JP2015182657A - Power supply device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to maintain adequate action of an electrical component and prevent an excessive battery load in a vehicle during idling stop.SOLUTION: A power supply device for a vehicle includes: a pressure rising part which rises an input voltage from a battery side and obtains an output voltage for a vehicular electrical component; a bypass part which is connected to the pressure rising part in parallel and obtains an output voltage having bypassed the pressure rising part; and a control part which performs control so as to block the bypass part during re-starting of an engine of the vehicle from idling stop and obtain an output voltage pressure-risen by the pressure rising part. Further, the control part determines deterioration of a battery and variably sets an output voltage value of the pressure rising part according to the result of such a deterioration determination.

Description

  The present invention relates to a technical field of a vehicle power supply device that supplies an operation power supply voltage based on a battery voltage to vehicle electrical components.

JP 2007-223385 A JP 2011-174414 A JP 2010-247556 A

As an idling stop system (ISS), there is known an idling stop system that stops a vehicle engine so as not to perform unnecessary idling when waiting for a signal or during other temporary stops.
Patent Document 1 describes a technique for suppressing power consumption in order to suppress battery rise and deterioration when a vehicle is temporarily stopped during idling stop and left unattended. .
Patent Document 2 describes a technique in which an idling stop device can grasp a voltage drop of a battery and notify a driver or the like of information indicating battery deterioration.
Patent Document 3 describes a technique for recognizing a deterioration state of a battery (measuring output voltage or the like) based on the number of idling stops, time, or the like.

By the way, in an ISS-equipped vehicle, a relatively large battery power is used to rotate the cell motor when the engine is restarted from the idling stop state.
On the other hand, while idling is stopped, the electrical components of the vehicle remain in the power-on state. For example, if electrical components such as a car audio system, a navigation device, a headlight, a backlight, a front panel display, and an air conditioner are turned on before idling is stopped, they continue to operate while the power is on.

Therefore, when the engine is restarted after idling is stopped, the starter (cell motor) is operated while the electrical components of the vehicle are powered on, so that the electrical load temporarily increases and the power supply voltage of the battery drops instantaneously. End up.
Due to the instantaneous drop in battery voltage, some electrical components have a major disadvantage. For example, in a navigation device or car audio, the sound is temporarily stopped or the navigation control is reset to the initial screen, which causes discomfort and inconvenience to the occupant and imposes an operation burden.
Accordingly, an object of the present invention is to avoid the inconveniences described above in the idling stop operation process, and to maintain an appropriate operation of the electrical component while not unnecessarily increasing the battery burden.

1stly, the vehicle power supply device which concerns on this invention is a vehicle power supply device which outputs the input voltage from a battery side as an operation power supply voltage of a vehicle electrical component, Comprising: The said input voltage is stepped up and the said vehicle electrical component A booster for obtaining an output voltage to the power supply, a bypass connected to the booster in parallel, and a voltage bypassing the booster as an output voltage, and restarting the vehicle engine from an idling stop state During the period, the bypass unit is shut off, and control is performed so that an output voltage boosted by the booster unit is obtained, and the battery deterioration is determined, and the output of the booster unit is determined according to the result of the deterioration determination. And a control unit that performs a process of variably setting the voltage value.
When the engine is restarted from the idling stop state, the battery voltage instantaneously decreases due to the operation of the starter. During this time, sufficient drive power may not be supplied to the vehicle electrical components. Therefore, at the time of restart, the voltage from the battery side is boosted by the boosting unit and supplied to the vehicle electrical components. Further, the boosted output voltage value is variably set according to the degree of deterioration of the battery so that the battery load is not excessive due to this operation.

Second, in the vehicle power supply device according to the present invention described above, when the control unit obtains a determination result that the battery is deteriorated by the deterioration determination, the output voltage of the booster unit is It is desirable to set the value to a value lower than the output voltage value when the determination result that the deterioration has not occurred is obtained.
As a result, when the battery is deteriorated, the burden due to boosting is reduced, and the degree of battery consumption is reduced.

