JPH05130709A - Battery voltage type controller for electric automobile - Google Patents

Abstract

PURPOSE:To provide a highly reliable safety electric automobile by notifying the variation of performance of a motor driven electric automobile to a driver. CONSTITUTION:A voltage limit circuit 9 detects battery voltage and operates corresponding maximum set speed and set torque which are then outputted to a motor drive control circuit 8, a speed indicator 18, and a torque indicator 19. The motor drive control circuit 8 performs control operation based on these values thus limiting the motor output. The speed indicator 18 and the torque indicator 19 indicate the set values together with actual motor speed and torque command. Consequently, current performance of electric automobile can be notified to a driver. According to the invention, safety operation corresponding to the performance can be realized even when the battery voltage drops below a predetermined level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery-driven electric vehicle control device, and more particularly to a battery voltage-compatible electric vehicle control device capable of operating with performance according to the voltage of the battery even when the battery voltage drops.

[0002]

2. Description of the Related Art Conventionally, as an electric vehicle control device that copes with a change in battery voltage, Japanese Patent Laid-Open No. 61-2620
The method described in Japanese Patent Publication No. 06 is known. This method detects the battery voltage and corrects the AC command signal based on the detected value so that the battery can always operate normally even when the battery voltage changes. Therefore, when the battery voltage is high, the AC command signal is reduced,
When the battery voltage decreases, the AC command signal is controlled to increase, so that the accelerator feeling can be kept constant and the harmful effect on safe driving can be eliminated.

As an example of the motor control device when the battery voltage fluctuates, there is a method described in Japanese Patent Publication No. 3-1918. This method is intended to always realize good vector control by controlling so as to reduce the magnetic flux of the induction motor even when the battery voltage V drops. That is, when the battery voltage V decreases, the motor speed ω _M , or the ratio of the battery voltage V to the primary frequency ω ₁ , V / ω _M , or V / ω
_Since the generated magnetic flux is determined by the value of ₁ , there is a feature that good vector control can be maintained even when the battery voltage drops.

[0004]

However, the above-mentioned conventional techniques have not been considered in the following points. First, the former method does not consider the case where the battery voltage in an electric vehicle further decreases.
In other words, if the battery voltage drops below a certain value,
Since the motor voltage applied to the motor does not reach a predetermined value simply by increasing the AC command signal, the motor control system may become unstable or the acceleration performance may deteriorate. Therefore, the predetermined performance of the electric vehicle may not be secured in some cases, and there is a problem that the driver's driving feeling is different from usual. Next, in the latter method, when the battery voltage drops, the influence of the magnetic flux is taken into consideration, but the maximum torque that can be generated is not taken into consideration. In general, the voltage applied to the motor is for flowing the current for generating the magnetic flux and the current for generating the torque, so that when the battery voltage drops,
Moreover, when torque is required, the latter method lacks the voltage for generating the torque. Therefore, similar to the former method, the latter method also has a problem in that the predetermined performance as an electric vehicle cannot be ensured and the driver's driving feeling may be different from usual.

A first object of the present invention is to provide a stable control system even when the battery voltage falls below the range of the battery voltage for ensuring the rated performance of the electric vehicle.
It is to ensure the performance of the electric vehicle according to the battery voltage.

A second object of the present invention is to provide a safe and highly reliable electric vehicle for a driver even when the performance of the electric vehicle changes.

[0007]

In the electric vehicle driven by a motor, the above-described object is to provide a battery voltage detecting means for detecting a battery voltage and a maximum speed set value at which the battery voltage can be input and the vehicle can travel according to the battery voltage. Alternatively, it is achieved by calculating the maximum torque setting value and using a control means for controlling the traveling speed and the output torque so that the maximum speed setting value or the maximum torque setting value is limited. ..

In order to achieve the second object,
By providing a means for inputting the maximum speed setting value, the maximum torque setting value obtained by the above means, or the maximum climbing angle calculated from the battery voltage and notifying them to the driver, the driver The operation can be performed according to the performance state at that time.

