JP2017103874A - Vehicle power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable restoration of the charge amount of a main power storage device as early as possible after the initiation of an internal combustion engine having been stopped, while appropriately securing a spare capacity of a sub-power storage device in preparation for the regenerative brake at the deceleration of a vehicle.SOLUTION: A vehicle power supply includes: a dynamo which rotates in cooperation with the rotation of an output shaft of the internal combustion engine loaded on the vehicle; a main power storage device connected to the dynamo; a sub-power storage device connected in parallel with the main power storage device in such a mode that a switch, which is switchable between connection and disconnection, is made to intervene between with the dynamo; and with the provision of an initial charge period in which, while maintaining the switch to be OFF after the initiation of the stopped internal combustion engine, the generated power of the dynamo is supplied to the main power storage device, without supplying to the sub-power storage device, a control unit which permits switching over the switch from OFF to ON after the lapse of the charge period, so as to set the length of the initial charge period according to the charge state of the main power storage device at the initiation of the internal combustion engine.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a power supply device for supplying electric power necessary for an electrical system of a vehicle.

  In general, a vehicle is equipped with a generator that serves as a power source and a power storage device that stores the power generated by the generator in order to supply power necessary for various electric loads mounted on the vehicle. Conventionally, a lead battery has been used as a power storage device. Recently, in addition to the lead battery as the main power storage device, a secondary battery suitable for charge / discharge of electric power, such as a nickel metal hydride battery or lithium ion, because the lead battery is not suitable for charging / discharging of high power. A battery or the like or a capacitor is increasingly used as a sub power storage device.

  In a power supply device that uses a main power storage device and a sub power storage device in combination, both power storage devices are connected in parallel to the generator so that the power generator can charge any power storage device. It is configured so that power can be supplied to the load. A switch such as a relay or a semiconductor switching element is interposed between the generator and the sub power storage device so that the electrical connection between the generator and the sub power storage device can be switched (for example, see the following patent document). In particular, the sub power storage device plays a role of effectively recovering the electric power generated by the regenerative braking of the vehicle.

JP-A-2015-144524

  During parking with the internal combustion engine stopped, electric power is supplied exclusively from the main power storage device to the electrical system of the vehicle. Therefore, after starting the internal combustion engine, it is necessary to charge the main power storage device with the electric power generated by driving the generator.

  Nevertheless, the switch is turned ON immediately after starting the internal combustion engine, and the sub power storage device may be connected in parallel to the generator together with the main power storage device, resulting in a situation where recovery of the charge amount of the main power storage device is delayed. It was. When the main power storage device is a lead battery, there is a concern that a decrease in the charge amount shortens the life of the lead battery. Furthermore, if the secondary power storage device is unnecessarily charged and the available capacity to accept the charge decreases, the vehicle's kinetic energy cannot be converted into electrical energy and recovered by the secondary power storage device when the vehicle decelerates. , Causing actual fuel consumption to deteriorate.

  The present invention has been made by paying attention to the above-mentioned problem for the first time, and recovers the charge amount of the main power storage device as soon as possible after starting the internal combustion engine, which has been stopped, and regenerative braking during deceleration of the vehicle. The intended purpose is to appropriately secure the free capacity of the secondary power storage device.

  In the present invention, a generator that rotates in conjunction with rotation of an output shaft of an internal combustion engine mounted on a vehicle, a main power storage device that is connected to the generator, and a switch that can be switched between connection and disconnection are interposed between the generator and the generator. After the start of the stopped internal combustion engine, the switch is turned off to supply the power generated by the generator to the sub power storage device. First, an initial charging period to be supplied to the main power storage device is provided, and after the initial charging period, the switch is allowed to be switched from OFF to ON, and the length of the initial charging period is set as the main power storage at the start of the internal combustion engine. A vehicle power supply device is provided that includes a control unit that is set according to the state of charge of the device.

  According to the present invention, the amount of charge of the main power storage device is recovered as soon as possible after starting the internal combustion engine that has been stopped, and the free capacity of the sub power storage device is appropriately adjusted in preparation for regenerative braking during vehicle deceleration. Can be secured.

