JP4661650B2 - Vehicle power supply system - Google Patents

Description

  The present invention relates to a vehicle power supply system, and more particularly to a vehicle power supply system capable of adjusting the power supply capability of a power supply.

Conventionally, a vehicle power supply system having two batteries as a power supply is known (see, for example, Patent Document 1). This power supply system for a vehicle collects main power that supplies power to a general electric load in preference to the sub power supply, and regenerative power that is generated by the generator when the vehicle decelerates, and stores the generated power of the generator And a sub power source, which enables charging from the sub power source to the main power source.
JP 2004-328988 A

  By the way, in the case of a system that can store the electric power generated by the generator in the battery, including the above-described conventional technology, in order to ensure the reliability of the system, the damage at the time of power generation failure of the generator is minimized as much as possible. It is desirable to provide the system with a function to limit it to the limit. In this regard, in the above-described conventional technology, when the generator becomes unable to generate power due to a failure or the like and the power supply capacity is insufficient, the secondary power source cannot be charged, so the secondary power source can be charged to the main power source. The original function cannot be demonstrated.

  Therefore, an object of the present invention is to provide a vehicle power supply system that can ensure power supply when the power supply capability of the power supply is insufficient.

In order to solve the above problems, as a first invention,
A starter motor for starting the vehicle engine;
A generator using the engine as a power source;
In a vehicle power supply system having a power generation operation detection means for detecting the power generation amount of the generator,
The pre SL starter motor with the starter motor connecting means for connecting to said engine,
When the amount of power generation below a predetermined value is detected by the power generation amount detection means during operation of the engine, the power generated by connecting the starter motor to the engine is operated by the power generated by the generator. A power supply system for a vehicle is provided, which is supplied to an electric load .

In order to solve the above problem, as a second invention,
A starter motor for starting the vehicle engine;
Power storage means;
A generator connected to the power storage means in a rechargeable manner and using the engine as a power source;
A power generation amount detecting means for detecting a power generation amount of the generator;
In a vehicle power supply system having charging rate detection means for detecting a charging rate of the power storage means,
The pre SL starter motor with the starter motor connecting means for connecting to said engine,
During operation of the engine, when the power generation amount that the generator can generate the maximum power is detected by the power generation amount detection means, and when the charge rate that is equal to or less than a predetermined value is detected by the charge rate detection means, A power supply system for a vehicle is provided , wherein electric power generated by connecting a starter motor to the engine is supplied to an electric load operated by electric power generated by the generator .

In order to solve the above problem, as a third invention,
A starter motor for starting the vehicle engine;
Power storage means;
A generator connected to the power storage means in a rechargeable manner and using the engine as a power source;
A power generation amount detecting means for detecting a power generation amount of the generator;
In a vehicle power supply system having a discharge state detection means for detecting a discharge state of the power storage means,
The pre SL starter motor with the starter motor connecting means for connecting to said engine,
When the power generation amount detecting means detects the power generation amount that the generator can generate as much as possible during the operation of the engine, and the discharge state detection means detects the discharge amount of the power storage means above a predetermined value Furthermore , the vehicle power supply system is characterized in that the electric power generated by connecting the starter motor to the engine is supplied to an electric load operated by the electric power generated by the generator .

In order to solve the above problem, as a fourth invention,
A starter motor for starting the vehicle engine;
Power storage means;
A power supply system for a vehicle having a generator connected to the power storage means in a chargeable manner and using the engine as a power source,
A regenerative control motor that stores regenerative power in the power storage means when the vehicle decelerates;
The pre SL starter motor with the starter motor connecting means for connecting to said engine,
When the regenerative control motor is regeneratively controlled during operation of the engine, the power generated by connecting the starter motor to the engine is supplied to an electric load that is operated by the power generated by the generator. A vehicle power supply system is provided.

In order to solve the above problem, as a fifth invention,
A starter motor for starting the vehicle engine;
Power storage means;
A power generator connected to the power storage means so as to be rechargeable and using the engine as a power source;
In the vehicle power supply system, the generator operates as a motor capable of regenerative control that stores regenerative power in the power storage means when the vehicle decelerates.
The pre SL starter motor with the starter motor connecting means for connecting to said engine,
When the generator is regeneratively controlled during operation of the engine, the power generated by connecting the starter motor to the engine is supplied to an electric load operated by the power generated by the generator. A vehicle power supply system is provided.

When the starter motor is connected to the engine by the starter motor connecting means in the vehicle power supply system according to any one of the first to fifth inventions, the vehicle running such as a vehicle acoustic device and a vehicle air conditioner It is preferable to further include a power supply stopping means for stopping the supply of power to the electrical load that is unnecessary .

