JP2001320802A - Device for controlling stalling torque of motor for driving electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the capability of escaping from a stalling state while suppressing the local heat generation of power devices including a motor for driving an electric vehicle or an inverter. SOLUTION: A searching value Ts of motor torque Tr is set in accordance with the opening of an accelerator Ac. When the searching value Ts is less than a second threshold torque Tr2, the value Ts is set to a target torque Tt. When the value Ts is more than the second threshold torque Tr2 and located in a second torque range β, the target torque Tt is fixed to the second threshold torque Tr2. When the value Ts exceeds a third threshold torque Tr3, a timer starts counting to set the value Ts to the target torque Tt. A torque command *T is set in such a way that an output torque Tout reaches the target torque Tt in steps gradually. When a given period of time elapses in the timer counting in the state that the output torque Tout is exceeding the second threshold torque Tr2, the target torque Tt is set to a given torque of less than the second threshold torque Tr2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stall torque control device for an electric vehicle running motor, and more particularly to a technique for escaping from a stall state.

[0002]

2. Description of the Related Art Conventionally, for example, an electric vehicle equipped with a permanent magnet type three-phase AC motor (commonly referred to as a DC brushless motor) using a permanent magnet as a field motor as a traveling motor, In the case where the motor is stopped by applying a motor torque that is not enough, that is, in a stall state in which the traveling motor is almost stopped despite the motor torque being applied, the current is applied only to the winding of the specific phase. Flows. In this case, among a plurality of switching elements including a semiconductor device or the like constituting the inverter, only a switching element corresponding to a specific phase of the motor is turned on, and a current is supplied to the motor via this switching element. For this reason, there is a problem that heat generated when current is supplied to the windings of the motor and the inverter concentrates on the windings of the specific phase and the specific switching elements. In order to solve such a problem, for example, when the stall state continues beyond the allowable time, as in the drive control device for an electric vehicle disclosed in Japanese Patent Application Laid-Open No. 7-336807, 2. Description of the Related Art A drive control device of an electric vehicle that performs a torque reduction process for protecting a power circuit such as an inverter and limits a retreat speed of a vehicle when performing a torque command reduction control is known.

[0003]

By the way, in a drive control device for an electric vehicle according to an example of the above-mentioned prior art,
Since the torque reduction process is only performed when the stall state continues beyond the allowable time, in order to improve the climbing ability of the vehicle, for example, the capacity of the switching element constituting the inverter and the heat resistance limit are increased, It is necessary to improve the performance of the cooling device that cools the inverter. However, in this case, there arises a problem that the size of the device is increased and the manufacturing cost of the device is increased. In addition, if the peak value of the current supplied to the motor is suppressed, the maximum current flowing to one switching element is reduced, and the heat generated by the switching element can be reduced. This causes a problem that the predetermined value cannot be obtained because the value is reduced. The present invention has been made in view of the above circumstances, and suppresses local heat generation of a power device such as a driving motor or an inverter, and improves an ability to escape from a stall state. It is an object to provide a stall torque control device.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and achieve the object, a stall torque control device for an electric vehicle running motor according to the present invention according to the first aspect of the present invention comprises: For example, for a vehicle including a motor 11 according to the embodiment described below, a speed change of the vehicle according to the rotation speed of the motor (for example, the rotation speed N according to the embodiment described later) is predetermined. A stall detecting unit (for example, a torque control mode determination unit 21 in the present embodiment described later) that detects a stall state that is equal to or less than a value, and an accelerator opening (for example, an accelerator opening Ac in the present embodiment described later). Required torque setting means (for example, a torque control mode determination in the present embodiment described later) for setting a required torque (for example, a search value Ts of the motor torque Tr in the present embodiment described later) based on A target torque calculating means for calculating a target torque (for example, a target torque Tt in the present embodiment described later) with respect to an output torque (for example, an output torque Tout in the present embodiment described later) of the motor. (For example, a target torque calculation unit 22 in the present embodiment described later) and a case where the stall detection unit detects the stall state, and the required torque is a predetermined first torque threshold value (for example, described later). When the target torque is equal to or more than the second threshold torque Tr2 in the present embodiment and equal to or less than a predetermined second torque threshold (for example, a third threshold torque Tr3 in the present embodiment described later), the target torque is set to the first torque threshold. A target torque correction unit (for example, described later) that sets the required torque to the target torque when the required torque exceeds the predetermined second torque threshold. It is characterized in that a target torque correcting unit 24) in this embodiment.

