JP2787499B2 - Electric car control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an inverter control device for controlling a main motor of an electric vehicle, and in particular, quickly re-adheses when wheels of an electric vehicle run idle or slide. The present invention relates to a suitable electric vehicle control device.

[Conventional technology]

In a conventional inverter-controlled electric vehicle, the amount of change in the main motor rotation frequency Fr with respect to a minute time, that is, the differential value dFr / dt is constantly monitored, and when the value exceeds a predetermined range, it is considered that slipping / sliding has occurred. , And output a slip / slide detection signal.

When slipping / sliding occurs, the adhesive force between the wheels and the rails becomes smaller than the torque of the main motor, so if left as it is, the slipping / sliding becomes larger and the acceleration / deceleration required by electric vehicles cannot be obtained. Not only that, in severe cases, it causes damage such as uneven wear of the drive system and wheels. Therefore, it is necessary to reduce the torque of the main motor promptly to eliminate idling and sliding, and to re-adhere the wheels.

As shown in FIG. 3, the frequency versus torque and current characteristics of the induction motor used as the main motor are reduced by reducing the slip frequency Fs as shown in FIG.

Utilizing this characteristic, a conventional technique for re-adhesion is described in the literature "Electric Vehicle Science", 207 series commuter DC trains (upper and lower), February and March 1987. As described above, in the event of slipping / sliding, the slip frequency Fs, which is the difference between the inverter control frequency Finv and the main motor rotation frequency Fr, was reduced to reduce the torque of the main motor and re-adhesive the wheels. Later, by increasing the reduced slip frequency Fs at a fixed rate to a value before the occurrence of slip and gliding, the torque of the main motor was restored while preventing re-slip and gliding.

[Problems to be solved by the invention]

In the above prior art, when slipping / sliding is detected, the slip frequency Fs is reduced to reduce the current of the main motor, thereby reducing the torque of the main motor.

In general, in an inverter-controlled electric vehicle, a single inverter drives a plurality of main motors, and FIG. 4 shows an example in which four main motors are driven. Considering the case where a wheel that engages with one of the four main motors for some reason causes the torque or the rotation speed to protrude beyond the other and causes a slight slip or gliding below the detection level, Since the load has become lighter, the current flowing through the main motor decreases. FIG. 5 shows the state at that time. Main motor control is 1
The total value of the currents of the four main motors driven by one inverter is detected and always matches the predetermined current pattern. As the control system increases the total main motor current in an attempt to recover to the current pattern before the decrease, the other main motor currents that have not caused idling / sliding increase, increasing the torque and causing idling / sliding. It triggers the trigger and finally drives with one inverter 4
All the main motors of the units slip and slide.

In addition to the above, all other causes of wheel slipping / sliding can be caused by groundwater falling on the rails in the tunnel, dampening the rail surface, or exuding the oil film on the rail surface with the rail oiler. This is due to the decrease in the coefficient of adhesion between the rails.

In the above prior art, consideration is given to a state in which all the shafts of wheels engaged with four main motors driven by one inverter slip and slip and the main motor rotation frequency Fr does not reach the reference speed. No, inverter control frequency Finv
There is a problem that the self-adhesiveness of the induction motor in which the slip frequency Fs, which is the difference between the rotation frequency Fr of the induction motor and the main motor, is reduced to reduce the torque of the main motor and re-adhesive the wheels, does not function. In other words, the self-adhesiveness of the conventional induction motor is based on the following technology. In the control system, Finv = Fr + Fs (1) At the time of regenerative braking, Finv = Fr-Fs (2) The inverter control frequency Finv output from the inverter control device is obtained by the arithmetic expression. At this time, if the main motor rotation frequency Fr used for control is not in the idling / sliding state and is the same as the speed of the electric vehicle, the inverter control frequency Finv becomes the main motor rotation frequency Fr value. As shown in FIGS. 3 and 5, the acceleration and deceleration of the wheels in the idling / sliding state are larger than those of the electric vehicle, so the control system operates so as to reduce the slip frequency Fs, and the main motor torque decreases. So it easily re-adheses. The conventional technology also utilizes this self-adhesive property, and when the power is high, the minimum value among the four main motor rotation frequencies is
At the time of regenerative braking, the maximum value is selected as the reference speed, and is used for Fr in the above equations (1) and (2). However, if all the wheels spin or slide, no matter whether the minimum value during powering or the maximum value during regenerative braking is selected, the vehicle is still in the slipping or sliding state and cannot be the reference speed, and such Fr and slip frequency Fs , The correct inverter control frequency Finv cannot be obtained, and it is difficult to perform control that reduces the torque of the main motor.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide an inverter control device for performing re-adhesion control during idling and sliding of an electric vehicle.

[Means for solving the problem]

The above object is achieved by detecting a rotation speed of an induction type main motor of an electric vehicle and outputting a main motor rotation frequency signal, and calculating an inverter control frequency from the input main motor rotation frequency signal and slip frequency. And an inverter for inputting the inverter control frequency and controlling the main motor, the inverter control means for inputting the inverter control frequency and controlling the main motor. An idling / sliding detecting means for detecting and outputting an idling / sliding signal; and, when the idling / sliding signal is input, the main motor speed signal is used to detect a main motor rotation of another electric vehicle which is traveling normally. And a first main motor rotation frequency signal switching means for switching to a frequency signal.

