JPH05103497A - Electric motor vehicle - Google Patents

Abstract

PURPOSE:To provide an electric motor vehicle which can obtain sufficient output characteristics in response to a load of a traveling motor having at least two armature systems, reduce power consumption particularly at the time of a low load and further travel as long as possible even when an operating malfunction of a composing element of a motor occurs. CONSTITUTION:The electric motor vehicle comprises a traveling motor 1 having two armature systems 4, 5, load sensing means 21 for sensing a load of the motor 1, and control means 2 for controlling to drive the motor 1 in response to the magnitude of the sensed load. The means 2 drives both the systems 4, 5 when the load of the motor 1 is heavy and selectively drive one of the systems 4, 5 when the load is light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vehicle that is driven by a traveling electric motor.

[0002]

2. Description of the Related Art For example, an electric vehicle which has been put into practical use in recent years generally has a structure in which a single traveling electric motor is driven by electric energy stored in a battery and the driving force is transmitted to driving wheels. I am trying to drive.

In this case, in particular, a traveling electric motor of an electric vehicle is required to have a wide torque characteristic or output characteristic in a wide speed range from low speed to high speed according to load conditions such as acceleration and deceleration due to its property. On the other hand, since the stored energy of the battery as an energy source is limited to a relatively small amount, it is required to reduce the power consumption.

However, in a single traveling electric motor,
Generally, for example, when it is attempted to obtain a sufficient output in a wide speed range, the number of armature windings and the length of the armature windings generally increase, and the electric resistance also increases. It has been difficult to sufficiently satisfy the above requirements such as increase.

Further, in the case of an electric traveling vehicle which is driven by a single electric motor for traveling, when the malfunction of the armature of the electric motor, the position detector of the rotor or the like occurs, the electric vehicle immediately becomes unable to travel. there were.

On the other hand, in an electric vehicle, as disclosed in, for example, Japanese Patent Laid-Open No. 59-144388,
It is known to have a traveling electric motor in which two armature systems having the same drive shaft are provided in the same case,
In this electric vehicle, by operating only one armature system at the time of starting the electric motor, the power consumption at the time of starting is reduced, and after starting, both armature systems are driven together. I am trying to drive.

However, in this electric vehicle, the armature systems of both systems are always driven in parallel during traveling, so that it is substantially the same as when traveling by a single electric motor. However, the above inconvenience cannot be solved.

[0008]

The present invention solves such inconveniences, uses a traveling electric motor having at least two armature systems, and is capable of obtaining sufficient output characteristics and the like according to its load. In particular, it is an object of the present invention to provide an electric vehicle capable of reducing its power consumption at a low load and capable of traveling as much as possible even when malfunction of components of an electric motor occurs. To do.

[0009]

In order to achieve such an object, the present invention provides a traveling electric motor having at least two armature systems, load detecting means for detecting the load of the electric motor, and the load detecting means. A control means for driving and controlling the electric motor according to the magnitude of the load detected by the control means, the control means using both systems of the electric motor when the load detected by the load detection means is larger than a predetermined value. Drive,
When the load is smaller than a predetermined value, only one system of the electric motor is selected and driven.

Further, the control means controls the electric power supplied to the electric motor to be variable in magnitude according to the magnitude of the load in both cases of combined driving of both systems and selection / driving of the one system. It has a power control means.

The control means detects the presence / absence of malfunction of each system, and an auxiliary drive for driving and controlling only the other system when the malfunction of one system is detected by the detection means. And means.

[0012]

According to the present invention, when the load of the traveling electric motor detected by the load detecting means is small, the
Since only one of the armature systems of the system is selected and driven by the control means, the power consumption can be reduced. When the load of the traveling electric motor is large, the armature systems of both systems are driven together, so that it is possible to obtain a sufficient output.

Further, when the control means has the electric power control means, the motor can be selected according to the magnitude of the load, regardless of whether only one system is selected / driven or both systems are driven together. Since the electric power supplied to the electric motor is variable, the electric power consumption of the electric motor is reduced as the load is reduced.

In this case, as a method of controlling the electric power supplied to the electric motor, for example, pulse width modulation can be cited.

