JPS60197104A - Controlling method for electric railcar - Google Patents

Abstract

PURPOSE:To rapidly control the readhesion by dividing the readhesion control mode when drive wheels slip at the regenerative time according to the speed of an electric railcar. CONSTITUTION:A brake command 1 is applied to a delay element 3, and becomes a current limit command 5. When the output of a slip detector 6 becomes ''1'' in this state, switches 4, 14 are shifted, and the command 5 is subtracted by the current limit value reduction value 12 at every one sampling time. When the output of the detector 6 becomes ''1'', the switch 14 returns to ''0'', and the command 5 holds the value at that time. A comparator 36 opens an AND circuit 38 in the low speed range that the speed V of the railcar is lower than the switching speed VCH, and does not control to decrease the command 5. Thus, the all shaft slips can be readhered as soon as possible.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention provides an electric vehicle driven by an induction motor controlled by a variable voltage variable frequency inverter, in which the driving wheels of the electric vehicle slip between the rails. The present invention relates to a method of controlling an electric vehicle when

[Technical background of the invention and its problems] In recent years, with the development of power electronics, variable voltage variable frequency inverters (hereinafter referred to as
An induction motor controlled by a VVVF inverter (VVVF inverter) is used. It has been widely known that this type of electric vehicle has a self-readhesion function with respect to wheel slipping and sliding. However, there are problems with skidding during regenerative braking, such as flattening of the driving wheels, and especially with all-axle skidding, in addition to this problem, it is impossible to obtain the reference rotation frequency FR that is converted to vehicle speed, and control Depending on the method, natural re-adhesion cannot be expected, so braking torque may be actively reduced through control.
It is necessary to reattach promptly.

FIG. 1 shows the relationship between the current limit value IC and the ratio V/F of the inverter output voltage 2 and the output frequency F with respect to time t during skidding.

When the VVVF inverter is operated under control that keeps V/Fli constant, the current of the induction motor is IM,
If the constant is K, the torque T is T=K (V/F)・I
It is given by M. However, it is an IM IC.

In FIG. 1, when one axis starts sliding at time t1, the current limit value IC (39) is reduced to reduce the torque. Normally, this would cause the vehicle to re-adhere immediately, but if the route conditions are poor, the skidding may expand, causing other wheels to start skidding one after another, potentially causing all axles to skid. When sliding on all axes begins at time t2, the current limit value IC(39)48 is kept constant,
At the same time, the V/F value (4
0) begins to gradually decrease at a certain rate. Since all the induction motors are in an unstable state from the start of all-axes sliding to the end of all-axes sliding (between time t2 and tB), it is necessary to prevent the slip frequency from becoming extremely low after all-axes sliding ends at time [3]. In addition, as a method of reducing torque, current limit value I
Stability is maintained as much as possible by fixing C (39) and lowering only the V/F value (40).

The brake torque decreases as the V/F value (40) decreases, and if readhesion is confirmed even on one axis, the V/F value (40) decreases.
) gradually returns to its original value, but the current limit value IC (39)
continues to decrease while sliding even on one axis. Then, when readhesion of all driving wheels is confirmed, the current limit value 2G (39) gradually returns to the value immediately before the start of skiing after a certain period of time.

Conventional arrangements for controlling such torque are shown in FIGS. 2 and 3.

FIG. 2 is a block diagram showing the current limit value command circuit. When the driver gives a brake force command 1, a delay element 3 provided to prevent a sudden change in the current limit value is passed through a switch 2.
The current limit value command 5 is then passed through the switches 4 in sequence.

If the driving wheels skid during driving in this state and the skidding detection circuit 6 becomes 1", the output of the logic NOT circuit 8 becomes 1" and the output of the AND circuit 9 becomes 1", so the switch 4 is turned on. “
Then, the switch 14 is switched to 1", and the current limit value command 5 is passed through the sampling hold circuit 15, and the current limit value reduction value 12 is subtracted by the subtracter 16 every sampling time. To go.

Here, if the skidding occurs on all the driving wheels, the all-axle skid detection circuit 7 will be activated.
1'', the output G of the logical NOT circuit 8 becomes #OII, and the switch 14 returns to 0''.

Therefore, the skid detection circuit 6 remains at 1", and the current limit value command 5 is held at a decreased value. When the all-axis skid detection circuit 7 returns to 0", the logical product circuit 9
Both of the two human forces are n I N, so switch 14
is switched to '1'' again, and the current limit value command 5 decreases.

When all the driving wheels readhere, the skid detection circuit 6 becomes "0", and the switches 2 and 4 return to "0" after a delay time 11 due to the off-delay 10. As a result, the current limit value command 5 gradually returns to the value of the brake command 1 due to the delay element 3.