[0009]

First, the battery voltage detection means detects the battery voltage and inputs it to the control means. In addition to the battery voltage, the control means inputs the depression amounts of the accelerator pedal and the brake pedal operated by the driver, that is, the accelerator amount and the brake amount. Here, the vehicle speed command is calculated from the accelerator amount and the brake amount, and the maximum speed setting value and the maximum torque setting value are calculated from the battery voltage. If the speed command exceeds the maximum speed setting value, the speed command is limited to the maximum speed setting value. The motor speed is fed back to this speed command, and the torque command is calculated from the difference between the speed command and the motor speed. At this time, when the absolute value of the torque command is larger than the maximum torque setting value obtained from the battery voltage, the torque command is limited so that the absolute value of the torque command becomes the maximum torque setting value. Thereby, speed control is performed. Furthermore, the current control for controlling the motor current is performed based on the current command corresponding to the torque command, and the voltage command is given. A control pulse is output from the control means to the power conversion means so as to obtain this voltage command. In this power conversion means, the motor voltage supplied to the motor is generated by the control pulse. As a result, output torque is generated from the motor to drive the tire.

Here, the operation when the battery voltage drops will be described. Generally, when the motor speed becomes high, a back electromotive force proportional to the magnetic flux and the motor speed is required, and the motor voltage to be applied to the motor must be increased. When torque is required, a voltage to generate the torque is needed, and the motor voltage needs to be further increased. Therefore, when the motor is running at high speed, when torque is required, either of them,
Alternatively, in both cases, when the battery voltage drops, the motor voltage that can be applied to the motor becomes insufficient. Therefore, when the battery voltage decreases, the control means reduces the maximum speed setting value and the maximum torque setting value, respectively, according to the detected battery voltage. At that time, when the speed command is larger than the maximum speed setting value, the speed command is reduced to the maximum speed setting value, and the absolute value of the torque command is calculated so as to be within the maximum torque setting value. As a result, the motor is operated within the speed range and the output torque range where the motor voltage does not become insufficient even if the battery voltage drops, and a stable control system can be secured.

When the battery voltage drops and the maximum speed setting value or the maximum torque setting value changes,
By informing the driver of the value, it is possible to allow the driver to determine the performance that the electric vehicle can output at that time, and thus it is possible to promote safe driving in accordance with the performance.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. FIG. 1 shows an embodiment in which the front wheels 2a, 2b of the electric vehicle 1 are driven by an induction motor 3. The front wheels 2 a, 2 b are connected to the induction motor 3 via the differential device 4 and are driven by the inverter 5. The inverter 5 is controlled by PWM pulses P _u , P _v , and P _w output from the control device 6, and converts electric power supplied to the motor 3 using the battery 7 as a power source. The control device 6 includes a motor drive control circuit 8 and a voltage correspondence limiting circuit 9. The motor drive control circuit 8, an accelerator depression amount x _a respectively obtained from the accelerator pedal 10 and the brake pedal 11 is operated the output of the driver, have entered the brake depression amount x _b. Other signals input to the motor drive control circuit 8 include a mode signal M _D , vehicle speed ω _V , motor speed ω
_M , motor currents i _u , _iv , i _w , maximum speed setting value ω _MAX ,
There is a maximum torque setting value τ _MAX . Here, the mode signal M
_D is a signal from the driving mode lever 12, which is an electric vehicle 1
The driver instructs the vehicle to move forward, reverse, or park. The vehicle speed ω _V is obtained by measuring the rotational speeds of the rear wheels 13a and 13b, which are subordinate wheels, by the wheel speed detectors 14a and 14b, respectively, and averaging them by the vehicle speed calculation circuit 15. Motor currents i _u , _iv , i _w , and motor speed ω _M
For the current detectors 16a, 16b, 1 respectively.
6c, the motor speed detector 17 detects it. further,
The maximum speed set value ω _MAX and the maximum torque set value τ _MAX are detected from the potential difference between the terminals T ₁ and T ₂ of the battery 7, that is, the battery voltage V _B by the voltage correspondence limiting circuit 9, and calculated from the battery voltage V _B. is doing. Further, the maximum speed setting value ω _MAX and the motor speed ω _M are output to the speed display 18, and the maximum torque setting value τ _MAX and a torque command τ * described later are output to the torque display 19, respectively. The performance of automobile 1 is displayed. The details of this display will be described later.