3rdly, in the vehicle power supply device which concerns on above-mentioned this invention, the said control part is the battery voltage value during engine operation, the battery voltage value during idling stop, and the battery voltage fall amount in the said restart period. It is desirable to perform the deterioration determination using all or a part of the above.
By these, the deterioration degree of a battery can be determined appropriately.

Fourthly, in the vehicle power supply device according to the present invention described above, the control unit also determines whether or not the output current of the battery during idling stop is greater than or equal to a predetermined value. It is desirable to use it as a voltage value setting condition.
Even when the current load is large, the boost voltage value is lowered to suppress the load increase, and the normal operation of each electrical component is maintained.

Fifth, in the above-described vehicle power supply device according to the present invention, the control unit causes the bypass unit to function during the period other than the restart period, and the output voltage not passing through the boosting unit is the vehicle electrical component. It is desirable to control so that it may be supplied to.
By not performing the boost operation except when the engine is restarted, the burden on the battery due to the boost is minimized.

  ADVANTAGE OF THE INVENTION According to this invention, the burden of a battery can be minimized and progress of battery deterioration can be prevented from progressing, avoiding that the problem of operation | movement of a vehicle electrical component arises at the time of restart from an idling stop.

1 is a block diagram of a vehicle power supply device and peripheral devices according to an embodiment of the present invention. It is a flowchart of the control processing of the power supply device for vehicles of an embodiment. It is a flowchart of the process of battery deterioration determination and converter output setting of the vehicle power supply device of the embodiment. It is explanatory drawing of the voltage sag and boost voltage value setting of embodiment.

<Configuration of the embodiment>
Hereinafter, a vehicle power supply device according to an embodiment of the present invention will be described.
FIG. 1 shows a converter device 7 as a vehicle power supply device according to the embodiment and its peripheral devices. Here, the power supply path from the battery 1 mounted on the vehicle to various vehicle electrical components is mainly shown. A solid line is a power supply path, and a broken line is a path for various signals (control signal, detection signal, etc.).

The battery 1 is a battery mounted on the vehicle and outputs, for example, 12.6V as a power supply voltage. The power supply voltage from the battery 1 is supplied to each part via the current sensor 2 and the main fuse 3. The current sensor 2 can be formed by, for example, a current detection resistor (shunt resistor).
After the main fuse 3, it is supplied to each vehicle electrical component (5a, 5b, 5c... 5x) via individual fuses (4a, 4b, 4c... 4x). Vehicle electrical components (5a, 5b, 5c... 5x) are control units such as headlights, backlights, turn signal lamps and other lamps, room lights, front display units, power windows, ECUs (Electronic Control Units), etc. There are various types such as an imaging unit, a car audio device, and a navigation device. However, here, the vehicle electrical component 5x is assumed to be, for example, a navigation device or a car audio device.
That is, the battery power supply voltage is supplied to each vehicle electrical component (5a, 5b, 5c...) Through the fuse (4a, 4b, 4c...), But the vehicle is a navigation device or a car audio device. A battery power supply voltage is supplied to the electrical component 5x via the fuse 4x and the converter device 7.

  The battery power supply voltage after the main fuse 3 is also supplied to the cell motor unit 9 via the fuse 8 and the starter switch 10. For example, the starter switch 10 is turned on by a cell start signal SS from a control unit (ECU) (not shown), the battery power supply voltage is supplied to the cell motor unit 9, and cranking by driving the cell motor is executed.

  An alternator 8 is connected to the load side of the main fuse 3. The alternator 8 generates power according to the rotation of the engine and supplies a charging current generated by the power generation to the battery 1. The output voltage by the alternator 8 is, for example, about 14V.