  ADVANTAGE OF THE INVENTION According to this invention, the power supply when the power supply capability of a power supply is insufficient can be ensured.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing an embodiment of a vehicle power supply system of the present invention. Vehicles are equipped with various electrical loads. Examples of the on-vehicle electric load include an air conditioner, an acoustic device, a seat heater, a cigar socket, various ECUs (Electronic Control Units), and a solenoid valve. These electric loads are merely examples and do not limit the types of loads. A power source for these electric loads is an alternator 1 and a battery 2. The alternator 1 and the battery 2 supply power to each electric load via the power supply line 14.

  In the vehicle power supply system of the present embodiment, the electric loads mounted on the vehicle are classified into two groups. The electric load classified into the first group is an electric load 6 indispensable for traveling of the vehicle, and the electric load classified into the second group is an electric load 7 unnecessary for traveling of the vehicle.

  Examples of the first group of electric loads 6 include a drive device for running the vehicle, a device for stabilizing the running of the vehicle, and a lighting device necessary for running. More specifically, an engine ECU, a brake ECU, various actuators, a headlight, and the like can be given.

  The electric load 7 of the second group is a device for ensuring the convenience and comfort of the occupant, and is an electric load that is not directly related to driving the vehicle. More specifically, an air conditioner such as an air conditioner or an air purifier, an acoustic device such as an amplifier or a speaker, a seat heater, a cigar socket, a defogger, or the like can be given.

  The alternator 1 is a generator that uses the engine 9 as a power source, and generates electric power based on the output of the engine 9 for running the vehicle. The electric load is operated or the battery 2 is charged by the electric power generated by the alternator 1.

  In addition, since charging to the battery 2 or the like can be performed by regenerating the motor (electric motor), a motor capable of regenerative control may be provided in the vehicle power supply system of this embodiment as a power generation means other than the alternator 1. . For example, in order to secure a braking force when the vehicle is decelerated, the battery 2 can be charged via an inverter by performing regenerative control of a motor connected to the wheel drive shaft.

  The alternator 1 may be a motor / generator (so-called MG) having both a generator function and a regenerative control motor function. For example, the MG can charge the battery 2 by performing regenerative control during vehicle deceleration.

  Similarly to the alternator 1, the battery 2 supplies power to the electric load via the power supply line 14. The battery 2 supplies power to the electric load when the power supply capability of the alternator 1 is insufficient, and supplies power to the starter motor 3 for starting the engine 9. Specific examples of the battery 2 include a lead battery, a nickel metal hydride battery, and a lithium ion battery. The battery 2 may be replaced with an electric double layer capacitor. The battery 2 may be a combination of any of a lead battery, a lithium ion battery, a nickel metal hydride battery, and an electric double layer capacitor.

  Further, when the alternator 1 is stopped, power can be supplied from the battery 2 to the electric load. For example, the electric power required when the engine 9 is stopped and the alternator 1 is in a stopped state can be supplied from the battery 2 to the electric load.

  The starter motor 3 receives power supply from the battery 2 and starts the engine 9. When an operation signal for starting the starter motor 3 is input, the starter motor 3 is energized, and the pinion gear of the starter motor 3 and the ring gear of the flywheel of the engine 9 are engaged (connected). Thereby, when the starter motor 3 rotates, the crankshaft of the engine 9 rotates via the flywheel, and the engine 9 starts. When the operation signal for stopping the starter motor 3 is input (when the input of the operation signal for starting the starter motor 3 is lost), the pinion gear of the starter motor 3 and the ring gear of the flywheel of the engine 9 are separated and are not energized. Thus, the rotation of the starter motor 3 is stopped.

  In other words, when the pinion gear of the starter motor 3 and the ring gear of the flywheel of the engine 9 are engaged (when connected), if the starter motor 3 is rotated by the rotation of the engine 9 The starter motor 3 can be operated as a generator. Note that the ECU 10 described later transmits a control signal for connecting the starter motor 3 to the engine 9. The starter motor 3 performs a connection operation with the engine 9 by receiving the control signal.

  The other ECU 16 is a sender of state information about the vehicle required by the ECU 10 (for example, vehicle speed information, engine speed information, brake information, side brake information, shift position information such as neutral and parking). is there. The ECU 10 may directly acquire vehicle state information from a predetermined sensor that detects vehicle state information such as vehicle speed information from the vehicle speed sensor and shift position information from the shift position sensor. In particular, it is not limited to the ECU.