On the other hand, FIG. 3 is a block diagram showing the V/F control circuit, in which the voltage command value calculated by the inverter output voltage control circuit 19 from the inverter output frequency 17 and the overhead line voltage 18 normally passes through the switch 20. , change rate limiter 21
A sudden voltage change is suppressed by this, and the voltage passes through the switch 22 and becomes the inverter output voltage command 23.

When a part of the driving wheels skids and all the axes start to skid, the all-axes skid detection circuit 7 becomes ``1'', and the switches 20 and 22 are switched to 1''. As a result, the inverter output voltage command 23 passes through the sampling hold circuit 26, and is subtracted by the sum of the voltage value reduction coefficient 24 and the inverter power frequency 17 by the multiplier 25 every sampling time. When all axes are no longer skidding, the all-axes skid detection circuit 7 returns to 0", which causes the switches 20 and 22 to return to 0", and the inverter output voltage command 23 returns to the original V according to the rate of change limiter 21. It returns to the value of the /F pattern.

According to such control, since the torque is reduced after skidding is detected, readhesion can be quickly performed. The braking system of a train consists of an electric brake and a pneumatic brake, and the braking force is the sum of these brakes.

FIG. 4 is for explaining the relationship between electrically controlled braking force, such as regenerative braking force, and air braking force.

That is, initially, the entire brake force command value is output as the regenerative brake force 41, but when the regenerative brake force 41 decreases at time ta, the air brake force 42 is supplemented by the decreased molecule Qs. . However, conventionally, there is usually some delay in the response of the air brake force 42, and therefore, even if the torque of the regenerative brake force 41 is temporarily lowered due to skid detection and readhesion control is performed, the air brake force 42 is There was no problem because it re-adhesed before it rose significantly. However, recently, the response of some air brakes has become faster than before, and during normal skiing there is no problem due to the self-re-adhesion property, but once it expands to full-axis skiing, it becomes unstable in terms of control. As a result, the regenerative braking force decreases, the sliding time becomes longer, and the air brake builds up considerably.No matter how much you lower the regenerative brake torque, the air brake force 42 will compensate for the shortfall, so it will re-adhesion. There was a problem that the effect was lost.

In addition, to deal with the problem of skidding, while it is desirable to make the vehicle re-adhere quickly, skidding occurs when decelerating to stop at a station, etc., and the braking torque must be suddenly reduced to force the vehicle to re-adhe. The reason is that at low speeds, for example, it takes a lot of effort to stop the train at the target location accurately, so there was a problem with the train driver getting rejected by the train driver.

[Objective of the Invention] The object of the present invention is to eliminate the psychological anxiety caused by the sudden decrease in brake torque at low speeds to the driver as much as possible, and to recover as quickly as possible all axes skidding, which is the most unstable state in terms of control. An object of the present invention is to provide a method for controlling an electric vehicle that makes it possible to apply adhesive.

[Summary of the invention] In order to achieve the above-mentioned object, the present invention provides a single unit.

In an electric car where multiple induction motors are driven by a variable voltage variable frequency inverter, and the driving wheels can run on rails using the driving force, when this electric car is in a regenerative braking state,
This is an electric vehicle control method in which readhesion control modes when the driving wheels slide are divided depending on vehicle speed. In particular, when the vehicle speed is low, determined by track conditions and operating conditions, for example, 20/h or less, the re-adhesion command is issued only when all axes are skidding, and the output voltage of the variable voltage variable frequency inverter and the output frequency F At the same time, the torque is reduced by decreasing the ratio V/F of the air brake, which acts as a supplement to the electrically controlled braking force, and the value of the current electrically controlled braking force is set to the value just before all axes skid, and the electrically controlled brake appears to be normal. This is an electric vehicle control method that generates torque but does not use supplementary air brakes, and in this case, the driving wheels can be reattached to the rails very quickly.

[Embodiments of the invention] Hereinafter, the present invention will be explained with reference to the drawings.

The configuration of the V/F control circuit is the same as the conventional block diagram shown in FIG. Furthermore, the configuration of the current limit value command circuit shown in FIG. 5 is similar to the conventional block diagram shown in FIG.
The vehicle speed (V) 35 and the mode switching speed (VcH) 37 are compared by a comparator 36, and when the former is greater than the latter (VCH), in the high speed region, the input of the AND circuit 38 is the skid detection signal. A signal from the circuit 6 is received, and control is performed to lower the current limit value command 5, thereby re-adhering the driving wheels and the rail.

Further, in the low speed region when the former is smaller than the latter (V<VCH), no output is generated from the comparator 36, so the AND circuit 38 does not accept the signal from the skid detection circuit 6 and sends the current limit value command 5. Normally, tIllF lowers depending on the slide.
Don't do B.

In other words, when V<Vcs, IC is not lowered (a and C in Figure 1).
control is not performed), and lowers the V/F at time t2.