Now, a control operation method performed by the motor drive control circuit 8 and the voltage correspondence limiting circuit 9 in the control device 6 will be described with reference to FIG. The motor drive control circuit 8 performs the following control calculation. First, in the reference motor speed calculation unit 20, the accelerator depression amount x _a , the brake depression amount x a
_The reference motor speed ω _R corresponding to the vehicle speed command is calculated from _b , the mode signal M _D , and the vehicle speed ω _V. This reference motor speed ω _R is input to the speed limiter 21, is compared with the maximum speed setting value ω _MAX obtained by the method described later, and is calculated so as to be within the maximum speed setting value ω _MAX . This result is output as the motor speed command ω *. Speed calculator 22
In performs proportional-integral operation on the difference between the motor speed command omega * and the motor speed omega _R, and calculates the reference torque tau _R. Next, the torque limiter 23, when the absolute value of the reference torque tau _R exceeds the maximum torque setting tau _MAX is calculated to limit the maximum torque setting value tau _MAX.
The torque command τ * obtained as a result is used as the current command calculation unit 2
It is output to 4. Here, torque command tau *, performs vector control calculation from motor speed omega _M, U induction motor, V, and current command W-phase i _u *, i _v *, and outputs the i _w *. In the current control calculation unit 25, the current commands _iu *, _iv *,
i _w motor current with respect to _{* i u, i v, i} w to by the current control calculation from the difference against each, U,
The respective voltage commands V _u *, V _v *, V _w * of the V and W phases are obtained.
As a result, the PWM generator 26 generates PWM signals P _u , P _v , and P _w , respectively.

Next, the voltage correspondence limiting circuit 9 which is a feature of the present invention will be described. The voltage detection unit 27 of the voltage correspondence limiting circuit 9 detects the potential difference between the terminals T ₁ and T ₂ of the battery 7, that is, the battery voltage V _B. The maximum speed calculator 28 calculates the maximum speed set value ω from the battery voltage V _B.
MAX is being calculated. FIG. 3 shows the relationship between the battery voltage V _B and the maximum speed setting value ω _MAX . Here, V ₀ > V ₁ > ...
…> V ₄ . The rated voltage fluctuation range refers to the range of battery voltage at which the preset performance of an electric vehicle (hereinafter referred to as rated performance) can be secured, and generally the voltage drops below this range. when,
The method of not operating an electric vehicle is taken. On the other hand, in the present invention, the following processing is performed. Figure 3
In (when it becomes the V _B <V ₀₎ the battery voltage V _B may falls below the rated voltage fluctuation range, the highest against the V _B V _0, V _1, ......, drops V ₄ The speed setting value ω _MAX is set to gradually decrease. Further, the maximum torque calculation unit 29 calculates the maximum torque setting value τ _MAX from the battery voltage V _B. The calculation has characteristics as shown in the table of FIG. That is, when the battery voltage V _B drops below V ₃ , the maximum torque setting value τ _MAX is gradually reduced. This method will be described from the characteristics of the induction motor shown in FIG. The maximum output torque that can be output from the motor with respect to the motor speed ω _M is shown by a thick line. Normally, if the battery voltage V _B is within the rated voltage fluctuation range, that is, if V _B ≧ V ₀ , the motor can generate this maximum output torque, so that the rated performance of the electric vehicle can be satisfied. Therefore, the maximum speed of the electric vehicle is determined by the motor speed ω ₀ at the point where the thick line intersects with the steady-state running load determined by the running resistance. However, when the battery voltage V _B drops to V ₁ , the voltage that can be applied to the induction motor in the high speed region becomes insufficient, so the output torque decreases as shown in FIG. Therefore, the motor speed ω _{M at} the intersection of the characteristic line and the fixed road traveling load decreases from ω ₀ to ω ₁ . For this reason, the rated performance of the electric vehicle cannot be satisfied, and thus the processing for stopping the electric vehicle has been conventionally performed. However, the present invention is characterized in that the maximum speed set value itself is lowered to ω ₁ so that the electric vehicle can be driven even if the battery voltage falls below the rated voltage fluctuation range. Similarly, when the battery voltage V _B drops to V ₂ and V ₃ , the electric vehicle can be driven at a speed within that range by setting the maximum speed set values to ω ₂ and ω ₃ . Further, when the battery voltage V _B drops to V _{4, the} torque that can be output also drops to τ ₄ as shown in FIG. 5, so the maximum torque setting value τ _MAX can also be set to τ _{4 as shown} in FIG. For the above reason, if the characteristics for the battery voltage as shown in FIGS. 3 and 4 are set, stable running can be performed without insufficient motor applied voltage.

