JP2679992B2 - Electric car control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved controller for an induction motor electric vehicle, and more particularly to a controller for an electric vehicle that operates at a constant speed. [Prior Art] Regarding constant speed operation of an induction motor type electric vehicle, first, Japanese Patent Application Laid-Open No. 4812418 discloses an electric vehicle intended for road traveling. That is, the slip frequency is determined by a function generator that linearly changes in proportion to the deviation between the commanded speed and the induction motor speed, and has positive and negative limits.
The other control system is the same as a general control system, and is configured to control its output voltage according to the frequency command given to the inverter. Further, Japanese Laid-Open Patent Publication No. 54-22607 discloses that in a railway electric vehicle, for example, one notch is 10 km / h, two notches are 30 km / h, three notches are 60 km / h, and four notches are 100 km / h. In detail, a method is disclosed in which a speed command is determined corresponding to each notch command and the output frequency of the inverter is controlled. [Problems to be Solved by the Invention] Further, in the magazine "Science of Electric Vehicles" 1985 Vol.38 No.2, pages 15 to 24, especially page 20, the speed of the electric vehicle approaches the speed limit. It is disclosed that constant speed control is performed by narrowing down the slip frequency. Further, in Japanese Patent Application No. 60-220124, by providing an operating means for generating a constant speed command, it is possible to operate at a constant speed at an arbitrary speed while leaving the operation handling similar to that of a conventional electric vehicle. The means for doing so are shown. By the way, considering the operation mode before entering the constant speed operation, there are three modes of power running, coasting, and braking. There are also three driving modes during constant speed operation: power running, coasting, and braking. Therefore, there are nine modes of changing the operation mode when the constant speed operation is started. Of these, the same type of mode transition (for example, transition from power running to power running) is not a problem if you continue the control as it is, but about the transition of different modes (for example, from power running to brake or from brake to power running) ,
As it is, the acceleration changes abruptly (for example, what was accelerating during powering suddenly becomes a brake and decelerates), which impairs the riding comfort and is unstable when control cannot keep up with a sudden change in powering or braking. There is a fear of becoming. An object of the present invention is to provide a control device for an electric vehicle that enables stable constant-speed driving at a free speed while leaving the driver's handling similar to that of a conventional electric vehicle. [Means for Solving Problems] The present invention relates to an operating means for instructing a constant speed traveling operation, a means for generating a speed command according to the constant speed command, and an electric device for controlling the speed to the commanded speed. In an electric vehicle control device including means for controlling traveling of a vehicle, when the electric vehicle shifts from the state of power running or braking to the constant speed traveling, after coasting mode is selected, shifts to constant speed traveling It is characterized in that it is configured as follows. [Operation] According to the present invention, since the vehicle always enters through the coasting mode when entering the constant speed operation, there is no abrupt change in the torque due to switching, the riding comfort is not impaired, and the control is stable. Constant speed operation can be enabled. [Embodiment] Hereinafter, a preferred embodiment of the present invention shown in the drawings will be described in detail. In FIG. 1, the direct current collected from the DC train line 1 is
It is converted into alternating current of variable voltage and variable frequency by the inverter 2 and is fed to the induction motors 31, 32. In order to obtain the vehicle speed equivalent signal _r , the pulse generator 4
1, 42 are provided, and the number N of output pulses of them is set as a frequency signal.
An N / converter 5 for converting to _r is provided. The main controller 6 has a constant speed notch position in addition to the off position, the power running 1 and 2 notches. First, in the power running 1 or 2 Notsuchi to generate a constant slip frequency pattern _sp1 by _s pattern generator 7, by I _M pattern generator 8, the motor current command I _Mp1
Generate. The switching switches 9 and 10 are in the illustrated state in the power running notch. Therefore, the slip frequency command
_sp1 is directly input to the adder 11. On the other hand, the motor current I _M is detected by the current detector 12 and compared with the motor current command I _Mp by the comparator 13. This comparator 13
Is the slip frequency command when the motor current I _M fluctuates.
An _S correction signal for correcting _sp is generated, and the adder 11
It becomes one other input of. The output of the adder 11 becomes a slip frequency signal _s , which is added (powered) or subtracted (regenerated) by the adder 14 to the above-mentioned vehicle speed-corresponding signal _r (which may be the rotor speed of the electric motor). The output _{INV of the} adder 14 is input to the PWM modulator 15 as an inverter frequency command. The inverter frequency command _INV is a voltage V that generates a control voltage V _C1 such that the ratio of voltage V to frequency (V /) is constant.
/ Input to converter 16. In the power running 1 or 2 notch, the notch stop voltage generator 17 generates the notch stop voltage V _C2 set for each notch as shown in the figure. The low-priority circuit 18 has the control voltage V _C1 and the notch stop voltage V
Select the lower level of _C2 and set PW as the inverter output voltage command V _C.
Output to the M modulator 15. The PWM modulation unit 15 uses the inverter frequency command _INV and the inverter output voltage command V _C
The operating frequency and the modulation degree of the inverter 2 are controlled according to the above. Well, I _M pattern generator 8, in the power running 2 Notsuchi, is a constant value, the power running 1 Notsuchi, with increasing _INV, to limit as shown. The reason for this is power running 1
Notch, control voltage V _C while slip frequency _s remains high
If only the notch stop voltage V _C2 is suppressed,
Next, when the switch is turned on for two notches, the voltage limitation is released and a large torque is generated. Therefore, the slip frequency signal _s is also narrowed down by the _y correction signal by the current control system. Further, in this embodiment, there are only two power running notches, and in the two notches, the notch stop voltage generator 17 is provided.
As shown by V _Cmax , a voltage corresponding to the maximum output voltage of the inverter can be output, and virtually no voltage limitation is performed. This is because the constant speed operation command described below is also used, and it is considered that a power running notch number higher than this is not required. In the above control system, the following control system may be used instead of the control voltage V _C control system when V / = constant.
That is, the control voltage V _C1 input to the low priority circuit 18 is obtained according to the output of the comparison amplifier 13 that amplifies the deviation between the current command I _MP and the current feedback value I _M. Under the frequency control system of _INV = _r ± _s , this is V /
= If constant, I _M ≈ constant, while if I _M = constant, V / ≈ constant, which means that any one of them can be selected as the control system. The above-described control during power running or regeneration is executed in the same manner as the well-known control of the induction motor type electric vehicle, as shown by the notch curve in "Science of the Electric Vehicle" on page 20 above. . Now, it is assumed that the master controller 6 is put in the constant speed operation position. Then, first, the constant speed command line 19 can convert the switching switches 9 and 10 to the open / close positions opposite to those shown in the drawing. On the other hand, when the constant speed command is given to the target speed setting device 20, a signal _r corresponding to the vehicle speed at that time (which may be the motor rotation speed)
Is set as the speed command signal _p . Also,
When the constant speed command is given and there is a signal that remembers that the immediately preceding notch was power running 2 notch, (latched vehicle speed equivalent signal _r ) + (5km / h equivalent signal)
= Set speed command signal _p . The comparison amplifier 21 compares the speed command signal _p with the vehicle speed equivalent signal _r, and with respect to the deviation Δ thereof, a second slip frequency signal _SP2 and a second current command signal I _MP2 as shown in FIG. To occur. These second command signals
_SP2 and I _MP2 become a new slip frequency command _SP and a motor current command I _MP via the switching switches 9 and 10, respectively. Therefore, the vehicle speed is near the desired speed (at 2 notches).
If a constant-speed notch is thrown in after accelerating, the vehicle will rise smoothly from that speed to a speed as high as 5 km / h, and then will perform constant-speed operation while performing powering or regeneration so as to maintain that speed. Also, when a constant speed notch is commanded from coasting (cutting notch) or power running 1 notch, a signal corresponding to the vehicle speed at that time is issued.
The same constant speed operation is performed with _r as the subsequent speed command _P. As shown in the characteristic of the comparison amplifier 21 in FIG. 2, a slight dead zone (corresponding to ± 0.8 km / h) is provided to smoothly switch between power running and regeneration. Also, ±
The constant speed characteristic within ± 5km / h can be obtained by setting the characteristic to saturate at 5km / h. By the way, for example, when a command for constant speed notch is issued during power running 1 notch on a downward slope, the vehicle speed equivalent signal _r at that time is set as a subsequent speed command _p , but since the vehicle is naturally accelerating on the downward slope. The brake will be activated immediately after entering the constant speed operation mode. However, the constant speed notch command activates the circuit breaker off operation circuit 22, opens the circuit breaker 23, and starts coasting operation. Since the circuit 22 is a one-shot circuit, after coasting once, the brake operates according to the output of the powering brake determination circuit 24 during constant speed operation. That is,
Since there is no direct transition from power running to regeneration, there is no sudden change in torque, the riding comfort is not impaired, and in terms of control, power running and regeneration can be clearly distinguished, making it extremely stable. In this embodiment, the master controller is provided with the operating means for generating the constant speed command, but the master controller may be installed separately. Also. Although the number of powering notches is only two, it is easy to set it to three or more. Furthermore, without determining the speed command for constant speed operation according to the actual vehicle speed equivalent signal, a method such as issuing a constant speed operation after designating a speed command at constant speed using a keyboard or the like is used. Modifications such as shifting to constant speed operation are easy. [Effect of the Invention] According to the present invention, it is possible to perform constant speed operation at an arbitrary speed while leaving the feeling of notching of a conventional electric railway vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an embodiment of a control device for an induction motor type electric vehicle according to the present invention, and FIG. 2 is an example diagram of tensile force command characteristics with respect to speed deviation. 2 ... Power converter (inverter), 6 ... Main controller (including constant speed notch), 9-10 ... Switching means (switch), 14 ... Addition (subtraction) calculator, 15 ... PWM modulation section , 16 …… V
/ Converter, 17 ... Notch stop voltage generator, 18 ... Low priority circuit, 20 ... Target speed setter, 21 ... Speed comparison amplifier (generates second slip frequency command), 22 ... Disconnection Switch off operation circuit, 23 ... Breaker, 24 ... Power line / brake discrimination circuit, 31-32 ... Induction motor, 41-42 ... Speed detection means (pulse generator), _r ... Speed signal, _s ... Slip frequency signal.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Tsutomu Ozawa               1070 Ichimo, Katsuta, Ibaraki Japan               Tate Factory Mito Factory (72) Inventor Shigetoshi Okamatsu               1070 Ichimo, Katsuta, Ibaraki Japan               Tate Factory Mito Factory (72) Inventor Koji Jimbo               1070 Ichimo, Katsuta, Ibaraki Japan               Tate Factory Mito Factory (72) Inventor Eiichi Toyoda               1070 Ichimo, Katsuta, Ibaraki Japan               Tate Factory Mito Factory                (56) References JP-A-62-81904 (JP, A)

Claims (1)

(57) [Claims] An electric vehicle control device including an operating means for instructing a constant-speed traveling operation, a means for generating a speed command in accordance with the constant-speed command, and a means for controlling travel of the electric vehicle so that the speed becomes the instructed speed. In the electric vehicle control device, the electric vehicle control device is configured to shift to the constant speed traveling after the coasting mode is selected when the electric vehicle transits to the constant speed traveling from the state of being powered or braking.