As described above, in the embodiment of the present invention, when the driving wheels of an electric vehicle driven by an induction motor using a VVVF inverter slide on the rail surface during regenerative braking, the current limit value IC
Alternatively, readhesion is attempted by lowering the V/F value. In addition, in the low-speed region (for example, 20 ICIA/h or less), during normal skiing other than all-axes sliding, the current limit value IC is not lowered and the re-adhesion characteristic of the induction motor is used, and the air brake force is not increased only during all-axes sliding. By lowering the V/F value to prevent this from happening, the driving wheels will re-adhere to the rail.

FIG. 6 shows a block diagram for calculating the electrically controlled brake output, which indicates how much regenerative braking force is currently being applied to the air brake.

The current limit value command 5 and the inverter output voltage command 23 are input to the calculation circuit 28 to calculate the regenerative braking force, and this regenerative braking force passes through the switch 29 and the delay element 30 and becomes the electrically controlled brake output 31. When the skidding expands and reaches skidding on all axes, the skid detection circuit 7 on all axes becomes 1', and the single shot 32 switches the switch 29 to "1" for a certain pulse time 33, and the sampling hold circuit 34
Therefore, the values immediately before skidding on all axes are held. When the switch 29 returns to °“O”, the value of the electrically controlled brake output 31 changes to the output value of the arithmetic circuit 28, and the delay element 30
Therefore, it gradually returns. However, since the pulse time 33 is selected based on the period from when the calculated value of the arithmetic circuit 28 drops by one degree to when it returns again, it is considered that the electric brake output 31 will hardly change due to skidding on all axes. It's good.

In this way, in the low speed region (for example, 20 KIA/h or less)
Now, by setting the value of the current electrically controlled braking force that is instructed to the air brakes as a supplement to the electrically controlled braking force to the value immediately before all axes skid, it is possible to unify the apparently normal electrically controlled braking torque. This prevents the air brake force from compensating for the lack of torque. This control is particularly effective in shortening the torque reduction time in the low speed range, but it may also be applied to all speed ranges.

[Effects of the Invention] According to the present invention, it is effective to suppress the psychological anxiety of the driver due to the sudden torque reduction when the electric car runs at low speed, and to stop the electric car in a fixed position at a station. It is possible to provide a method for the electric car 111m that allows the electric car 111m to be reattached very quickly even if shaft slippage occurs.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the relationship between time and current limit value or time and V/F value to explain the conventional electric vehicle control method;
3 and 3 are block diagrams showing the current limit value command circuit and V/F III 111 circuit for implementing the conventional electric vehicle control method, and FIG. 4 is a block diagram showing the regenerative braking force and air 5 and 6 are diagrams showing the relationship with the braking force, and show a current limit value command circuit and a circuit for calculating the electrically controlled brake output for explaining an embodiment of the electric vehicle control method according to the present invention. It is a block diagram. 1...Brake force command, 2.4.14.20°22.
29...Switch, 3.30...Delay element, 5...
・Current limit value command, 6...Slippage detection circuit, 7...All axis slippage detection circuit, 8...Logic NOT circuit, 9, 38...AND circuit, 10...Off delay, 11. ...Delay time, 12...Current limit value reduction value, 13...Zero command, 1
5゜26.34...Sampling hold circuit, 16
゜27... Subtractor, 17... Inverter output frequency, 18... Overhead line voltage, 19... Inverter output voltage calculation circuit, 21... Change rate limiter, 23... Inverter output voltage command, 24... Voltage value reduction coefficient, 25.
...Multiplier, 28...Electric brake calculation circuit, 31.
...Electronic brake output, 32...Single shot,
33...Pulse time, 35...Vehicle speed, 36...
Comparator, 37...Mode switching speed, 39...Current limit value IC140...V/F value, 41...Regenerative brake force, 42...Air brake force. Applicant's agent Patent attorney Takeshi Suzue 7 poison

Claims (1)

[Claims] (1) In an electric car in which multiple induction motors are driven by one variable voltage variable frequency inverter, and the driving wheels can run on rails by this driving force, when this electric car is in a regenerative braking state, the driving wheels An electric vehicle control method characterized in that readhesion control modes when a vehicle skids are divided according to vehicle speed. (In the low speed region where the vehicle speed described in claim 21 (1) is determined by route conditions and driving conditions,
A re-adhesion command is issued only when all axes are skidding, and the ratio V/F of the output voltage V and output frequency F of the variable voltage variable frequency inverter is reduced to reduce torque, and the air brake acts as a supplement to the electrically controlled braking force. The current electrically controlled braking force that is instructed to the vehicle is set to the value immediately before all axes skid, so that an apparently normal electrically controlled braking torque is generated, and the supplementary air brake is not activated. Electric car tII1wh.