The figure which shows schematic structure of the internal combustion engine and control part in one Embodiment of this invention. The figure which shows typically the structure of the connection of the internal combustion engine and generator / motor in the embodiment. The figure which shows the electric circuit of the power supply device for vehicles of the embodiment. The flowchart which shows the example of the procedure of the process which the control part of the embodiment performs.

  An embodiment of the present invention will be described with reference to the drawings. A vehicle internal combustion engine 100 shown in FIG. 1 is a spark ignition type four-stroke engine and includes a plurality of cylinders 1 (one of which is shown in FIG. 1). In the vicinity of the intake port of each cylinder 1, an injector 11 for injecting fuel is provided. A spark plug 12 is attached to the ceiling of the combustion chamber of each cylinder 1. The spark plug 12 receives spark voltage generated by the ignition coil and causes spark discharge between the center electrode and the ground electrode.

  The intake passage 3 for supplying intake air takes in air from the outside and guides it to the intake port of each cylinder 1. On the intake passage 3, an air cleaner 31, an electronic throttle valve 32, a surge tank 33, and an intake manifold 34 are arranged in this order from the upstream.

  The exhaust passage 4 for discharging the exhaust guides the exhaust generated as a result of burning the fuel in the cylinder 1 from the exhaust port of each cylinder 1 to the outside. An exhaust manifold 42 and an exhaust purification three-way catalyst 41 are disposed on the exhaust passage 4.

  An external EGR (Exhaust Gas Recirculation) device 2 realizes a so-called high-pressure loop EGR. The EGR device 2 includes an external EGR passage 21 that communicates the upstream side of the catalyst 41 in the exhaust passage 4 and the downstream side of the throttle valve 32 in the intake passage 3, an EGR cooler 22 provided on the EGR passage 21, and an EGR passage 21. And an EGR valve 23 that controls the flow rate of the EGR gas flowing through the EGR passage 21. The inlet of the EGR passage 21 is connected to the exhaust manifold 42 in the exhaust passage 4 or a predetermined location downstream thereof. The outlet of the EGR passage 21 is connected to a predetermined location downstream of the throttle valve 32 in the intake passage 3, specifically to a surge tank 33.

  As shown in FIG. 2, the internal combustion engine 100 according to the present embodiment includes a starter motor (cell motor) 140, an ISG (Integrated Starter Generator) that is a generator / motor, or a compressor 130 and other auxiliary machines. Accompanying.

  The starter motor 140 is an electric motor dedicated to cranking that rotates the crankshaft 10 of the internal combustion engine 100 mainly during cold start (the driver operates the ignition switch or the ignition key to start the internal combustion engine 100). The starter motor 140 has a pinion gear 141 on its output shaft, and the pinion gear 141 rotates on the crankshaft 10 by meshing with a ring gear 103 fixed to the crankshaft 10 that is the output shaft of the internal combustion engine 100. Transmits driving force. The pinion gear 141 is detached from the ring gear 103 except when the starter motor 140 is cranking the internal combustion engine 100.

  The ISG 110 has a function as an electric motor that drives the crankshaft 10 and thus an axle (and driving wheels) of the vehicle, and a function as a generator that receives power from the crankshaft 10 and generates electric power. The ISG 110 is connected to one end side of the crankshaft 10 of the internal combustion engine 100 via the winding transmission mechanisms 112, 113, and 101.

  The ISG 110 is, for example, an inner-rotor type AC synchronous machine, and includes a rotor (rotor) having both permanent magnets and a rotor coil (excitation (field) winding) 116, and a three-phase AC facing the outer peripheral surface of the rotor. A stator (stator) including a stator coil (stator winding) 115 is used as an element. The rotor is fixed to the outer periphery of the rotor shaft 111. Pulleys (or sprockets) 112 and 101 are fixed to the rotor shaft 111 and the crankshaft 10, respectively, and the crankshaft 10 and the rotor shaft are secured by a belt (or chain) 113 wound around the pulleys 112 and 101. The rotational driving force is transmitted to and from 111 (bidirectionally).