Further, the control means is the detection means and 1
When the system control means is provided, when it is detected by the detection means that an operation failure of the armature system of one system of the electric motor has occurred, the auxiliary drive means causes the armature system of the other system to operate. It is driven so that it can travel.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of an electric vehicle according to the present invention will be described with reference to FIGS. FIG. 1 is a circuit diagram of a main part of the electric traveling vehicle, FIG. 2 is an explanatory sectional view of a traveling electric motor, FIGS. 3 and 4 are operation explanatory diagrams, and FIG. 5 is a flowchart.

In FIG. 1, 1 is a traveling electric motor, 2 is a controller (control means), 3 is a battery, and these are mounted on the vehicle body of an electric traveling vehicle.

The electric motor 1 has, for example, two systems of three-phase armature systems 4 and 5. That is, as shown in FIG. 2, the main components of the electric motor 1 are a drive shaft 7 rotatably supported by a housing 6, a magnet 8 that is a rotor fixed to the drive shaft 7 in the housing 6, and a magnet. 8, an armature core 9 that is a stator fixed to the inner peripheral surface of the housing 6 and three-phase armature coils 10 and 11 that are wound around the armature core 9 so as to be insulated from each other. Child system 4, 5
Respectively have the armature coils 10 and 11. Then, on the inner wall of the housing 6, for example, two systems of position detection sensor groups 12 and 13 composed of known Hall elements and magnetoresistive elements are fixed, and these position detection sensor groups 12 and 13 are connected to the armature coil 10. , 11 magnets 8
The relative rotation position with respect to is detected, and the detection signal is output to the controller 2.

The drive shaft 7 of the electric motor 1 is connected to the drive wheels via a power transmission mechanism (not shown) so as to transmit the rotational driving force to the drive wheels (not shown).

In the electric motor 1, both or one of the armature coils 10 and 11 is energized by an appropriate method (details will be described later).
The drive shaft 7 is rotationally driven by electromagnetic interaction with the magnet 8, and the driving force drives the electric vehicle.

As shown in FIG. 1, the armature coils 10 and 11 of the armature systems 4 and 5 have the same structure as the drive circuit 1 respectively.
It is connected to the battery 3 via 4, 15.

In this case, the drive circuits 14 and 15 have three sets of switching transistors Q _i , which are connected in series with each other.
Q _{i + 1} (i = 1 to 3) is connected in parallel to the battery 3, and the upper transistor Q _i (i = 1 to 3) in the figure is used.
Of the U-phase and V-phase of the armature coils 10 and 11,
The transistors Q _{1 to} Q ₆ are respectively connected to the W phase and the bases of the transistors Q _{1 to} Q ₆ are connected to the controller 2. Furthermore, between the emitter and collector of the transistors Q ₁ to Q _6, the diode D for reverse voltage absorbing it is connected.

Each transistor Q of each drive circuit 14, 15
₁ to Q _6, which will be described in detail later, by a control signal applied from the controller 2 to the base, as appropriate, ON / O
The armature coils 10 and 11 are energized from the battery 3 by FF.

In FIG. 1, the controller 2 includes a vehicle speed sensor 16 for detecting the vehicle speed of the electric vehicle, a rotational speed sensor 17 for detecting the rotational speed of the electric motor 1, and an operation of an accelerator (not shown) of the electric vehicle. An accelerator sensor 18 that detects the amount via a potentiometer or the like, and a non-contact type current sensor 19 or 20 that detects the energization amount in each drive circuit 14, 15 and each armature coil 10, 11 are connected, and the controller 2 Are each of these sensors 16 to
Twenty detection signals are successively received.

The controller 2 constitutes the load detecting means 21 for detecting the load of the electric motor 1 together with the accelerator sensor 18, and, for example, the operation amount of the accelerator detected via the accelerator sensor 18 and its per unit time. The load of the electric motor 1 is detected according to the amount of change.

Specifically, for example, the load of the electric motor 1 is
A function map corresponding to the accelerator operation amount and its change amount is previously stored in the memory of the controller 2 or the like, and the load value of the electric motor 1 is read by this map. In this case, the value of the load on the electric motor 1 increases as the accelerator operation amount and its change amount increase.

The controller 2 includes the drive circuits 14,
15 through each phase U, V of each armature coil 10, 11,
The induced voltage in W is detected.

Next, driving / control of the electric motor 1 by the controller 2 will be described in detail.

