JP5409660B2 - 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 that can realize regeneration of braking energy of a vehicle and improvement of fuel consumption of the vehicle.

  A conventional vehicle power supply system regenerates braking energy by generating electricity with a generator and charging a battery during braking of the vehicle, reducing the amount of power generated by the generator during normal driving of the vehicle, and during normal driving The engine load is reduced to improve fuel efficiency (see, for example, Patent Document 1).

Japanese Patent No. 4172148

In a conventional vehicle power supply system, the power generation amount, that is, the regeneration amount varies depending on the state of the field winding. Therefore, since the driver who stepped on the foot brake receives the fluctuation of the regeneration amount as it is as the fluctuation of the brake, the driver feels uncomfortable and drivability is lowered.
Conventionally, in order to reduce the driver's uncomfortable feeling, the regenerative operation is performed only in a range where the regenerative amount is small, that is, in a range where the torque fluctuation is small, so that the regenerative amount supplied to the in-vehicle load and the battery is small.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a vehicle power supply system that can reduce the driver's uncomfortable feeling in braking operation and increase the amount of braking energy regeneration. To do.

  A vehicle power supply system according to the present invention includes a generator that is driven by an engine to generate AC power, a rectifier that rectifies and outputs AC power generated by the generator to DC power, and a high-voltage side output of the rectifier A first DC / DC converter connected to a terminal via a generator-side wiring, converting the voltage value of the output voltage of the rectifier to a different DC voltage, and outputting to the first DC / DC converter via a load-side wiring Connected to the first power storage device that supplies power to the vehicle-mounted load, and is connected to the high-voltage side output terminal of the rectifier via the generator-side wiring, and converts the voltage value of the output voltage of the rectifier to a different DC voltage. A second DC / DC converter that outputs, a second power storage device connected to the second DC / DC converter, a regulator circuit that supplies a field current to a field winding of the generator, and A power generation command is issued to the regulator circuit to cause the generator to generate electric power, and the first DC / DC converter and the second DC / DC converter are driven to control the generated electric power of the generator to the first power storage device and the above And a control device for storing power in the second power storage device. Then, the control device estimates a possible power generation amount of the generator, estimates a first regenerative amount of the first power storage device and a second regenerative amount of the second power storage device, and performs the first regeneration. The composite regenerative amount is adjusted from the magnitude relationship between the combined regenerative possible amount of the possible amount and the second regenerative possible amount and the power generation possible amount, and the travel braking amount is corrected by the adjusted composite regenerative possible amount. It is configured.

  According to this invention, the power generation possible amount of the generator is estimated from the rotation speed of the rotor of the generator and the voltage of the generator side wiring, and the first regenerative amount of the first power storage device and the second power storage device Estimated 2 regenerative amount, adjusted combined regenerative amount based on magnitude relationship between combined regenerative amount and power generation possible amount of first regenerative amount and second regenerative amount, adjusted combined regenerative amount Since the traveling braking amount is corrected by the above, it is possible to suppress a decrease in the regeneration amount and improve the driver's uncomfortable feeling when the brake pedal is depressed.

1 is a schematic configuration diagram of a vehicle power supply system according to an embodiment of the present invention. 1 is a circuit configuration diagram of a vehicle power supply system according to an embodiment of the present invention. It is a figure which shows the electric power generation characteristic of the generator used for the vehicle power supply system which concerns on one embodiment of this invention. It is a figure which shows the output characteristic of the generator used for the vehicle power supply system which concerns on one embodiment of this invention. It is a flowchart explaining regeneration amount control at the time of braking in the power supply system for vehicles concerning one embodiment of this invention. It is a flowchart explaining the operation | movement which estimates the electric power generation possible amount of a generator. It is a flowchart explaining the operation | movement which estimates the amount which can be regenerated. It is a flowchart explaining the maximum electric power tracking control of a generator. It is a flowchart explaining the maximum efficiency control of a generator. It is a flowchart explaining the monitoring operation | movement of the internal state of the generator in the vehicle power supply system which concerns on one embodiment of this invention.

  Hereinafter, preferred embodiments of a vehicle power supply system of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a vehicle power supply system according to an embodiment of the present invention, and FIG. 2 is a circuit configuration diagram of the vehicle power supply system according to an embodiment of the present invention.