  The ISG 110 receives the supply of electric power from the in-vehicle power storage device 61 to rotate and drive the crankshaft 10 mainly when the internal combustion engine 100 that has been idle-stopped is restarted or during motor assist that increases the driving force supplied to the axle. In turn, when power is generated by being rotationally driven by the crankshaft 10, the power storage device 61 is charged with the generated power. When the vehicle decelerates, regenerative braking is performed by the ISG 110, and the kinetic energy of the vehicle can be recovered as electric energy.

  Power storage device 61 includes a battery and / or a capacitor. In this embodiment, the main power storage device 611 and the sub power storage device 612 are mounted on the vehicle. The main power storage device 611 is, for example, a well-known lead battery for vehicles. The sub power storage device 612 is, for example, a nickel metal hydride battery, a lithium ion battery, a capacitor, or the like. The sub power storage device 612 can recover and store regenerative power that cannot be necessarily recovered by the main power storage device 611. The rated voltage of the main power storage device 611 and the rated voltage of the sub power storage device 612 are equivalent, for example, 12V.

  A switch 613 that can be connected and disconnected is provided on an electric circuit that connects the sub power storage device 612 to the ISG 110 and the like. The switch 613 is, for example, a relay or a semiconductor switching element (power transistor, power MOSFET, IGBT, or other power device). The switch 613 is disconnected (opened) at the time of cold start of the internal combustion engine 100 and immediately after the cold start, and is connected only after the main power storage device 611 is charged to a fully charged state or a state close to full charge. Is done.

  The compressor 130 for compressing the refrigerant of the air conditioner mounted on the vehicle is also connected to one end side of the crankshaft 10 of the internal combustion engine 100 via the winding transmission mechanisms 102, 134, 133, similarly to the ISG 110. . Pulleys (or sprockets) 133 and 102 are fixed to the input shaft 132 and the crankshaft 10 of the compressor 130, respectively. The rotational driving force is transmitted to the input shaft 132. The belt 134 may transmit driving force to a lubricating oil pump (not shown), a cooling water pump (not shown), or the like, which is an auxiliary machine other than the compressor 130. A magnet clutch 131 that can be connected and disconnected is provided between the main body of the compressor 130 and the input shaft 132, and the clutch 131 is disconnected when the air conditioner is not operated.

  A transmission 120 that connects the internal combustion engine 100 and the axle is installed on the other end side of the crankshaft 10.

  As is well known, various electric loads 7 are mounted on the vehicle. Specific examples of the electrical load 7 include a blower for an air conditioner, a defogger that removes fog on the rear glass, an audio device, a car navigation system, an illumination light (head lamp, tail lamp, stop lamp (brake lamp), fog lamp, blinker ( Turn signal lamp)), a radiator fan for cooling the cooling water of the internal combustion engine, an electric power steering device, and the like. These electric loads 7 are supplied with necessary power from the ISG 110 and / or the power storage device 61 that function as a generator.

  FIG. 3 shows an equivalent circuit of ISG110. When the ISG 110 is operated as a generator, a three-phase AC induced current is generated in the stator coil 115 which is a three-phase coil. This induced current is converted into a direct current by a rectifier 113 using a diode and then supplied to the power storage device 61 and the electric load 7.

  The controller 114 attached to the ISG 110 receives a control signal n for instructing a target value of the output voltage of the ISG 110, which is issued from an ECU (Electronic Control Unit) 0 that is a control unit of the present embodiment. Then, in order to make the terminal voltage of the power storage device 61 (in other words, the power supply voltage supplied to the electrical system) follow the commanded target voltage, the exciting current applied to the rotor coil 116 by switching the semiconductor switching element 119 PWM (Pulse Width Modulation) control is performed to adjust the size of. The output voltage of the ISG 110, that is, the generated voltage induced in the stator coil 115, increases as the exciting current flowing through the rotor coil 116 increases.

  The ISG 110 that operates as a generator is a mechanical load when viewed from the internal combustion engine 100. When the output voltage of ISG 110 exceeds the terminal voltage of power storage device 61, power storage device 61 is charged and power is supplied from ISG 110 to electrical load 7. That is, the ISG 110 spends the energy of rotation of the crankshaft 10 to generate electrical energy. The amount of charge to the power storage device 61 and the amount of power supplied to the electrical load 7 depend on the potential difference between the output voltage of the ISG 110 and the terminal voltage of the power storage device 61.