According to the stall torque control device for an electric vehicle running motor having the above-described configuration, for example, a stall state occurs when the vehicle starts on an uphill, that is, a state in which the motor cannot rotate and continues to energize a winding of a specific phase. For example, current continues to flow in a specific power device that constitutes an inverter that outputs AC power for driving a motor, and local heat is generated in the specific phase (winding) of the motor and the power device. For this heat generation, an allowable stall time is set according to the motor torque so that, for example, a power device such as an inverter does not overheat. Here, for example, when the accelerator opening is increasing, if the required torque calculated by, for example, a map search or the like based on the accelerator opening is continuously set to the target torque set for the output torque of the motor. However, the permissible stall time gradually decreases. Then, before the motor torque required to escape the stall state is obtained, the time required for a series of processing until the required torque is set according to the driver's accelerator operation and the accelerator opening is the stall allowable time. The power device such as a motor winding or an inverter is overheated, or an appropriate overheat protection process is activated, for example, the target torque is reduced and the stall condition can be escaped. Disappears.

On the other hand, when the required torque is equal to or more than the predetermined first torque threshold and equal to or less than the predetermined second torque threshold, the target torque is fixed to the first torque threshold, so that the allowable stall time is set. By preventing the power device such as the inverter from being overheated by preventing the power device from becoming short, it is possible to maintain the stop state (hill hold state) when climbing a slope. When the required torque exceeds a predetermined second torque threshold, the required torque is set to the target torque, and the output torque is set within a relatively short time than the stall allowable time corresponding to the required torque. So that the motor torque reaches a target torque. If the output torque at this time exceeds the motor torque required to escape from the stall state, it is possible to escape from the stall state, and the current starts to alternate again and the energized phase is switched. The current is prevented from being concentrated on a specific phase, and the generation of local heat can be suppressed. That is, the power device such as a motor or an inverter becomes overheated without increasing the size of the device or increasing the manufacturing cost of the device as compared with a case where the heat resistance performance, the cooling performance, and the like of the power device such as an inverter are increased. In this way, the ability to escape from the stalled state can be improved while preventing such a situation.

Further, in the stall torque control device for an electric vehicle running motor according to the present invention, when the required torque is set to the target torque by the target torque correcting means, the output torque is reduced. Torque delay means for setting a predetermined delay time so as to reach the target torque according to a predetermined function form relating to time (for example, a step shape in the present embodiment described later) (for example, a torque delay in the present embodiment described later) (Part 25).

According to the stall torque control device for an electric vehicle traveling motor having the above configuration, for example,
Since the output torque is set to reach the target torque according to a predetermined function form with respect to time, it is possible to prevent a sudden change in the behavior of the vehicle and escape from the stall state without impairing drivability. Ability can be improved.

Further, according to a third aspect of the present invention, there is provided a stall torque control device for an electric vehicle traveling motor according to the present invention, wherein when the output torque exceeds the predetermined first torque threshold for a predetermined time or more, It is characterized by including a torque limiting means (for example, a torque limiting unit 26 in the present embodiment described later) for setting at least a predetermined torque equal to or less than the predetermined first torque threshold to the target torque.

[0010] According to the stall torque control device for an electric vehicle traveling motor having the above-described configuration, the output torque is set to the predetermined first torque.
When the state exceeding the torque threshold continues for a predetermined time or more,
That is, even if a large motor torque is output in a relatively short time, if the vehicle cannot escape from the stall state due to, for example, a steep slope or a curb, the target torque is reduced and the motor, the inverter, etc. To prevent the power device from being overheated.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a stall torque control device for an electric vehicle running motor according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a configuration diagram of a stall torque control device 10 for an electric vehicle running motor according to an embodiment of the present invention, FIG. 2 is a configuration diagram of an inverter shown in FIG. 1, and FIG. FIG. 3 is a functional block diagram of a stall torque control device for a motor for driving an automobile. The stall torque control device 10 for an electric vehicle traveling motor according to the present embodiment drives and controls a motor 11 (permanent magnet type three-phase AC motor) mounted on an electric vehicle as a traveling motor, for example. The motor 11 is, for example, a permanent magnet type three-phase AC synchronous motor that uses a permanent magnet as a field. As shown in FIG. 1, a stall torque control device 10 for an electric vehicle traveling motor includes a motor 11, an inverter 12,
3 and a motor ECU 14.

