JPH07264714A - Driver for hybrid vehicle - Google Patents

Abstract

PURPOSE:To improve traveling performance when a battery having large energy density and small power density is used. CONSTITUTION:A driver for a hybrid vehicle comprises motors L10, R12 for rotating drive wheels, an AC generator 16 as a motor generator for supplying drive powers to the motors L10 and R12 and having an engine 14 as a power source, a battery 18 to be charged by the generator 16 to supply drive powers to the motors L10 and R12, and a drive controller 20 as a controller for controlling a generating amount of the generator 16 in response to a charge amount of the battery 18. The controller 20 has functions of stopping charging of the battery 18 when the charge amount of the battery 18 is constant or more and idling the generator 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive system for a hybrid vehicle using both an engine and a battery as power sources.

[0002]

2. Description of the Related Art A conventional hybrid vehicle of this type uses a lead oxide battery as a battery. The lead oxide battery has a large power density (output current per unit weight), but has a small energy density (charge storage amount per unit weight). Therefore, if the lead oxide battery is increased to increase the total amount of energy, the total weight of the hybrid vehicle becomes large, and it is difficult to improve the traveling performance such as acceleration performance and traveling distance.

[0003]

On the other hand, for example, a sodium-sulfur battery is known as a battery having a high energy density. However, the sodium-sulfur battery has the drawback of low power density. Therefore, the hybrid vehicle loaded with the sodium-sulfur battery has a problem in running performance such as acceleration and climbing.

[0004]

SUMMARY OF THE INVENTION Therefore, the main object of the present invention is a hybrid which can improve running performance such as acceleration and climbing ability even when a battery having a large energy density but a small power density such as a sodium-sulfur battery is used. It is to provide a drive device for a vehicle.

[0005]

A drive system for a hybrid vehicle according to the present invention has been made in order to achieve the above-mentioned object, and a motor for rotating drive wheels and a drive power supply to this motor. Along with this, an engine generator as a power source, a battery that supplies driving power to the motor and is charged by the engine generator, and a power generation amount of the engine generator that is controlled according to the amount of electricity stored in the battery And a control unit for controlling the operation.

The battery may be a sodium-sulfur battery.

Further, the control unit may have a function of stopping charging of the battery and putting the engine generator into an idle state when the amount of electricity stored in the battery is equal to or more than a certain level.

[0008]

The engine generator uses the engine as a power source to generate electric power and supplies the electric power to the battery and the motor. On the other hand, the battery also supplies electric power to the motor. Therefore,
Since the motor is supplied with electric power from both the engine generator and the battery, it can be driven with a large current.

The control unit controls the amount of power generated by the engine generator according to the amount of electricity stored in the battery. For example, when the amount of electricity stored in the battery is equal to or more than a certain amount, the charging of the battery is stopped and the engine generator is set to the idle state.

[0010]

【Example】

FIG. 1 is a block diagram showing an embodiment of a drive system for a hybrid vehicle according to the present invention. Hereinafter, description will be given with reference to this drawing.

The drive system of the present embodiment is a motor L10 and a motor R12 for rotating drive wheels (not shown), and a drive power generation for supplying a drive power to the motor L10 and the motor R12 and using the engine 14 as a power source. An AC generator 16 as a generator, a battery 18 that supplies driving power to the motor L10 and the motor R12 and is charged by the AC generator 16, and an amount of power generated by the AC generator 16 according to the amount of electricity stored in the battery 18. The drive controller 20 is provided as a control unit for controlling. A sodium-sulfur battery is used as the battery 18. The drive controller 20 has a function of stopping the charging of the battery 18 and setting the AC generator 16 in an idle state when the amount of electricity stored in the battery 18 is equal to or more than a certain amount.

In the hybrid vehicle in which the drive device of this embodiment is installed, another engine (not shown) drives the front wheels and the motors L10 and R12 drive the rear wheels.

