JP2000166008A - Electric vehicle controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a control system utilizing the self-readhesion characteristics of an induction motor in which the actual slip frequency of the induction motor is decreased when it is idling. SOLUTION: An electric vehicle controller comprises induction motors 7, 8 for driving a vehicle under control of a variable voltage variable frequency inverter 6 having output frequency being determined by adding or subtracting a slip frequency to or from the rotational frequency of the induction motor 7, 8 to be controlled, and a circuit 34 for selecting a minimum rotational frequency out of a value obtained by expressing a detected speed of an electric vehicle in terms of the rotational frequency of the induction motor and the rotational frequency of the induction motor to be controlled. The difference between the minimum rotational frequency and the rotational frequency of the induction motor to be controlled is inputted to a low-pass filter 36 and the output frequency of the inverter is determined by adding or subtracting a slip frequency to or from the rotational frequency of the induction motor 7, 8 from which the output value of the low-pass filter 36 is subtracted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vehicle control device for performing re-adhesion control using the self-re-adhesion characteristic of an induction motor when wheels of an electric vehicle idle or slide.

[0002]

2. Description of the Related Art FIG.
FIG. 1 is a configuration diagram of a conventional electric vehicle control device disclosed in Japanese Patent Application Publication No. 5 (JP-A) No. 5;
Is a current breaker, 4 is a filter reactor, 5 is a filter capacitor, and 6 is a VVVF (variable voltage variable frequency) inverter. Reference numerals 7 and 8 denote three-phase induction motors, and reference numerals 9 and 10 denote speed sensors for detecting the number of revolutions of the induction motor.

[0003] Current transformers 11 and 12 detect primary currents of the induction motors 7 and 8; 13 a speed calculation circuit;
5 is a fundamental wave current detection circuit, 16 is a maximum value detection (high priority) circuit, 17 is a powering command 24 and a brake command 25
, A current command generator for commanding a primary current value of the induction motor.

Reference numeral 18 denotes a current command Ip and a motor current maximum value I.
A comparison circuit for comparing the Max and calculating the deviation ΔI, and 19 is a current controller. Reference numeral 20 denotes a correction circuit for correcting the slip frequency set value fsp with the output of the current control system to obtain the slip frequency fs.

Reference numeral 21 denotes an addition / subtraction circuit for adding / subtracting the slip frequency fs to / from the rotation frequency fr of the motor. The addition / subtraction circuit 21 serves as an addition circuit during power running and a subtraction circuit during regenerative braking. 22 is f
r ± fs, that is, a modulation degree γ command circuit for outputting the motor voltage V with the inverter frequency fINV as an input.

[0006]

Since the conventional electric vehicle control device is configured as described above, when the wheels connected to the induction motor being controlled are simultaneously idle, the rotation frequency fr of the induction motor is reduced. Increases, and accordingly, the inverter frequency fINV and the modulation factor γ increase. That is, even when idling occurs, control is performed such that the slip frequency fs of the induction motor is kept constant and the output torque is kept constant. For this reason, it is necessary to detect the slipping at an early stage and to adopt a readhesion control for positively reducing the output Ip of the current command generator. This causes a problem that the output torque of the induction motor is reduced more than necessary during the slipping. there were.

[0007]

An electric vehicle control device according to the present invention includes an induction motor for driving a vehicle controlled by a variable voltage variable frequency inverter, and adds or subtracts a slip frequency to or from a rotation frequency of the induction motor to be controlled. In determining the inverter output frequency, the minimum rotation frequency is selected from the value obtained by detecting the electric vehicle speed and converting it to the rotation frequency of the induction motor and the rotation frequency of the induction motor to be controlled. The difference between the frequency and the rotation frequency of the controlled induction motor is input to the low-pass filter, and the slip frequency is added to or subtracted from the rotation frequency of the controlled induction motor minus the low-pass filter output value to determine the inverter output frequency. It was done.

In addition, a second variable voltage variable frequency inverter is connected in parallel to the variable voltage variable frequency inverter, and a minimum of the rotation frequency of the induction motor controlled by the second inverter and the rotation frequency of the controlled induction motor is controlled. A value is selected and input to a low-pass filter.

Further, a second minimum value is selected instead of selecting the minimum value.

As means for detecting the speed of the electric vehicle, A
It uses a speed sensor for TO operation.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 shows a configuration of an electric vehicle control device according to Embodiment 1 of the present invention. In the drawing, reference numerals 1 to 25 are the same as those of the conventional electric vehicle control device shown in FIG. 29 is a VVVF inverter 6
A second VVVF inverter connected in parallel with
Reference numeral 6 denotes a second inverter disconnector, 27 denotes a second inverter filter reactor, and 28 denotes a second inverter filter capacitor.

Reference numerals 30, 31 denote three-phase induction motors controlled by a second inverter, and reference numerals 32, 33 denote three-phase induction motors 30, 3
A speed sensor 34 for detecting the number of rotations of 1 is a minimum rotation frequency frmin among speed sensors 9, 10, 32 and 33.
Is a minimum value selection circuit for selecting.

35 is a subtraction circuit for subtracting the minimum rotation frequency frmin from the rotation frequency fr of the controlled induction motors 7 and 8 detected by the speed sensors 9 and 10, 36 is a low-pass filter, 37 is the controlled induction motor 7, In the subtraction circuit for subtracting the output of the low-pass filter 36 from the rotation frequency fr of No. 8, the slip frequency fs is added to or subtracted from the output signal fM by the addition / subtraction circuit 21 to determine the inverter frequency fINV.

Next, the operation will be described. When the wheels connected to the controlled induction motors 7 and 8 run idle, the rotation frequency fr increases. At this time, if the wheels connected to the induction motors 30 and 31 controlled by the second inverter 29 are not idling, the minimum rotation frequency frmin becomes equal to the rotation frequency of the induction motors 30 and 31 not idling. Subtraction circuit 3
The output fr-frmin of 5 is the difference between the rotational frequency of the induction motor that is idle and the rotational frequency of the induction motor that is not idle, and is equal to the increase in the rotational frequency due to the idle rotation of the induction motors 7 and 8 that are being controlled.

If the frequency characteristic of the low-pass filter 36 is set, for example, as shown in FIG. 2, the output fr of the subtraction circuit 35 for the increase in the rotational frequency during idling of about 1 Hz.
−frmin is input to the subtraction circuit 37 as it is.
Vibration components above z can be attenuated.
That is, for a change in the rotational speed of about 1 Hz such as a slip phenomenon, fM = fr- (fr-frmin) = frmin (the term (fr-frmin) is not attenuated by the low-pass filter 36), and When the steady-state value of the control frequency fM is
The rotation frequency is set to be equal to the rotation frequency frmin of the induction motor that is not idling. As a result, for the idling induction motor, the rotation frequency approaches the inverter frequency, the motor current decreases, and the motor torque decreases. That is,
Due to the self-adhesion property of the induction motor, torque is reduced,
The wheels connected to the induction motor re-adhere.

On the other hand, for a frequency vibration component of 10 Hz or more, fM = fr- (fr-frmin) = fr (the term (fr-frmin) is attenuated by the low-pass filter 36), and the induction motor 7 to be controlled. , 8 to determine the control frequency fM following the change in the rotation frequency fr. As a result, with respect to the component in which the rotation speed of the induction motor changes oscillatingly, the inverter frequency fINV is determined according to the movement of the rotation frequency fr, so that the slip frequency can be kept constant and the current vibration of the induction motor can be prevented. It is possible to do.

Referring further to FIG. 3, in region 1, when the rotational frequency fr of the induction motors 7 and 8 is oscillating at about 10 Hz, the inverter frequency fINV oscillates in the same phase. Then, control is performed so that the true slip frequency fINV-fr of the induction motor becomes constant. As a result, the current of the induction motor becomes constant, the output torque of the induction motor also becomes constant, the output torque of the induction motor also becomes constant, and the control system is prevented from vibrating at about 10 Hz.

In the region 2, when idling occurs and the rotation frequency fr of the induction motor being controlled becomes higher than the rotation frequency of the second induction motor, the subtraction circuit 35 reduces the component of about 1 Hz. The output fr -frmin of the above works effectively, and the value of the average inverter frequency fINV is
This is the rotation frequency of the induction motor that is not running idle. on the other hand,
Since the vibration component of about 10 Hz follows the movement of the rotation frequency fr of the induction motor being controlled, the true slip frequency fINV-fr of the induction motor decreases according to the amount of idling, and the induction motor at about 10 Hz. Current does not oscillate. Therefore, also in the region 2, the output torque does not vibrate at about 10 Hz, and only the current and the torque decrease according to the amount of idling.

As described above, the re-adhesion control utilizing the self-re-adhesion characteristic of the induction motor is realized by controlling the rotation frequency of the induction motor controlled by the second inverter using the output of the low-pass filter. be able to.

Embodiment 2 In the first embodiment, the minimum value selection circuit 34 is used to use the minimum number of rotations of the speed sensors 9, 10, 32, and 33. When the number is erroneously detected with a small value, the minimum value selection circuit 34 selects the wrong value, and the inverter frequency f _INV becomes abnormal. If a second minimum value selection circuit is used instead of this minimum value selection circuit to extract and use the second minimum rotation speeds of the speed sensors 9, 10, 32, and 33, one detected rotation speed is erroneously small. Even when the value is detected, the value is ignored, so that a highly reliable device can be realized.

Embodiment 3 In the first embodiment, the method of inputting the rotation frequency of the induction motor controlled by the second inverter to the minimum value selection circuit 34 has been described.
Instead, the same control can be realized by converting the output signal of another speed sensor for detecting the speed of the electric vehicle, for example, the speed sensor for ATO operation into the rotation frequency of the induction motor and inputting it to the minimum value selection circuit. be able to. in this case,
Since the second inverter can be omitted, the circuit can be simplified.

[0022]

As described above, according to the present invention, there is an effect that the re-adhesion control utilizing the self-re-adhesion characteristic of the induction motor for driving an electric vehicle can be realized.

In addition, since an existing device can be partially used, there is an effect that it can be realized with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an electric vehicle control device according to Embodiment 1 of the present invention.

FIG. 2 is a diagram illustrating frequency characteristics of the low-pass filter according to the first embodiment.

FIG. 3 is a diagram showing a change over time of an inverter frequency and an induction motor current according to the first embodiment.

FIG. 4 is a diagram showing a configuration of a conventional electric vehicle control device.

[Explanation of symbols]

1 DC overhead wire, 2 Pantograph, 3 Current breaker, 4 Filter reactor, 5 Filter capacitor,
6 VVVF inverter, 7, 8 3-phase induction motor,
9, 10 speed sensor, 11, 12 current transformer, 13 speed calculation circuit, 14, 15
Basic wave current detection circuit, 16 Maximum value detection (high priority) circuit, 17 Current command generator, 18
Comparison circuit, 19 current controller, 2
0 slip frequency correction circuit, 21 addition / subtraction circuit,
22 modulation degree γ command circuit, 24 power running command, 25 brake command, 26
A second inverter disconnector, 27 a second inverter filter reactor, 28 filter capacitors,
29 second inverter, 30, 31 three-phase induction motor controlled by second inverter, 32, 33 second
Speed sensor for detecting the number of revolutions of the induction motor, 34
Minimum value selection circuit, 35 subtraction circuit, 36
Low-pass filter, 37 subtraction circuit.

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[Procedure amendment]

[Submission date] December 27, 1999 (1999.12.
27)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claim 2

[Correction method] Change

[Correction contents]

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] Claim 4

[Correction method] Change

[Correction contents]

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

[0007]

An electric vehicle control device according to the present invention is mounted on an electric vehicle, and an invitation to drive the electric vehicle is provided.
Variable voltage to control conductive motive motor as controlled induction motor
Variable frequency inverter, this variable voltage variable frequency inverter
Electric vehicle control device for determining the output frequency of
The minimum rotation frequency is selected from the value obtained by converting the speed of the electric vehicle into the rotation frequency of the induction motor and the rotation frequency of the control target induction motor, and the difference between this minimum rotation frequency and the rotation frequency of the control target induction motor is determined by the low-pass method. Fill in the filter,
Low-pass filter based on the rotation frequency of the induction motor to be controlled
Yes by adding or subtracting a slip frequency to those obtained by subtracting the output value of the
The output frequency of the variable voltage variable frequency inverter is determined.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

In addition, a second variable voltage variable frequency inverter is connected in parallel to the variable voltage variable frequency inverter, and the rotation frequency of the induction motor controlled by the second variable voltage variable frequency inverter and the rotation frequency of the controlled induction motor are controlled. select the minimum rotation frequency from within, control and the minimum rotation frequency
The difference from the rotation frequency of the induction motor to be controlled is input to the low-pass filter, and the difference from the rotation frequency of the induction motor to be controlled is
The slip frequency is calculated by subtracting the output value of the
To the output frequency of the variable voltage variable frequency inverter.
The number is determined .

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

[0010] As electric vehicle speed, in which had use the output signal of the ATO operation for speed sensor.

Continued on the front page F term (reference) 5H115 PC02 PG01 PI03 PI29 PU09 PV09 QE14 RB11 RB22 RB24 SE03 TB02 TB10 TO12 TU07 TW07 5H572 AA01 BB10 CC01 DD03 EE03 FF10 GG04 HB09 HB20 HC08 JJ25 JJ26 JJ28 EE01 DD02 DD01 DD02 EE11 EE19 EE30 GG04 HB01 HB05 JJ25 JJ26 JJ28 LL01 LL22

Claims (4)

[Claims] 1. An electric vehicle control device comprising a vehicle driving induction motor controlled by a variable voltage variable frequency inverter, wherein a slip frequency is added to or subtracted from a rotation frequency of the controlled induction motor to determine an inverter output frequency. The minimum rotation frequency is selected from the value obtained by detecting the vehicle speed and converting it to the rotation frequency of the induction motor and the rotation frequency of the control target induction motor, and the minimum rotation frequency and the rotation frequency of the control target induction motor are selected. An electric vehicle control device, wherein the difference is input to a low-pass filter, and an inverter output frequency is determined by adding or subtracting a slip frequency to a value obtained by subtracting a low-pass filter output value from a rotation frequency of the induction motor to be controlled. 2. A variable voltage variable frequency inverter, wherein a second variable voltage variable frequency inverter is connected in parallel to the variable voltage variable frequency inverter, and a minimum of the rotation frequency of the induction motor controlled by the second inverter and the rotation frequency of the control target induction motor is controlled. 2. The electric vehicle control device according to claim 1, wherein a value is selected and input to a low-pass filter. 3. The electric vehicle control device according to claim 1, wherein a second minimum value is selected instead of selecting the minimum value. 4. ATO as means for detecting the speed of an electric vehicle
2. A driving speed sensor is used.
An electric vehicle control device as described in the above.