The idling stop control unit 6 is shown as a part that performs control related to idling stop as the ISS operation. Actually, the idling stop control unit 6 can be considered as one of functions realized by software in an ECU (not shown) constituted by, for example, a microcomputer.
The idling stop control unit 6 performs temporary stop control of an engine (not shown) when detecting stoppage of the vehicle due to waiting for a signal or the like. The idling stop control unit 6 monitors the driver's starting operation (releasing the brake, etc.) based on detection information from various sensors, and controls the engine to restart in response to the detection of the starting operation.
In addition to these, in the case of the present embodiment, the idling stop control unit 6 exchanges various types of information with the converter device 7. For example, when the engine is restarted from the idling stop state, the engine restart signal RS is supplied to the converter device 7.
Further, the vehicle information IM can be transmitted and received between the idling stop control unit 6 and the converter device 7 by communication using, for example, a CAN (Controller Area Network), a LIN (Local Interconnect Network), or the like.
Further, the idling stop control unit 6 can obtain the battery output current value by the output from the current sensor 2. This battery output current value is supplied to the converter device 7 as one of the vehicle information IM.

The converter device 7 or the power supply device having at least the converter device 7 is an embodiment of the vehicle power supply device of the present invention.
Converter device 7 outputs an input voltage from battery 1 as an operating power supply voltage of vehicle electrical component 5x. The converter device 7 includes a bypass circuit 21, a booster circuit 22, a control circuit 23, and a memory 24.

In the power supply path via the fuse 4x, in the converter device 7, the bypass circuit 21 and the booster circuit 22 are connected in parallel.
The bypass circuit 21 is a switch composed of a relay, for example, and is connected to the input side and the output side of the booster circuit 22. This relay is, for example, a normally closed type, and the bypass circuit 21 is normally turned on, but is opened when the bypass open signal Bop from the control circuit 23 is supplied (that is, the bypass path is cut off).
The booster circuit 22 is configured as a DC-DC converter, and boosts an input voltage from the battery 1 side via the fuse 4x to generate an output voltage to the vehicle electrical component 5x. The booster circuit 22 performs a boost operation in response to the boost instruction signal S1 from the control circuit 23. The boosted output voltage value is set by a boosted voltage instruction signal S2 from the control circuit 23.

The control circuit 23 is formed by, for example, a microcomputer, and controls the bypass circuit 21 and the booster circuit 22 and performs a communication operation with the idling stop control unit 6 and the like. The memory 24 stores various information for processing of the control circuit 23. The memory 24 may be an internal memory of a microcomputer as the control circuit 23, or may be a memory of another chip.
This control circuit 23 basically shuts off the bypass path by turning off the bypass circuit 21 during the period when the engine of the vehicle restarts from the idling stop state, and the output voltage boosted by the booster circuit 22 is It controls so that it may be supplied to the electrical component 5x.
In addition, the control circuit 23 determines the deterioration of the battery 1 based on various information, and performs a process of variably setting the output voltage value of the booster circuit 22 according to the result of the deterioration determination.

Specifically, the control circuit 23 controls the bypass circuit 21 with the bypass open signal Bop. Further, the boosting operation of the boosting circuit 22 is controlled by the boosting instruction signal S1 and the boosting voltage instruction signal S2.
The control circuit 23 communicates an engine restart signal RS and vehicle information IM with the idling stop control unit 6. The control circuit 23 also receives an ignition signal IGN from the ECU or the like. The control circuit 23 monitors the input voltage Vin and the output voltage Vout. The control circuit 23 can also monitor the output voltage Vout during the converter operation of the booster circuit 22 and perform control for stabilizing the converter output.