The inverter 12 is, for example, a PWM inverter, and includes a switching element such as an IGBT. Then, the inverter 12 converts DC power supplied from a power supply 13 composed of, for example, a battery or a fuel cell, into three-phase AC power, and supplies the three-phase AC power to the motor 11. For example, as shown in FIG.
Six power device of BT, such as ^{U +, U -, V +} , V -, W
^+, W ^- are constituted by bridge connection of 3 arms, these power devices U ^+, ..., W ^- is by being switched by the gate control, the motor 11 from the DC power inputted from a power source 13 AC power for driving is obtained. The power devices U ⁺ ,
.., W ⁻ are switched by applying a predetermined drive pulse to a gate for switching.

In the inverter 12 composed of these power devices U ⁺ ,..., W ⁻ , a device on the positive side of one arm and a device on the negative side of the other arm (for example, FIG.
To indicate power device U ⁺ and power devices W ^-) and the was ON at the same time, three-phase windings (U-phase of the motor 11, V-phase,
(W phase). Further, based on the rotation speed N output from the rotation speed detection unit 15 provided in the motor 11,
By moving the arm through which the current flows, the motor 11 is rotated to generate a driving force.

The motor ECU 14 controls the power conversion operation of the inverter 12, and outputs U
Phase AC voltage command values of the V-phase and W-phase
2 to output the U-phase current, the V-phase current, and the W-phase current corresponding to these voltage command values from the inverter 12 to each phase of the permanent magnet AC motor 11. For this reason,
The motor ECU 14 includes a signal of a rotation speed N output from a rotation speed detection unit 15 provided in the motor 11 and an accelerator opening detection unit that detects an accelerator opening Ac related to, for example, an accelerator pedal operation amount by a driver. 16 and the shift position Sp (for example, D range, R
Range, etc.) and a phase current detector 18 for detecting AC currents Iu, Iv, Iw supplied to each phase between the inverter 12 and the permanent magnet AC motor 11. , The signal of the power supply voltage Vc output from the inverter voltage detector 19 provided in the power supply 13, and the actual rotation direction Rd output from the actual rotation direction detector 20 provided in the motor 11. Signal is input.

As shown in FIG. 3, the motor ECU 14
Torque control mode determination unit 21 and target torque calculation unit 22
Stall protection unit 23, target torque correction unit 24,
It comprises a torque delay unit 25, a torque limiting unit 26, and a motor torque control unit 27.

The torque control mode judging section 21 generates a signal of the rotational speed N detected by the rotational speed detecting section 15, a signal of the accelerator opening Ac detected by the accelerator opening detecting section 16, and the actual rotation direction. The torque control mode is determined based on the signal in the actual rotation direction Rd detected by the detection unit 20. For example, it is determined whether the mode is a torque control mode during a stall or a normal torque control mode other than a stall. The target torque calculation unit 22 calculates a target torque Tt by searching a map of, for example, a predetermined torque map based on the determination result of the torque control mode determination unit 21 and signals of the rotation speed N and the accelerator opening Ac. .

As will be described later, the stall protection unit 23
Stall protection is performed based on the target torque Tt calculated by the target torque calculation unit 22 and the rotation speed N. That is, for example, the target torque Tt calculated by the map search
Is in the predetermined torque region beyond the predetermined threshold torque, a command is issued to set the predetermined threshold torque to the target torque Tt without setting the value searched in the map as the target torque Tt. The target torque correction unit 24 corrects the target torque Tt calculated by the target torque calculation unit 22 based on a command from the stall protection unit 23, and sets the corrected target torque Tt to a new target torque. Torque Tt
Output as

The torque delay unit 25 sets a predetermined delay time for the torque command * T so that the output torque Tout generated by the motor 11 reaches the target torque Tt according to a predetermined function such as a step function. . For example, when a torque equal to or greater than a predetermined value is output for a predetermined time, the torque limiting unit 26 limits the torque command * T so that the output torque Tout becomes equal to or less than the predetermined torque. The motor torque control unit 27 determines a current command value corresponding to the torque command * T and the AC current I detected by the phase current detection unit 18.
Based on the deviation from the current measurement values for u, Iv, and Iw, the motor 11 is controlled by feedback control such as PI operation.
The respective voltage command values for the phase voltages supplied to the respective phases are calculated. Each of these voltage command values is, for example, IGB
A switching command (inverter command) is input to an inverter 12 including a switching element such as T, and AC power for driving the motor 11 is output from the inverter 12 according to the switching command.