  The ECU 10 determines whether or not the vehicle is decelerating based on the vehicle state information from the other ECU 16. For example, the ECU 10 determines that the vehicle is in a deceleration state when the brake information is in an operating state, and determines that the vehicle is not in a deceleration state when the brake information is not in an operating state. Alternatively, the ECU 10 determines that the vehicle is in the deceleration state when the differential value of the vehicle speed is negative, and determines that the vehicle is not in the deceleration state when the differential value of the vehicle speed is not negative. The deceleration state can be determined by combining any of the vehicle speed information, brake information, engine speed information, and acceleration / deceleration sensor information. For example, it may be determined that the vehicle is decelerating when the brake information is in the activated state and the differential value of the vehicle speed is negative. Further, the ECU 10 may determine that it is in the deceleration state when it receives a deceleration signal representing the deceleration state from the other ECU 16.

  Further, the ECU 10 calculates the charge / discharge current value (battery current value) of the battery 2 based on the output value of the current sensor 4 that detects the charge / discharge current of the battery 2. The current detection unit built in the current sensor 4 includes a type that detects current using a Hall element and a type that detects current using a shunt resistor. For example, the current sensor 4 outputs a voltage (0 to 5 V) corresponding to the detected current. Further, the ECU 10 calculates the voltage value of the battery 2 based on the output value of the voltage sensor 5 that detects the voltage of the battery 2. As is clear from FIG. 1, the voltage of the battery 2 corresponds to the voltage of the power supply line 14 and applied to the electric loads 6 and 7.

  Further, the ECU 10 detects the current value or voltage value of the battery 2 by using the current sensor 4 that detects the charge / discharge current of the battery 2 or the voltage sensor 5 that detects the voltage of the battery 2, whereby the capacity of the battery 2 is increased. A “state of charge (SOC)” indicating how much remains is calculated. The charge rate indicates the remaining capacity with respect to the full charge capacity. The ECU 10 calculates the charging rate (remaining capacity) by, for example, integration (integration) of the charging / discharging current of the battery 2. This is because the rate of change over time in the amount of electricity (the capacity of the battery 2) corresponds to the current. Since the remaining capacity corresponds to a value obtained by subtracting the discharge capacity discharged from the battery 2 from the capacity when the battery 2 is fully charged, the ECU 10 connects the power line connected to the battery 2 with the current sensor 4 or the like. By monitoring the charge / discharge current and recording the history in the memory, the charge rate (remaining capacity) can be calculated. Note that the initial capacity at the time of full charge is stored in the memory.

  Further, the ECU 10 may estimate the charging rate by measuring the minimum value of the voltage of the battery 2 at the initial stage of discharging. Since it is known that there is a correlation between the minimum value caused by the voltage drop at the initial stage of discharge and the charging rate, the ECU 10 can estimate the charging rate based on the correlation (for example, map data).

  Further, the ECU 10 may calculate the charging rate and the full charge capacity by measuring the internal resistance of the battery 2 at the initial stage of discharging. The internal resistance is calculated from the initial discharge current and the initial discharge voltage. It is known that there is a correlation between the internal resistance and the charging rate, and the internal resistance and the full charge capacity. The ECU 10 refers to a charging rate calculation map for the internal resistance of the battery 2 and calculates a charging rate corresponding to the internal resistance of the battery 2. The ECU 10 calculates a full charge capacity corresponding to the internal resistance of the battery 2 with reference to a calculation map of the full charge capacity with respect to the internal resistance of the battery 2.

  If the battery 2 can be replaced with an electric double layer capacitor and its capacitance is known, the ECU 10 determines the charge rate of the electric double layer capacitor based on the voltage value and capacitance of the electric double layer capacitor. (Remaining capacity) can be calculated.

  In addition, charge / discharge control is executed so that the charge rate is maintained within the SOC management range having a predetermined charge rate as an upper and lower limit value. By providing the SOC management width, it is possible to prevent the progress rate of deterioration of the battery 2 due to, for example, excessive charging / discharging from being accelerated.

  Further, the ECU 10 performs feedback control for adjusting the power generation amount of the alternator 1 so that the voltage of the battery 2 becomes a predetermined constant value mainly based on the output value of the voltage sensor 5. Note that the ECU 10 may acquire the power generation state of the alternator 1 as information in order to determine whether the alternator 1 is actually generating power. For this purpose, the alternator 1 may be provided with means for outputting to the ECU 10 a power generation state indicating whether power generation is in progress. As a specific example, a so-called L terminal that outputs a Hi signal when power is being generated and outputs a Lo signal when power is not being generated can be used. Moreover, it is also possible to determine whether or not the alternator 1 is actually generating power by directly monitoring the output current and output voltage of the alternator 1 without providing the alternator 1 with such means. Further, in order to obtain the actual power generation amount, the ECU 10 may calculate the actual power generation amount of the alternator 1 based on the output current and output voltage of the alternator 1, or detect that the detected power generation amount is output to the ECU 10. Means may be provided in the alternator 1.