  1 and 2, the vehicle power supply system includes a generator 5 that is driven by rotational torque of an engine 1 that is an internal combustion engine to generate AC power, and the AC power generated by the generator 5 is rectified to DC power. The rectifier 14 to be output, the first DC / DC converter 19 as the first power converter that converts the output voltage of the rectifier 14 to a DC voltage having a different voltage value, and the output voltage of the rectifier 14 to different voltage values The second DC / DC converter 20 as a second power conversion device that converts and outputs the direct current voltage and the direct current power converted by the first DC / DC converter 19, and supplies the power to the in-vehicle load 17. Controls the amount of current supplied to the power storage device 16, the second power storage device 18 that stores the DC power converted by the second DC / DC converter 20, and the field winding 8 of the generator 5. Regulator circuit 11, the first and second DC / DC converters 19 and 20, and the regulator circuit 11 based on the rotational speed f of the engine 1, the terminal voltage Vc of the second power storage device 18, the voltage of the load side wiring 22 b, etc. A control device 21 that controls driving and a notification unit 23 that notifies disconnection of the field winding 8 are provided.

  The generator 5 is connected to a pulley 3 fixed to a crankshaft 2 of the engine 1 via a belt 4 with a pulley 6 fixed to a rotating shaft, and is driven by rotational torque of the engine 1. The generator 5 is a Landel type AC provided with a claw pole type rotor 7 having a field winding 8, a stator 9 having a three-phase AC winding 10 as a stator winding, and a regulator circuit 11. It is a generator.

  The regulator circuit 11 includes a MOSFET 12 and a diode 13. The drain terminal of the MOSFET 12 is connected to the anode terminal of the diode 13, the source terminal is grounded, and the gate terminal is connected to the control circuit. The cathode terminal of the diode 13 is connected to the generator-side wiring 22 a that connects the high-voltage side output terminal 14 a of the rectifier 14 and the input voltage terminal of the first DC / DC converter 19. Furthermore, both ends of the field winding 8 are respectively connected to the cathode terminal of the diode 13 and the connection point between the anode terminal of the diode 13 and the drain terminal of the MOSFET 12. The regulator circuit 11 is built in the generator 5, but may be configured separately from the generator 5.

  The rectifier 14 is configured as a three-phase full-wave rectifier circuit including a diode bridge circuit in which three diode pairs formed by connecting two diodes 15 in series are connected in parallel, and an AC induced in the three-phase AC winding 10. Rectify power to DC power. The rectifier 14 is configured separately from the generator 5, but may be built in the generator 5.

The first power storage device 16 is a secondary battery such as a lead storage battery or a nickel-cadmium storage battery, and constitutes a low-voltage in-vehicle power source of, for example, 15 V (rated voltage). The first power storage device 16 is connected to a load-side wiring 22 b that connects the output voltage terminal of the first DC / DC converter 19 and the vehicle-mounted load 17. The in-vehicle load 17 is an electric device such as an air conditioner or an audio device mounted on the vehicle, and is driven by the first power storage device 16.
For the second power storage device 18, a secondary battery such as a lead storage battery or a nickel / cadmium storage battery, or an electric double layer capacitor capable of instantaneously discharging a large amount of power is used. And the 2nd electrical storage apparatus 18 is connected to the generator side wiring 22a which connects the high voltage side output terminal 14a of the rectifier 14 and the input voltage terminal of a 1st DC / DC converter via the 2nd DC / DC converter 20. .

Next, the operation of the generator 5 will be described.
A current is supplied to the field winding 8 of the rotor 7 to generate a magnetic flux. Thereby, the N pole and the S pole are alternately formed in the circumferential direction on the outer peripheral portion of the rotor 7. Then, the rotational torque of the engine 1 is transmitted to the rotating shaft of the rotor 7, and the rotor 7 is rotationally driven. Therefore, a rotating magnetic field is applied to the three-phase AC winding 10 of the stator 9, and an electromotive force is generated in the three-phase AC winding 10. This AC electromotive force is rectified to DC power by the rectifier 14 and output.

