JP2009073266A - Power supply - Google Patents

Abstract

A power supply apparatus capable of accurately measuring an open-circuit voltage of a lead battery while avoiding the influence of polarization associated with charge / discharge and the influence of dark current due to an electric load.
A lead battery 3 that is charged by an alternator 1 to supply power to electric loads 2, 2... And a lithium ion battery that is charged by a voltage boosted by a DC / DC converter 6 and supplies power to another electric load 8. 7 is a power supply device. When the engine is stopped, a part of the remaining capacity of the lead battery 3 is discharged, the battery switch 4 disconnects the lead battery 3, and the DC / DC converter 6 steps down the voltage of the lithium ion battery 7 to the electric loads 2, 2・ Supply power. Thereafter, when a predetermined time has elapsed, the voltage detector 5 measures the open voltage of the lead battery 3.
[Selection] Figure 1

Description

  The present invention relates to a power supply device capable of accurately measuring an open circuit voltage of a lead battery of a vehicle.

  Electric loads mounted on vehicles tend to increase year by year. Electrification of equipment that has been operated with hydraulic pressure or engine power to increase control performance and fuel efficiency has become active, and electric loads that require high reliability such as electric brakes and electric power steering devices (EPS) Adoption is progressing.

Corresponding to such an increase in electrical load, the importance of grasping the remaining capacity of a battery (battery) is increasing. In order to grasp the remaining capacity of the battery, it is necessary to know the state of charge of the battery (hereinafter referred to as SOC), and the SOC can be known from the open voltage of the battery. Patent Document 1 discloses a technique for estimating the SOC by estimating the open circuit voltage of the battery from the measured values of the battery terminal voltage and current. Patent Document 2 includes two batteries, and when the voltage of one battery is measured, by switching the load to the other battery, the open circuit voltage of the battery is measured without being affected by the load current. Technology is disclosed.
JP 2004-14231 A JP-A-8-54940

  However, the technique disclosed in Patent Document 1 requires a means for detecting the current of the battery, and the open circuit voltage obtained by calculation is an estimated value. In addition, when the open-circuit voltage is measured by cutting off the load current of the battery by the technique disclosed in Patent Document 2, since the influence of polarization accompanying charge / discharge is large particularly in a lead battery, an accurate open-circuit voltage must be measured. There was a problem that it was not possible.

The present invention has been made in view of the above-described circumstances. In the first invention, the lead battery is once discharged to reduce the polarization accompanying charging, and then separated from the electric load, and a predetermined for eliminating the polarization. Providing a power supply device capable of measuring the open-circuit voltage accurately by avoiding the influence of polarization associated with charge / discharge of the lead-acid battery by configuring the open-circuit voltage of the lead battery after time. Objective.
In the second invention, when the lead battery is disconnected, the power of the second battery is supplied to the electric load, thereby continuously supplying the electric load and measuring the open voltage of the lead battery. It is an object of the present invention to provide a power supply device capable of performing the above.
It is an object of the third invention to provide a power supply apparatus that can be applied even when the voltages of the lead battery and the second battery are different, by transforming the voltage and supplying power.
According to the fourth aspect of the present invention, the lead battery is configured so that the electric power of the lead battery is supplied to the second battery only for a predetermined time for polarization reduction accompanying charging, so that the lead battery is automatically shortened when the open-circuit voltage is measured. It is an object of the present invention to provide a power supply device capable of discharging time.
According to the fifth aspect of the invention, when an instruction related to the discharge of the lead battery is received, the power of the lead battery is supplied to the second battery. An object of the present invention is to provide a power supply device capable of discharging a lead battery for a short time.
In the sixth aspect of the invention, when a predetermined operation is received, the electric load corresponding to the operation is operated for a predetermined short period of time, so that when the open-circuit voltage is measured, the lead battery is discharged to the electric load for a short period of time. It is an object of the present invention to provide a power supply device capable of performing the above.