  The ECU 10 includes a plurality of ROMs such as a ROM for storing control programs and control data, a RAM for temporarily storing control program processing data, a CPU for processing control programs, and an input / output interface for exchanging information with the outside. It is composed of circuit elements. The ECU 10 is not limited to one control unit, and may be a plurality of control units so that control is shared.

  Now, an operation flow of the vehicle power supply system according to this embodiment will be described.

  FIG. 2 is a first example of an operation flow of the vehicle power supply system according to the present embodiment. The ECU 10 acquires information on the power generation state of the alternator 1 to determine whether or not the alternator 1 has a power generation failure (step 10). If the alternator 1 is not generating power even if the engine 9 is operating based on the engine speed information of the other ECU 16 or the like (or if the amount of power generation is less than a specified normal value), the alternator 1 has a power generation failure. It can be determined that the state is present. When the ECU 10 determines that the alternator 1 has a power generation failure, the ECU 10 connects the starter motor 1 to the engine 9 in order to secure a power supply source (step 12).

  On the other hand, when determining that the alternator 1 has no power generation failure (step 10; No), the ECU 10 determines whether the power generation amount of the alternator 1 is the maximum (step 18). When it is determined that the power generation amount of the alternator 1 is the maximum (step 18; Yes), it is determined whether or not the charging rate of the battery 2 is equal to or less than a specified normal value (step 20). When the charging rate of the battery 2 is equal to or less than the specified value (step 20; Yes), a power supply source is secured on the assumption that the battery 2 cannot be stored even though the power generation amount of the alternator 1 is maximum. Therefore, the starter motor 1 is connected to the engine 9 (step 12). If it is determined that the power generation amount of the alternator 1 is not the maximum (Step 18; No), or if the charging rate of the battery 2 is not less than the specified value (Step 20; No), it is assumed that there is no problem in the power generation capacity. This flow ends.

  After connecting the starter motor 1 to the engine 9 in step 12, the ECU 10 determines whether or not the discharge of the battery 2 is equal to or greater than a specified normal value (step 14). If the discharge of the battery 2 is greater than or equal to the specified value (step 14; Yes), it is assumed that a discharge exceeding the specified value is generated from the battery 2 due to the power generation failure of the alternator 1, or the power generation amount of the alternator 1 is the maximum. In spite of this, it is assumed that the power consumption of the electric load is large and the battery 2 has discharged more than a specified value, and the power supply to the electric load 7 is cut off by the cut-off circuit 8 (step 16). If the discharge of the battery 2 is not greater than or equal to the specified value (step 14; No), this flow ends, assuming that there is no problem with the power generation capacity.

  FIG. 3 is a second example of the operation flow of the vehicle power supply system according to the present embodiment. The vehicle power supply system in this case is assumed to include a motor or MG that can store regenerative power in the battery 2 by regenerative control during deceleration of the vehicle.

  The ECU 10 acquires information on the power generation state of the alternator 1 to determine whether or not the alternator 1 has a power generation failure (step 30). If the alternator 1 is not generating power even if the engine 9 is operating based on the engine speed information of the other ECU 16 or the like (or if the amount of power generation is less than a specified normal value), the alternator 1 has a power generation failure. It can be determined that the state is present. When the ECU 10 determines that the alternator 1 has a power generation failure, the ECU 10 connects the starter motor 1 to the engine 9 in order to secure a power supply source (step 32).

  On the other hand, when the ECU 10 determines that the alternator 1 has no power generation failure (step 30; No), it determines whether or not the vehicle is decelerating (step 36). When the vehicle is decelerating, the regenerative power is supplied to the battery 2 by regenerative control of the motor or MG capable of storing the regenerative power in the battery 2. Therefore, when it is determined that the vehicle is decelerating (step 36; Yes), the starter motor 1 is connected to the engine 9 in order to secure a power supply source (step 32). When it is determined that the vehicle is not decelerating (step 36; No), this flow is finished assuming that there is no problem with the power generation capacity.

