SU806488A2 - Device for pulsed control of electric drive of rolling stock - Google Patents

Description

The invention relates to a pulsed control of a traction drive, mainly mine electric locomotives, using multi-tact thyristor converters and is intended to maintain optimum traction force over the entire range of operating modes depending on the varying conditions of adhesion of the wheels to the rails. Known by the main author. Ev, no. 481472 A device for pulsed control of a rolling stock electric drive containing traction motors controlled by thyristor-pulse converters having a main and suppressing thyristors, a voltage sensor connected to a pulse-width modulator using a resistor and a shuntrue of another transistor , two groups of pulse shapers to switch on the main and quenching thyristors, one of which is connected to the pulse-width modulator directly, and the other through the delay elements built For example, on the base of standby multivibrators with a bias source, wheelset speed sensors and actual train speed sensors having access to individual voltage dividers, the positive poles of which are combined into a common point, k, and the middle points of the individual voltage dividers connected to the displacement source of the delay elements of the main pulses, and the average points of the individual voltage dividers connected to the sensors of the actual speed and speed th due wheelsets are connected to the emitter-base junction of the shunt transistor fl. However, in the known device, when a traction motor is operating on a natural characteristic, the operation of the future multivibrator is prevented and the thyristor converter does not respond to the signal of blocking or skidding. The purpose of the invention is to improve the implementation of optimum traction power according to the adhesion condition in the whole range of operating modes. . This goal is achieved by the fact that the device for impulse control of the electric drive of the rolling stock is equipped with a unit for switching motors into a pulse mode, connected parallel to the input of a pulse-width modulator and connected via an additionally introduced pulse shaper to the midpoint of an individual voltage divider connected to the speed sensor of another wheelset.

The drawing shows a circuit diagram of the proposed device.

The device for pulse control of the electric drive of the rolling stock contains traction motors .1 and 2, controlled by thyristor-pulse converters 3,4, unit 5 voltage, connected kg kg pulse-width modulator b, in parallel with which the switching transistor 7 and block 8 are connected converting motors into a pulsed mode, for example, in the form of a series-connected transistor and a Zener diode, pulse formers 9 and 10 for switching on the main and dead thyristors of the converter 3, individually connected to the modulator b and through the elements 11,12 delays associated with the formers 13,14 pulses for turning on the thyristors of the converter 4, the sensors 15,16 wheelset speeds and the sensor 17 of the actual train speed, respectively, associated with the individual dividers 18 , 19 and 20 voltages,. the positive outputs of which are combined into a common point, and the middle point of the divider 19 is connected with the delay element 11 and through the driver 21 with the block 8 for switching the engines into a pulsed mode. To the collector of the transistor 7 is connected to the setting device 5 for example

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The device works as follows i.

With a change: the input voltage changes the duty cycle of rectangular pulses at the output of the modulator b. The leading and trailing edges of these pulses are amplified and amplified and multiplied by 9/10 pulse shapers, one of which (driver 9) serves to turn on the main thyristors of the pulse converter 3, and the other (driver 10) to turn on the dying thyristors. These same shapers trigger elements 11, 12 of delay, which are completed, for example, at the base of the waiting multivibrators with a bias source, which are connected to the same shapers 13, 14 to turn on the corresponding transistor 4 thyristors.

Thyristor converters 3, 4 regulate the voltage of electric motors 1.2. The speed of each wheelset, as well as the speed of an electric locomotive, is controlled by the respective sensors 15-17, which have a constant voltage proportional to the speed at the output. The output voltage of each sensor is supplied to individual voltage dividers 18-20.

In the normal operation mode of an electric locomotive, in the absence of blocking of wheel pairs, the voltage at the output of the sensors 15-17 is equal to each other, therefore, the voltages between the middle points of the dividers 18-20 are zero. Suppose that the wheelset associated with the electric motor has become blocked. 1. The potential between the middle points of the dividers 19 and 20 increases. The voltage at the base of the transistor 7 becomes positive and it opens slightly by decreasing caNttiJM at the input voltage of the pulse width modulator b, and accordingly, the pulse ratio at its output.-.

The voltage on the electric motor 1 decreases (shaded area) in connection with its low power and normal grip is restored.

Changing the duty cycle of the pulse-width modulator 6 at a constant delay time can cause a decrease in the voltage on the non-boxing motor 2. To eliminate this, element 11 of the main thyristor pulse delays is made to controllers For this purpose (an additional voltage is supplied to the source of the waiting multivibrator) the voltage from the mid-points of the dividers 18, 19. In the case of boxing of the electric motor 1, this voltage is positive. The delay time i of the pulses of the main thyristors is reduced, due to which the duty cycle the course of converter 4 remains unchanged, therefore, the voltage on the motor 2 also does not change.

If the wheel pair associated with the motor 2 is boxed, then the midpoint potential of the divider 19 changes. The metered voltage of the transistor 7 remains zero and does not affect the operation of the pulse-width modulator. The generated pulse is generated by the shaper 21 and causes the switching to the pulsed mode unit 8, which causes the voltage at the input of the pulse width modulator to decrease to a value sufficient for the system to go into the pulse mode, which practically does not reduce the pulling power of the blocking engine.

the additional bias applied from the divider points 19, 20 of the voltage to the standby multivibrator causes an increase in the delay time and the voltage on the electric motor 2 decreases. If both box pairs are boxed simultaneously, the stress between the middle points of the dividers 18 and 19 remains equal to zero and does not affect the delay time of the main types (

Claims (1)

Claim Device for pulse regulation of electric rolling stock according to ed. St. »481472, distinguished by the fact that, in order to improve the implementation of the optimum traction according to the clutch condition in the entire range of operating modes, it is equipped with a block for converting the engines to pulsed mode, connected in parallel to the input of the pulse-width modulator and connected via an additional pulse shaper with the midpoint of an individual voltage divider connected to the speed sensor of another wheelset.