JP2001224102A - Charging and discharging controlling device for vehicle storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charge and discharge controlling device that will cause no reverse charging to a single capacitor cell, even when changing or discharging is performed with current and that can be miniaturized in the charge and discharge controlling device that controls the charging or discharging to a vehicle storage device for a hybrid electric vehicle. SOLUTION: This device is provided with a charged-state-of-storage-device discriminating means 11, that discriminates the charged state of the voltage of a storage device 5 and a charged-state-of-single-cell discriminating means 12, that discriminates the charged state of each single capacitor cell. Based on the discriminations by both the discriminating means 11, 12, a power-generation command value to a generator 3 is selected by a power-generation command value selecting means 13, a motor drive command value to electric motors 1A, 1B is limited by a motor drive force limiting means 23, and a motor-regeneration command value to the electric motors 1A, 1B is limited by a motor regeneration output limiting means 26. Also, the actuation of the generator 3 with its maximum output in the overdischarged state of the storage device 5 is counted by a maximum output generation time accumulative counting means 15 to be limited within a limited time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charge / discharge control device for controlling charging / discharging of a power storage device for a vehicle in a hybrid electric vehicle.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. Hei 10-201091 discloses that
In a vehicle power storage device (power supply device) using a plurality of electric double layer capacitors, by connecting a balance resistor to each capacitor cell via a relay switch, a variation in capacitance and internal resistance of each capacitor cell is caused. There have been proposed ones that prevent overcharging and enable long-term power storage.

[0003]

However, in this power storage device for a vehicle, a relay switch and a balance resistor are provided for each capacitor cell. Therefore, when the number of capacitor cells increases, the device becomes large.

In addition, in this vehicle power supply device, when charging and discharging with a large current, the influence of variations among a plurality of capacitor cells is unavoidable, and some of the capacitor cells are overdischarged. There is a possibility that charging may occur.

The present invention has been made in view of such a problem, and a charge / discharge control device for controlling charging / discharging of a power storage device for a hybrid electric vehicle performs charging / discharging with a large current. It is another object of the present invention to provide a single capacitor cell in which reverse charging does not occur and which can reduce the size of the device.

[0006]

According to a first aspect of the present invention, there is provided a power storage device for a vehicle including a plurality of single capacitor cells, an electric motor serving as a drive source of the vehicle and supplying a regenerative output to the power storage device for the vehicle. A charge / discharge control device provided in a vehicle including a generator for supplying power to the vehicular power storage device and the electric motor, and an engine for driving the power generator, and controlling charging / discharging of the vehicular power storage device; A total voltage state determining means for determining a state of charge of a total voltage of the vehicle power storage device; and a single capacitor cell state determining means for determining a state of charge of each capacitor cell of the vehicle power storage device; Charging / discharging the power storage device for a vehicle by controlling the operation of the generator and the electric motor based on the determination results of the determination unit and the single capacitor cell state determination unit; To control.

According to a second aspect of the present invention, the generator switches the output of the generator to a maximum output value when overdischarge is determined by at least one of the total voltage state determining means and the single capacitor cell state determining means. Output switching means is provided.

[0008] In the third invention, the generator output switching means, when the driving time at the maximum output value of the generator becomes equal to or longer than a predetermined time limit, sets the generator to a rated value for a predetermined interval time. Operate with output value.

In the fourth invention, when overdischarge is determined by at least one of the total voltage state determination means and the single capacitor cell state determination means, discharge from the power storage device to the electric motor is limited. Discharge limiting means was provided.

According to a fifth aspect of the present invention, when at least one of the total voltage state judging means and the single capacitor cell state judging means judges overcharging, the overcharge generator stopping means for stopping the generator is provided. With.

In a sixth aspect, a regenerative output limit for limiting a regenerative output from the electric motor when overcharge is determined by at least one of the total voltage state determining means and the single capacitor cell state determining means. With means.