The above object is achieved when the main motor rotation frequency signal switching means is switching to the main motor rotation frequency signal from the other electric vehicle, and the other electric vehicle causes a slip / slide, and the slip / slide signal is input. This is achieved by having a second main motor rotation frequency signal switching means for switching the main motor rotation frequency signal from the another electric vehicle to a main motor rotation frequency signal of another electric vehicle.

[Action]

According to the above configuration, when the rotation speed detecting means detects the rotation speed of the induction type main motor connected to the wheels of the electric vehicle and outputs the main motor rotation frequency signal, when some of the wheels spin or slip, The idling / sliding detecting means detects the idling / sliding of the wheel from the change of the main motor rotation frequency signal and outputs the idling / sliding signal, and the first main motor rotation frequency signal switching means outputs the idling / sliding signal. When input, the main motor rotation speed signal is switched to a main motor rotation frequency signal output by another electric vehicle that is not in the idling / sliding state, and the main motor rotation frequency that is not in the idling / sliding state is added as a reference speed. By reducing the frequency and setting the inverter control frequency, the main motor rotation frequency and the inverter control frequency become almost equal, and the power supply frequency output by the inverter and the main motor Translocation frequency difference becomes smaller. As a result, the slippage of the main motor is reduced, the output torque of the main motor is reduced, and the rotational speed is close to a normal speed that is not in a slipping / sliding state. It is possible to prevent sticking and spreading of other wheels to a slipping / sliding state.

Also, when another electric vehicle that is not in the idle / sliding state selected as the reference speed falls into the idle / sliding state, the main motor rotation frequency signal output by the inverter control device of the other electric vehicle that is not in the idle / sliding state is further output. By switching, re-adhesion can be achieved as described above.

〔Example〕

 Embodiments of the present invention will be described with reference to the drawings and tables.

FIG. 1 is a block diagram of the inverter control device used in the present embodiment.

The output of a motor speed detector 1 for detecting a plurality of main motor speeds of the electric vehicle is input to a minimum value selector 2, a maximum value selector 3, and a slip / slide detector 13. Since the possibility of idling is high when the number of rotations is high during the running, the minimum value selection unit 2
The output of the maximum value selection unit 3 is selected by the changeover switch 4 as the main motor rotation frequency signal Fr _{1 because} the output of the maximum value selection unit 3 is low in the number of rotations at the time of regeneration because the possibility of sliding is high. The output of the changeover switch 4 is connected to one input of the changeover switch 5. The other input of the changeover switch 5 uses the main motor rotation frequency signal Fr ₂ output from the inverter control device of the vehicle immediately before the last train of the same train, which is not the vehicle, as the reference speed. rearmost vehicle inverter control apparatus using the traction motor rotational frequency signal Fr ₃ yet another vehicle that same organization of the train in preparation for the slipping-sliding occurrence of. The use of the main motor rotation frequency signal of the last train or the last train of the same train as the reference speed is based on the empirical fact that they are unlikely to cause slipping / sliding. However, the present invention is not necessarily limited to this, and the main motor rotation frequency signal as the reference speed may be obtained from any vehicle in the formation.
Main motor rotation frequency signal Fr ₂ and main motor rotation frequency signal F
Switching of r ₃ is selected by the changeover switch 14 by a second total Jikusora-skid signals from the inverter control device for outputting a main motor rotation frequency signal Fr _2. In FIG. 1, the inverter control device 8 for the electric vehicle immediately before the rearmost vehicle, the inverter control device for the rearmost electric vehicle, and the other vehicle 9 are described, but a switch for switching the main motor rotation frequency signal from all vehicles in the same train. It is also possible to input to 14 and assign priority to switch. The determination of switching the changeover switch 14 may be made by the own vehicle, or may be made by the inverter control device of another vehicle that outputs the main motor rotation frequency signal as the reference speed, and the location is not limited. When switching the main motor rotation frequency signal as the reference speed,
If there is a difference in wheel diameter between the vehicles, a difference occurs between the main motor rotation frequency signal Fr _{1 of the} own vehicle and the main motor rotation frequency signal Fr ₂ or Fr ₃ of the other vehicle even if the train speed is the same. . A wheel diameter correction calculation unit 10 is provided to correct the difference, and the main motor rotation frequency signal Fr of the own vehicle is provided while the train is coasting.
The main motor rotation frequency signal Fr ₂ of another vehicle with respect to ₁ or ₂
By calculating a correction coefficient from the ratio to Fr ₃ and multiplying the correction coefficient by Fr ₂ or Fr ₃ , the difference in wheel diameter between the vehicles is eliminated. The idling / sliding detecting unit 13 monitors the fluctuation of the plurality of main motor rotation speeds, and judges that all the axes are in the idling / sliding state when all the fluctuation values exceed a predetermined fluctuation width,
A first all-axis idle / slide signal is output. When the first all-axis idling / sliding signal is input to the flip-flop 7, the flip-flop 7 outputs a signal for switching the input of the changeover switch 5 to the other one. Main motor rotation frequency signal Fr ₁ of the own vehicle by the signal is switched to the main motor rotational frequency signal Fr ₂ or Fr ₃ of other vehicles. When all of the main motor rotation speeds of the vehicle exceed the idling / sliding detection sensitivity, the changeover switch 5 is switched over, so that the main motor rotation speed as the reference speed and the detection sensitivity as shown in FIG. However, since the value of the main motor rotation frequency Fr becomes discontinuous and the inverter control frequency Finv changes abruptly, if a change rate limiter 6 is provided after the changeover switch 5 to avoid this, the change will be smooth as shown in FIG. 2b. In the arithmetic unit 12, the slip frequency Fs is added to the obtained main motor rotation frequency Fr at the time of power generation, and the slip frequency Fs is added at the time of regeneration.
Is subtracted, and the damping component Cfs is further added to obtain the inverter control frequency Finv. The slip frequency Fs is obtained by adding a main motor current feedback Imt that detects a current flowing through the main motor to a predetermined current pattern Imp to be a control target of the main motor current, and inputting a deviation thereof to the compensation system 11 to obtain ΔFs. It is output and obtained by adding the slip frequency pattern Fsp to ΔFs. The operation of re-adhering the wheels in the idling / sliding is performed by changing the slip frequency pattern Fsp by a known technique and utilizing the change of the slip frequency Fs. The first that the slip / slide state of the own vehicle has been resolved and the slip / slide detector 13 has output
When all axes slipping-skid signal is turned off, the flip-flop 7 changeover switch 5 is reset by return to select the main motor rotational frequency signal Fr ₁ of the own vehicle, the inverter control device returns to the normal control. In addition, the reset condition of the flip-flop 7 is as described above.
The condition may be such that, for example, once the slide signal is set, it is not reset until the notch is turned off, not when the slide signal is turned off.

〔The invention's effect〕

According to the present invention, when all the axes of a specific electric vehicle that is performing inverter control fall into a slipping / sliding state, the frequency is switched to the main motor rotation frequency of another vehicle and input to the inverter control device, thereby to be controlled. By changing the slip frequency as the reference speed, re-adhesion can be achieved by utilizing the self-adhesion characteristics of the dielectric motor.

[Brief description of the drawings]

FIG. 1 is a block diagram of an inverter frequency calculation unit of an inverter control device according to an embodiment of the present invention, and FIG. 2a is a main motor when a main motor rotation frequency signal as a reference speed is switched without a change rate limiter. FIG. 2b shows the relationship between the main motor rotation frequency and the inverter control frequency when the main motor rotation frequency signal is switched as the reference speed when a change rate limiter is provided. FIG. 3 is a chart showing a power supply frequency and a torque / current characteristic of a typical induction type electric motor performing inverter control. FIG. 4 is a main motor control block diagram of an electric car performing conventional inverter control. Fig. 5 shows the power supply frequency and torque / current characteristics when one shaft idles during powering of a typical electric vehicle under inverter control. FIG. 1 ... motor rotation speed detecting unit, 2 ... minimum value selecting unit, 3 ... maximum value selecting unit, 4 ... switching switch, 5 ... switching switch, 6 ... change rate millimeter, 7 ... flip-flop, 8… Inverter control device of the electric vehicle one position before the last part 9 …… Inverter control device of the last electric vehicle 10 …… Wheel diameter correction operation unit 11… Compensation system 12… Operation unit , 13… idling / sliding detector, 14… changeover switch

────────────────────────────────────────────────── (5) References JP-A-59-136004 (JP, A) JP-A-56-132186 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B60L 3/00-3/12 B60L 9/00-9/32 B60L 13/00 B60L 15/00-15/42

Claims (2)

(57) [Claims] 1. A rotational speed detecting means for detecting a rotational speed of an induction type main motor of an electric vehicle and outputting a main motor rotational frequency signal, and detecting an inverter control frequency from the input main motor rotational frequency signal and slip frequency. In an electric car control device having an inverter control means for calculating and outputting, and an inverter for inputting the inverter control frequency and controlling the main motor, the main motor rotation frequency signal is input, and the wheel idling / sliding is performed based on the change. And a slip / sliding detecting means for detecting a slip / sliding signal, and the main motor of another electric vehicle running normally when the slip / sliding signal is input. An electric vehicle control device, comprising: first main motor rotation frequency signal switching means for switching to a rotation frequency signal. 2. When the main motor rotation frequency signal switching means is switching to the main motor rotation frequency signal from the another electric vehicle, the other electric vehicle causes idling / sliding, and the idling / sliding signal is input. And a second main motor rotation frequency signal switching means for switching the main motor rotation frequency signal from the other electric vehicle to a main motor rotation frequency signal of another electric vehicle when the operation is performed. 3. The electric vehicle control device according to claim 1.