  Here, the relationship between the electric power generated by the generator 5 and the rotational speed will be described with reference to FIG. FIG. 3 is a diagram showing the power generation characteristics of the generator used in the vehicle power supply system according to the embodiment of the present invention. The vertical axis represents the generated power, and the horizontal axis represents the rotational speed of the rotor 7. In FIG. 3, the solid line indicates the power generation characteristic line when the output terminal voltage is V1 (V), the alternate long and short dash line indicates the power generation characteristic line when the output terminal voltage is V2 (V), and the broken line indicates the output terminal voltage. Shows a power generation characteristic line when V is V3 (V). The magnitude relationship among V1, V2, and V3 is V1 <V2 <V3. Also, in FIG. 3, the rotational speed of the rotor at the intersection of the output characteristic line of V1 (V) and the output characteristic line of V2 (V) is α, the output characteristic line of V2 (V) and the output characteristic line of V3 (V). Let β be the rotational speed of the rotor at the intersection with the output characteristic line.

  As can be seen from FIG. 3, in the region where the rotational speed is less than α, a large generated power can be output when the output terminal voltage is set to V1 (V), and in the region where the rotational speed is greater than α and less than β, When the output terminal voltage is set to V2 (V), large generated power can be output. When the output terminal voltage is set to V3 (V), large generated power is output in the region where the rotation speed is β or more. can do.

  From this, the control device 21 controls the driving of the first and second DC / DC converters 19 and 20 so as to change the output terminal voltage, that is, the voltage of the generator-side wiring 22a according to the rotational speed of the rotor 7. By doing so, the generated power of the generator 5 can be increased. That is, when the rotational speed of the rotor 7 is less than α, the control device 21 drives the first and second DC / DC converters 19 and 20 so that the voltage of the generator-side wiring 22a becomes V1 (V). Further, the control device 21 drives the first and second DC / DC converters 19 and 20 so that the voltage of the generator-side wiring 22a becomes V2 (V) when the rotational speed of the rotor 7 is not less than α and less than β. To do. Furthermore, the control device 21 drives the first and second DC / DC converters 19 and 20 so that the voltage of the generator-side wiring 22a becomes V3 (V) when the rotational speed of the rotor 7 is β or more. Thereby, the electric power generated by the generator 5 is increased, and the charging speed of the first and second power storage devices 16 and 18 can be increased.

  Here, the rotation speed of the rotor 7 is calculated from the rotation speed f of the engine 1 and the pulley ratio (power transmission ratio). A rotation sensor is attached to the generator 5 to directly detect the rotation speed of the rotor 7. May be.

  Next, the relationship between the output power of the generator 5 and the output terminal voltage will be described with reference to FIG. FIG. 4 is a diagram showing output characteristics of the generator used in the vehicle power supply system according to the embodiment of the present invention, where the vertical axis represents output power and the horizontal axis represents output terminal voltage.

As can be seen from FIG. 4, the output power of the generator 5 increases as the output terminal voltage increases, takes a maximum value when the output terminal voltage reaches a predetermined value, and the output voltage exceeds the predetermined value. It decreases when it gets bigger. As the field current increases, the torque of the generator 5 increases and the output power increases.
From this, it can be seen that when the field current and the output terminal voltage are determined, the output power of the generator 5 is uniquely determined.

  The control device 21 includes a microcomputer having a CPU, a memory, an input / output circuit, and the like. The memory includes an output terminal voltage search map based on the relationship between the generated power of the generator 5 shown in FIG. 3 and the rotational speed of the rotor 7, and the output power and output terminal of the generator 5 shown in FIG. An output power search map based on the relationship with the voltage, an efficiency search map described later, and the like are stored.

  Next, regenerative amount control during braking of the vehicle power supply system will be described with reference to FIGS. FIG. 5 is a flowchart for explaining the regeneration amount control during braking in the vehicle power supply system according to the embodiment of the present invention, FIG. 6 is a flowchart for explaining the operation for estimating the power generation possible amount of the generator, and FIG. FIG. 8 is a flowchart for explaining the operation for estimating the regenerative amount, FIG. 8 is a flowchart for explaining the maximum power follow-up control of the generator, and FIG. 9 is a flowchart for explaining the maximum efficiency control of the generator.

  In the vehicle power supply system, the voltage Va of the generator-side wiring 22a and the terminal voltage Vc of the second power storage device 18 are detected by a voltage sensor (not shown), and a current Ia flowing through the generator-side wiring 22a, and A current Ic flowing through the path between the second power storage device 18 and the second DC / DC converter 20 is detected by a current sensor (not shown), and the rotational speed f of the engine 1 is detected by a rotation sensor (not shown). The Then, detection signals from the voltage sensor, current sensor, and rotation sensor are input to the control device 21. The control device 21 controls operations of the generator 5, the first DC / DC converter 19, and the second DC / DC converter 20 based on the running state of the vehicle, the terminal voltage Vc of the second power storage device 18, and the like.