The reason for providing such a converter device 7 is as follows.
The idling stop system (ISS) is a system that temporarily stops the engine when waiting for a signal or the like, and restarts the engine upon detection of the start operation of the driver.
The vehicle electrical components (a part or all of 5a, 5b, 5c... 5x) that was turned on before idling stop remain on during idling stop and restart. At the time of restart, the cell motor unit 9 is driven with all or some of the vehicle electrical components turned on. Therefore, the electrical load increases temporarily, and the power supply voltage of the battery 1 temporarily decreases momentarily. End up. In this case, the vehicle electrical component 5x as a car audio or navigation device is particularly problematic. In these devices, for example, the sound is interrupted due to an instantaneous drop in the battery voltage, causing the passenger to feel uncomfortable, or the navigation screen becomes the initial screen, which causes an inconvenience of forcing the passenger to operate.
In particular, car audio and navigation devices usually have a lower electrical resistance to power supply voltage sag than other vehicle electrical components.

Therefore, in the present embodiment, the booster circuit 22 (DC-DC converter) is applied to the vehicle electrical component 5x having low electrical resistance against such a power supply voltage sag and the voltage is boosted when the power supply voltage decreases. As a result, the instantaneous drop of the operating power supply voltage is suppressed, and a normal power supply voltage, for example, about 13 V is maintained. As a result, the problem at the time of engine restart is solved.
However, this operation also contributes to speeding up the deterioration of the battery 1 when it is deteriorated. This is because when the battery output voltage is lowered due to battery deterioration, the boosting width is increased, so that current consumption during boosting is increased and the burden on the battery 1 is increased.

Therefore, converter device 7 of the present embodiment operates as follows.
The converter device 7 normally supplies the power supplied from the battery 1 to the downstream vehicle electrical component 5 x via the bypass circuit 21.
The control circuit 23 obtains information related to idling stop by the engine restart signal RS and the vehicle information IM. Only when the engine is restarted after idling is stopped, the bypass circuit 21 is opened and the boosted circuit 22 boosts the reduced power supply voltage to, for example, 13 V and supplies it to the vehicle electrical component 5x. This pressure increase continues until the engine restart is completed. When the restart of the engine is confirmed, the control circuit 23 closes the bypass circuit 21, stops the booster circuit, and returns to the normal state.
In these operation processes, the control circuit 23 determines the deterioration of the battery 1 and sets the boosted voltage value of the booster circuit 22 in accordance with the deterioration determination result.

<Processing example of embodiment>
A specific example of control processing by the control circuit 23 will be described with reference to FIGS.
FIG. 2 shows the processing of the control circuit 23 from the first engine start.
In step S101, the control circuit 23 monitors engine start with the ignition signal IGN. In this case, the “start” of the engine is a start when the driver appears in the vehicle and performs an ignition operation. It is not a "restart" from idling stop. In the following, “start” and “restart” of the engine are distinguished in this sense.
The “stop” of the engine means the engine stop based on the driver's key operation or the like when getting off the vehicle, and the engine stop by the ISS is expressed as “idling stop”.

When the engine is started, such as when the driver gets on, the cell motor unit 9 is driven and cranked by the control of the ECU or the like. At this time, the control circuit 23 proceeds to step S102, and the converter device 7 Turn off the voltage output. That is, the bypass open signal Bop is output to open the bypass circuit 21, and the booster circuit 22 is not operated. For this reason, the vehicle electrical component 5x is in a state where the operation power supply is cut off, and the operation is temporarily stopped. By doing in this way, the current load of the battery 1 can be reduced at the time of engine starting. In addition, since this is when riding, even if the sound is interrupted by the audio device, the occupant is not so concerned and there is no problem.
Such a state in which the voltage output is turned off is continued until it is determined in step S103 that the start is completed. Completion of the start can be confirmed by the end of the ignition signal IGN or the vehicle information IM. When the completion of engine start is confirmed, the control circuit 23 turns on the bypass circuit 21 in step S104. That is, the bypass open signal Bop that has opened the bypass relay is stopped.
Note that the processing in steps S102, S103, and S104 described above may be omitted, and the bypass circuit 21 may be allowed to function when the engine is started.