The stall torque control device 10 for an electric vehicle running motor according to the present embodiment has the above-described configuration. Next, the operation of the stall torque control device 10 for an electric vehicle running motor, particularly when the stall torque Will be described with reference to the accompanying drawings. FIG. 4 is a flowchart showing the operation of the stall torque control device 10 for the electric vehicle traveling motor, FIG. 5 is a flowchart showing the stall torque control process shown in FIG. 4, and FIG. FIG. 7 is a graph showing motor torque Tr and behavior of a vehicle,
FIG. 7 is a graph showing the relationship between the motor torque Tr, the ascending and descending slope speed V of the vehicle and the stall allowable time T _limit after a predetermined time from the start of the ascent and descent.

First, in step S01 shown in FIG. 4, based on the rotation speed N of the motor 11, the actual rotation direction Rd, and the accelerator opening Ac, the stall state, that is, the motor 1
It is determined whether or not the vehicle is almost stopped even though a torque command * T that is equal to or greater than a predetermined value is given to 1. If this determination result is “NO”,
In step S02, normal torque control, for example, a predetermined torque map is searched to set a target torque Tt, and then the process proceeds to step S04.

On the other hand, if the determination result in step S01 is "Y
In the case of "ES", torque control during stall described later is performed, and the process proceeds to step S04. In step S04, a torque command * T for causing the motor 11 to generate the calculated target torque Tt is output, and the series of processing ends.

Hereinafter, the torque control process at the time of stall in step S03 will be described with reference to the accompanying drawings. First, as described above, when it is determined in step S01 that the vehicle is in the stall state, the process proceeds to step S11, for example, the accelerator opening Ac
Based on the above, a predetermined torque map is searched for a map and a search value Ts of the motor torque Tr (for example, a dotted line T shown in FIG. 6).
s), and the search value Ts is set to a predetermined second threshold torque T
It is determined whether or not the vehicle is located in a second torque region β set by r2 and the third threshold torque Tr3 (for example, a region β shown in FIGS. 6 and 7, where Tr2 <Tr3). If this determination result is “NO”, that is, the motor torque Tr
The search value Ts does not exceed the predetermined second threshold torque Tr2, for example, a first torque region α set by the predetermined first threshold torque Tr1 and the second threshold torque Tr2 (for example, FIG.
And the area α shown in FIG. However, Tr1 <Tr2) or a region exceeding a predetermined third threshold torque Tr3, for example, a third torque region γ set by the predetermined third threshold torque Tr3 and the fourth threshold torque Tr4 (for example, FIGS. 6 and 7). 7, when Tr3 <Tr4), the search value Ts of the motor torque Tr is set to the target torque T
t (for example, a two-dot broken line Tt shown in FIG. 6), and the process proceeds to step S14 described later.

Each of the threshold torques Tr1,..., Tr4 and each of the torque regions Trα, Trβ, Trγ are set based on, for example, an allowable stall time T _limit as shown in FIG. _limit (solid line T _limit shown in FIG. 7) is the motor torque T in the stall state.
The allowable time (stall toughness) is set so that the local heat generated in the motor 11, the inverter 12, and the like stays within a predetermined allowable range and does not reach an overheat state in accordance with r. The stall permissible time T _limit is set to a predetermined constant time in a torque region equal to or less than the second threshold torque Tr2, for example, and is gradually set according to a predetermined function form in a torque region exceeding the second threshold torque Tr2. Is set to be shorter.

FIG. 7 shows three different uphill gradients θ.
1, θ2, θ3 (θ1 <θ2 <θ3), the ascending and descending slope speed V and the motor torque T after a predetermined time from the start of the ascending and descending slope.
The relationship with r is shown. Here, a dotted line θ shown in FIG.
1, θ2, θ3 indicate a change between the motor torque Tr and the downhill speed Vd, and two-dot broken lines θ1, θ2, θ3 indicate a change between the motor torque Tr and the uphill speed Vu,
For example, for the uphill gradient θ1, the region of TrD ≦ Tr ≦ TrU corresponds to the stall state with respect to the motor torque TrD at the downhill speed Vd = 0 and the motor torque TrU at the uphill speed Vu = 0. For example, at a slope gradient θ1,
A relatively long stall allowable time T _limit is also set for the motor torque Tr required to obtain a relatively large uphill speed Vu. On the other hand, for example, at the uphill gradient θ3, a relatively short stall allowable time T _limit is set for the motor torque Tr required to maintain the stall state, and the uphill speed Vu exceeding zero is set. Motor torque Tr required to obtain
, The allowable stall time T _limit becomes extremely short.

On the other hand, if the determination result in step S11 is "Y
ES ”, that is, the search value of the motor torque Tr is the second
If it is located in the torque region β, a predetermined second threshold torque Tr2 is set as the target torque Tt, and the process proceeds to step S14. In step S14, the torque command * T is set such that the output torque Tout (for example, the solid line Tout shown in FIG. 6) actually generated by the motor 11 gradually reaches the target torque Tt according to a predetermined function such as a step-like function.
To perform delay processing.

Then, in a step S15, it is determined whether or not the output torque Tout is larger than a predetermined second threshold torque Tr2. If the result of this determination is "NO", the flow proceeds to step S16, where the count of the timer is reset, and the processing of step S20 and thereafter, which will be described later, is performed.
On the other hand, if the decision result in the step S15 is "YES", the process proceeds to a step S17 to determine whether or not the count of the timer is within a predetermined time. The result of this determination is “YE
In the case of "S", the process proceeds to step S18, where the count of the timer is continued, and the processes from step S20 described below are performed. On the other hand, the determination result in step S17 is “NO”
In the case of, the process proceeds to step S19, in which the target torque Tt is set to a predetermined torque at least equal to or less than the second threshold torque Tr2, and then proceeds to step S20. In step S20, a torque command * T for causing the motor 11 to output the target torque Tt is set, and the series of processing ends.

That is, as shown in FIG. 6, for example, on a slope having a certain slope, in the process of going uphill from a downhill state through a stall state with an increase in the accelerator opening Ac, the accelerator is first opened. The search value Ts of the motor torque Tr is synchronized with the change of the degree Ac.
(Dotted line Ts shown in FIG. 6) is set. Until the search value Ts becomes equal to the predetermined second threshold torque Tr2, the search value Ts is set to the target torque Tt, and the motor 1
The torque command * T is set so that the output torque Tout to be generated at 1 becomes equal to the target torque Tt.

When the search value Ts exceeds the second threshold torque Tr2 and is located in the second torque region β, the target torque Tt is fixed to the second threshold torque Tr2, and the output is fixed. The torque command * T is set so that the torque Tout becomes equal to the second threshold torque Tr2. Further, when the search value Ts exceeds a predetermined third threshold torque Tr3 (see FIG. 6).
At time t1), the timer starts counting and sets the search value Ts to the target torque Tt. However, in this case, the torque command * T is set so that the output torque Tout does not suddenly become equal to the target torque Tt but gradually reaches the target torque Tt, for example, in a step-like manner. After the timer counts a predetermined time in a state where the output torque Tout exceeds the predetermined second threshold torque Tr2, the target torque Tt is at least equal to or less than the second threshold torque Tr2 regardless of the search value Ts. Set the specified torque.

As described above, according to the stall torque control device 10 for an electric vehicle running motor according to the present embodiment, for example, the local heat generated in the motor 11, the inverter 12, and the like remains within a predetermined allowable range, and Even in a torque region where the predetermined stall allowable time T _limit set so as not to reach the _limit , the escape ability from the stall state can be improved without exceeding the stall allowable time T _limit. Can be. That is, even if the stall allowable time T _limit is gradually shortened in the torque region in the stall state, for example, as in the case of the uphill gradient θ3 shown in FIG. 7, the search value Ts of the motor torque Tr becomes the second torque. while located in the region β, since the target torque Tt is fixed to the second threshold torque Tr2, never stall allowable time T _{li mit} becomes shorter,
For example, it takes too much time to reach the motor torque Tr required for climbing the vehicle, and the stall allowable time T _limit
To prevent the motor 11 and the inverter 12 from being overheated, and to prevent problems such as the target torque Tt being reduced by appropriate protection processing to make it impossible to climb a hill. .
As a result, as compared with a case in which the stall toughness is improved by increasing the capacity, heat resistance performance, cooling performance, etc. of the inverter 12, for example, the device can escape from the stall state without increasing the size of the device or increasing the manufacturing cost of the device. Ability can be improved.