[0012]

According to the present invention, the overcharge state and the overdischarge state of the power storage device for a vehicle are determined by both the total voltage of the power storage device and the voltage of each single capacitor cell, and based on the determination result. Since the operation of the generator and the electric motor is controlled, charging and discharging of the power storage device for the vehicle can be appropriately controlled. For example, in the second invention, the output of the generator is switched to the maximum output at the time of overdischarge, so that the vehicle power storage device is quickly charged. In the third invention, the discharge from the vehicle power storage device is minimized by limiting the discharge from the vehicle power storage device to the electric motor at the time of overdischarge. In the fifth invention, the generator is stopped at the time of overcharging, so that the vehicle power storage device is discharged to the electric motor, and the overcharged state is quickly eliminated. In the sixth aspect, the regenerative output of the electric motor is limited during overcharge, thereby preventing the vehicle power storage device from being further charged. As described above, according to the present invention, overcharging is performed for each single capacitor cell constituting the power storage device for a vehicle,
Since overdischarge is managed, even when charging and discharging with a large current, there is no room for a single capacitor cell to be reversely charged. Also, since an extra configuration such as a relay switch is not included, the size and cost of the device can be reduced.

In the third invention, when the operation at the maximum output of the generator exceeds the time limit, the operation of the generator is reduced to the rated output over the interval period, so that the overheating of the generator is reduced. Can be prevented.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a configuration diagram showing a hybrid electric vehicle.

As shown, the hybrid electric vehicle is of a series type and includes electric motors 1A and 1B, an engine 2, a generator 3, a controller 4, a power storage device 5, and the like.

The power storage device 5 mainly stores electric power required at the time of starting the vehicle, and is configured by combining a plurality of electric double layer capacitors. When the vehicle is started, the engine 2 is started via the driving of the generator 3 by the power supply from the power storage device 5.

The engine 2, which is an internal combustion engine, drives a generator 3. Electric power generated by the generator 3 is transmitted to the electric motors 1A and 1B and the power storage device 5 via the controller 4.
And is used for driving the electric motors 1A and 1B or charging the power storage device 5. The engine 2 includes various auxiliary devices (air conditioner, power steering,
It is also a driving source for the air compressor 6).

The electric motors 1A and 1B
And a joint 8 connected to the axle 9 of the rear wheel of the automobile, and drives the axle 9 to rotate during normal running. When the vehicle is braked, the regenerative braking is performed, and the regenerative output is stored in the power storage device 5 via the controller 4.

FIG. 2 shows a configuration relating to control of the generator 3 by the controller 4.

As shown, the controller 4 includes:
Power storage device charge state determination means 11 provided with power storage device charge state determination means 11, single cell charge state determination means 12, power generation command value selection means 13, rated output power generation time continuous counting means 14, and maximum output power generation time accumulation count means 15 Is
Based on the total voltage signal from the power storage device 5, it is means for determining whether or not the total voltage of the power storage device 5 (sum of voltages of a plurality of capacitor cells) is overcharge or overdischarge. In addition, the single-cell charged state determination unit 12 determines whether or not the single-cell overcharge signal from the power storage device 5 (a signal that detects that any single capacitor cell in the power storage device 5 is overcharged). To determine whether or not there is an overcharged capacitor cell, and based on a single cell overdischarge signal (a signal for detecting that any single capacitor cell in power storage device 5 is in an overdischarged state). Is a means for determining whether or not there is an overdischarged single capacitor cell.

The power generation command value selection means 13 converts the power generation command value of the generator 3 into a rated power generation output or a maximum power generation output, based on the determination results by the power storage device charging state determining means 11 and the single cell charging state determining means 12. Select from power generation stop. The generator 3 is driven based on the power generation command value selected by the power generation command value selection means 13.

Rated output power generation time continuous counting means 14
Is means for counting the continuous duration of the rated power output when the rated power output is selected as the power generation command value. The maximum output power generation time accumulation counting means 1
Reference numeral 5 denotes a means for counting the accumulated time of the maximum power generation output when the maximum power generation output is selected as the power generation command value.

The selection of the power generation command value by the power generation command value selection means 13 is also switched based on the count results by the rated output power generation time continuous counting means 14 and the maximum output power generation time accumulation counting means 15. Specifically, when the cumulative time of the maximum power generation output by the maximum power generation time cumulative counting means 15 exceeds a predetermined time, the power generation command value is switched to the rated power generation output in order to prevent overheating of the generator 3. . Note that when the rated power generation output continues for a predetermined time, the count value of the maximum output power generation time accumulation counting means is reset, and power generation by the maximum power generation output becomes possible again.

FIG. 3 shows a configuration related to control of the electric motors 1A and 1B by the controller 4.

As shown, the controller 4 includes:
Motor operation switching means 21, motor driving force calculation means 22,
A motor driving force limiting unit 23, a motor driving command value setting unit 24, a motor regeneration output calculating unit 25, a motor regeneration output limiting unit 26, and a motor regeneration command value setting unit 27 are provided.