After the engine is started, steps S105 to S115 are repeatedly executed.
In step S <b> 105, the control circuit 23 acquires the battery voltage average value Vav <b> 1 and stores it in the memory 24. The control circuit 23 obtains the battery voltage average value Vav1 based on the monitored input voltage Vin, for example. For example, the value of the input voltage Vin is converted into a digital value, and the battery voltage average value Vav1 is obtained by cumulatively adding in step S105 each time and dividing the cumulative added value by the cumulative number. Alternatively, it may be obtained in an analog manner. For example, an output voltage obtained by a time constant circuit or a low-pass filter circuit is averaged, converted into digital data, and stored in the memory 24.
This battery voltage average value Vav1 is an average value during engine operation. That is, this is the value of the period during which the battery 1 is charged based on the power generation by the alternator 8.
The control circuit 23 returns from step S107 to S105 except when idling is stopped until the engine is stopped in step S106, and calculates / stores (updates the stored value) the battery voltage average value Vav1.

In step S <b> 106, the control circuit 23 determines whether or not the engine is stopped (the engine is stopped when getting off other than ISS). If the engine stop is confirmed by the vehicle information IM, the process of FIG. 2 is finished.
In step S107, the control circuit 23 checks whether or not idling is stopped. As described above, the idling stop control unit 6 controls the idling stop during stoppage such as waiting for a signal. The control circuit 23 detects an idling stop state based on the vehicle information IM. During idling stop, the process proceeds to step S108.

In step S108, the control circuit 23 determines whether or not the engine is restarted and branches the process. When the engine restart signal RS is supplied from the idling stop control unit 6, it is determined that the engine is restarted.
When the engine restart signal RS is not supplied, that is, during the period when idling is stopped and the restart is not yet started, the control circuit 23 proceeds to step S109 to obtain the battery voltage average value Vav2 and store it in the memory 24. . For example, the value of the input voltage Vin is converted into a digital value and cumulatively added in step S109 while idling is stopped, and the battery voltage average value Vav2 is obtained by dividing the cumulative added value by the cumulative number. Alternatively, in this case, for example, the output voltage of the time constant circuit or the low-pass filter may be converted into digital data and stored in the memory 24. That is, the same processing as step S105 may be performed.
The battery voltage average value Vav2 is an average value when the engine rotation is stopped. That is, the value is a period during which no power is generated in the alternator 8 and the battery 1 is not charged.

  Subsequently, in step S110, the control circuit 23 acquires the current sensor value obtained by the current sensor 2 from the idling stop control unit 6, obtains the current sensor average value Iav, and stores it in the memory 24. That is, the average value of the current amount from the battery 1 during idling stop is detected. This is to determine the degree of load caused by the vehicle electrical component 5 (5a to 5x) during idling stop.

  Subsequently, in step S111, the control circuit 23 performs deterioration determination of the battery 1 and boosted output voltage setting processing. The boosted output voltage setting is a setting of an output voltage value by boosting of the booster circuit 22. The processing in step S111 will be described later with reference to FIG.

After step S111, the control circuit 23 proceeds from step S106 → S107 → S108.
Thus, during idling stop, the control circuit 23 executes steps S109, S110, and S111.
If restart is detected by the engine restart signal RS, the process proceeds to step S112. In this case, the control circuit 23 outputs the bypass open signal Bop to open the bypass circuit 21. At the same time, the boost instruction signal S1 is output to the booster circuit 22 to start the boosting operation. At this time, the control circuit 23 simultaneously instructs the booster circuit 22 with the boosted output voltage value set in step S111 by the boosted voltage instruction signal S2.
Thereby, at the time of restart, the output voltage by the booster circuit 22 is supplied to the vehicle electrical component 5x.
The control circuit 23 may instruct the boosted output voltage by giving the boosted voltage instruction signal S2 to the booster circuit 22 at an earlier time point (for example, at the time of setting in step S111).