By the way, the speed indicator 18 of FIG.
An example of the torque indicator 19 will be described with reference to FIGS. 6 and 7. In the speed indicator 18 of FIG. 6, when the motor speed ω _M is input, the speed instruction unit 30
Is displayed, and the current vehicle speed of the electric vehicle 1 is displayed to the driver. Further, a maximum speed instruction section 31 driven according to the maximum speed setting value ω _MAX is arranged on the display surface.
The maximum speed instructing section 31 has its lit part 31a and unlit part 3
It is divided into 1b and the boundary is the maximum speed setting value ω _MAX
This electric vehicle 1 is displayed to the driver by displaying as
You can inform the current maximum speed that can be traveled. Similarly, in the torque indicator 19 as well, a torque instruction section 32 for displaying a torque command τ * corresponding to the motor torque and a maximum torque instruction section 33 for displaying a maximum torque set value τ _MAX (lighting portion 33a, light-off portion 33b). By displaying and on the same display surface, the driver can easily understand how much the current output torque is with respect to the maximum torque that can be generated. Therefore, if the present embodiment is used, this speed indicator 1
8. By arranging the torque indicator 19 in a place visible from the driver's seat, the driver can confirm the current performance of the electric vehicle. Therefore, even if the battery voltage drops, drive according to the performance. You can In addition, if the maximum speed and maximum torque instructions decrease, it will notify the driver that the battery performance has deteriorated.
It will prompt the driver to charge the battery.
In this way, there is a feature that the user can travel with peace of mind without stopping on the road.