  A power supply device according to a first aspect of the present invention includes an in-vehicle generator that generates power in conjunction with an engine, a lead battery that is charged by electric power generated by the in-vehicle generator and supplies electric power to an electric load, and a voltage of the lead battery In a power supply apparatus comprising a measuring means for measuring a value, when the engine is stopped, a discharging means for discharging a part of the remaining capacity of the lead battery, and the discharging means discharges a part of the remaining capacity of the lead battery. And separating means for separating the lead battery from the in-vehicle generator and the electric load, and time measuring means for timing the time during which the separation means separates the lead battery, and the measuring means includes the time keeping The means measures the voltage value of the lead battery separated by the separating means after measuring a predetermined time for depolarization of the lead battery. .

In this power supply device, the on-vehicle generator generates power in conjunction with the engine, and the lead battery is charged with the generated power to supply power to the electric load. Moreover, a measurement means measures the voltage value of a lead battery. When the engine is stopped, the discharging means discharges a part of the remaining capacity of the lead battery, and then the separating means disconnects the lead battery from the in-vehicle generator and the electric load. And after a time measuring means time-measures the predetermined time for the polarization elimination of a lead battery, a measurement means measures the voltage value of a lead battery.
This reduces the polarization associated with charging due to the discharge of the lead battery, and further waits for a predetermined time in a state where the load current from the lead battery to the electric load is cut off, and then releases the open voltage after the polarization associated with the discharge is eliminated. measure.

  A power supply device according to a second aspect of the present invention includes a second battery that is supplied with electric power generated by the on-vehicle generator and is charged to supply electric power to another electric load, and the separation unit disconnects the lead battery. In this case, the electric power of the second battery is supplied to the electric load.

  In this power supply apparatus, the second battery is supplied with power generated by the on-vehicle generator and charged to supply power to other electric loads. When the separation means disconnects the lead battery, the power of the second battery is supplied to the electric load. Thereby, supply of electric power to the electric load is continued.

  A power supply device according to a third aspect of the invention is characterized in that the electric power generated by the on-vehicle generator or the electric power of the second battery is supplied by transforming a voltage.

  In this power supply device, the electric power generated by the in-vehicle generator and the electric power of the lead battery (or the electric power of the second battery) transform the voltage and send it to the second battery (or the electric load). Thereby, even when the voltage of a lead battery and a 2nd battery differs, electric power is sent mutually.

  In the power supply device according to a fourth aspect of the present invention, when the engine is stopped, the second battery is charged by supplying power of the lead battery for a predetermined time shorter than the predetermined time. It is characterized by.

  In this power supply device, when the engine is stopped, the power of the lead battery is supplied to the second battery only for a predetermined time for polarization reduction accompanying charging, and the supplied power charges the second battery. Thereby, the electric power for charging the second battery discharges the lead battery for a predetermined time. In this case, the polarization accompanying the charging of the lead battery is reduced by the discharge for a relatively short predetermined time.

  A power supply device according to a fifth aspect of the present invention includes means for receiving an instruction relating to discharge of a lead battery.

  In this power supply device, when an instruction related to discharging is received, the power of the lead battery is supplied to the second battery for the predetermined time, and the supplied power charges the second battery. Thereby, in response to a user's instruction, the lead battery is discharged for a relatively short predetermined time.

  According to a sixth aspect of the present invention, there is provided a power supply device having means for receiving a predetermined operation, and when the means receives the predetermined operation, the electric load is operated to consume power. .

  In this power supply device, when a predetermined operation is received, an electric load corresponding to the operation is activated to consume power. As a result, the electric load discharges the lead battery for a predetermined short time.

According to the power supply device of the first aspect of the present invention, after discharging a part of the remaining capacity of the lead battery after the engine is stopped, the lead battery is disconnected from the electric load. And the voltage value of a lead battery is measured after the predetermined time for the polarization elimination of a lead battery passes.
This reduces the polarization associated with charging due to the discharge of the lead battery, and further waits for a predetermined time in a state where the load current from the lead battery to the electric load is cut off, and the open circuit voltage when the polarization associated with the discharge is eliminated. Measure. Therefore, it is possible to realize a power supply device that can accurately measure the open circuit voltage while avoiding the influence of polarization associated with charging / discharging of the lead battery.

  According to the power supply device of the second invention, when the lead battery is disconnected, the power of the second battery is supplied to the electric load. Thereby, supply of electric power to the electric load is continued. Therefore, it is possible to realize a power supply device capable of continuously measuring power to the electric load and measuring the open voltage of the lead battery.

  According to the power supply device according to the third aspect of the present invention, the electric power generated by the in-vehicle generator, the electric power of the lead battery, and the electric power of the second battery are supplied with voltage transformed. Thereby, even when the voltage of a lead battery and a 2nd battery differs, electric power is sent mutually. Therefore, it is possible to provide a power supply device that can be applied even when the voltages of the lead battery and the second battery are different.

  According to the power supply device of the fourth aspect of the invention, after the engine is stopped, the electric power of the lead battery is supplied to the second battery for charging for a predetermined time for polarization reduction accompanying charging, and is charged. Thereby, the electric power for charging the second battery discharges the lead battery for a predetermined time. In this case, the polarization accompanying the charging of the lead battery is reduced by the discharge for a relatively short predetermined time. Therefore, it is possible to realize a power supply device capable of automatically discharging the lead battery for a short time when measuring the open circuit voltage.

  According to the power supply device of the fifth aspect of the invention, when an instruction relating to discharging is received after the engine is stopped, the electric power of the lead battery is supplied to the second battery for charging for the predetermined time. Accordingly, the lead battery is discharged for the predetermined time in response to a user instruction. Therefore, it is possible to realize a power supply device that can cause a lead battery to discharge in a short time in response to a user instruction when measuring an open circuit voltage.

  According to the power supply device of the sixth aspect of the present invention, when a predetermined operation is received after the engine is stopped, the electric load corresponding to the operation is activated to consume power. As a result, the electric load discharges the lead battery for a predetermined short time. Therefore, it is possible to realize a power supply device that can discharge the lead load from the lead battery for a short time when measuring the open circuit voltage.

Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof.
FIG. 1 is a block diagram showing a schematic configuration of an embodiment of a power supply device according to the present invention. The output terminal of the alternator (on-vehicle generator, AC generator) 1 is connected to one terminal of a plurality of electric loads 2, 2,... 3 is connected to the anode of the lead battery 3 through a battery switch (NC contact) 4 for disconnecting 3. A voltage detection unit 5 for detecting an output voltage value (terminal voltage value) of the lead battery 3 is connected to the anode of the lead battery 3. A lithium ion battery (second battery) 7 and an electric load (other electric load) 8 are connected to the other terminals of the DC / DC converter 6.

  The input of the control unit 9 mainly composed of a microcomputer includes a detection terminal of the voltage detection unit 5, a first switch SW1 for detecting an on / off state of power supply to the ignition device in conjunction with the ignition switch, and an open voltage measurement. Second switch SW2 for instructing short-time discharge of lead battery 3, third switch SW3 for detecting on / off state of power supply to an accessory device (not shown) in conjunction with the accessory switch, and keyless entry by the user A keyless entry detection unit 10 for detecting the operation is connected. The output of the control unit 9 is connected to a control unit of the battery switch 4, a control terminal of the DC / DC converter 6, and a display unit 11 including a liquid crystal display for performing various displays.

  When the engine is rotating, DC power generated and rectified by the alternator 1 is supplied to the lead battery 3 and the electric loads 2, 2,... Connected in parallel to the alternator 1. The DC voltage generated and rectified by the alternator 1 is boosted by a DC / DC converter 6 composed of parts such as a chopper and a coil, and the boosted voltage and the current accompanying the boosted voltage are the lithium ion battery 7 and the electric The load 8 is supplied. The DC / DC converter 6 also performs step-down in the direction opposite to the step-up direction.

  The detection value VM1 of the voltage detector 5, the detection result of the first switch SW1 and the third switch SW3, the result of the operation performed on the second switch SW2, and the detection result of the keyless entry detection unit 10 are the control unit 9 Given to. The controller 9 performs on / off control of the battery switch 4, step-up / step-down switching control and on / off control of the DC / DC converter 6.

  FIG. 2 is a chart comparing the open voltage when the terminal of the lead battery 3 is opened and the terminal voltage when the vehicle is mounted. The terminal voltage when the vehicle is mounted is lower than the open-circuit voltage due to the influence of dark current caused by a load such as the electric load 2.

FIG. 3 and FIG. 4 are actual measurement diagrams showing how the open-circuit voltage goes to a stable value when the lead battery 3 is charged and discharged and the polarization is eliminated with the passage of time. In the figure, the vertical axis represents the battery voltage (open voltage) (V), and the horizontal axis represents the elapsed time (sec) after charging or discharging.
FIG. 3 shows that when the lead battery 3 is charged, it takes tens of thousands of seconds or more to eliminate the polarization. On the other hand, FIG. 4 shows that when the lead battery 3 is discharged, the polarization is substantially eliminated in about 2,000 seconds.
In addition, since the polarization accompanying charging and discharging has opposite polar characteristics, charging the battery 3 and discharging it for a short time cancels the polarization due to charging / discharging and stabilizes the open circuit voltage. The time to reach the value can be shortened.

  5 and 6 are flowcharts showing the processing procedure of the control unit 9. When the control unit 9 is connected to a predetermined circuit of the vehicle and is supplied with power, the control unit 9 starts the following processing following the initialization processing. The controller 9 first turns on the battery switch 4 as part of initialization (step S11) and turns off the DC / DC converter 6 (step S12).

  Thereafter, the control unit 9 determines whether or not the first switch SW1 that is linked to the ignition switch is turned on (step S13), and waits when it is determined that the first switch SW1 is not turned on (step S13: NO). When it is determined that the first switch SW1 is turned on (step S13: YES), the control unit 9 gives a boost command to the DC / DC converter 6 (step S14) and gives an on command (step S15). ). Thereby, the DC / DC converter 6 converts the voltage of the lead battery 3 and starts charging the lithium ion battery 7.

  Next, the control unit 9 determines whether or not the first switch SW1 is turned off (step S16). If it is determined that the first switch SW1 is not turned off (step S16: NO), the control unit 9 stands by. When it is determined that the first switch SW1 is turned off (step S16: YES), the control unit 9 gives an off command to the DC / DC converter 6 assuming that the engine has stopped (step S17). .

  The control unit 9 determines whether or not the second switch SW2 related to the discharge instruction is turned on (step S18). If the control unit 9 determines that the second switch SW2 is not turned on (step S18: NO), the control unit 9 uses the accessory switch. It is determined whether or not the third switch SW3 linked to is turned on (step S19). When it determines with 3rd switch SW3 having been turned ON (step S19: YES), in order to supply electric power to the accessory apparatus from the lead battery 3, the control part 9 returns a process to step S11.

  When it is determined that the third switch SW3 is not turned on (step S19: NO), the control unit 9 determines whether or not an operation of a keyless entry has been detected (step S20). When it determines with the said operation not being detected (step S20: NO), the control part 9 returns a process to step S18.

If it is determined that the operation of the keyless entry has been detected (step S20: YES), the control unit 9 turns on the solenoid of the keyless entry unit (not shown) (step S21), and then turns on and off the lamp (not shown) as an answer back. (Step S22). As a result, the lead battery 3 is discharged for a short time. In this case, the solenoid and the lamp correspond to discharging means.
Then, the controller 9 gives an ON command to the DC / DC converter 6 (step S23).

When it determines with 2nd switch SW2 having been turned ON by step S18 (step S18: YES), the control part 9 gives an ON command to the DC / DC converter 6 (step S24). Thereby, the lithium ion battery 7 is charged and the discharge of the lead battery 3 starts. In this case, the DC / DC converter 6 and the lithium ion battery 7 correspond to discharging means.
And the control part 9 determines whether 1 second passed (step S25), and when it determines with not having passed (step S25: NO), it waits. Note that the time for waiting for the passage is not limited to one second, but may be a time that can secure a necessary discharge amount in order to reduce the polarization accompanying the charging of the lead battery 3.