  Conversely, when the output voltage of the ISG 110 is less than or close to the terminal voltage of the power storage device 61, the power storage device 61 is not charged, and no power is supplied from the ISG 110 to the electrical load 7 (from the power storage device 61 to the electrical load 7). May be powered). In other words, the ISG 110 does not perform work that consumes the energy of rotation of the crankshaft 10, or the work is reduced. In short, when a high power generation voltage is commanded from the ECU 0 to the ISG 110, the mechanical load of the ISG 110 with respect to engine rotation increases, and when a low power generation voltage is commanded, the mechanical load of the ISG 110 with respect to engine rotation decreases.

  The ISG 110 normally generates power so as to maintain the system voltage of the electrical system above a predetermined target voltage. For example, assuming that the target voltage is 12.5 V, power generation is not performed when the terminal voltage of power storage device 61 (particularly, main power storage device 611) is 12.8 V, which is higher than this. When the electrical load 7 increases and the terminal voltage of the power storage device 61 falls below 12.5V, power generation is performed so that the system voltage is restored to 12.5V.

  Incidentally, the controller 114 has a gradual excitation function that gradually increases the excitation current instead of increasing the excitation current in a stepwise manner when increasing the amount of power generated by the ISG 110 as the electrical load 7 increases. This gradual excitation function avoids temporary concentration of the mechanical load on the internal combustion engine 100 and prevents a decrease in engine rotation in an idle operation or low load operation region.

  In addition, the controller 114 receives a control signal n that is issued from the ECU 0 and commands an upper limit value of the excitation current, detects the magnitude of the excitation current flowing through the rotor coil 116 via the sensor 117, and commands the excitation current. Regulated below the specified upper limit. The upper limit of the excitation current is intended to prevent the mechanical rotation on the internal combustion engine 100 from becoming excessive and the engine rotation from becoming unstable. Therefore, for example, when the refrigerant compression compressor 130 is operated and when it is not operated, the upper limit value of the excitation current is lower in the former case.

  Clipping to the upper limit value of the excitation current has priority over following the target voltage value of the generated voltage of the ISG 110. In other words, even if the terminal voltage of the power storage device 61 is still less than the target voltage commanded from the ECU 0, the controller 114, when the excitation current flowing through the rotor coil 116 has already reached the upper limit commanded from the ECU 0, The excitation current is not increased further.

  On the other hand, when the ISG 110 is operated as an electric motor for driving the crankshaft 10, a three-phase alternating current is passed through the inverter 118 using a semiconductor switching element to the stator coil 115 while energizing the rotor coil 116 with a required excitation current. Is applied to generate a rotating magnetic field around the rotor. The high side switch and the low side switch of each phase of the inverter 118 are fired / extinguished by the controller 114. At this time, the controller 114 receives a control signal n, which is issued from the ECU 0 and commands an output level of the ISG 110 that functions as an electric motor. Then, in order to make the output of the ISG 110 follow the commanded output level, PWM control for adjusting the magnitude of the excitation current applied to the rotor coil 116 and / or the magnitude of the three-phase current applied to the stator coil 115. To implement. The output of the ISG 110 that applies a rotational driving force to the crankshaft 10 of the internal combustion engine 100 increases as the excitation current flowing through the rotor coil 116 increases, and increases as the three-phase current flowing through the stator coil 115 increases.

  The ECU 0 is a microcomputer system having a processor, a memory, an input interface, an output interface, and the like. The input interface includes a vehicle speed signal a output from a vehicle speed sensor that detects an actual vehicle speed of the vehicle, a rotation angle of the crankshaft 10, and a crank angle output from a crank angle sensor (engine rotation sensor) that detects the engine speed. Signal b, accelerator pedal depression amount or throttle valve 32 opening as an accelerator opening (in other words, a required load on the internal combustion engine 100), an accelerator opening signal c output from a sensor, an intake passage 3 (especially surge) An intake air temperature / intake pressure signal d output from a sensor for detecting the intake air temperature and intake pressure in the tank 33), a coolant temperature signal e output from a water temperature sensor for detecting a coolant temperature indicating the temperature of the internal combustion engine, and a brake Output from a switch that detects pedal depression or a sensor that detects the amount of brake pedal depression Brake signal f, a voltage / current signal g output from a sensor that detects a terminal voltage and / or terminal current (particularly, battery voltage or battery current) of the main power storage device 611, a terminal voltage of the sub power storage device 612, and / or A voltage / current signal h output from a sensor for detecting a terminal current (in particular, battery voltage or battery current), a status signal s provided from the controller 114 of the ISG 110, and the like are input. The status signal s includes various information related to the ISG 110, such as the rotation speed and temperature, the magnitude of the excitation current flowing through the rotor coil 116, the current operation mode (that is, whether the power generation is being performed, the internal combustion engine 100 is being cranked, Information on whether the internal combustion engine 100 is motor-assisted or in a no-load state in which neither the generator nor the motor works.

