermined reference voltage value according to the ambient temperature, and the on / off control circuit outputs the charging voltage value divided by the voltage dividing circuit as the reference voltage value output by the reference voltage circuit. Control the switch on / off when lower / higher.

  In the auxiliary storage battery charge control device according to a fourth aspect of the invention, the reference voltage circuit divides and outputs a predetermined voltage value output from the constant voltage source by a high-voltage side resistor and a low-voltage side resistor, and an NTC thermistor and a resistor are connected in series. A circuit is connected in parallel to the low-voltage side resistor.

  In this auxiliary capacitor charging control device, the reference voltage circuit divides and outputs the predetermined voltage value output from the constant voltage source by the high-voltage side resistor and the low-voltage side resistor, and the series circuit of the NTC thermistor and the resistor is the reference voltage circuit. Is connected in parallel to the low-voltage side resistor.

  According to the auxiliary storage battery charging control device according to the present invention, the charging voltage to the auxiliary storage battery can be continuously variably controlled according to the ambient temperature, the deterioration of the auxiliary storage battery can be suppressed, and parts cost is not wasted. An auxiliary capacitor charging control device for a power supply device can be realized.

It is a block diagram which shows the principal part structure of embodiment of the auxiliary storage battery charge control apparatus which concerns on this invention. It is a characteristic view which shows the example of the relationship between the ambient temperature of a large capacity capacitor, and a charging voltage. It is a block diagram which shows the principal part structure of embodiment of the auxiliary storage battery charge control apparatus which concerns on this invention.

Hereinafter, an auxiliary storage battery charge control device according to the present invention will be described with reference to the drawings showing embodiments thereof.
(Embodiment 1)
FIG. 1 is a block diagram showing the main configuration of Embodiment 1 of an auxiliary storage battery charging control device according to the present invention.
This auxiliary storage battery charge control device is connected to an engine 9 by an alternator (generator, AC generator) 8 to generate and rectify the electric power from a battery (main storage battery) B and a large capacity capacitor (auxiliary storage battery, electric double layer capacitor). ) It is provided in a vehicle power supply device that charges C and supplies power to the load group 3 from the alternator 8, the battery B, and the large-capacitance capacitor C.

The electric power output from the alternator 8 and the battery B is given to the load group 3 through the fuse F2 and the diode D2.
The power output from the alternator 8 and the battery B is also large in capacity through the ignition relay 1, the fuse F1, the diode D1, the P-channel type MOSFET (metal oxide semiconductor field effect transistor) T1, and the resistor R4 that limits the charging current. The capacitor C is charged. For example, four large-capacity capacitors C are connected in series with four electric double layer capacitors.

The power charged in the large-capacitance capacitor C is boosted by the booster circuit 2 and then supplied to the load group 3 through the diode D3.
The charging voltage Vch of the large-capacity capacitor C is divided by the charging voltage control unit 6 and is corrected according to the ambient temperature.
The charging voltage control unit 6 includes a voltage dividing circuit in which a resistor (high-voltage side resistor) R1 and a resistor (low-voltage side resistor) R2 are connected in series between an input / output terminal and a ground terminal of the large-capacity capacitor C, and a large-capacity capacitor A series circuit of an NTC thermistor Rt and a resistor R3 provided around C includes a temperature correction circuit connected in parallel to the high-voltage side resistor R1 of the voltage dividing circuit.

The resistance value of the NTC thermistor Rt decreases as the ambient temperature of the large-capacitance capacitor C increases.
The resistance value Rt of the NTC thermistor Rt is expressed by equation (1).
Rt = Rt0 × exp (B ((1 / Tt) − (1 / Tt0))) (1)
Rt0: resistance value (Ω) at a reference temperature (for example, 25 ° C.)
Tt: arbitrary temperature (K)
Tt0: reference temperature (for example, 25 ° C. = 298 K) (K)
B: Thermistor coefficient

The charging voltage Vpc of the large-capacitance capacitor C that has been divided by the voltage dividing circuits R1 and R2 of the charging voltage control unit 6 and corrected by the temperature correction circuits Rt and R3 is applied to the inverting input terminal of the comparator 4.
Here, the divided and corrected charging voltage Vpc is expressed by equation (2).
Vpc = Vch · R2 (Rt + R1 + R3) /
(Rt (R1 + R2) + R1R2 + R2R3 + R1R3) (2)
The charging voltage control unit 6 is given the ambient temperature of the large-capacitance capacitor C detected by the external temperature detector, and corrects the voltage division by the voltage dividing circuits R1 and R2 according to the given ambient temperature. Anyway.

The comparator 4 is supplied with a power supply having a voltage value Vc from the control power supply P, and a predetermined voltage value Vs is supplied from the constant voltage source 7 to the non-inverting input terminal through the resistor R6.
The comparator 4 is positively fed back by the resistor R7, the output terminal is connected to the gate of the N-channel MOSFET T2, and is pulled up by the control power source P through the resistor R8.

The comparator 4 has a dead zone Vh calculated by Vh = (Vc−0) × R6 / (R6 + R7) = Vc × R6 / (R6 + R7) with a predetermined voltage value Vs as the center, and has hysteresis.
That is, when the voltage value Vpc divided and corrected by the charging voltage control unit 6 of the charging voltage Vch of the large-capacity capacitor C rises from a low value, the comparator 4 determines that Vpc = Vs + Vh / 2 = Vs + Vc × R6 / 2. Negative inversion at (R6 + R7). Further, when the voltage value Vpc falls from a high value, the comparator 4 is positively inverted by Vpc = Vs−Vh / 2 = Vs−Vc × R6 / 2 (R6 + R7).

The drain of the FET T2 is connected to the gate of the FET T1 through the resistor R5, and the source of the FET T2 is grounded.
The comparator 4, the circuit attached to the comparator 4, the FETs T <b> 1 and T <b> 2, and the resistor R <b> 5 constitute a charging on / off circuit (on / off control circuit) 5.
The cathodes of the diodes D4 and D5 are connected to the control power source P. The anode of the diode D4 is connected to the anode of the diode D1, and the anode of the diode D5 is connected to the input / output terminal of the large-capacitance capacitor C. Thereby, the control power supply P can obtain power from both the battery B side and the large-capacitance capacitor C side.

Below, operation | movement of the auxiliary | assistant capacitor | condenser charging control apparatus of such a structure is demonstrated.
When the ignition relay 1 is off and the engine 9 is stopped, the alternator 8 is also stopped, and the output power of the battery B is supplied to the load group 3 through the fuse F2 and the diode D2.
When the ignition relay 1 is on and the engine 9 is driven, the alternator 8 can generate power (may be stopped by charging control to the battery B), and the output power of the alternator 8 charges the battery B. And supplied to the load group 3 through the fuse F2 and the diode D2. The output power of the alternator 8 and the battery B is charged to the large-capacity capacitor C through the ignition relay 1, the fuse F1, the diode D1, the FET T1, and the resistor R4.

  When the engine 9 is started from a stopped state such as an idling stop and an inrush current to a starter (not shown) occurs, or when the battery B is lost due to a vehicle collision, the voltage on the load group 3 side suddenly decreases. The booster circuit 2 operates, and the boosted output power of the large-capacity capacitor C is given to the load group 3 through the diode D3.

  When the ignition relay 1 is on and the output power of the alternator 8 and the battery B is charged to the large-capacity capacitor C, if the charging voltage Vch is reduced at the start of charging, the charging voltage control unit 6 The divided and corrected charging voltage Vpc is lower than Vs + Vh / 2, and the comparator 4 outputs the voltage Vc to turn on the FET T2. As a result, the FET T1 is turned on with the gate grounded (the gate-source voltage is increased), and the large-capacitance capacitor C is charged.

  When charging to the large-capacitance capacitor C proceeds, the charging voltage Vch rises, and when the charging voltage Vpc divided and corrected by the charging voltage control unit 6 reaches Vs + Vh / 2, the comparator 4 outputs 0 V, and FETT2 Turn off. As a result, the FET T1 is turned off with the gate voltage rising (the gate-source voltage is reduced), and charging of the large-capacitance capacitor C is stopped.

  When discharging from the large-capacity capacitor C proceeds, the charging voltage Vch decreases, and when the charging voltage Vpc divided and corrected by the charging voltage control unit 6 decreases to Vs−Vh / 2, the comparator 4 outputs the voltage Vc. Then, FETT2 is turned on. As a result, the FET T1 is turned on with the gate grounded (the gate-source voltage is increased), and the large-capacitance capacitor C is charged.

As described above, the charging voltage Vpc divided and corrected by the charging voltage control unit 6 is held between Vs ± Vh / 2, so that the charging voltage Vch of the large-capacitance capacitor C is
Vs = Vch · R2 (Rt + R1 + R3) /
(Rt (R1 + R2) + R1R2 + R2R3 + R1R3) (2)
Than,
Vch = Vs · (Rt (R1 + R2) + R1R2 + R2R3 + R1R3)
/ R2 (Rt + R1 + R3)
It is held at the voltage value before and after.

  Here, the NTC thermistor Rt changes according to the ambient temperature of the large-capacitance capacitor C as shown in the equation (1). For example, R1 = 10 kΩ, R2 = 4.7 kΩ, R3 = 47 kΩ, Rt = 47 kΩ (@ 25 C), thermistor coefficient B = 4050, and predetermined voltage value Vs = 2.32 V, the charging voltage Vch of the large-capacitance capacitor C changes as shown in FIG. 2 according to the ambient temperature. The charging voltage Vch is held at a lower voltage value as the ambient temperature becomes higher.

(Embodiment 2)
FIG. 3 is a block diagram showing a main configuration of Embodiment 2 of the auxiliary storage battery charging control apparatus according to the present invention.
In this auxiliary capacitor charging control device, the NTC thermistor Rt is not connected to the voltage dividing circuit R1 and the resistor R2 connected between the input / output terminal of the large-capacitance capacitor C and the ground terminal.

In the charge on / off circuit (on / off control circuit) 5 a, the charge voltage Vp of the large-capacitance capacitor C divided by the voltage dividing circuits R 1 and R 2 is applied to the inverting input terminal of the comparator 4.
The comparator 4 is supplied with a power supply having a voltage value Vc from the control power supply P, and a predetermined voltage value Vs is supplied from the constant voltage source 7 to the non-inverting input terminal through a resistor (high-voltage side resistor) R6.
The comparator 4 is positively fed back by the resistor R7, the output terminal is connected to the gate of the N-channel MOSFET T2, and is pulled up by the control power source P through the resistor R8.

  The charging on / off circuit 5a includes a reference voltage circuit 10. The reference voltage circuit 10 includes a series circuit of an NTC thermistor Rt1 and a resistor R9 provided around the large-capacitance capacitor C, and a resistor (low-voltage side resistor) R10. And a series circuit of the resistor R6 and the constant voltage source 7 are connected in parallel. The reference voltage circuit 10 corrects and outputs the predetermined voltage value Vs output from the constant voltage source 7 according to the ambient temperature of the large-capacitance capacitor C. Since the other principal part structure is the same as that of the principal part structure of Embodiment 1 mentioned above, description is abbreviate | omitted.

Below, operation | movement of the auxiliary | assistant capacitor | condenser charging control apparatus of such a structure is demonstrated.
Since the NTC thermistor Rt1 changes as shown in the equation (1) according to the ambient temperature of the large-capacitance capacitor C, the resistance value Rt1 decreases as the ambient temperature increases. When the resistance value Rt1 decreases, the predetermined voltage value Vs output from the constant voltage source 7 is also corrected to be lower. As a result, the charging voltage Vch is held at a lower voltage value as the ambient temperature of the large-capacitance capacitor C becomes higher, and changes according to the ambient temperature in the same manner as the charging voltage shown in FIG. Other operations are the same as the operations of the first embodiment described above, and thus description thereof is omitted.

  Although the first and second embodiments have been described as applied to a booster type vehicle power supply device that boosts the voltage of the capacitor (auxiliary capacitor) and supplies power to the load group, the primary power supply voltage is stepped down. Needless to say, the present invention can also be applied to capacitor charging in a step-down vehicle power supply device that charges a capacitor (auxiliary capacitor).

1 Ignition Relay 3 Load Group 4 Comparator 5, 5a Charging On / Off Circuit (On / Off Control Circuit)
6 Charging voltage controller 7 Constant voltage source 8 Alternator (generator, AC generator)
9 Engine 10 Reference voltage circuit B Battery (main battery)
C Large capacity capacitor (auxiliary capacitor, electric double layer capacitor)
T1 FET (switch)
T2 FET
R1 resistance (high voltage side resistance, voltage divider circuit)
R2 resistance (low voltage side resistance, voltage divider circuit)
R3 resistance (temperature correction circuit)
R6 resistance (high voltage side resistance)
R9 resistance R10 resistance (low-voltage side resistance)
Rt NTC thermistor (temperature correction circuit)
Rt1 NTC thermistor

Claims (4)

A generator linked to the engine generates power to charge the main capacitor and the auxiliary capacitor, and is provided in a vehicle power supply device that supplies power to a plurality of loads from the generator, the main capacitor and the auxiliary capacitor, and charges the auxiliary capacitor. In the auxiliary capacitor charging control device to control,
A switch provided between the generator, the main capacitor, and the auxiliary capacitor; a voltage dividing circuit that divides a charging voltage to the auxiliary capacitor; and a charging voltage value divided by the voltage dividing circuit, A temperature correction circuit for correcting the temperature according to the temperature; and an on / off control circuit for controlling the switch on / off when the charging voltage value corrected by the temperature correction circuit is lower / higher than a predetermined voltage value. An auxiliary capacitor charge control device characterized by the above.   2. The auxiliary circuit according to claim 1, wherein the voltage dividing circuit divides the voltage by a high voltage side resistor and a low voltage side resistor, and the temperature correction circuit has a series circuit of an NTC thermistor and a resistor connected in parallel to the high voltage side resistor. Capacitor charge control device. A generator linked to the engine generates power to charge the main capacitor and the auxiliary capacitor, and is provided in a vehicle power supply device that supplies power to a plurality of loads from the generator, the main capacitor and the auxiliary capacitor, and charges the auxiliary capacitor. In the auxiliary capacitor charging control device to control,
A switch provided between the generator, the main capacitor, and the auxiliary capacitor, a voltage dividing circuit that divides the charging voltage to the auxiliary capacitor, and a predetermined reference voltage value is corrected according to the ambient temperature of the auxiliary capacitor. An output reference voltage circuit and an on / off control for controlling the switch on / off when a charging voltage value divided by the voltage dividing circuit is lower / higher than a reference voltage value output by the reference voltage circuit And an auxiliary storage battery charge control device.   The reference voltage circuit divides and outputs a predetermined voltage value output from a constant voltage source by a high-voltage side resistor and a low-voltage side resistor, and a series circuit of an NTC thermistor and a resistor is connected in parallel to the low-voltage side resistor. The auxiliary capacitor charging control device according to claim 3.

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