JPS6331402A - Re-adhesion control method for inverter controlled electric motor car on sliding - Google Patents

Abstract

PURPOSE:To enable an adhesion to be used at its maximum, by making the ratio of motor voltage to inverter frequency small for a previously set time, in case where total axle sliding takes place continuously as often as a previously set frequency within a previously set time. CONSTITUTION:From a frequency arithmetic section 17, the output of the rotating frequency fR1-fR4 of respective motors and reference rotating frequency fR is generated. Besides, a current command value IMP and reference slip frequency fSP are computed by a current/slip frequency pattern generating section 19 according to mass-com command CM, the bearing load VL of a car body, and the reference rotating frequency fR. Then, inverter frequency fINV and reference modulation factor rp are computer by the reference slip frequency fSP and correction slip frequency fS according to current deviation IM. When total axle sliding is generated continuously by previously set frequency within a previously set time, then arithmetic is performed on modulation factor reducing factor KR by a sliding detection arithmetic section 25. Then, the modulation factor (r) of the product of the modulation factor reducing factor KR and the reference modulation factor rp is kept for a set time, and is slowly returned to the reference modulation factor rp.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is applicable to an electric vehicle driven by an induction motor controlled by a variable voltage variable frequency inverter, when the driving wheels slip on all axes with respect to the rails. This invention relates to an electric vehicle control method.

(Prior art) With the recent development of power electrox, variable voltage variable frequency inverters (hereinafter referred to as V
An induction motor controlled by a VVF inverter (VVF inverter) is used.

Figure 1 shows a typical main circuit configuration example of a VVVF inverter vehicle, in which an input current is applied from a pantograph 1 to an inverter 5 via a breaker 2, a filter reactor 3, and a filter capacitor 4, and a signal from an inverter control section (described later) is input to the inverter 5. By operating the inverter 5 based on this, the vehicle induction motor 7°8, 9. Drive 10. In addition, the first
11゜12.13.14 in the figure is the induction motor 7. 8.
9. It is a pulse generator that detects 10 rotations.

15 is a motor current detector, 16 is a motor voltage detector, 6
is GT○ (gate turn-off) that constitutes inverter 5.
It is a thyristor. Conventionally, the circuit configuration shown in FIG. 2 has been adopted as a control section of such a VVVF inverter vehicle. That is, in FIG. 2, 17 is the output PG of the pulse generators 11, 12° 13.14 (shown in FIG. 1).
When I to PG4 are input, each electric! l
Rotational frequency fR1, fR2, fR3, fa+ of J machine
and a frequency calculation unit that calculates the reference rotation frequency 1 shaku. When moving, the rotational frequencies fR1, rR2, fR3, [
The minimum value of the screams is selected and the maximum value is selected and output during the second regeneration. 18 is a master controller that outputs a brake command MC, and 19 is a current/slip frequency pattern that calculates a current command value MP and a reference slip frequency rsP according to the master controller command MC and the variable load VL of the vehicle (which changes depending on the occupancy rate). Occurrence part.

20 is a corrected slip frequency fs according to the current command value IMP outputted from the current/slip frequency pattern generation section 19 and the motor current IM outputted from the motor current detection section 15.
21 is a change rate limiter that limits sudden changes in the rotational frequency fQ.

Since the output of the motor current detection section 15 is an inverter output current, the motor current 1 is defined as the value obtained by dividing the current value by the number of induction motors driven by the same inverter. During regeneration, the inverter frequency f INV is determined from the output fRO of the rate of change limiter 21 by the current/slip frequency pattern generator 19
It is obtained by subtracting the reference slip frequency fsp, which is the output of , and fs, which is the output of the corrected slip frequency calculation section. 22 is a modulation rate calculation unit that calculates a modulation rate corresponding to the inverter frequency flN+/, and 23 is a pulse width modulation (PWM) control that generates a thyristor gate signal for the inverter 5 from the inverter frequency fKV and the output γ of the modulation rate calculation unit. This is the PWM modulation section that performs the PWM modulation. 24 from the frequency calculation unit 17 to the induction motors 7, 8. 9. 10 rotational frequency rR1,
This is a skid detection section that obtains f'R2, fR3°rR0, detects wheel skid from the time rate of change (differential value) of these rotational frequencies and the rotational frequency difference, and outputs a skid detection signal.

As mentioned above, the inverter-controlled electric vehicle uses the output signals PGI to PG4 of the pulse generators 11.12 and 13.14.
The reference rotational frequency fR is calculated from 2.If all axes slide, in which all the driving wheels corresponding to induction motors 7 to 10 driven by the same inverter slide, the rotational frequency fR becomes 2.
Q no longer corresponds to the train speed, leading to a large skid. therefore.