Further, when the search value Ts of the motor torque Tr exceeds the third threshold torque Tr3, the target torque Tt is set to the search value Ts within a relatively short time. Stall allowable time T for Ts
_{Even if the limit} is a short value, it is possible to surely escape from the stall state. For this reason, for example, compared with the case where the search value Ts of the motor torque Tr is always set to the target torque Tt and the torque command * T is set so that the output torque Tout becomes equal to the target torque Tt, the state from the stall state is reduced. The escape ability can be improved, and the amount of local heat generated in the motor 11, the inverter 12, and the like can be reduced to prevent an overheating state. Furthermore, when the search value Ts of the motor torque Tr exceeds the third threshold torque Tr3 and the search value Ts is set to the target torque Tt, the output torque Tout gradually increases in accordance with a predetermined function such as a step-like function. Since the torque command * T is set so as to reach the target torque Tt, it is possible to prevent an abrupt change in the behavior of the vehicle and to improve the climbing ability without impairing the drivability.

Further, when the output torque Tout is the predetermined second
When the threshold torque Tr2 is exceeded, the timer counts
After a lapse of a predetermined time, regardless of the search value Ts,
The target torque Tt is not less than at least the second threshold torque Tr2.
In order to set the specified torque,
Stall allowable time T
_limitIf you cannot escape from the stall state within
To prevent the motor 11 and inverter 12 from overheating.
Can be stopped.

In the present embodiment, the stall state is, for example, a state in which the vehicle is almost stopped when climbing a hill. However, the present invention is not limited to this. There may be.

[0033]

As described above, according to the stall torque control device for an electric vehicle running motor of the present invention, the heat resistance performance and the cooling performance of a power device such as an inverter are increased. As compared with the case, it is possible to prevent a power device such as a motor or an inverter from being overheated and to improve the ability to escape from a stall state without increasing the size of the device or increasing the manufacturing cost of the device. . Further, according to the stall torque control device for an electric vehicle traveling motor according to the second aspect, it is possible to prevent a sudden change in the behavior of the vehicle and to escape from the stall state without impairing drivability. Ability can be improved. Further, according to the stall torque control device for an electric vehicle traveling motor according to claim 3,
If the vehicle cannot escape from the stall state, the target torque can be reduced to prevent the power devices such as the motor and the inverter from being overheated.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a stall torque control device for an electric vehicle traveling motor according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of the inverter shown in FIG.

FIG. 3 is a functional block diagram of the stall torque control device for the electric vehicle running motor shown in FIG. 1;

FIG. 4 is a flowchart showing the operation of the stall torque control device for the electric vehicle running motor shown in FIG. 1;

FIG. 5 is a flowchart showing a process of a stall torque control shown in FIG. 4;

FIG. 6 is a graph showing a motor torque Tr and a behavior of a vehicle with respect to a driver's accelerator operation.

FIG. 7 shows a motor torque Tr, an ascending and descending slope speed V of a vehicle and a permissible stall time T after a predetermined time from the start of the ascent and descent.
It is a graph which shows the relationship with _limit .

[Explanation of symbols]

Reference Signs List 10 Stall torque control device for electric vehicle traveling motor 11 Motor (permanent magnet type three-phase AC motor) 21 Torque control mode determination unit (stall detection unit, required torque setting unit) 22 Target torque calculation unit (target torque calculation unit) 24 Target torque correction unit (target torque correction unit) 25 Torque delay unit (torque delay unit) 26 Torque limiting unit (torque limiting unit)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H115 PA01 PA08 PC06 PG04 PI16 PI18 PU10 PU11 PV09 PV23 QE04 QN03 QN12 QN27 RB22 SE01 SE03 TB01 TO12 TO13 TO21 TO30

Claims (3)

[Claims] 1. A stall detecting means for detecting a stall state in which a speed change of the vehicle according to the number of revolutions of the motor is equal to or less than a predetermined value, for a vehicle having a motor for driving an electric vehicle; Request torque setting means for setting a required torque based on the degree; target torque calculation means for calculating a target torque for the output torque of the motor; and a stall state detected by the stall detection means, When the required torque is equal to or more than a predetermined first torque threshold and equal to or less than a predetermined second torque threshold, the target torque is set to the first torque threshold, and the required torque exceeds the predetermined second torque threshold. And a target torque correction means for setting the required torque to the target torque. Control device. 2. A predetermined delay time is set so that when the required torque is set to the target torque by the target torque correction means, the output torque reaches the target torque according to a predetermined function form with respect to time. The stall torque control device for an electric vehicle traveling motor according to claim 1, further comprising a torque delay unit that performs the operation. 3. A torque limit for setting the target torque to a predetermined torque at least equal to or less than the predetermined first torque threshold when the output torque exceeds the predetermined first torque threshold for a predetermined time or more. 3. The stall torque control device for an electric vehicle running motor according to claim 1, further comprising means.