In FIG. 1, the electric motor 1 is shown in Table 1 below.
According to the energization sequence (1), (2), ... (6), (1) ...
Both the armature coils 10 and 11 of 4,5, or
By energizing each of the one phase or the other phase, the drive shaft 7
The rotational driving force of
Basically, each transistor Q of each drive circuit 14 and 15
₁~ Q₆By applying a control signal to the base of the
Each transistor Q ₁~ Q₆ON as shown in the table
/ OFF to energize each armature coil 10, 11,
Thereby, the electric motor 1 is driven.

[0030]

[Table 1]

Specifically, for example, each armature coil 10,
11 When energizing from U phase to V phase (Energizing sequence (1) in Table 1)
In the case of), turn on only the transistors Q ₁ and Q ₄ ,
The other transistors Q ₂ , Q ₃ , Q ₅ , Q ₆ are turned off. At this time, a current flows from the battery 3 through the transistor Q ₁ , the U-phase and V-phase of the armature coils 10 and 11 and the transistor Q ₄ in order. The same applies to other energizations.

In this case, the controller 2 basically detects the vehicle speed detected by the vehicle speed sensor 16, the rotation speed sensor 17, and the accelerator sensor 18, the rotation speed of the electric motor 1, the operation amount of the accelerator, and the change amount thereof. Output torque and rotation speed required for the electric motor 1 are obtained from a drive map or the like stored in a memory in advance, and each armature coil 10, so that the required torque and rotation speed can be obtained.
The power supply to 11 is controlled via the drive circuits 14 and 15. And at this time, details will be described later,
As described above, the controller 2 uses the accelerator sensor 1
According to the magnitude of the load of the electric motor 1 detected via 8,
Both of the armature coils 10 and 11 are synchronously energized, or only one of them is energized.

During the energization drive, the transistors Q _{1 to} Q ₆ of the drive circuits 14 and 15 are turned on / off.
The timing of is normally the position detection sensor group 12, 1
It is appropriately determined according to the detection signal of any one of the three.

On the other hand, as a control function of the controller 2, the controller 2 applies the load to the electric motor 1 in both cases of energizing both of the armature coils 10 and 11 and energizing either one of them. Accordingly, an electric power control means 22 is provided for controlling the amount of electricity supplied to the armature coils 10 and 11, that is, the electric power supplied to the electric motor 1. The power control means 22 turns on / off the transistors Q _{1 to} Q ₆ of the drive circuits 14 and 15 as described below.
The F control is performed by two methods, so-called full energization and pulse width modulation, to control the energization amount to each armature coil 10, 11.

That is, for example, each armature coil 10, 1
When energizing the U-phase to the V-phase of No. 1 (the energizing sequence in Table 1 above
In the case of (1)), by applying an ON signal of a predetermined value to the bases of the transistors Q ₁ and Q ₄ for a time corresponding to the rotation speed of the motor 1, these transistors Q ₁ and Q ₄ are turned on.
To be Then, at full energization, as shown in FIG. 3A, the controller 2 causes the transistors Q ₁ and Q _{4 to}
The transistors Q ₁ , Q
The ON signal of a predetermined value is applied to the base of ₄ . The same applies to other energizations.

On the other hand, in pulse width modulation, as shown in FIG.
As shown in (b), the controller 2 has one of the transistors Q ₁ and Q ₄ , for example, the base of the transistor Q ₁ ,
The transistor Q ₁ is turned on as in the case of full energization above.
The ON signal is applied for the entire period that should be set to ON, and the transistor Q ₄ is turned ON at the base of the other transistor Q _4.
Pulsed ON with a predetermined period T over the entire period
Apply a signal. The same applies to other energizations.

Thus, for each energization in Table 1 above, a set of transistors Q _i ,
If the ON signal applied to one of the Q _j is pulsed, the armature coils 10 and 11 will be compared with the case of full energization.
The average value of the amount of current flowing in the ON signal is the pulse width t of the ON signal or the duty ratio (pulse width t in FIG. 3B).
And the ratio of T−t), and therefore the power supplied to each armature system 4, 5 of the electric motor 1 decreases.

In the pulse width modulation, the power supplied to each armature system 4 and 5 is adjusted by adjusting the duty ratio of the ON signal to each transistor (Q _{4 to} Q ₆ in this embodiment) in this way. This is a control method.

When the motor 1 is driven, the controller 2 drives the armature systems 4 and 5 together, or selectively drives only one of them. By using the two control methods of energization and pulse width modulation, the electric motor 1 can be driven by, for example, four types of drive patterns, as shown in Table 2 below.

[0040]

[Table 2]

FIG. 4 shows exemplary characteristics of the electric motor 1 in each of the drive patterns (1) to (4).