FIG. 8 shows another embodiment in which a function for displaying climbing performance is added to FIG. 8 is different from that in FIG. 1 in that a tilt angle meter 34 and a tilt angle indicator 35 are provided. The tilt angle meter 34 measures the tilt of the electric vehicle 1 in the front-rear direction (pitching direction), and indicates the tilt θ of the road on which the vehicle is currently traveling. That is, the slope has a large positive value when climbing uphill, and has a negative value when downhilling. This inclination θ is input to the inclination angle display 35. Further, the maximum uphill angle θ _MAX calculated by the voltage limiting circuit 9 is also input to the inclination angle display 35. Here, a method of calculating the maximum uphill angle θ _MAX will be described with reference to FIGS. 9 to 11. In the voltage limitation support circuit 9 of FIG.
When the battery voltage V _B is input to the maximum slope angle calculation unit 36, the table as shown in FIG. 10 is referred to and the maximum slope angle θ _MAX is calculated. This table is obtained from the characteristics shown in FIG. 11, and the inclination angle at which the electric vehicle can climb at a predetermined motor speed (for example, ω ₃ in FIG. 11) is the maximum climbing angle θ _MAX . It should be noted that the predetermined motor speed should generally be set so as not to interfere with the passage of other vehicles on the road. Figure 1
In No. 1, the curve using the uphill angles θ ₀ and θ ₂ as parameters is a running load curve when climbing at that angle. Here, when the battery voltage V _B becomes V ₁ or less, the motor output torque becomes insufficient at the uphill angle θ ₀ , so the maximum uphill angle θ _MAX must be made smaller than θ ₀ . For example, when the battery voltage V _B becomes V ₂ and V ₃ , the maximum climbing angle θ _MAX becomes θ ₂ and 0 ° (running on a fixed surface), respectively. FIG. 10 shows a table of these characteristics. FIG. 12 shows a tilt angle indicator 35 for inputting the maximum uphill angle θ _MAX and the tilt θ obtained in this way. When the inclination θ is input, the inclination instruction section 37 is driven by the size, and the current inclination θ is displayed to the driver. Also, the maximum slope angle θ
_{For MAX} , the lighting part 3 of the maximum climbing angle display section 38
It is indicated by 8a and the extinguished portion 38b. That is, the boundary line between the lit portion 38a and the unlit portion 38b is displayed so as to have the maximum climbing angle θ _MAX . As a result, it is possible to easily read how far the vehicle can travel at a predetermined vehicle speed and the difference between the current running inclination and the steep uphill road where the battery voltage is low and it is unlikely that the vehicle can travel in advance. The driver can judge. In addition, when it is necessary to travel on such an uphill, the driver is prompted to charge the battery, so that it is possible to prevent the electric vehicle from being stopped on a slope due to being unable to climb. ..

Therefore, according to the present embodiment, even when the battery voltage drops, it is possible to secure the uphill performance corresponding to the battery voltage and notify the driver of the performance, so that the driver can feel more reliable and feel more secure. Can be given to.

FIG. 13 shows another embodiment in which the characteristics of the maximum torque calculating unit 28 in FIG. 2 or 9 are different from those in FIG. Compared with the characteristic of FIG. 4 in which the maximum torque setting value τ _MAX is reduced when the battery voltage V _B drops below V ₃ , the characteristic of FIG. 13 shows that the battery voltage V _B is V ₀ (V ₀ >).
When V ₃ ) or less, the maximum torque setting value τ _MAX is gradually reduced. Originally, battery voltage V _B
It is clear from FIG. 5 that the output torque can be generated up to τ ₀ if the motor speed ω _M is low even if is reduced to V ₀ or less. However, the fact that the battery voltage V _B drops below V ₀ indicates that the remaining capacity of the battery has decreased considerably, so it is better to save energy and extend one mileage. Good. Therefore, as shown in the characteristic of FIG. 14, the battery voltage V
_{This is} to control the maximum value of output torque by _B in a controlled manner. For example, the battery voltage V _B is V ₁ ,
If V ₂ , V ₃ and V ₄ , the maximum torque setting values τ ₁ , τ ₂ and
It is suppressed to τ ₃ and τ ₄ . FIG. 13 shows this as a table. As a result, when the battery voltage decreases, rapid acceleration cannot be performed, and the driver does not perform rapid deceleration as much as possible, so that energy consumption can be suppressed. Further, when the battery is low, the maximum torque setting value becomes smaller than the characteristic of FIG.
As the performance of the electric vehicle will be reduced, the rate at which the driver will charge faster will increase.

From the above, using this embodiment,
It is possible to improve the mileage per charge after the battery voltage drops.