  In step S <b> 113, the control circuit 23 acquires the battery voltage decrease amount Vt and stores it in the memory 24. At restart, the battery voltage drops momentarily. This is because cranking by the cell motor unit 9 is performed at the time of restart, and the load on the battery 1 increases. For example, FIG. 4A shows an example of a battery voltage waveform when restart is started at time t0. For example, the control circuit 23 detects the bottom value immediately after the restart for the input voltage Vin. Then, by obtaining the difference between the value of the input voltage Vin monitored in step S109 during idling stop (or the calculated battery voltage average value Vav2) and the bottom value, the battery voltage decrease amount Vt shown in FIG. 4A can be obtained. It can be detected. The value of the battery voltage drop amount Vt is used in step S111 during the next idling stop.

Thereafter, when the control circuit 23 detects that the restart has been completed, for example, from the vehicle information IM, the process proceeds from step S114 to S115 to stop the boosting operation by the boosting circuit 22 and terminate the bypass open signal Bop to activate the bypass circuit 21. Turn on (relay closed). Accordingly, the battery voltage is supplied as it is to the vehicle electrical component 5x, and the process returns to step S105.
The control circuit 23 repeats the processes during engine operation and idling stop as described above until engine stop is detected in step S106.

The battery deterioration determination and boosted output voltage setting process performed in step S111 while idling is stopped will be described in detail with reference to FIG.
In step S201, the control circuit 23 checks the battery voltage average value Vav1 acquired during engine operation and stored in the memory 24, and checks whether this is less than a predetermined value (for example, 12.5 V).
If the battery voltage average value Vav1 exceeds 12.5 V, the process proceeds to step S205, and normal output determination is performed. That is, it is assumed that the control circuit 23 does not particularly recognize battery deterioration. In this case, the output voltage set value by the booster circuit 22 is set to 13V.

When the battery voltage average value Vav1 is less than 12.5V in step S201, the control circuit 23 determines in step S202 whether the battery voltage average value Vav2 during the current idling stop is less than a predetermined value (for example, 12V). To check. The battery voltage average value Vav2 is a value obtained in the previous step S109 and stored in the memory 24.
If the battery voltage average value Vav2 exceeds 12V, the process proceeds to step S205, where it is similarly determined that there is no battery deterioration, and the output voltage set value by the booster circuit 22 is set to 13V.

When the battery voltage average value Vav2 is less than 12V in step S202, the control circuit 23 determines in step S203 whether or not the current sensor average value Iav during the current idling stop is less than a predetermined value (for example, 80A). Check. The current sensor average value Iav is a value acquired in the immediately preceding step S110 and stored in the memory 24. If the current sensor average value Iav exceeds 80 A, the process proceeds to step S206.
If the current sensor average value Iav is less than 80 A, the control circuit 23 determines whether or not the battery voltage drop amount Vt at the previous engine restart exceeds a predetermined value (for example, 3.5 V) in step S204. To do. The battery voltage drop amount Vt is a value acquired in step S113 and stored in the memory 24 at the previous engine restart. If the battery voltage drop Vt is 3.5 V or less, the process proceeds to step S206.

The case where the process proceeds from step S203 to S206 is a case where the current load is large. The case where the process proceeds from step S204 to S206 is a case where the possibility of battery deterioration is recognized.
Therefore, the control circuit 23 determines in step S206 that the battery has deteriorated or is in a high load state. That is, the control circuit 23 sets the output voltage of the booster circuit 22 in view of the possibility of battery deterioration and a high load state. For example, the output voltage is set according to the input voltage according to the characteristics shown in FIG. 4B. For example, if the input voltage Vin is 12V or more, the output voltage setting value = 13V, if the input voltage Vin is 11V or less, the output voltage setting value = 10V, and the input voltage Vin is between 11-12V, the output voltage setting The value is 10 to 13V.

  If the battery voltage drop amount Vt at the previous engine restart exceeds a predetermined value (for example, 3.5 V) in step S204, the control circuit 23 proceeds to step S207 and performs battery deterioration determination. That is, assuming that the battery 1 is deteriorated, the output voltage setting value of the booster circuit 22 is set to 10V.