If sliding on all axes occurs, it is necessary to reattach it immediately. Conventionally, when all-axis skidding occurs during the first regeneration, as shown in FIG. As a result, the motor current decreases and the sliding wheels re-stick. When all axes skid ends and all axes skid detection signals disappear, the current command value ρ of the current/slip frequency pattern generating section 19 gradually returns, and at the same time, the motor current IM also returns.

(Problem to be solved by the invention) When all-axle skidding occurs, the adhesion coefficient between the wheels and rails slightly decreases. As a result of reducing the motor current 1 at a predetermined constant rate, control is performed in accordance with the lowest value of the adhesion coefficient between the wheels and the rail, resulting in a large drop in driving force.

(Means for Solving Problems) An object of the present invention is to prevent an inverter-controlled electric train from causing all axes to skid during regeneration and causing the motor rotation frequency "R" for inverter control to no longer correspond to the train speed. If all axes skid repeatedly, the motor torque is reduced to take into account the adhesion coefficient at that point to make re-adhesion less likely to occur, and to maximize adhesion. The purpose is to propose an electric vehicle control method for use.

(Function) The present invention provides an electric vehicle driven by an induction motor using a VVVF inverter, in the event that all axes of the driving wheels skid during the first regeneration.
When all axes skid is detected, the adhesion coefficient is calculated from the wheel axle deceleration and the motor voltage V and inverter frequency rlNV are calculated.
By reducing the ratio VM/f +Nv, the motor torque is lowered below the adhesion coefficient, and after all axis sliding is completed, the ratio VVI of motor voltage V and inverter frequency ftFJV is reduced.
/ r (In a control method that gradually returns Nv,
If all axes skid occurs a predetermined number of times in a row within a predetermined time, the motor voltage ■
and the ratio of inverter frequency rlNV VM/f IN
By decreasing V, the motor torque is lowered to a value corresponding to the adhesion coefficient, and the above value is held for a predetermined period of time, and after the elapse of the above period of time, the ratio of motor voltage vM to inverter frequency f INV is gradually reduced to VM/r. I
This is a method of controlling an electric vehicle to restore NV.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 shows an example of the configuration of the inverter control section in the electric vehicle control device according to the present invention. Components that are the same as those in FIG. 2 are indicated by the same symbols. In FIG. output signals PGI to PG4 (shown in the figure)
is input, the frequency calculation unit calculates the rotational frequency fR1~[2] and the reference rotational frequency [λ of each motor from these input signals. ] long value of the awn
Select R and output. 18 is a master controller that outputs a brake command MC, and 19 is a master controller command MC.

A current/slip frequency pattern generation unit that calculates a current command value IMF and a reference slip frequency fsp according to the variable load VL and rotational frequency r1< of the vehicle; 20 is a current deviation between the current command value IMρ and the motor current IM; 21 is a change rate limiter that limits the time rate of change of the output fR of the frequency calculation unit 17 to 1:11, and 22 is a change rate limiter that calculates the corrected slip frequency △fs according to the inverter frequency rINv. A modulation rate calculation unit that calculates a corresponding reference modulation rate rp.

23 is a PWM modulation section which inputs the inverter frequency rlnv and modulation rate γ and performs PWM control, and provides a gate signal to the inverter 5 shown in FIG. 25 is the rotational frequency fR1~r of the motor, the motor voltage VM which is the output of the motor voltage detector 16, and the inverter frequency f INV, and in the case of all axes sliding, the adhesion coefficient between the rail and the wheels is taken into account and the adhesion coefficient is below. The control of the VVVF inverter vehicle during skidding on all axes is based on the inverter control unit configured as described above, which is the skid detection calculation unit that calculates the modulation rate reduction rate KR to set the motor torque to an appropriate value. Part 5 about its effect
If the adhesion coefficient μ between the rail and the wheels (ratio F/W of traction force F and axle load W per axle) decreases during the third regeneration based on the figure, and all driving wheels skid, the skid detection calculation unit 25
All-axis sliding is detected by , and the adhesion coefficient μ in that case is calculated by the following equation.

η: Transmission efficiency of the gear system G: Gear ratio P: Number of poles of the induction motor 'r, A: Maximum shaft deceleration, maximum full deceleration torque of the motor (N-m
) Iw : Moment of inertia of wheel shaft (Kg-rn, )fR
DM: Differential value of the rotational frequency of the motor with respect to the axle that shows the maximum axle deceleration dust (becomes a negative value) W: Axle load of the axle that shows the maximum axle deceleration dust (1) DM: Axle load that shows the maximum axle deceleration dust Wheel diameter (m) SM: Slip of the motor with respect to the axle showing maximum axle deceleration dust V: Motor phase voltage (V) Between 11: Inverter frequency (Hz) rwn: Rotational frequency of the motor with respect to the axle showing maximum axle deceleration dust ( Hz) R1, Xl: Resistance on the primary side of the induction motor using a T-type equivalent circuit Actance (Ω) (shown in Figure 6) R2, X2: Primary equivalent resistance on the secondary side of the induction motor using a T-type equivalent circuit Actance (Ω) (shown in FIG. 6) Next, the motor torque TM was converted into an adhesion coefficient. The set adhesion coefficient μe is determined from equation (4), and the ratio μ/μe of the set adhesion coefficient μe to the set adhesion coefficient μe is determined. The modulation rate reduction rate KR is calculated from this μ/μe using equation (5) and output from the skid detection calculation section 25.