FIG. 15 shows another embodiment different from FIG.
15 in addition to the battery current i _B of the battery voltage V _B
Is detected by using the battery current detector 39 and is input to the voltage correspondence limiting circuit 9. The remaining capacity calculation unit 40 of the voltage correspondence limiting circuit 9 temporally integrates the electric power consumed from the battery voltage V _B and the battery current i _B or the electric power to be charged in consideration of the discharge efficiency, the charging efficiency, and the like. Thus, the remaining capacity W _B is calculated. The remaining capacity W _B and the battery voltage V _B are input to the maximum speed calculating unit 28, the maximum torque calculating unit 29, and the maximum climbing angle calculating unit 36, and the maximum speed setting value ω _MAX , the maximum torque setting value τ _MAX , and the maximum speed setting value ω _MAX , respectively. Calculates the climbing angle θ _MAX . As a result, when the battery voltage V _B decreases, the operable state can be detected more accurately by the value of the remaining capacity, and thus it is possible to perform control so as to further extend the one-charge traveling distance.

FIG. 16 shows another embodiment different from FIGS. 9 and 15 in which the limit value can be switched according to a driver's instruction. In FIG. 16, an economy switch 41 is provided and this signal SW is input to the voltage correspondence limiting circuit 9. Thereby, the tables of the maximum speed calculation unit 28, the maximum torque calculation unit 29, and the maximum uphill angle calculation unit 36 can be switched. When the driver turns off the economy switch 41, the respective limit values are set so that the motor can output the most to the battery voltage at that time.
That is, the maximum speed set value ω _MAX and the maximum torque set value τ _MAX as shown in the tables of FIGS. Next, when the driver selects the economy switch 41 to be on, the table is set so that one charging mileage is obtained. For example, as shown in FIG. 13, the maximum torque setting value τ _M is set. As a result, even when the battery voltage of the electric vehicle drops, the driver can select the performance of the vehicle, and the vehicle that meets the driver's taste can be provided.

FIG. 17 shows the current command calculator 24 shown in FIG.
It is another embodiment in which the battery voltage V _B is input to the. FIG. 17 shows a portion where vector control calculation of the so-called induction motor 3 is performed. In the magnetic flux calculation unit 42, the field weakening control for the normal motor speed ω _M is performed. However, when the battery voltage V _B has dropped, in order to further reduce the magnetic flux, calculation is performed on the battery voltage and the magnetic flux command φ _M is output. With this magnetic flux command φ _M ,
The magnetic flux current calculator 43 obtains a current for generating a magnetic flux, that is, a magnetic flux component current i _M. Further, the torque current calculation unit 44 calculates the torque component current i _T that generates the torque of the induction motor 3. The torque current i _T is obtained by dividing the torque command τ * by the magnetic flux command φ _M. The slip angular frequency command ω _S can also be obtained from the torque command τ * and the magnetic flux command φ _M, and is calculated by the slip angular frequency calculation unit 45. Next, the vector calculation unit 46 that calculates the vector sum of the magnetic flux current i _M and the torque current i _T
Outputs the primary current command i ₁ and the phase angle θ _S.
The integrator 47 determines the motor speed ω _M and the slip angular frequency command ω _S
And the primary angular frequency ω ₀ which is the sum of
The phase angle command θ * of the primary current command i ₁ is obtained by the sum of the output θ ₀ and the phase angle θ _S. Based on this, in the primary current command calculation unit 48, the current command i _u *, i of each phase of the induction motor is generated.
_{I have v} *, _iw *. According to this method, when the battery voltage V _B is lowered, not only the torque component current but also the magnetic flux component current can be reduced, so that one charging traveling distance can be further extended.

The embodiment of the present invention has been described above, and the case of driving with an induction motor has been described, but it may be applied to the case of driving with another motor. Also, the maximum speed to limit,
The maximum torque may be variable depending on the type, performance, temperature, etc. of the battery. Although the speed control method of calculating the speed command from the accelerator and the brake has been described, the present invention is also applicable to the case of driving by the torque control method of calculating the torque command. Note that these embodiments can be configured by using a vehicle speed equivalent to the motor speed instead of the motor speed. Further, it goes without saying that the display method may be a method such as a digital method or a bar graph method.