  With the processing in FIG. 3 described above, the output voltage setting value set in any of steps S205, S206, and S207 is set as the output voltage setting value of the booster circuit 22 at the subsequent restart. That is, the output voltage of the booster circuit 22 at the time of restart is variably set depending on the deterioration determination of the battery 1 and the load state.

<Summary>
In the present embodiment, the following effects can be obtained.
The converter device 7 of the embodiment boosts the input voltage Vin from the battery 1 to obtain the output voltage Vout to the vehicle electrical component 5x, and is connected in parallel with the booster circuit 22 and bypasses the booster circuit 22. The bypass circuit 21 is provided so that the output voltage is set to the output voltage Vout. Then, the control circuit 23 controls the bypass circuit 21 to be shut off (relay open) during the restart period from the idling stop state so that the output voltage Vout boosted by the boost circuit 22 is obtained.
When the engine is restarted from the idling stop state, the battery voltage instantaneously decreases due to the operation of the starter. In this embodiment, the output voltage Vout boosted to, for example, 13 V by the booster circuit 22 during this period is the vehicle electrical component. 5x is supplied. For this reason, the normal operation state is maintained in the vehicle electrical component 5x, and it is possible to eliminate the discomfort and inconvenience to the occupant. For example, problems such as the sound being interrupted in the case of a car audio device and resetting in the case of a navigation device are eliminated.

Further, in the present embodiment, the control circuit 23 determines the deterioration of the battery 1 and variably sets the output voltage setting value of the booster circuit 22 according to the result of the deterioration determination. In particular, when the control circuit 23 obtains the determination result that the battery 1 is deteriorated, the output voltage setting value of the booster circuit 22 is obtained as the output voltage setting value obtained when the battery 1 is not deteriorated. Lower value.
As described above, the boosted output voltage is varied according to the deterioration determination of the battery 1, thereby reducing the load on the battery 1, suppressing the progress of the battery deterioration, and consequently contributing to the extension of the life of the battery 1.
In the first place, when the load for operating the cell motor unit 9 is large, it is a heavy burden on the battery 1 to perform boosting. Therefore, when the battery is in a degraded state, the output voltage set value of the booster circuit 22 is lowered (for example, 10 V) so that the battery load is not excessive.
For example, if the boosted output voltage during normal operation is 13 V and the boosted output voltage during battery deterioration is 10 V, the current output at the commercial outlet can be reduced by about 20%, and the battery 1 can be put into the idling stop control prohibited region along with the extension of the battery life. It can be delayed until it enters.

The control circuit 23 uses the battery voltage value during operation of the engine (battery voltage average value Vav1), the battery voltage value during idling stop (battery voltage average value Vav2), and the battery voltage decrease amount Vt during the restart period. The battery deterioration is determined. Thereby, the deterioration degree of a battery can be determined appropriately.
Since the battery voltage average value Vav1 is being generated by the alternator 8, the input voltage Vin does not depend only on the battery 1. However, if the battery voltage average value Vav1 is a sufficient value, the battery 1 is not deteriorated. It becomes an indicator.
Since the battery voltage average value Vav2 is a value during a period in which power generation by the alternator 8 is not performed, it is a direct index for the deterioration of the battery 1.
Since the battery voltage drop amount Vt increases as it deteriorates, this is also an appropriate index for battery deterioration determination.
Therefore, by performing the deterioration determination by the process of FIG. 3, the reliability of the determination can be increased.
Note that, for example, a difference between the battery voltage average value Vav1 and the battery voltage average value Vav2 may be used as a deterioration determination index.
Further, the deterioration determination may be performed using one or two of these indices without using three of the battery voltage average values Vav1 and Vav2 and the battery voltage drop amount Vt.
Further, although the average value is used as the battery voltage value during engine operation and idling stop, the latest value may be used instead of the average value. However, by using the average value, it is possible to avoid erroneous determination due to voltage fluctuation due to some other cause not caused by battery deterioration.