The motor operation switching means 21 changes the operation mode of the electric motors 1A, 1B based on the accelerator opening detection signal from the accelerator opening detection means 31 or the brake pedal pressure detection signal from the brake pedal pressure detection means 32. ,
Switch to powering mode or electric regeneration mode.

In the powering mode, the motor driving force calculating means 22 calculates the driving force required for the electric motors 1A and 1B based on the accelerator opening. Motor drive command values for the electric motors 1A and 1B are set by the motor drive command value setting means 24 based on the required value of the driving force. In this case, the power storage device charging state determination unit 11
When it is determined that the total voltage of the power storage device 5 is in the over-discharge state, or when the single-cell charging state determination unit 12 determines that any single capacitor cell of the power storage device 5 is in the over-discharge state, Motor driving force limiting means 2
3, the motor drive command value is set to an upper limit value, and the motor drive command value setting means 24 sets the motor drive command value to a value in consideration of the upper limit value. This allows
Discharge from power storage device 5 is prevented.

In the electric regenerative mode, the regenerative output required for the electric motors 1A and 1B is calculated by the motor regenerative output calculating means 25 based on the brake pedal pressure. The motor regeneration command values of the electric motors 1A and 1B are:
The motor regenerative command value setting means 27 sets the regenerative force based on the required value. In this case, when the total voltage of the power storage device 5 is determined to be in the overcharged state by the power storage device charge state determination means 11, or when one of the single capacitor cells of the power storage device 5 is When it is determined that the battery is in the charged state, the motor regenerative force limiting means 26 sets a limit on the motor regeneration command value such that the charging of the power storage device 5 is stopped. The motor regeneration command value setting means 27 sets a value in consideration of this limitation as the motor regeneration command value. As a result, charging of the power storage device 5 is stopped.

FIG. 4 is a flowchart showing a processing procedure for controlling the operation of the generator 3 to cope with overdischarge of the power storage device 5. This control is repeated at a predetermined timing in the controller 4.

In step S1, the total voltage signal from power storage device 5 is read.

In step S2, based on the total voltage signal, it is determined whether or not the total voltage of power storage device 5 is in an overdischarged state. Proceed to S4.

In step S3, the power generation command value of the generator 3 is set to the maximum output value, and the flow advances to step S6.

On the other hand, in step S4, it is determined whether or not the single cell overdischarge signal is detected. If it is detected, the process proceeds to step S3, and if not, the process proceeds to step S5. In step S5, the power generation command value of the generator 3 is set to the rated output value, and the process proceeds to step S6.

In step S6, the generator 3 is operated according to the power generation command value set in step S3 or step S5.

In step S7, it is determined whether or not the power output value of the generator 3 is the maximum output value. If the output value is the maximum output value, the process proceeds to step S8. If not, the process proceeds to step S11.

In step S8, the driving time (maximum output power generation time) of the generator 3 at the maximum output value is cumulatively counted. In a succeeding step S9, it is determined whether or not the accumulated count value is equal to or longer than a predetermined set time (limit time). If so, the process proceeds to step S10. In step S10, the generator is cooled by limiting the output of the generator 3 to rated output power generation, and the process proceeds to step S11. Thus, step S9
When it is determined that the maximum output power generation has been performed cumulatively for the set time or more, the temperature of the generator 3 is considered to have risen, and the generator 3 is returned to the rated output power generation and cooled.

In step S11, the drive time of the generator 3 at the rated output (rated output power generation time) is continuously counted. In the following step S12, based on the continuous count value, the rated output power generation is set for a set time (interval time).
It is determined whether or not the operation has been continuously performed as described above. If the operation has not been continuously performed for the set time or more, the routine ends, and if the operation has been continuously performed for the set time or more, the process proceeds to step S13.

In step S13, the continuous count of the rated output power generation time and the cumulative count of the maximum output power generation time are calculated as follows:
Reset both. In the subsequent step S14, it is determined whether or not the power generation command value is the maximum output value. If the power generation command value is the maximum output value, the process returns to step S8. If not, the routine ends.

As described above, when the total voltage of the power storage device 5 or the single capacitor cell is overdischarged, the generator 3 is driven at the maximum output value, and the power storage device 5 is quickly charged.
Further, the driving time at the maximum output value of the generator 3 is monitored, and when the accumulated time reaches the time limit, the output of the generator 3 is reduced to the rated output value during the interval time, Prevents the generator 3 from overheating.

FIG. 5 is a flowchart showing a processing procedure of operation control of electric motors 1A and 1B to cope with overdischarge of power storage device 5. This control is executed when the electric motors 1A and 1B are driven, for example, when the vehicle starts or runs.

In step S21, the drive output required for the electric motors 1A and 1B is calculated from the accelerator opening.

In step S22, the total voltage signal from power storage device 5 is read. In subsequent step S23, it is determined whether or not the total voltage of power storage device 5 is in an overdischarge state based on the total voltage signal. If not, the process proceeds to step S24. Proceed to S26.

In step S24, it is determined whether or not the single-cell overdischarge signal from power storage device 5 has been detected. If detected, the process proceeds to step S26, and if not, the process proceeds to step S25. In step S25, the motor drive command values of the electric motors 1A and 1B are set to a value corresponding to the required value of the drive output (a value corresponding to the accelerator opening), and the process proceeds to step S28.

On the other hand, in step S26, the system drivable voltage of electric motors 1A and 1B is set lower than the total voltage of power storage device 5 so as to limit discharge from power storage device 5 to electric motors 1A and 1B. . Subsequent step S2
7, the motor drive command values of the electric motors 1A and 1B are
The calculated value in consideration of the voltage of the power storage device 5 (a value in consideration of the system drivable voltage) is set, and the process proceeds to step S28.

In step S28, the electric motors 1A and 1B are driven based on the motor drive command value set in step S25 or step S28, and the routine ends.

As described above, when the total voltage of the power storage device 5 or the single capacitor cell is over-discharged, the motor drive command value is reduced to a value corresponding to the total voltage of the power storage device 5 so that the electric motor 1A, 1B is ensured, and the discharge from the power storage device 5 is minimized.

FIG. 6 shows a state in which the power storage device 5 is charged.
A processing procedure of operation control of the generator 3 is shown in a flowchart. This control is repeated at a predetermined timing in the controller 4.

In step S31, the total voltage signal from power storage device 5 is read. In subsequent step S32, it is determined whether or not power storage device 5 is in a fully charged state based on the total voltage signal. If not, the process proceeds to step S33. If the power storage device 5 is in the fully charged state, the process proceeds to step S35. .

In step S33, it is determined whether or not the single-cell overcharge signal is detected. If it is detected, the process proceeds to step S35, and if not, the process proceeds to step S34. In step S34, a rated output value is set as a power generation command value to the generator 3, and the process proceeds to step S37.

On the other hand, in step S35, a power generation stop request is made. In step S36, the power generation command value for the generator 3 is set to 0, and the flow advances to step S37.

In step S37, the generator 3 is operated based on the power generation command value set in step S34 or S36, and the routine ends.

As described above, when the total voltage of the power storage device 5 or the single capacitor cell is overcharged, the power generation by the generator 3 is stopped, and the electric motors 1A, 1B are powered by the power overcharged in the power storage device 3. Is driven, the overcharge state of the power storage device 5 is eliminated.

FIG. 7 is a flowchart showing processing means for controlling the operation of the electric motors 1A and 1B in the power regeneration mode.

In step S41, the regenerative output of the electric motors 1A and 1B corresponding to the operation amount of the brake pedal is calculated.

In step S42, the total voltage signal of power storage device 5 is read. In subsequent step S43, it is determined whether or not the total voltage of power storage device 5 is in an overcharged state based on the total voltage signal. If overcharged, the process proceeds to step S44, and if not, the process proceeds to step S46. .

In step S44, the electric motors 1A, 1B are stopped so that the charging of the regenerative output to the power storage device 5 is stopped.
Set the upper limit of the power regeneration command value. Specifically, the system allowable voltage of the electric motors 1A and 1B is set as the total voltage of the power storage device 5. In a succeeding step S45, the electric motor 1
The regenerative command values of A and 1B are set to calculated values (values in consideration of the system allowable voltage) in consideration of the total voltage of the power storage device 5, and the process proceeds to step S50.

On the other hand, in step S46, it is determined whether or not the single-cell overcharge signal from power storage device 5 has been detected. If detected, the process proceeds to step S47, and if not, the process proceeds to step S49.

In step S47, the upper limit of the regenerative command value of the electric motors 1A and 1B is determined so that the charging of the power storage device 5 is stopped and the single cell overcharge signal is stopped.
In the following step S48, a calculated value (a value equal to or less than the upper limit of the regenerative command value) in consideration of the generation of the single-cell overcharge signal is set as the regenerative command value, and the process proceeds to step S50.