[0024]

According to the present invention, even when the battery drops below a predetermined value, the maximum speed and the maximum torque are limited accordingly, and these are displayed to the driver.
There is an effect that the stable control system and the performance of the electric vehicle according to the battery voltage can be secured, and the safe driving according to the performance can be enabled.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of an electric vehicle control device showing an embodiment of the present invention.

FIG. 2 is a block diagram showing a control method of the control device in FIG.

FIG. 3 is a characteristic diagram showing the relationship between the battery voltage and the maximum speed setting value, which shows the contents of calculation performed by the maximum speed calculation unit of the present invention.

FIG. 4 is a characteristic diagram showing a relationship between a battery voltage and a maximum torque set value, which shows the contents of calculation performed by the maximum torque calculation unit of the present invention.

FIG. 5 shows the battery voltage of the present invention as a parameter.
It is a characteristic view which shows the motor speed of an induction motor, and the relationship of output torque.

FIG. 6 is a front view of the speed indicator displayed to the driver of the present invention.

FIG. 7 is a front view of the torque indicator displayed to the driver of the present invention.

FIG. 8 is a block configuration diagram of an electric vehicle control device showing another embodiment of the present invention.

9 is a block diagram of a control device in which a block for calculating a maximum uphill angle is added in the embodiment of FIG.

FIG. 10 is a characteristic diagram showing the relationship between the battery voltage and the maximum climbing angle.

11 is a characteristic diagram showing the relationship between the motor speed and the output torque of the induction motor for explaining the contents of the table of FIG.

FIG. 12 is a plan view of a tilt angle indicator used in the present invention.

FIG. 13 is a characteristic diagram showing the relationship between the battery voltage and the maximum torque setting value in another embodiment of the present invention.

FIG. 14 is a characteristic diagram showing the relationship between the motor speed and the output torque of the induction motor for explaining the contents of the table of FIG.

FIG. 15 is a block diagram showing another embodiment of the voltage corresponding limiting circuit considering the remaining capacity.

FIG. 16 is a block diagram showing another embodiment of a voltage-compatible limit circuit provided with an economy switch for a driver.

17 is a block diagram showing another embodiment in which a battery voltage is input to the current command calculation unit in FIG.

[Explanation of symbols]

1 ... Electric vehicle, 2a, 2b ... Front wheels, 3 ... Induction motor,
4 ... Differential device, 5 ... Inverter, 6 ... Control device, 7 ... Battery, 8 ... Motor drive control circuit, 9 ... Voltage corresponding limit circuit, 10 ... Accelerator pedal, 11 ... Brake pedal,
12 ... Driving mode lever, 13a, 13b ... Rear wheel, 14
a, 14b ... Wheel speed detector, 15 ... Vehicle speed calculation circuit, 1
6a, 16b, 16c ... Current detector, 17 ... Motor speed detector, 18 ... Speed indicator, 19 ... Torque indicator, 20
... Reference motor speed calculator, 21 ... Speed limiter, 22 ...
Speed calculation unit, 23 ... Torque limiter, 24 ... Current command calculation unit, 25 ... Current control calculation unit, 26 ... PWM generation unit, 2
7 ... Voltage detection unit, 28 ... Maximum speed calculation unit, 29 ... Maximum torque calculation unit, 30 ... Speed instruction unit, 31 ... Maximum speed instruction unit, 32 ... Torque instruction unit, 33 ... Maximum torque instruction unit, 3 ...
4 ... Inclinometer, 35 ... Inclination indicator, 36 ... Maximum climbing angle calculation unit, 37 ... Inclination indicator, 38 ... Maximum climbing angle display unit, 39 ... Battery current detector, 40 ... Remaining capacity computing unit, 41 ... Economy switch, 42 ... Magnetic flux calculator, 4
3 ... Magnetic flux current calculation unit, 44 ... Torque current calculation unit, 45 ...
Slip angular frequency calculator, 46 ... Vector calculator, 47 ...
Integrator, 48 ... Primary current command calculator.