The motor L10 drives the left rear wheel, and the motor R12 drives the right rear wheel. A DC three-phase brushless motor is used for the motor L10 and the motor R12. Therefore, dedicated motor drivers L22 and R24 are attached to the motors L10 and R12. The motor driver L22 and the motor driver R24 are composed of, for example, a switching transistor circuit that selects energization of the winding U-phase, V-phase, and W-phase, and a PWM circuit that controls the energization amount with a pulse width.

The AC generator 16 is provided with an AC-DC converter 26 for converting AC into DC. The AC power generated from the AC generator 16 is converted into DC power by the AC-DC converter 26, and the battery 18, the motor driver L22, and the motor are passed through the NFB (no fuse breaker) 28, the NFB 30, the terminal 32, and the like. It is supplied to the driver R24 and the like.

The drive controller 20 is, for example, C
It is configured by a PU, a ROM, a RAM, an input / output interface circuit, and the like, and various functions are realized by a computer program. Further, the drive controller 20 inputs an accelerator signal, a brake signal, a shift position signal (forward / reverse switching signal), etc. from the speed control system 34 to calculate the rotation directions of the motors L10 and R12, torque command values, etc. The result is output as a control signal to the motor driver L22 and the motor driver R24.

During traveling, the AC 100 [V] generated from the AC generator 16 is transferred to the DC 70 by the AC-DC converter 26.
Converted to [V]. Then, it merges with the power supplied from the battery 18 at the terminal 32 and flows into the motor L10 and the motor R12 via the motor driver L22 and the motor driver R24.

When stopped, the motor driver L22 and the motor driver R24 do not request electric power. Therefore, the direct current 70 [V] from the AC-DC converter 26 is charged into the battery 18 (output voltage 60 [V]).

The drive controller 20 is a battery 1
While the signal of the storage amount and temperature of 8 can be input, AC-D
A signal for turning on / off the operation of the C converter 26 can be output, and a signal for adjusting the power generation amount of the AC generator 16 can be output. Therefore, the drive controller 20
Can control the output of the AC generator 16 based on the amount of electricity stored in the battery 18. For example, as shown in FIG. 2, when the charge amount of the battery 18 reaches 100%, the operation of the AC-DC converter 26 is turned off to turn off the battery 1.
The charging to 8 is stopped, and the AC generator 16 is set to the idle state.

Further, when the temperature of the battery 18 is out of a certain range, the drive controller 20 issues an alarm and electrically shuts off the battery 18 by turning off (opening) the NFB 28.

Next, the operation of the driving apparatus of this embodiment will be described in detail with reference to the flowcharts of FIGS. 3 and 4 and the block diagram of FIG.

The flowchart of FIG. 3 shows the operation of the hybrid vehicle in which the drive device of this embodiment is installed. First, turn on NFB28 and NFB30 (closed)
(Step 101). Then, the motor driver L
22 and the motor driver R24 are activated (step 10).
2). Then, a main switch (not shown) is turned on. As a result, the drive controller 20 and the like are activated (step 103). The drive controller 20
The shift position is detected via the speed control system 34 (steps 104 and 105). When the shift position is the forward mode, the rotation directions of the motors L10 and R12 are set to the forward side (step 106), and when the shift position is the reverse mode, the rotation directions of the motors L10 and R12 are set to the backward side (step 106). Step 107). Subsequently, the drive controller 20 detects the accelerator depression amount via the speed control system 34 (step 108). Based on the accelerator depression amount, torques of the motor L10 and the motor R12,
A rotation command value is calculated (step 109). Based on these information, the motor driver L22, the motor driver R
The controller 24 controls the electric current that flows through the motor L10 and the motor R12 (step 110). When these series of operations are completed, the drive controller 20 detects the state of the main switch (step 111). If the main switch is on, the process returns to step 104 and the above operation is repeated again. If the main switch is off, NFB2
8. Turn off the NFB 30 (step 112). As a result, the motor driver L22 and the motor driver R2
4. The drive controller 20 and the like stop (step 113).

The flow chart of FIG. 4 shows the power-related control of the drive controller 20. First, a main switch (not shown) is turned on. As a result, the drive controller 20 and the like are activated (step 12
1). The drive controller 20 acquires the torque command value via the speed control system 34 (step 122) and determines whether the torque command value is positive or negative (step 123). If the torque command value is negative, the regenerative braking mode is entered and the operation of the AC-DC converter 26 is turned off (step 124). Then, the AC generator 16 automatically enters the idle state when the output current becomes zero (step 125). On the other hand, if the torque command value is positive, the acceleration or stop mode is entered, the amount of electricity stored in the battery 18 is acquired (step 126), and the amount of electricity stored is determined (step 127). The storage amount is acquired by integrating the input and output of current. Also, when the external charging is completed,
It is set to 0% (fully charged). If the amount of electricity stored in the battery 18 is fully charged, steps 124 and 125 are performed. If the amount of electricity stored in the battery 18 is not fully charged, the operation of the AC-DC converter 26 is turned on (step 128). Then, according to the amount of electricity stored, the AC generator 1
6 is controlled (step 129). For example, as shown in FIG. 2, the throttle valve of the engine 14 is controlled to 50% to 100% of the rated operation to generate power in the most efficient rotation range. Then, the drive controller 20
After steps 125 and 129, acquires the temperature of the battery 18 (step 130) and determines whether or not the temperature is within an appropriate range (step 131). If the temperature of the battery 18 is within the proper range, the process returns to step 122 and the above operation is repeated. If the temperature of the battery 18 is not within the proper range, an alarm lamp (not shown) is turned on (step 132) and after waiting for 5 minutes (step 13).
3), turn off the NFB 28 (step 134).

[0024]

The hybrid vehicle drive device according to the first aspect of the present invention has the following effects. Since electric power can be supplied to the motor from both the engine generator and the battery, the motor can be driven with a large current. Therefore, as a result of being able to use a battery having a high energy density but a low power density, it is possible to extend the mileage of the hybrid vehicle.

The hybrid vehicle drive device according to the second aspect of the present invention has the following effects in addition to the above effects. Since the sodium-sulfur battery has extremely high energy density, the weight of the hybrid vehicle can be reduced by using the sodium-sulfur battery. Therefore, the traveling distance of the hybrid vehicle can be further extended, and the body of the hybrid vehicle and the suspension can be easily reinforced.

In addition to the above effects, the hybrid vehicle drive device according to the third aspect of the invention has the following effects. When the amount of stored electricity in the battery is equal to or higher than a certain level, the charging of the battery is stopped and the engine generator is set to the idle state, whereby the fuel of the engine can be efficiently used without waste.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a drive device for a hybrid vehicle according to the present invention.

FIG. 2 is a graph showing an example in which the drive controller controls the output of the alternator based on the amount of electricity stored in the battery in the drive device of FIG. 1.

FIG. 3 is a flowchart showing an operation of a hybrid vehicle in which the drive device of FIG. 1 is installed.

FIG. 4 is a flow chart showing electric power-related control of a drive controller in the drive device of FIG.

[Explanation of symbols]

 10 motor L 12 motor R 14 engine 16 AC generator (engine generator) 18 battery 20 drive controller (control unit)

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H02P 9/14 H

Claims (3)

[Claims] 1. A motor for rotating drive wheels, an engine generator that supplies drive power to the motor and uses an engine as a power source, and a drive generator that supplies drive power to the motor and is charged by the engine generator. And a control unit that controls the power generation amount of the engine generator in accordance with the stored amount of the battery. 2. The drive device for a hybrid vehicle according to claim 1, wherein the battery is a sodium-sulfur battery. 3. The control unit has a function of stopping charging of the battery and putting the engine generator into an idle state when the amount of electricity stored in the battery is equal to or more than a certain amount. Item 2. A drive device for a hybrid vehicle according to item 1.