  Then, during non-braking (non-decelerating), the control device 21 outputs a signal with a duty ratio of 0 to the regulator circuit 11 so that the generator 5 does not generate power. In this state, the power stored in the second power storage device 18 is supplied to the first power storage device 16 and the in-vehicle load 17 via the second DC / DC converter 20 and the first DC / DC converter 19. However, when there is no electric power stored in the first power storage device 16 and the second power storage device 18 even during non-braking, the duty ratio is not set to 0, and the first power storage device 16 and the second power storage device are changed from the generator 5 to each other. Power is supplied to 18.

  On the other hand, during braking (deceleration), the control device 21 issues a power generation command (duty ratio) and the generator 5 generates power. The generated electric power is converted into direct current power by the rectifier 14, supplied to the second power storage device 18 via the second DC / DC converter 20, and the first power storage device 16 and the vehicle-mounted load via the first DC / DC converter 19. 17 is fed.

First, the control device 21 estimates the power generation possible amount of the generator 5 (step 100). The specific operation in this step 100 is shown in FIG.
That is, the control device 21 detects the voltage Va (output terminal voltage) of the generator-side wiring 22a (step 200), and calculates a field current from the power generation command (duty ratio) (step 201). Next, the process proceeds to step 202, where an output power search map stored in the memory is searched based on the detected voltage Va and the calculated field current, and the output power, that is, the power generation possible amount of the generator 5 is determined. presume.

  Here, in step 202, the output power is obtained from the output voltage search map based on the detected output terminal voltage and field current, but the method of obtaining the output power is not limited to this. For example, the relationship between the output terminal voltage and the output power may be converted into a function and stored in a memory, and the output power may be obtained from the detected output terminal voltage and the stored function, or the output terminal voltage and the output power may be obtained. Data with power may be stored in a memory, and the output power may be calculated from data in the vicinity of the detected output terminal voltage by a linear approximation method, a spline approximation method, or the like.

In step 100, when the power generation possible amount of the generator 5 is estimated, the process proceeds to step 101 to determine whether or not the vehicle is decelerating. Note that the running state of the vehicle, such as acceleration, deceleration, constant speed running (cruising), and stopping, is determined from the ECU signal, the increase / decrease of the engine speed f, the state of the accelerator pedal and brake pedal, and the like.
If it is determined in step 101 that the vehicle is not decelerated, the process returns to step 100. If it is determined that the vehicle is in a decelerating state, the process proceeds to step 102 to estimate the regenerative amount.

  Here, the regenerative amount is, for example, electric power supplied from the generator 5 to the first power storage device 16 and the second power storage device 18. The power supply path from the generator 5 includes a power path P1 from the generator 5 to the first DC / DC converter 19 and a power path P2 from the second DC / DC converter 20 to the second power storage device 18. The first regenerative amount PW1, which is the power fed through the power path P1, is represented by the product of the feed current Ia from the generator 5 and the voltage Va of the generator-side wiring 22a. The second regenerative amount PW2, which is the power supplied through the power path P2, is the voltage Vc stored in the second power storage device 18 and the current Ic flowing from the second DC / DC converter 20 to the second power storage device 18. It is represented by the product of Va, Vc, Ia, and Ic are all direct current.

  At the time of non-braking, since the generator 5 does not generate power, the power stored in the second power storage device 18 is discharged and supplied to the first power storage device 16. On the other hand, at the time of braking, the generator 5 generates power and supplies power to the first power storage device 16 and the second power storage device 18. For this reason, since the 2nd electrical storage apparatus 18 charges / discharges according to a driving | running | working state, direction of the electric current Ic changes. That is, PW2 is the combined regenerative amount during non-braking, and the combined power (PW1 + PW2) is the combined regenerative amount during braking.

The specific operation in this step 102 is shown in FIG.
First, the control device 21 detects the voltage Va of the generator side wiring 22a (step 210), detects the current Ia flowing through the generator side wiring 22a (step 211), and proceeds to step 212. In step 212, a first regenerative amount PW1 (= Va × Ia), which is power supplied from the generator 5 to the first power storage device 16, is calculated. Next, the terminal voltage Vc of the second power storage device 18 is detected (step 213), the current Ic flowing through the wiring between the first power storage device 18 and the second DC / DC converter 20 is detected (step 214), and step 215. Migrate to In step 215, a second regenerative amount PW2 (= Vc × Ic) that is electric power supplied from the generator 5 to the second power storage device 18 is calculated, and the process proceeds to step 216. In step 216, the combined regeneration possible amount PW is estimated from the sum of PW1 and PW2.

  Here, when the voltage Vc is higher than the threshold value, it is determined that the second power storage device 18 is fully charged, and the second DC / DC converter 20 is configured so that the power of the generator 5 is not supplied to the second power storage device 18. It is preferable to control the drive.

  Next, in step 103, the magnitude relationship between the estimated combined regeneration possible amount and the power generation possible amount is determined. If it is determined that the combined regeneration possible amount is larger than the power generation possible amount, the routine proceeds to step 104 where the generator 5 is caused to generate power by the maximum power generation amount tracking control. If it is determined that the combined regeneration possible amount is equal to or less than the power generation possible amount, the routine proceeds to step 105, where the generator 5 is caused to generate power by maximum efficiency control.

A specific operation in step 104 will be described with reference to FIG.
First, the control device 21 detects the rotation speed of the rotor 7 (step 220), searches the output terminal voltage search map stored in the memory, and calculates the target voltage Vff of the output terminal voltage from the rotation speed of the rotor 7. Is estimated (step 221). Next, the process proceeds to step 222, and the voltage conversion ratio of the first DC / DC converter 19 and the second DC / DC converter 20 is adjusted so that the voltage Va of the generator side wiring 22a becomes the target voltage Vff. Next, the process proceeds to step 223, and the voltage conversion ratio of the first DC / DC converter 19 and the second DC / DC converter 20 is adjusted so that the voltage Va of the generator-side wiring 22a becomes a voltage deviated from the target voltage Vff by a certain amount Vε. Then, the process proceeds to step 224. In step 224, it is determined whether or not the differential value of the output terminal voltage of PW (= PW1 + PW2) is zero. If the differential value of the PW output terminal voltage is not 0 in step 224, the process returns to step 223. In step 224, when the differential value with respect to the output terminal voltage of PW is 0, it is determined that PW has become maximum, and the process proceeds to step 106.

Next, a specific operation in step 105 will be described with reference to FIG.
First, the control device 21 detects the voltage Va (output terminal voltage) of the generator-side wiring 22a (step 230), and calculates a field current from the power generation command (duty ratio) (step 231). Next, the process proceeds to step 232, and the efficiency η is searched from the efficiency search map stored in the memory based on the detected voltage Va and the calculated field current. Next, the process proceeds to step 233, and the voltage conversion ratio of the first DC / DC converter 19 and the second DC / DC converter 20 is adjusted so that the voltage Va of the generator-side wiring 22a becomes a voltage deviated by a certain amount Vε from the current voltage. Then, the process proceeds to step 234. In step 234, it is determined whether or not the differential value of the efficiency η of the generator 5 with respect to the output terminal voltage is zero. If the differential value of the efficiency η with respect to the output terminal voltage is not 0 in step 234, the process returns to step 233. In step 234, when the differential value of the efficiency η with respect to the output terminal voltage is 0, it is determined that the efficiency η is maximized, and the process proceeds to step 106.

  Here, in step 232, the efficiency is obtained from the efficiency search map based on the detected voltage Va and the field current, but the method for obtaining the efficiency is not limited to this. For example, the relationship between the output terminal voltage and the efficiency may be converted into a function and stored in a memory, and the efficiency may be obtained from the detected output terminal voltage and the stored function. Data may be stored in a memory, and efficiency may be calculated from data in the vicinity of the detected output terminal voltage by a linear approximation method, a spline approximation method, or the like.

  The efficiency η of the generator 5 is output / input, the output can be calculated as PW (= PW1 + PW2), and the input is the product of the torque of the engine 1 and the rotational speed of the engine 1. In the memory, the efficiency η calculated using the voltage Va and the field current as parameters is stored as an efficiency search map.

In step 106, the control device 21 calculates the regenerative braking amount by dividing the regenerative possible amount PW (= PW1 + PW2) by the rotational speed of the generator 5 and the efficiency η of the generator 5. Here, the regenerative braking amount is a regenerative torque.
Next, the process proceeds to step 107, and the control device 21 calculates the difference between the calculated regenerative torque and the target torque required by the driver estimated from the brake pedal depression amount, and obtains the actual brake correction amount (travel braking correction amount). Then, the process proceeds to step 108, and the regenerative amount corresponding to the actual brake correction amount is stored in the first power storage device 16 and the second power storage device 18. Thereby, the brake torque desired by the driver can be provided, and the driver's uncomfortable feeling when the brake pedal is depressed can be improved.

  Next, monitoring of the internal state of the generator in the vehicle power supply system will be described with reference to FIG. FIG. 10 is a flowchart for explaining the monitoring operation of the internal state of the generator in the vehicle power supply system according to the embodiment of the present invention.

  First, the control device 21 detects the voltage across the field winding 8 (step 240), and calculates the field current from the duty ratio (step 241). Next, the routine proceeds to step 242 where the resistance of the field winding 8 is estimated from the voltage at both ends of the field winding 8 and the field current. Next, the process proceeds to step 243 where the current temperature of the field winding 8 is estimated from the resistance of the field winding 8. Next, it is determined whether or not the estimated temperature of the field winding 8 has increased (step 244). If it is determined in step 244 that the temperature of the field winding 8 has increased, the process proceeds to step 245 where the temperature determination flag δ stored in the memory is set to 1. If it is determined in step 244 that the temperature of the field winding 8 does not increase, the process proceeds to step 246, the temperature determination flag δ stored in the memory is set to 0, and the process proceeds to step 247. In step 247, the duty ratio is set to 0, and the power generation of the generator 5 is stopped. Then, the process proceeds to step 248, where the notification means 23 informs the driver of the internal abnormality of the generator 5, that is, the occurrence of disconnection of the field winding 8. Inform.

  Here, the field winding 8 generates heat when a field current is applied. Metals have the property that resistance increases with temperature. Therefore, the temperature of the field winding 8 can be estimated from the resistance of the field winding 8. Whether or not the temperature of the field winding 8 has risen can be determined, for example, based on the magnitude relationship between the temperature of the field winding 8 and the environmental temperature.

  In this embodiment, a combined regeneration possible amount and a power generation possible amount that are the sum of the first regenerative amount of the first power storage device 16 and the second regenerative amount of the second power storage device 18 are estimated, and combined regeneration is possible. Since the combined regenerative amount is adjusted from the magnitude relationship between the amount and the power generation amount, and the travel braking amount is corrected by the adjusted combined regenerative amount, the reduction in the regeneration amount, that is, the power generation amount is suppressed, This can improve the driver's uncomfortable feeling when the brake pedal is depressed.

When the combined regeneration possible amount is larger than the power generation possible amount, the generator 5 is driven by the maximum power generation follow-up control. When the combined regeneration possible amount is less than the power generation possible amount, the generator 5 is driven by the maximum efficiency follow-up control. Since it is driven, the power generation amount of the generator 5 can be increased, and overcharge of the first and second power storage devices 16 and 18 is eliminated.
When the terminal voltage Vc of the second power storage device 18 exceeds the threshold value, the second DC / DC converter is driven so that the generated power of the generator 5 is not supplied to the second power storage device 18. Charging is prevented and the life of the second power storage device 18 is extended.

  The memory of the control device 21 only stores the output characteristics of the generator 5 at a predetermined temperature state. In addition, the calculation error of the control device 21, the measurement error of the voltage sensor or the current sensor, the field winding When the output terminal voltage Va is the target voltage Vff, the generated power of the generator 5 is not always maximized. However, the generator 5 is driven by maximum power generation follow-up control. That is, in step 223, the voltage exchange ratio of the first and second DC / DC converters 19 and 20 is adjusted so that the output terminal voltage Va, which is the voltage of the generator-side wiring 22a, is shifted by a certain amount Vε. In step 224, Electric power PW1 fed through the power path P1 from the generator 5 to the first DC / DC converter 19 and electric power PW2 fed through the power path P2 reaching from the second DC / DC converter 20 to the second power storage device 18 It is determined whether or not the differential value of the combined power PW with respect to the output terminal voltage is 0. If the differential value is not 0, the process returns to step 223. As described above, since the feedback control for adjusting the voltage conversion ratio of the first and second DC / DC converters 19 and 20 is performed so that the differential value of the combined power with respect to the output terminal voltage becomes 0, the generator 5 It can be driven to always have the maximum power generation.