Claims (9)

[Claims] 1. A motor for driving an automobile, a battery for accumulating drive energy of the automobile, a power conversion means for converting a battery voltage of the battery to generate a motor voltage to be supplied to the motor, and the automobile. In an electric vehicle control device including a control means for controlling the motor voltage according to a driver's instruction to drive and a traveling speed of the vehicle, the maximum speed set value that the vehicle can travel is changed according to the battery voltage, An electric vehicle controller for a battery voltage, wherein the motor voltage is controlled so that the traveling speed is within the maximum speed set value. 2. A motor for driving an automobile, a battery for accumulating drive energy of the automobile, a power conversion unit for converting a battery voltage of the battery to generate a motor voltage to be supplied to the motor, and the automobile. In an electric vehicle control device including a control means for controlling the motor voltage according to a driver's instruction to drive and a traveling speed of the vehicle, the maximum speed set value that the vehicle can travel is changed according to the battery voltage, A battery voltage compatible electric vehicle control device, characterized in that the motor voltage is controlled so that the traveling speed is within the maximum speed setting value, and the driver is notified of the maximum speed setting value. 3. A motor for driving an automobile, a battery for accumulating drive energy for the automobile, a power conversion means for converting a battery voltage of the battery to generate a motor voltage to be supplied to the motor, and the automobile. In an electric vehicle control device including a control means for controlling the motor voltage according to a driver's instruction to drive and a traveling speed of the vehicle, the maximum torque set value that can be output by the vehicle is changed according to the battery voltage, A battery voltage compatible electric vehicle control device, wherein the motor voltage is controlled so that the output torque of the motor is within the maximum torque setting value. 4. A motor for driving an automobile, a battery for accumulating drive energy for the automobile, a power conversion means for converting a battery voltage of the battery to generate a motor voltage to be supplied to the motor, and the automobile. In an electric vehicle control device including a control means for controlling the motor voltage according to a driver's instruction to drive and a traveling speed of the vehicle, the maximum torque set value that can be output by the vehicle is changed according to the battery voltage, A battery voltage-compatible electric vehicle control device characterized in that the motor voltage is controlled so that the output torque of the motor is within the maximum torque setting value, and the driver is notified of the maximum torque setting value. 5. The battery voltage compatible electric vehicle control device according to claim 2, wherein the traveling speed and the maximum speed setting value are displayed on the same scale. 6. The battery voltage compatible electric vehicle control device according to claim 4, wherein the output torque and the maximum torque set value are displayed on the same scale. 7. A motor for driving an automobile, a battery for accumulating drive energy for the automobile, a power conversion unit for converting a battery voltage of the battery to generate a motor voltage to be supplied to the motor, and the automobile. In an electric vehicle control device comprising a control means for controlling the motor voltage according to a driver's instruction to drive and a traveling speed of the vehicle, the battery voltage is used to calculate a maximum climbing angle at which the vehicle can climb, and the maximum climbing angle is calculated. An electric vehicle control device for a battery voltage, characterized in that the driver is informed of the angle. 8. The battery voltage-compatible electric vehicle control device according to claim 7, wherein the current uphill angle and the maximum uphill angle of the vehicle are displayed on the same scale. 9. A motor for driving an automobile, a battery for accumulating driving energy for the automobile, a power conversion unit for converting a battery voltage of the battery to generate a motor voltage to be supplied to the motor, and the automobile. In an electric vehicle controller provided with a control means for controlling the motor voltage according to a driver's instruction to drive and a traveling speed of the vehicle, the motor voltage has a magnetic flux current command giving a secondary interlinkage magnetic flux and an output torque. A method for calculating a torque current command to be given by vector control calculation, wherein the magnetic flux current command and the torque current command are changed according to the battery voltage and the traveling speed. Electric vehicle control device.