  From the output interface of the ECU 0, an ignition signal i for the igniter of the spark plug 12, a fuel injection signal j for the injector 11, an opening operation signal k for the throttle valve 32, and an opening operation for the EGR valve 23. Signal l, control signal n for controlling the controller 114 of the ISG 110, ON / OFF switching signal o for the switch 613 on the electric circuit connecting the sub power storage device 612 to the ISG 110 and the electric load 7, magnet A clutch engagement signal p or the like is output to the switch 62 on the electric circuit for energizing the clutch 131. The control signal n is a signal for instructing the operation mode of the ISG 110 and commanding the target value of the generated voltage output from the ISG 110 when operating as a generator, the output level of the ISG 110 when operating as an electric motor, and the like. The ON / OFF switching signal o causes the switch 613 to be switched between the ON state and the OFF state, so that the sub power storage device 612 is connected to the ISG 110 or the like and the sub power storage device 612 is disconnected from the ISG 110 or the like. Is a control signal for switching between and. Specifically, it may be a signal for energizing a solenoid that drives the relay 613 or a signal for firing the semiconductor switching element 613.

  The processor of the ECU 0 interprets and executes a program stored in advance in the memory, calculates operation parameters, and controls the operation of the internal combustion engine 100. The ECU 0 obtains various information a, b, c, d, e, f, g, h, and s necessary for operation control of the internal combustion engine 100 via the input interface, and requests the required throttle valve 32 opening degree and request. Fuel injection amount, fuel injection timing (including the number of fuel injections per combustion), fuel injection pressure, ignition timing, required EGR rate, necessity of operation of refrigerant compression compressor 130 of the air conditioner, ISG 110 Various operation parameters such as power generation amount or output are determined. The ECU 0 applies various control signals i, j, k, l, n, o, and p corresponding to the operation parameters via the output interface.

  In addition, the ECU 0 inputs the control signal q to the starter motor 140 when the internal combustion engine 100 is started, particularly during cold start, and engages the pinion gear 141 with the ring gear 103 to crank the internal combustion engine 100.

  The ECU 0 of the present embodiment turns on the switch 613 to connect the sub power storage device 612 to the ISG 110 when the accelerator opening is 0 or less than a threshold value close to 0, and uses the sub power storage device 612 to generate power generated by the ISG 110. The regenerative braking to be recovered is performed. Alternatively, when the power storage device 61 is already fully charged, the motor assist (coast) that supplies the electric power stored in the sub power storage device 612 to the ISG 110 and operates the ISG 110 as an electric motor to apply the driving force to the axle. Assist driving).

  On the other hand, when the accelerator opening is equal to or greater than a predetermined value, that is, when there is a vehicle acceleration request, regenerative braking is not performed, but the electric power stored in the sub power storage device 612 may be supplied to the electric load 7. .

  In addition, the ECU 0 performs an idle stop for improving the fuel consumption by stopping the idle rotation of the internal combustion engine 100 when the vehicle is temporarily stopped. The ECU 0 has a brake pedal depressed, the cooling water temperature of the internal combustion engine 100 is higher than a predetermined level, the charge amount or the terminal voltage of the power storage device 61 (particularly, the main power storage device 611) is higher than a predetermined level, The refrigerant compression compressor 130 is not in operation, the shift range is the travel range, there is a history of acceleration to a certain vehicle speed or higher since the end of the previous idle stop, and the current vehicle speed is below a certain vehicle speed (for example, the vehicle speed Was determined to have met the idle stop condition because all of the above conditions were satisfied, for example, 13.5 km / h to 13 km / h or 9.5 km / h to 7 km / h) To do.

  When a predetermined idle stop end condition is satisfied after the idle stop condition is satisfied, the internal combustion engine 100 is restarted. The ECU 0 is in the idling stop state for a predetermined time when the brake pedal is not depressed, the brake pedal is depressed more strongly (the brake pedal depression amount or the master cylinder pressure is further increased), the accelerator pedal is depressed. It is determined that the condition for ending the idle stop is satisfied when any of (for example, 3 minutes) has elapsed. As already described, when the internal combustion engine 100 is restarted from the idle stop, cranking is mainly performed by the ISG 110.

  During parking in which the ignition switch (or the ignition key) is turned OFF by the driver's hand and the internal combustion engine 100 is stopped, electric power is supplied exclusively from the main power storage device 611 to the electrical system of the vehicle, and the sub power storage device No power is supplied from 612. While the internal combustion engine 100 is stopped, naturally the power generation by the ISG 110 cannot be performed, and the amount of electric charge stored in the main power storage device 611 during parking is reduced. Accordingly, after the ignition switch is operated from OFF to ON and the internal combustion engine 100 is started again, the ISG 110 is operated as a generator, and the electric power generated by the ISG 110 is supplied to the main power storage device 611 to charge the main power storage device 611. Need to recover quickly.

  Therefore, as shown in FIG. 4, the ECU 0 of the present embodiment maintains the switch 613 in the OFF state immediately after the completion of cranking for starting the internal combustion engine 100 that has been stopped (step S1), and generates power from the ISG 110. An initial charging period for supplying power only to the main power storage device 611 without supplying power to the sub power storage device 612 is provided (steps S2 and S3). Then, after the initial charging period has passed (step S4), the switch 613 is allowed to be switched from OFF to ON for the first time (step S5), thereby recovering the charge amount of the main power storage device 611 as quickly as possible.

  The length of the initial charging period after restart of internal combustion engine 100 is set according to the state of charge of main power storage device 611 when internal combustion engine 100 is started. Specifically, the amount of charge of the main power storage device 611 at the time when the ignition switch is turned off (or when the operation of the internal combustion engine 100 is stopped) and the ignition switch is turned off (or the internal combustion engine). It is set according to the length of time from when the operation of 100 is stopped) until the ignition switch is turned ON (or the internal combustion engine 100 is restarted).

  The ECU 0 integrates (time-integrates) the current amount flowing into the main power storage device 611 and the current amount flowing out from the main power storage device 611, which are known with reference to the output signal g of the current sensor, The charge amount of the main power storage device 611 is repeatedly estimated. In addition, ECU 0 lengthens the initial charging period as the charge amount of main power storage device 611 decreases when the ignition switch is turned off. In addition, under the condition that the amount of charge of the main power storage device 611 when the ignition switch is turned off is equal, the time from when the ignition switch is turned off to when it is turned on again (in other words, the internal combustion engine The longer the engine stop time), the longer the initial charging period. After all, it can be said that the charge amount of the main power storage device 611 at the start of the internal combustion engine 100 is estimated, and that the initial charge period is set longer as the charge amount is smaller.

  In the memory of the ECU 0, map data that prescribes the relationship between the amount of charge of the main power storage device 611 when the ignition switch is OFF, the ignition switch OFF time, and the length of the initial charging period is stored. In step S2, the ECU 0 searches the map using the charge amount of the main power storage device 611 when the ignition switch is OFF and the ignition switch OFF time as keys, and knows the length of the initial charging period to be set.

  During the initial charging period, the ISG 110 is operated as a generator to forcibly charge the main power storage device 611 (step S3). Therefore, a control signal n is given to controller 114 so that the output voltage of ISG 110 is higher than the terminal voltage of main power storage device 611.

  Further, after the internal combustion engine 100 is started, the switch 613 is prohibited from being turned ON until the initial charging period elapses, and fuel is supplied to the cylinder 1 without performing idle stop even if the idle stop condition is satisfied. That is, it is preferable to continue the operation of the internal combustion engine 100. This is intended to suppress discharge of main power storage device 611 during the initial charging period. After the initial charging period elapses, the execution of the idle stop accompanying the establishment of the idle stop condition is permitted.

  In the present embodiment, the generator 110 that rotates in conjunction with the rotation of the output shaft 10 of the internal combustion engine 100 mounted on the vehicle, the main power storage device 611 connected to the generator 110, and the generator 110 are disconnected. After starting the auxiliary power storage device 612 connected to the generator 110 in parallel with the main power storage device 611 and the internal combustion engine 100 that has been stopped, the switch 613 is kept OFF. An initial charging period for supplying the generated power of the generator 110 to the main power storage device 611 without supplying it to the sub power storage device 612 is provided, and the switch 613 is allowed to be switched from OFF to ON after the initial charging period. And a control unit 0 for setting the length of the initial charging period according to the state of charge of the main power storage device 611 at the time of starting the internal combustion engine 100.

  According to the present embodiment, the charge amount of main power storage device 611 can be recovered as soon as possible after starting internal combustion engine 100 that has been stopped. In particular, when the main power storage device 611 is a lead battery or the like, shortening of the life of the main power storage device 611 can be suppressed. Further, by charging only the main power storage device 611 and not charging the sub power storage device 612 during the initial charging period, the amount of fuel consumed for power generation by the generator 110 can be reduced. In addition, since the free capacity of the secondary power storage device 612 can be appropriately secured, the kinetic energy of the vehicle can be collected and reused as power in the secondary power storage device 612 through regenerative braking when the vehicle is decelerated. It can contribute to improvement.

  In addition, since the number and frequency of ON / OFF switching of the switch 613 are reduced, when the switch 613 is a relay or the like, the improvement of NV (Noise and Vibration) performance due to the reduction of the generation opportunity of the operation sound, In addition, the life of the switch 613 is extended.

  The present invention is not limited to the embodiment described in detail above. For example, if it is possible to monitor the amount of charge supplied from the main power storage device 611 to the electrical load 7 of the electrical system during parking while the internal combustion engine 100 is stopped, that is, the amount of discharge of the main power storage device 611, the ignition switch is turned off. The amount of charge of the main power storage device 611 when the internal combustion engine 100 is started is obtained by subtracting the amount of discharge of the main power storage device 611 when the internal combustion engine 100 is stopped from the amount of charge of the main power storage device 611 at that time. In step S2, the initial charging period can be set longer as the charging amount of main power storage device 611 at the time of starting is smaller.

  Alternatively, the main power storage at the start of the internal combustion period 100 is lower as the terminal voltage (or open circuit voltage) of the main power storage device 611 immediately before the start of the internal combustion engine 100 (just before the start of cranking) or just after the start (after the complete explosion) is lower. Considering that the charging amount of the device 611 is small, the initial charging period may be set longer as the charging amount of the main power storage device 611 at the time of starting is smaller.

  The generator associated with the internal combustion engine 100 is not limited as long as it can generate electric power by receiving a rotational driving force transmitted from the crankshaft 10 or the axle of the internal combustion engine 100 and does not necessarily have a function as an electric motor.

  Other specific configurations of each part can be variously modified without departing from the spirit of the present invention.

  The present invention can be applied to a power supply device mounted on a vehicle.

0 ... Control unit (ECU)
10 ... Output shaft (crankshaft)
DESCRIPTION OF SYMBOLS 100 ... Internal combustion engine 110 ... Generator (ISG)
611 ... Main power storage device 612 ... Sub power storage device 613 ... Switch

Claims (1)

A generator that rotates in conjunction with the rotation of the output shaft of the internal combustion engine mounted on the vehicle;
A main power storage device connected to the generator;
A sub power storage device connected to the generator in parallel with the main power storage device in a mode in which a switch that can be connected and disconnected is interposed between the generator and the generator,
After starting the internal combustion engine that has been stopped, the switch is kept OFF to provide an initial charging period for supplying the main power storage device without supplying the generated power of the generator to the sub power storage device, and after passing through the initial charging period A vehicle power supply apparatus comprising: a control unit that allows the switch to be switched from OFF to ON, and sets a length of an initial charging period according to a state of charge of the main power storage device when the internal combustion engine is started.

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