  Therefore, according to the vehicle power supply system of this embodiment, even if a power generation failure occurs in the alternator 1, the starter motor 3 is operated as a generator by connecting the starter motor 3 to the engine 9. The power supply capability of the battery 2 is improved as compared with the power supply capability of the battery 2 alone. As a result, since the time during which power can be supplied to the electric load is extended, it is possible to extend the travel distance, the parking time, and the like. In addition, it is possible to further extend the power supply possible time by cutting off the power supply to the electric load that is unnecessary for traveling.

  Further, according to the vehicle power supply system of the present embodiment, the starter motor 3 is connected to the engine 9 when the vehicle is decelerated, so that the regenerative power from the motor or MG that can be controlled for regeneration is supplied to the engine 9. Since the regenerative electric power from the starter motor 3 can also be obtained, more regenerative electric power can be obtained.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, the vehicle deceleration determination performed in step 36 in FIG. 3 may be inserted between step 10 and step 18 in FIG. If it is determined that the vehicle is decelerating, the process proceeds to step 18;

It is a block diagram which shows one Embodiment of the power supply system for vehicles of this invention. It is a 1st example of the operation | movement flow of the power supply system for vehicles which concerns on a present Example. It is a 2nd example of the operation | movement flow of the power supply system for vehicles which concerns on a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Alternator 2 Battery 3 Starter motor 4 Current sensor 5 Voltage sensor 6 Electrical load indispensable for traveling 7 Electrical load unnecessary for traveling 8 Shut-off circuit 10 ECU
14 Power line 16 Other ECU

Claims (6)

A starter motor for starting the vehicle engine;
A generator using the engine as a power source;
In a vehicle power supply system having a power generation operation detection means for detecting the power generation amount of the generator,
The pre SL starter motor with the starter motor connecting means for connecting to said engine,
When the amount of power generation below a predetermined value is detected by the power generation amount detection means during operation of the engine, the power generated by connecting the starter motor to the engine is operated by the power generated by the generator. A power supply system for a vehicle, characterized by being supplied to an electric load . A starter motor for starting the vehicle engine;
Power storage means;
A generator connected to the power storage means in a rechargeable manner and using the engine as a power source;
A power generation amount detecting means for detecting a power generation amount of the generator;
In a vehicle power supply system having charging rate detection means for detecting a charging rate of the power storage means,
The pre SL starter motor with the starter motor connecting means for connecting to said engine,
During operation of the engine, when the power generation amount that the generator can generate the maximum power is detected by the power generation amount detection means, and when the charge rate that is equal to or less than a predetermined value is detected by the charge rate detection means, A power supply system for a vehicle, characterized in that electric power generated by connecting a starter motor to the engine is supplied to an electric load operated by the electric power generated by the generator . A starter motor for starting the vehicle engine;
Power storage means;
A generator connected to the power storage means in a rechargeable manner and using the engine as a power source;
A power generation amount detecting means for detecting a power generation amount of the generator;
In a vehicle power supply system having a discharge state detection means for detecting a discharge state of the power storage means,
The pre SL starter motor with the starter motor connecting means for connecting to said engine,
When the power generation amount detecting means detects the power generation amount that the generator can generate as much as possible during the operation of the engine, and the discharge state detection means detects the discharge amount of the power storage means above a predetermined value In addition , the vehicle power supply system is characterized in that the electric power generated by connecting the starter motor to the engine is supplied to an electric load that is operated by the electric power generated by the generator . A starter motor for starting the vehicle engine;
Power storage means;
A power supply system for a vehicle having a generator connected to the power storage means in a chargeable manner and using the engine as a power source,
A regenerative control motor that stores regenerative power in the power storage means when the vehicle decelerates;
The pre SL starter motor with the starter motor connecting means for connecting to said engine,
When the regenerative control motor is regeneratively controlled during operation of the engine, the power generated by connecting the starter motor to the engine is supplied to an electric load that is operated by the power generated by the generator. A power supply system for a vehicle. A starter motor for starting the vehicle engine;
Power storage means;
A power generator connected to the power storage means so as to be rechargeable and using the engine as a power source;
In the vehicle power supply system, the generator operates as a motor capable of regenerative control that stores regenerative power in the power storage means when the vehicle decelerates.
The pre SL starter motor with the starter motor connecting means for connecting to said engine,
When the generator is regeneratively controlled during operation of the engine, the power generated by connecting the starter motor to the engine is supplied to an electric load operated by the power generated by the generator. A vehicular power supply system. 6. The apparatus according to claim 1, further comprising power stopping means for stopping power supply to an electric load unnecessary for traveling of the vehicle when the starter motor is connected to the engine by the starter motor connecting means. The vehicle power supply system according to one item .

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