On the other hand, in step S49, the electric motor 1
A calculated value corresponding to the regenerative output calculated corresponding to the operation amount of the brake pedal is set to the regenerative command values A and 1B, and the process proceeds to step S50.

In step S50, the electric motors 1A and 1B are operated for power generation based on the regenerative command value set in step S45 or step S48 or step S49, and a regenerative output of the generated power is obtained.

As described above, when the total voltage of the power storage device 5 or the single capacitor cell is overcharged, the motor regeneration command value is limited to a value at which the power storage device 5 is not charged. .

As described above, according to the present invention, the overcharge state and the overdischarge state of power storage device 5 are detected by both the total voltage of power storage device 5 and the voltage of each single capacitor cell. Even when charging / discharging with a large current, there is no room for some of the single capacitor cells to be reversely charged. Also, since an extra configuration such as a relay switch is not included, the size and cost of the device can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a hybrid electric vehicle according to an embodiment of the present invention.

FIG. 2 is a block diagram related to generator control of the controller.

FIG. 3 is a block diagram related to the electric motor control of the controller.

FIG. 4 is a flowchart showing a processing procedure of generator control for coping with overdischarge of the power storage device.

FIG. 5 is a flowchart showing a processing procedure of electric motor control for coping with overdischarge of the power storage device.

FIG. 6 is a flowchart showing a processing procedure of a generator control for charging the power storage device.

FIG. 7 is a flowchart showing processing means of electric motor control in the electric power regeneration mode.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1A, 1B Electric motor 2 Engine 3 Generator 4 Controller 5 Power storage device 11 Power storage device charge state determination means 12 Single cell charge state determination means 13 Power generation command value selection means 14 Rated output power generation time continuous counting means 15 Maximum output power generation time cumulative count Means 23 Motor drive force limiting means 26 Motor regeneration output limiting means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02J 7/00 302 B60K 9/00 EF Term (Reference) 5G003 AA07 BA02 CA11 DA04 DA13 FA06 GC05 5G065 BA09 DA04 EA10 GA09 HA16 LA01 NA01 5H115 PA00 PC06 PG04 PI11 PI22 PI29 PO02 PO06 PO17 PU01 PU24 PU26 QE01 QE08 QE10 QI04 QN27 RB08 SE04 SE06 SE08 TI02 TI05 TI07 TO14 TO21 TO23 TO30 TR19 TU16 TU17 UI23

Claims (6)

[Claims] 1. A vehicle power storage device having a plurality of single capacitor cells, an electric motor serving as a drive source of a vehicle and supplying regenerative output to the vehicle power storage device, and a vehicle power storage device and an electric motor. A vehicle provided with a generator for supplying power and an engine for driving the generator,
In a charge / discharge control device that controls charging / discharging of the vehicle power storage device, a total voltage state determination unit that determines a state of charge of a total voltage of the vehicle power storage device, and charging of each capacitor cell of the vehicle power storage device. A single-capacitor cell state determining means for determining a state, wherein the operation of the generator and the electric motor is controlled based on a determination result of the total voltage state determining means and the single-capacitor cell state determining means. A charge / discharge control device for controlling charging / discharging of a power storage device. 2. A generator output switching means for switching an output of the generator to a maximum output value when overdischarge is determined by at least one of the total voltage state determining means and the single capacitor cell state determining means. The charge / discharge control device according to claim 1, further comprising: 3. The generator output switching means operates the generator at a rated output value for a predetermined interval time when the driving time at the maximum output value of the generator exceeds a predetermined time limit. The charge / discharge control device according to claim 2, wherein the control is performed. 4. A discharge limiting means for limiting a discharge from the power storage device to the electric motor when an overdischarge is determined by at least one of the total voltage state determining means and the single capacitor cell state determining means. The charge / discharge control device according to any one of claims 1 to 3, further comprising: 5. An overcharged generator stopping means for stopping the generator when at least one of the total voltage state determining means and the single capacitor cell state determining means determines overcharging. Claim 1 characterized by the following:
The charge / discharge control device according to any one of claims 1 to 4. 6. A regenerative output limiting means for limiting a regenerative output from the electric motor when overcharge is determined by at least one of the total voltage state determining means and the single capacitor cell state determining means. The charge / discharge control device according to any one of claims 1 to 5, wherein: