JPH06245320A - Controller for engine driven generator in electric automobile - Google Patents

Abstract

PURPOSE:To improve charge/discharge balance of a battery by controlling the power generated from an engine driven generator while correcting a target power based on the average value of input power to a motor from the engine driven generator and the battery. CONSTITUTION:Input power to a motor A from an engine driven generator E and a battery B is detected and averaged through an average value operating means G and the set value of target power is corrected based on the average value. Power generated from an engine driven generator E is then controlled based on the target power thus corrected. Since the target value of power generated from the engine driven generator E is corrected depending on the fluctuation between vehicles, drift of the motor A, operating manner of operator, etc., fluctuation in charge/discharge balance of the battery B is suppressed. This constitution prevent) deterioration of the battery B and enhances total efficiency of a vehicle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vehicle equipped with a motor, a battery and an engine driven generator, and more particularly to a control device for the electric vehicle.

[0002]

2. Description of the Related Art An electric vehicle is a vehicle whose drive source is a motor. Electric power for driving the motor is obtained not only by a vehicle-mounted battery but also by an engine-driven generator. The engine-driven generator is composed of an engine and a generator driven by the mechanical output of the engine. The generated output of the generator is used not only as driving power for the motor but also as charging power for the battery. . An electric vehicle having such a system configuration is a series hybrid vehicle (SHV).
Called.

In order to improve the engine emission and maintain a good fuel consumption rate in such a configuration, the engine speed may be set to a rotation speed belonging to the best emission range and the best fuel consumption range. Japanese Unexamined Patent Publication No. 51-39813 discloses a technique for keeping the engine speed constant. In the device disclosed in this publication, the engine-driven generator is controlled under a predetermined target generated power, and the field output of the generator is controlled for load fluctuations, so that the power generation output is The control is performed so that the generated power is obtained, that is, the constant value is obtained. Further, the target generated power is set to a different value when the vehicle is traveling at a low speed and when the vehicle is traveling at a high speed.

[0004]

However, even in the configuration in which the power generation output is switched between when the vehicle is traveling at high speed (high load) and when the vehicle is traveling at low speed (low load) as described above, The target generated power set for each of the load and the low load is a predetermined fixed value. On the other hand, the input power to the motor varies among vehicles, changes with time of the vehicle,
It depends on the driver's driving style. Therefore, the charge / discharge balance of the battery varies due to these factors, which causes a great difference in the efficiency of the vehicle as a whole. Also,
This fluctuation in charge / discharge balance of the battery causes shortening of the life of the battery.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a motor with a variation among vehicles, a change in vehicles (motors, etc.) with time, and a driving method of a driver. It is an object of the present invention to provide an electric vehicle that has a good charge / discharge balance of the battery and has good overall efficiency of the vehicle, life of the battery, and the like, regardless of fluctuations in the input power.

[0006]

In order to achieve such an object, the control device of the present invention has a structure as shown in FIG. That is, it has a motor A, a chargeable / dischargeable battery B that supplies electric power to the motor A, an engine C, and a generator D that is driven by the mechanical output of the engine C and that supplies electric power to the motor A and the vehicle-mounted battery B. In a control device mounted on an electric vehicle equipped with an engine-driven generator E, input power detection means F for detecting input power from the engine-driven generator E and the battery B to the motor A, and a predetermined time of the detected power. Means G for calculating the average value of
And a target power correction means H that corrects and sets a preset target power according to the obtained average value, and a generated power control means I that controls the generated power of the engine-driven generator E according to the set target power. And is provided.

Further, in the control device according to claim 2 of the present invention, a plurality of kinds of values are preset as the target electric power, and one of the values is selected according to the vehicle speed to perform the correction setting and the generated electric power control. It is characterized by offering.

[0008]

In the present invention, first, the input power from the engine-driven generator E and the battery B to the motor A is detected.
The detected input power is averaged by the average value calculating means G, and the correction setting of the target power is executed based on the average value obtained by this averaging. Further, the power generated by the engine-driven generator E is controlled according to this target power. Therefore, the target value (target power) of the generated power of the engine-driven generator E is corrected and set according to the input power fluctuation caused by the variation between vehicles, the change of the motor with time, the driving method of the operator, and the like. Therefore, the charge / discharge balance fluctuation of the battery B is reduced, deterioration of the battery B is prevented, and the efficiency of the entire vehicle is improved.

Further, in the present invention, the above-mentioned target electric power is set to different values, for example, during high speed traveling and during low speed traveling. The target power that is the target of the correction setting is
It is selected according to the vehicle speed. The target power that has undergone the correction setting is used for the generated power control. With such a configuration, in the second aspect, the updating range of the target electric power becomes small and the fluctuation range of the output of the engine C becomes small, so that the state of low fuel consumption and low emission can be maintained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows an SHV according to an embodiment of the present invention.
The system configuration of is shown. The system shown in this figure comprises a motor 14 connected to drive wheels 12 via a transaxle 10 or the like. The motor 14 is a three-phase AC induction motor, and is driven by the three-phase AC power supplied from the inverter 16. The inverter 16 is
The DC power supplied from the battery 18 and the DC power supplied from the engine drive generator 22 via the rectifier 20 are
Under the control of the ECU 24, it is converted into three-phase AC power and supplied to the motor 14. The motor 14 inputs a vehicle signal indicating an accelerator operation, a brake operation, etc. of a vehicle operator, and calculates a torque command value while detecting the rotation speed of the motor 14 by a rotation speed sensor (not shown). This torque command value indicates the value of the torque to be output from the motor 14. The ECU 24 controls the switching operation of each switching element forming the inverter 16 based on the obtained torque command value, so that the motor 14 outputs a required torque.

The engine-driven generator 22 is the engine 2
5, the gearbox 26 and the generator 28 are provided. The output shaft of the engine 25 is connected to a generator 28 via a speed increaser 26, and the power output of the generator 28 is rectified by the rectifier 20. The speed increaser 26 is a mechanism for increasing the output speed of the engine 25 to a speed suitable for the input of the generator 28. The engine-driven generator 22 is controlled by the ECU 24.

The ECU 24 has a function of controlling the throttle opening degree of the engine 25 and the like. That is, the rotation speed of the engine 25 is controlled by controlling the throttle opening degree or the like so that the emission is always good and the fuel efficiency is good. The ECU 24 also controls the field current of the generator 28. The ECU 24 controls the engine 25 and the generator 28 so that the power output of the engine-driven generator 22 becomes a predetermined target electric power.

The ECU 24 drives the engine-driven generator 2
The target power used for the control of No. 2 is set to different values at low speed and at high speed. The ECU 24 has a function of updating this target generated power based on the outputs of the current sensor 30 and the voltage sensor 32. The current sensor 30 is a sensor that detects the input current I _in to the inverter 16, and the voltage sensor 32 is a sensor that detects the input voltage V _in to the inverter 16. Specifically, the ECU 24 calculates the electric power input to the motor 14 via the inverter 16 based on the current I _in and the voltage V _in , calculates the average value of the calculated input power, and based on the calculated average value. Correcting the target power.

FIG. 3 shows a control flow according to the characteristics of this embodiment, that is, a flow of operations related to updating the target power.

The operation shown in this figure is started by interruption from a timer built in the ECU 24. E
The CU 24 first executes the determination 100 relating to the vehicle speed.
The vehicle speed is obtained as rotation speed information from a rotation speed sensor (not shown) attached to the motor 14, or from various other vehicle speed sensors. The ECU 24 determines in step 100 whether the vehicle speed V is equal to or lower than a predetermined threshold value V _th . This threshold value V _th is, for example, 60
Set to km / h, etc. Step 100 corresponds to the determination of whether the vehicle is traveling at a low speed.

When it is determined in step 100 that V ≦ V _th , the ECU 24 performs the operation (1
02-114) is executed. That is, the ECU 24
First, the detected value I _in of the current sensor 30 and the voltage sensor 32
The electric power P _ML input to the motor 14 via the inverter 16 is calculated based on the detected value V _in of (102). EC
U24 integrates the calculated power P _ML into the variable S _ML (10
4) After incrementing the variable i (106), the process returns to the main routine.

When such an operation is repeated a predetermined number of times K _L (108), the ECU 24 divides the variable P _ML by K _L to obtain the average input power P to the motor 14.
_ML (-) is calculated (110). The ECU 24 updates the low-speed-side power generation amount P _GeL that is the target power of the engine-driven generator 22 by dividing the calculated average input power P _ML (−) by the charge / discharge efficiency η _Bat of the battery 18. (112). After that, the variables i and S _ML are set to 0 (114), and the process proceeds to the main routine.

In step 100, V> V _th
If it is determined that, the ECU 24 executes steps 116 to 128 related to high speed. In step 116, the ECU 24 calculates the electric power P _MH input to the motor 14 via the inverter 16 based on the detected value I of the current sensor 30 and the detected value V of the voltage sensor 32. Here, in order to distinguish from the input power P _ML obtained in step 102, the variable subscripts are changed (the same applies hereinafter). In the following step 118, the input power P _MH is integrated with the variable S _MH , the variable j is incremented (120), and then the process returns to the main routine.

When such an operation is repeated j = K _H times (122), the ECU 24 divides the variable S _MH by K _H to calculate the average input power P _MH (−) to the motor 14. (124). The ECU 24 updates the high-speed-side power generation amount P _GeH , which is the target power of the engine-driven generator 22, by dividing the obtained average input power P _MH (−) by the charge / discharge efficiency η _Bat of the battery 18 (126). . After this, EC
U24 resets variables j and S _MH to 0 (12
8) Return to the main routine.

As described above, in this embodiment, the low-speed side power generation amount P _GeL and the high-speed side power generation amount P _GeH used as the target power of the engine-driven generator 22 are the average input power P _ML ( −) Or P _MH (−). Therefore, due to variations between vehicles, changes over time, driving methods of the operator, etc.
Even if the electric power P _ML or P _MH input to is changed, the charge and discharge balance of the battery 18 is unlikely to change, and as a result, the life of the battery 18 is extended and the efficiency of the entire vehicle is improved. That is, in the generator 28 that constitutes the engine-driven generator 22, the electric power that has flowed from the battery 18 to the motor 14 via the inverter 16 flows into the battery 18 via the rectifier 20 from the generator 28 on average. Since the target control is performed so as to be offset / compensated by the electric power, the charge / discharge balance fluctuation of the battery 18 is suppressed.

Further, in this embodiment, the target electric power related to the control of the engine drive generator 22 is set to different values on the low speed side and the high speed side, and the updating operation thereof is also executed separately. Therefore, when viewed from the low speed side and the high speed side, the update width of the low speed side power generation amount P _GeL or the high speed side power generation amount P _GeH that is the target power becomes small. As a result, when the control of the power generation output of the engine-driven generator 22 is executed as the control of the field current of the generator 28 or the like, the load fluctuation of the engine 25 is suppressed, and the emission and fuel consumption are always good. It is possible to maintain a good state.

In the operation shown in FIG. 3, the charging / discharging efficiency η _Bat of the battery 18 is _treated as a constant. However, it can also be treated as a variable. The charge / discharge efficiency η _Bat of the battery 18 is, for example,
Changes according to the deterioration of
By correcting the charging / discharging efficiency η _Bat used in _No. 6 according to the degree of deterioration that is separately detected, the target power (the low-speed side power generation amount P _GeL and the high-speed side power generation amount P _GeL corresponding to the progress of deterioration of the battery 18 is corrected. _GeH ) update can be performed. The degree of deterioration of the battery 18 is a value obtained by dividing the amount of electric power of the battery 18 at the time of full charge at the present time by the amount of fully charged electric power when the battery 18 is not deteriorated (when the battery 18 is new) (Japanese Patent Application No. No. 4-70650), the ECU 24
Is stored and the charging / discharging efficiency η _Bat is updated according to the stored content.

In the above description, the setting of the target power and the updating operation thereof are performed separately for low speed and high speed, but this may be performed for both low speed and high speed. Also, this target power update operation is preferably
The engine 25 is executed in a rotation speed range in which fuel consumption and emission are low, for example, 1200 to 2800 rpm.

[0025]

As described above, according to the present invention,
The input power from the engine-driven generator E and the battery B to the motor A is detected, the average value of the detected input power is calculated, and the generated power of the engine-driven generator E is controlled while correcting the target power by the calculated average value. Therefore, even if the input power of the motor A fluctuates due to variations among vehicles, changes over time, the driving method of the driver, and the like, fluctuations in the charge / discharge balance of the battery B are suppressed, and the battery B is suppressed. The effects of prolonging the service life of the vehicle and improving the efficiency of the entire vehicle can be obtained. Also,
According to the second aspect of the present invention, the target control of the generated electric power for the engine-driven generator E is performed by using the different target electric power depending on the vehicle speed. Emissions and fuel efficiency can be constantly maintained at good levels.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a block diagram showing a system configuration of an SHV according to an embodiment of the present invention.

FIG. 3 is a flowchart showing a control flow of the ECU in this embodiment.

[Explanation of symbols]

A, 14 Motor B, 18 Battery C, 25 Engine D, 28 Generator E, 22 Engine drive generator F Input power detection means G Average value calculation means H Target power correction means I Generated power control means 24 ECU 30 Current sensor 32 Voltage sensor I _in Current sensor detection value V _in Voltage sensor detection value V Vehicle speed V _{th Vehicle} speed determination threshold P _ML , P _MH Motor input power P _ML (-), P _MH (-) Motor input Average input power η _Bat Battery charge / discharge efficiency P _GeL , P _GeH Low-speed and high-speed power generation (target power)

Claims (2)

[Claims] 1. An engine-driven generator having a motor, a chargeable / dischargeable battery for supplying electric power to the motor, an engine and a generator driven by the mechanical output of the engine to supply electric power to the motor and the vehicle-mounted battery. In a control device mounted on an electric vehicle equipped with, an input power detection means for detecting input power from an engine-driven generator and a battery to a motor, and an average value calculation means for obtaining an average value of the detected power for a predetermined time. And a target power correction means for correcting and setting the preset target power according to the calculated average value, and a generated power control means for controlling the generated power of the engine-driven generator according to the set target power. A control device comprising. 2. The control device according to claim 1, wherein a plurality of kinds of values are preset as the target electric power, and any one of the values is selected according to the vehicle speed to be used for the correction setting and the generated electric power control. Characteristic control device.