  The control circuit 23 also uses the determination result of whether or not the output current (current sensor average value Iav) of the battery during idling stop is equal to or greater than a predetermined value as the setting condition of the output voltage set value of the booster circuit 22. . Even when the current load is large, the boosted voltage value is reduced to suppress the current consumed by the boost, which is preferable in terms of reducing the load on the battery 1 and maintaining the normal operation of each electrical component.

Further, the control circuit 23 controls the bypass circuit 21 to function so that the output voltage Vout not via the booster circuit 22 is supplied to the vehicle electrical component 5x except for the restart period (step S104 in FIG. 2). S115). By not performing the boost operation except when the engine is restarted, the burden on the battery 1 due to the boost can be minimized. This also contributes to not accelerating battery deterioration.
In the process of FIG. 2, the period during which the bypass circuit 21 is opened is only at the time of restart and engine start, and is usually much shorter than the period during which the bypass circuit 21 is closed. Therefore, it is desirable to configure the bypass circuit 21 with a normally closed relay. However, of course, an example using a normally open relay is also conceivable. Further, a switching element other than the relay may be used.

Note that the configuration and processing of the embodiment are merely examples. Various configuration examples and processing examples other than the above are conceivable.
In the process of FIG. 3, when there is a possibility of deterioration of the battery 1, the current sensor average value Iav is confirmed in step S203. However, the current sensor average value Iav is confirmed regardless of the deterioration of the battery 1, and the current load is When is large, an example in which the output voltage set value is lowered is also conceivable.
The predetermined values used in the determination of FIG. 3, that is, 12.5V in step S201, 12V in step S202, 80A in step S203, and 3.5V in step S204 are all examples. Of course, it is conceivable to use a value other than this as a criterion.
Further, 13V and 10V as the output voltage set value of the booster circuit 22, and the characteristics of FIG. 4B are merely examples.
Further, although the control circuit 23 has been described as a component of the converter device 7, for example, an ECU may function as the control circuit 23.
Needless to say, the vehicle electrical component 5x provided with the converter device 7 is not limited to a car audio device or a navigation device.

  DESCRIPTION OF SYMBOLS 1 ... Battery, 5a, 5b-5x ... Vehicle electrical component, 6 ... Idling stop control part, 7 ... Converter apparatus, 21 ... Bypass circuit, 22 ... Booster circuit, 23 ... Control circuit, 24 ... Memory

Claims (5)

A vehicle power supply device that outputs an input voltage from a battery side as an operation power supply voltage of a vehicle electrical component,
A booster that boosts the input voltage to obtain an output voltage to the vehicle electrical component;
A bypass unit connected in parallel with the booster unit, so that a voltage bypassing the booster unit is an output voltage;
During the restart period from the idling stop state of the engine of the vehicle, the bypass unit is shut off and control is performed so as to obtain the output voltage boosted by the boosting unit, and the battery is determined for deterioration, and the deterioration determination is performed. And a control unit that performs a process of variably setting the output voltage value of the boosting unit according to the result. When the control unit obtains a determination result that the battery is deteriorated by the deterioration determination, the output when the output voltage value of the boosting unit is not deteriorated is obtained. The vehicle power supply device according to claim 1, wherein the power supply device is set to a value lower than the voltage value. The controller is
The deterioration determination is performed using all or a part of a battery voltage value during engine operation, a battery voltage value during idling stop, and a battery voltage decrease amount during the restart period. The vehicle power supply device described in 1. The controller is
The vehicle determination device according to any one of claims 1 to 3, wherein a determination result as to whether or not the output current of the battery during idling stop is equal to or greater than a predetermined value is also used as a setting condition for the output voltage value of the booster. Power supply. The controller is
5. The vehicle according to claim 1, wherein the vehicle is controlled so that an output voltage that does not pass through the boosting unit is supplied to the vehicle electrical component except for the restart period. Power supply.

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