  Further, the generator 5 is driven by maximum efficiency tracking control. That is, in step 233, the voltage conversion ratio of the first and second DC / DC converters 19 and 20 is adjusted so that the voltage Va of the generator-side wiring 22a becomes a voltage deviated from the current voltage by a predetermined amount Vε. Then, it is determined whether or not the differential value of the efficiency η of the generator 5 with respect to the output terminal voltage is 0. If the differential value is not 0, the process returns to step 233. In this way, feedback control is performed to adjust the voltage conversion ratio of the first and second DC / DC converters 19 and 20 so that the differential value of the efficiency of the generator 5 with respect to the output terminal voltage becomes zero. The machine 5 can be driven so as to always have the maximum efficiency.

  Since the temperature of the field winding 8 is estimated from the resistance of the field winding 8 and it is determined whether or not the estimated temperature of the field winding 8 has risen, the field winding 8 is disconnected. Occurrence can be easily determined. If it is determined that the estimated temperature of the field winding 8 has not risen, the notification means 23 notifies the driver of the occurrence of the disconnection of the field winding 8, so that the driver can quickly You can stop and ask for repairs.

In the above embodiment, the rectifier is configured as a three-phase full-wave rectifier circuit using a diode bridge. However, there are many rectifiers such as a MOSFET that performs synchronous rectification and a MOSFET that performs rectification by a parasitic diode. You may comprise with a phase inverter.
In the above embodiment, the stator winding of the stator of the generator is configured as a three-phase AC winding, but the stator winding is limited to a three-phase AC winding. Alternatively, a multi-phase AC winding or a multi-phase AC winding (for example, 5-phase, 7-phase) may be used. In that case, the rectifier rectifies AC power into DC with a full-wave rectifier circuit according to the number of phases.

  DESCRIPTION OF SYMBOLS 1 Engine, 5 Generator, 7 Rotor, 8 Field winding, 11 Regulator circuit, 14 Rectifier, 14a High voltage side output terminal, 16 1st electrical storage device, 18 2nd electrical storage device, 19 1st DC / DC converter, 20 2nd DC / DC converter, 22a Generator side wiring, 22b Load side wiring, 23 Notification means.

Claims (4)

A generator driven by an engine to generate AC power;
A rectifier that rectifies and outputs AC power generated by the generator to DC power;
A first DC / DC converter connected to the high-voltage side output terminal of the rectifier via a generator-side wiring and converting the voltage value of the output voltage of the rectifier into a different DC voltage;
A first power storage device connected to the first DC / DC converter via a load-side wiring and supplying electric power to a vehicle-mounted load;
A second DC / DC converter connected to the high-voltage side output terminal of the rectifier via a generator-side wiring, and converting the voltage value of the output voltage of the rectifier into a different DC voltage and outputting it;
A second power storage device connected to the second DC / DC converter;
A regulator circuit for supplying a field current to the field winding of the generator;
A power generation command is issued to the regulator circuit to cause the generator to generate electric power, and the first DC / DC converter and the second DC / DC converter are driven and controlled, and the electric power generated by the generator is supplied to the first power storage device and A control device for storing power in the second power storage device,
The control device
Estimate the power generation capacity of the above generator,
Estimating the first regenerative amount of the first power storage device and the second regenerative amount of the second power storage device;
Adjusting the combined regenerative amount from the magnitude relationship between the combined regenerative amount of the first regenerative amount and the second regenerative amount and the power generation amount;
A vehicle power supply system configured to correct a travel braking amount based on the adjusted combined regenerative amount. The control device
When the combined regeneration possible amount is larger than the power generation possible amount, the generator is driven by maximum power generation follow-up control, and when the combined regeneration possible amount is equal to or less than the power generation possible amount, the generator is 2. The vehicle power supply system according to claim 1, wherein the power supply system is driven by efficiency tracking control.   The control device controls driving of the second DC / DC converter so that power generated by the generator is not supplied to the second power storage device when a terminal voltage of the second power storage device exceeds a threshold value. The vehicle power supply system according to claim 1 or 2. Informing means for informing the disconnection of the field winding,
The control device estimates the temperature of the field winding at the time of power generation by the generator, determines whether or not the field winding is disconnected based on the estimated temperature of the field winding, and 4. The system according to claim 1, wherein the notification means is operated to notify a driver of the disconnection of the field winding when the field winding is disconnected. The vehicle power supply system according to any one of the preceding claims.

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