In FIG. 4, the characteristics indicated by the solid line, the broken line, the alternate long and short dash line and the alternate long and two short dashes line are the characteristics of the electric motor 1 in the respective drive patterns (1) to (4) shown in Table 2 above. In the characteristics of the drive patterns (1) to (4), the straight line shows the torque / rotational speed characteristic of the electric motor 1, and the curve shows the torque / output characteristic.

In the characteristics of FIG. 4, the drive pattern
The duty ratios of pulse width modulation in (2) and (4) are, for example, 50% and 75%, respectively.

As shown in the figure, each drive pattern
The output characteristics in (1) to (4) are as follows:
The torque decreases according to the order of (4), and the torque at which the maximum output is obtained shifts to the low torque side. this is,
The power supplied to the electric motor 1 is smaller when either one of the armature systems 4 and 5 is selectively driven, and when pulse width modulation is performed than when the motor is fully energized. This is because the electric power supplied to the electric motor 1 is reduced.

As will be described in detail later, the controller 2 determines each of these drive patterns (1) to
Any one of (4) is appropriately selected to drive the electric motor 1.

Further, in FIG. 1, the controller 2 is
As its control function, a detection means 23 for detecting the presence or absence of malfunction of each drive circuit 14, 15 and each armature system 4, 5, etc.
And an auxiliary drive means 24 for performing an auxiliary drive of the electric motor 1 when the detection means 23 detects a malfunction of the drive circuits 14, 15 or the armature systems 4, 5, etc.

In this case, the detecting means 2 will be described in detail later.
3 is each drive circuit 1 via the current sensors 19 and 20.
4, 15 and the armature coils 10, 12 by sequentially detecting and monitoring the energization amount, so that each drive circuit 1
4, 15 and the presence or absence of malfunction of each armature coil 10, 12 and the position detection sensor group 12, 13
The presence or absence of malfunction of is detected.

The auxiliary drive means 24 will be described in detail later, but each drive circuit 14, 15 and armature coil 10, 1 is described.
2, or when an operation failure of the position detection sensor groups 12 and 13 is detected, the armature systems 4 and 5 are operated as much as possible to drive the electric motor 1. Then, in this case, the auxiliary drive means 24 includes the position detection sensor group 12,
A so-called sensorless motor controller 24a is provided so that the motor 1 can be driven even when any of the 13 malfunctions. The sensorless motor controller 24a is configured by a general-purpose IC or the like, and detects the induced voltage in each phase U, V, W of each armature coil 10, 11 via each drive circuit 14, 15. The relative rotational position of the armature coils 10 and 11 with respect to the magnet 8 (see FIG. 2) is detected.

Next, the operation of the electric vehicle will be described.

In FIG. 1, when an accelerator (not shown) of this electric vehicle is operated, the controller 2 causes the vehicle speed sensor 16, the rotation speed sensor 17 and the accelerator sensor 1 to operate.
The vehicle speed, the rotation speed of the electric motor 1, the operation amount of the accelerator and the amount of change thereof are detected via 8, and the required torque and the rotation speed of the electric motor 1 are obtained from the map or the like in accordance with these.

In parallel with this, the controller 2
Is obtained from a map or the like which is provided beforehand with the load of the electric motor 1 according to the amount of operation of the accelerator and the amount of change thereof, and the drive pattern (1) to drive the electric motor 1 according to the magnitude of the value of this load. ) To (4) is selected, and the electric motor 1 is driven to drive the electric traveling vehicle so as to satisfy the above required torque and rotational speed according to the drive pattern.

More specifically, referring to FIG.
Load increases or decreases almost in proportion to the required torque.
The controller 2 has drive patterns (1) to (4).
As a criterion for selecting the deviation, for example, three types of load thresholds
Value L₁~ L₃(L₁<L₂<L ₃) Is preset
Has been.

[0053] Then, the controller 2, the value of the load of the motor 1, when the load threshold L ₁ or less, select drive pattern (4), when L ₂ following load threshold L ₁ or more, the drive pattern ( 3) is selected and L is above the load threshold L ₂
When it is ₃ or less, the drive pattern (2) is selected, and when it is the load threshold L ₃ or more, the drive pattern (1) is selected.

That is, the controller 2 operates one of the armature systems 4 and 5, for example, the armature system 4 by the drive pattern (3) or (4) when the load is low (when the load threshold is less than L ₂ ). The energization control is performed to drive the electric motor 1. Further, even at the time of the low load, the electric motor 1 is driven by selectively using two control methods of full energization and pulse width modulation according to the magnitude of the load.

On the contrary, the controller 2 controls the energization of both the armature systems 4 and 5 by the drive pattern (1) or (2) at the time of high load (when the load threshold value is L ₂ or more). Drive the electric motor 1, and further, even at the time of this high load, full energization and pulse width modulation are performed depending on the size of the load.
The electric motor 1 is driven by selectively using one of the control methods.

In this case, as described above, the drive pattern
Although the output of the motor 1 decreases in the order of (1), (2), (3), and (4), the drive patterns (3) and (4) with relatively low output are used when the load is low. , It is possible to drive without hindrance, and at the time of high load, high output drive pattern (1),
Since (2) is used, it is possible to drive without hindrance. Then, as described above, the drive patterns (1), (2),
Since the electric power supplied to the electric motor 1 decreases in the order of (3) and (4), the power consumption of the battery 3 can be reduced especially when the load is low.

On the other hand, in FIG. 1, the controller 2 of the electric vehicle detects the presence or absence of malfunction of the drive circuits 14 and 15 and the armature systems 4 and 5 successively by the detection means 23 during traveling. In case of malfunction,
The auxiliary control means 24 drives the electric motor 1 as much as possible so as to travel.

This operation will be described below with reference to the flow chart of FIG. 5 while referring to FIG.

The outline of this operation will be described with reference to FIG. 1 and FIG.
Presence / absence of malfunction of each of the position detection sensor groups 12 and 13 is detected and determined, and further presence / absence of malfunction of each of the drive circuits 14 and 15 and each of the armature coils 10 and 11 paired therewith is detected and determined. To do.

Then, the main body of the controller 2 or
The auxiliary control means 24 drives the electric motor 1 as follows according to these determination results.

That is, first, each position detection sensor group 1
2, 13, each drive circuit 14, 15 and each armature coil 1
When both 0 and 11 are operating normally, the normal drive of the electric motor 1 is performed by the drive patterns (1) to (4) as described above. In this case, when driving the electric motor 1, one of the position detection sensor groups 12 and 13, for example, the position detection sensor group 12 is used.

When one of the position detection sensor groups 12 and 13 has a malfunction, the other is normal, and the drive circuits 14 and 15 and the armature coils 10 and 11 are normal, the normal position is detected. Only the detection sensor group 12 or 13 is used to drive the electric motor 1 normally by the drive patterns (1) to (4).

At least one of the position detection sensor groups 12 and 13 is normal, and the set of the drive circuit 14 and the armature coil 10 and the drive circuit 15 and the armature coil 11 are set.
When one of the two sets is malfunctioning and the other set is normal, the drive circuit 14, which is normal,
The motor 1 is driven by the drive patterns (3) and (4) using the set 15 and the armature coils 10 and 11, that is, using only one of the armature systems 4 and 5. In this case, as a matter of course, the combined drive of the armature systems 4 and 5 cannot be performed,
Therefore, the electric motor 1 is not driven by the drive patterns (1) and (2).

Further, when the position detection sensor groups 12 and 13 both malfunction and the drive circuits 14 and 15 and the armature coils 10 and 11 are normal, the sensorless motor controller 24a is used. , The electric motor 1 is driven by the drive patterns (1) to (4).

Further, the position detection sensor groups 12 and 13 both have malfunctions, and any one of the set of the drive circuit 14 and the armature coil 10 and the set of the drive circuit 15 and the armature coil 11 is set. When the other pair is normal, the drive circuits 14 and 15 that are normal are
And drive patterns (3) and (4) using the set of the armature coils 10 and 11 and the sensorless motor controller 24a.
The electric motor 1 is driven by.

In the drive using these sensorless motor controllers 24a, the position detection sensor group 1
Each drive pattern (1) ~
Although the output of (4) decreases slightly, basically the same output characteristics are obtained.

When any of the position detection sensor groups 12 and 13, the drive circuits 14 and 15 and the armature coils 10 and 11 has malfunctioned, a display device (not shown) or the like indicates the fact. The person is notified and the operation of the electric motor 1 is stopped.

The determination as to whether or not there is a malfunction in each of the position detection sensor groups 12 and 13 and the determination as to whether or not there is a malfunction in each of the drive circuits 14 and 15 and each of the armature coils 10 and 11 is specifically described. This is done as follows.