FIG. 7 shows the modulation rate reduction rate KR with respect to the adhesion coefficient/set adhesion coefficient ratio μ/μe.
Mru. As a result, the electric motor torque is reduced to an appropriate value that takes into account the adhesion coefficient, and the driving wheels re-adhesion. When the all-axis sliding is completed and the all-axis sliding detection signal disappears, the modulation rate T is gradually restored.

When all-axis sliding is repeated, the above: fr! I control is repeated, but if all axes skid occurs a predetermined number of times within a predetermined time, the modulation rate reduction rate KR is calculated,
The product of the base 1 modulation rate Tρ, which is the output of the modulation rate calculating section 22, is taken to obtain the base 1 modulation rate γ.

The modulation rate γ is maintained for a predetermined time and then gradually returned to the basic modulation rate 7p. The viscosity coefficient μ is constantly calculated during sliding on all axes, and when the viscosity coefficient μ further decreases, the modulation rate reduction rate KR is determined based on the decreased value.

FIG. 8 shows the operation of each part versus time during full-axis sliding. When the adhesion coefficient μ between wheels and rails decreases and all axes skid, all axes skid is detected and the ratio VM/flNv of motor voltage and inverter frequency is reduced to lower the motor torque, thereby ending all axes sliding. In the example shown in Figure 8, when all-axis skidding occurs for the fourth time, the ratio of motor voltage to inverter frequency VM / f INI /
at the same time as reducing the value at a predetermined time Tp.
After that, the value of /fINV is gradually restored for 7 days.

(Effect of the invention) By applying the present invention as explained above.

Even if an inverter-controlled electric train causes all axes to skid due to a decrease in the adhesion coefficient between wheels and rails during regeneration, the reference rotation frequency fR that creates the inverter frequency is maintained at a value corresponding to the train speed, and the distance between wheels and rails is maintained. can maintain maximum adhesive strength.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the main circuit of a VVVF inverter-controlled electric car, Fig. 2 is a block diagram of the control section of a conventional VVVF inverter-controlled electric car, and Fig. 3 is a schematic diagram of the control section of a conventional VVVF inverter-controlled electric car. A state diagram of adhesion control, FIG. 4 is a block diagram of the inverter control section according to the present invention, FIG. 5 is a calculation flowchart of the skidding detection calculation section according to the present invention, FIG. 6 is a T-type equivalent circuit of the induction motor, and FIG. 7 is the modulation rate reduction rate KR characteristic with respect to the adhesion coefficient/set adhesion coefficient ratio μ/μe. FIG. 8 is a state diagram of readhesion control during skiing according to the present invention. 1... Pantograph 2... Breaker 3... Filter reactor 4... Filter capacitor 5... Inverter 6... GTO Cyrisk 7, 8. 9. 10...Induction motor 11.12,
13.14...Pulse generator 15...Motor current detector 16...Motor voltage detector 17...Rotation frequency controller 18...Mascon 19...Current/slip frequency pattern generator 20・・・
- Corrected slip frequency calculation unit 21... Rate of change limiter 22... Modulation rate calculation unit 23... PWM modulation unit 24... Skid detection unit 25... Skid detection calculation unit 26...-Next side Resistance 27...-Next side glue actance 28...Secondary side resistance (-Next side conversion value) 29...Secondary side Gli actance (-Next side conversion value) 30...Excitation reactance specification Agent: Director of Legal Affairs Division, Office of the President of Japan National Railways, Onozawa Sozojur7

Claims (1)

[Claims] In an electric vehicle where multiple induction motors are driven by one variable voltage variable frequency inverter, when all axes slip, the adhesion coefficient is calculated from the wheel axle deceleration and the ratio of motor voltage to inverter frequency is reduced. In this system, the motor torque is lowered to below the adhesion coefficient, and after all axes have finished sliding, the ratio of the motor voltage to the inverter frequency is gradually restored. If all axes continue to skid, reduce the ratio of motor voltage and inverter frequency to reduce the motor torque to correspond to the adhesion coefficient, maintain the above motor torque for a predetermined period of time, and then reduce the motor voltage. Electric vehicle control method that gradually restores the inverter frequency ratio