When it determines with 1 second having passed (step S25: YES), or when the process of step S23 is complete | finished, the control part 9 gives the pressure | voltage fall command to the DC / DC converter 6 (step S26). Then, the control unit 9 executes a delay of 100 mS in order to wait for the step-down output of the DC / DC converter 6 to be stabilized (step S27). The delay time is not limited to 100 mS.
Thereafter, the control unit 9 turns off the battery switch 4 (step S28), disconnects the lead battery 3 from other circuits, and starts measuring time (step S29). In this case, a stable voltage has already been supplied from the DC / DC converter 6 to the electric loads 2, 2,.

Next, the control unit 9 determines whether or not 30 minutes have elapsed from the start of timing (step S30). The time for determining the progress is not limited to 30 minutes, but may be a time until the polarization of the lead battery 3 is eliminated.
When it determines with 30 minutes not having passed (step S30: NO), the control part 9 determines whether 3rd switch SW3 interlock | cooperated with an accessory switch was turned on (step S31). When it determines with not being turned on (step S31: NO), the control part 9 returns a process to step S30. When it determines with 3rd switch SW3 having been turned on (step S31: YES), the control part 9 returns a process to step S11 in order to supply electric power to the accessory apparatus from the lead battery 3. FIG.

  When it is determined that 30 minutes have elapsed from the start of timing (step S30: YES), the control unit 9 measures the open voltage of the lead battery 3 with the voltage detector 5 (step S32), and displays the measured value VM1. 11 for display (step S33). Then, the control part 9 returns a process to step S11 in order to prepare for the next engine starting.

  If it is detected in step S16 that the first switch SW1 is turned off (step S16: YES), that is, if engine stop is detected, the DC / DC converter 6 is turned on in step S17 as shown by the broken line in the figure. The process may be moved to step S25 without giving an OFF command. In this case, discharge of the lead battery 3 is automatically started. Further, at this time, a predetermined time may elapse before the process proceeds to step 25.

It is a block diagram which shows schematic structure of embodiment of the power supply device which concerns on this invention. It is the table | surface which compared the open circuit voltage at the time of opening the terminal of a lead battery, and the terminal voltage at the time of vehicle mounting. When a lead battery is charged, it is an actual measurement figure which shows a mode that polarization is eliminated with progress of time and an open circuit voltage goes to a stable value. When a lead battery is discharged, it is an actual measurement figure which shows a mode that polarization | polarized-light is canceled with progress of time and an open circuit voltage goes to a stable value. It is a flowchart which shows the process sequence of a control part. It is a flowchart which shows the process sequence of a control part.

Explanation of symbols

1 Alternator (on-vehicle generator)
2,8, Electric load 3 Lead battery 4 Battery switch (separation means)
5 Voltage detector 6 DC / DC converter (conversion means)
7 Lithium ion battery (second battery)
9 Control Unit 10 Keyless Entry Detection Unit 11 Display Unit SW1 First Switch SW2 Second Switch SW3 Third Switch

Claims (6)

An in-vehicle generator that generates power in conjunction with an engine, a lead battery that is charged by electric power generated by the in-vehicle generator and supplies electric power to an electric load, and a measuring unit that measures a voltage value of the lead battery In power supply,
When the engine is stopped, discharging means for discharging a part of the remaining capacity of the lead battery;
Separation means for separating the lead battery from the in-vehicle generator and the electric load after the discharging means discharges a part of the remaining capacity of the lead battery;
Timing means for timing the time for which the separation means disconnects the lead battery,
The measuring means measures the voltage value of the lead battery separated by the separating means after the time measuring means has timed a predetermined time for depolarizing the lead battery. Power supply. A second battery that is supplied and charged with power generated by the on-vehicle generator and supplies power to another electrical load;
2. The power supply device according to claim 1, wherein when the separation unit separates the lead battery, power of the second battery is supplied to the electric load.   The power supply device according to claim 2, wherein the power generated by the on-vehicle generator or the power of the second battery is configured to be supplied with voltage transformed.   4. The second battery is configured such that when the engine is stopped, the electric power of the lead battery is supplied and charged only for a predetermined time shorter than the predetermined time. 5. The power supply device described in 1.   5. The power supply device according to claim 4, further comprising means for receiving an instruction relating to discharging of the lead battery. A means for receiving a predetermined operation;
The power supply apparatus according to any one of claims 1 to 3, wherein when the means receives a predetermined operation, the electric load is operated to consume power.

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