That is, the controller 2 drives the above-described electric motor 1 regardless of whether the armature systems 4 and 5 are used together or selectively.
The electric motor 1 is driven using one of the positions 2 and 13, for example, the position detection sensor group 12. During this driving, the detection means 23 constantly monitors the energizing currents of the drive circuits 14 and 15 and the armature coils 10 and 11 via the current sensors 19 and 20, and determines whether or not the energizing current is normal. To judge. When the determination result is "normal", the timing comparison of the detection signals of the position detection sensor groups 12 and 13, that is, the synchronism is further checked, and the detection signal of the position detection sensor group 13 detects the position. When it is not synchronized with that of the sensor group 12, it is determined that the position detection sensor group 13 is “abnormal”. Further, when the position detection sensor group 13 is synchronized, it is determined that the position detection sensor group 13 is “normal”.

On the other hand, when the result of the determination of the energized current is "abnormal", then the controller 2 drives the electric motor 1 by using the other position detection sensor group 13, and the same as above. , It is determined whether or not the energizing currents of the drive circuits 14 and 15 and the armature coils 10 and 11 are normal. When the determination result is "normal", it is determined that the position detection sensor group 12 is "abnormal".

When the above judgment result is "abnormal", each drive circuit 14, 15 and armature coil 1
By confirming the energization currents of 0 and 11 again, the correctness of the drive circuits 14 and 15 and the armature coils 10 and 11 is determined.

As described above, in this electric vehicle, the electric motor 1 is driven and can therefore travel as long as neither of the armature systems 4 and 5 malfunctions.

[0073]

As is apparent from the above description, according to the electric traveling vehicle of the present invention, the traveling electric motor having at least two armature systems is provided, and the load of the electric motor detected by the load detecting means is When it is large, both systems of the electric motor are driven together, and when the load of the electric motor is small, only one system of the electric motor is selectively driven, so that sufficient output characteristics necessary for traveling can be obtained according to the load of the electric motor. In addition, the electric power consumption of the electric motor can be reduced especially when the load is low, and the electric traveling vehicle having excellent traveling performance and energy efficiency can be provided.

Further, the combined drive of both systems of the electric motor and 1
In both cases of selective drive of the system, the electric power supplied to the electric motor is controlled to be large or small according to the size of the load on the electric motor, so that the electric motor can be driven with multiple types of drive patterns with different output characteristics and power consumption. Can be driven, and an efficient and appropriate electric motor can be driven according to the magnitude of the load.

Further, the presence or absence of malfunction of each system of the electric motor is detected by the detecting means, and when the malfunction of one system is detected, only the other system is driven by the auxiliary driving means. Even if one of the systems malfunctions, the other system can be driven to drive the electric vehicle without hindrance, and the electric vehicle will travel as much as possible even if the electric motor components malfunction. can do.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of a main part of an example of an electric vehicle of the present invention,

FIG. 2 is an explanatory sectional view of a traveling electric motor of the electric traveling vehicle,

FIG. 3 is an operation explanatory view of the traveling electric motor,

FIG. 4 is an operation explanatory view of the traveling electric motor,

FIG. 5 is a flowchart for explaining the operation of the electric vehicle,

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electric motor for traveling, 2 ... Controller (control means), 2
DESCRIPTION OF SYMBOLS 1 ... Load detection means, 22 ... Electric power control means, 23 ... Detection means, 24 ... Auxiliary drive means.

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[Procedure amendment]

[Submission date] October 15, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Delete

Claims (3)

[Claims] 1. A traveling electric motor having at least two armature systems, load detecting means for detecting a load of the electric motor, and drive control of the electric motor according to the magnitude of the load detected by the load detecting means. And a control means for operating the electric motor in combination when the load detected by the load detecting means is larger than a predetermined value.
An electric vehicle characterized in that when the load is smaller than a predetermined value, only one system of the electric motor is selected and driven. 2. The control means, in both cases of combined drive of both the systems and selection / drive of the one system,
2. The electric vehicle according to claim 1, further comprising a power control unit that controls the power supplied to the electric motor to be variable in magnitude depending on the magnitude of the load. 3. The control means detects the presence / absence of malfunction of each system, and an auxiliary drive for controlling only the other system when malfunction of one system is detected by the sensing means. The electric traveling vehicle according to claim 1, further comprising: