SU419426A1 - DEVICE FOR MANAGING TRACTORY ELECTRIC MOTORS - Google Patents

Description

one

The invention is intended to control the speed of vehicles equipped with direct current traction motors powered by thyristor-pulse converters, for example, on electric locomotives, tram x, trolley buses, etc., and in particular on mine electric locomotives.

Devices are known for controlling the traction motors of an electric rolling stock of direct current using thyristor-pulse converters. In such devices, the engine applied to the engines is smoothly controlled by a thyristor-pulse converter, (controlled by a control circuit that has a vehicle speed master. The driver controls the speed of the locomotive. In addition, these devices usually the current of the traction motors is automatically limited.At the increase in the current of the motors above a predetermined value by a signal from the current sensor, the control system issues a command to decrease tiristornoimpulsnogo one voltage converter, and the current in the engines is reduced. At present, find use devices in which the thyristor-pulse converter is used only during acceleration of the vehicle. After dispersal shunted converter and motors are powered directly from the power source.

However, in the known device, after shunting the thyristor-pulse converter, the motor current is not automatically limited to the permissible value. After shunting the converter, the voltage on the motors is equal to the voltage of the power source and if now for any reason the current of the thrusters increases above the allowable value, for example, when the profile of the path changes, the converter remains bridged

and reduce the current can not. In addition, a special contact device is used to shunt the converter, and its contacts are included in the chain of traction motors.

To automatically limit the current of the traction motors when the permissible value is exceeded after the traction motors reach the natural characteristic and ensure the output of the traction motors

for a natural characteristic without the use of a contact device in the proposed device, the output transformer of the control system, which generates pulses for controlling the extinguishing thyristor of the thyristor-pulse converter, is provided with an additional winding, one end of which through the contacts that close when the speed limiter is set to the position corresponding to the maximum speed, connected to the thyristor cathode, the thyristor anode is connected to the second end of the auxiliary winding, and the control electrode and the cathode the thyristor is connected to a non-linear bridge diagonal, the second diagonal of which is connected to the current sensor. In this case, there is no need for the use of a contactor for shunting the converter, and the automatic limitation of the current of the motors is also carried out on the output of their natural characteristic. The circuit diagram of the device is shown in the drawing. The thyristor converter 1 with power thyristor 2, quenching thyristor 3, switching capacitor 4p and resistor 5 is controlled by control system 6. The secondary winding 7 of output transformer 8 of control system 6 is connected to the control electrode and cathode of power thyristor 2, and the secondary winding 9 of output transformer 10 is connected to control electrode 25 and extinguishing thyristor 3 cathode. Block And pulse shift of control system 6 is connected to current sensor 12 connected in series with excitation winding 13 and 14 traction motor. 30 The output transformer 10 of the control system 6 has an additional winding 15, one end of which is connected via contact 16 to the cathode of the additional thyristor 17. The second end of the winding 15 is connected to the anode 35 of the additional thyristor. The control electrode and the cathode of the additional thyristor 17 are connected to the diagonal of the nonlinear bridge 18, in one arm of which there is a zener diode 19. The second diagonal of the nonlinear 40 bridge 18 is connected to the current sensor 12. The contact 16 is interlocked with the handle 20 of the unit speed setting knob AND the pulse shift. From the output transformers 8 and 10 of the control system 6, the control transitions of the power 45 and the extinguishing 3 thyristors of the thyristor-pulse converter 1 receive pulses that are shifted in time relative to each other. This shift is adjusted by the locomotive driver with the help of a handle 50 ki 20 speed knob. A pulse that connects to the control transition of the power thyristor 2 opens it, and the power source is applied to the pulser. The control transition of the quenching - 55 thyristor 3 impulse from the control system 6 is supplied with a shift relative to the impulse that turns on the power thyristor 2. When the extinguishing thyristor 3 is opened, the switching capacitor 4 is recharged and 60 closes the power thyristor 2. Voltage on the traction motor becomes equal to the bullet. Thus, adjusting the shift between pulses, including the power thyristor. and pulses, including damping tirk-65

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419426 stop, the driver adjusts the average voltage on the engine, and consequently, his speed-prf mialmalonol will drop the voltage aa of the engine to be minimal, and iipii lhiksimalnom - olizky to the voltage source hstani. When a vehicle is accelerated, the engine using the knob 20 of the knob of the network speeds up the SBIT between pulses, including power and extinguishing thyristors, at which motor current will exceed the acceptable value, then node ii of the pulse shift, to which input from current sensor 12 comes A voltage proportional to the motor current reduces the pulse shift and, consequently, the motor voltage BEFORE icx until the motor current becomes equal to the allowable one. When the handle 20 of the speed master is set to the position corresponding to the maximum pulse shift, pin 16 interlocked with the handle closes and prepares the circuit for shorting the winding 1o of the output transformer 10. The magnitude and polarity of the diagonal of the bridge to which the coupling is connected additional thyristor 17 (bridge output) depends on the voltage at the input of the bridge connected to current sensor 12. At motor current values below the allowable voltage at the output of the bridge, such that the thyristor opens. If the motor current is equal to or exceeds the allowable value, the polarity at the output of the bridge changes and the thyristor cannot open, Assume that with a constant load on the motor shaft and setting the handle 20, the speed setting knob 20 is in the position corresponding to the maximum pulse shift , the motor current exceeds the permissible value. By a signal from the current sensor 12, the pulse shift unit 11 reduces the pulse shift and the current becomes equal to the donable value. The additional thyristor 17 is closed and the winding 15 is not shorted. As the engine accelerates, the counter electromotive force of the engine increases and the current decreases. The shift of the pulses increases, etc. The current in this case is equal to the permissible frequency, and the thyristor 17 remains locked. After the pulse shift becomes maximum, and the current decreases and falls below the allowable decrease, the polarity of the voltage across the nonlinear bridge will change. The thyristor 17 will open, the winding 15 will short out and the pulses received by the control transition of the extinguishing thyristor 3 from the winding 9 of the transformer 10 will disappear. From the winding 7 of the transformer 8, the pulses continue to 1stress1. to go to the control transition; About thyristor 2. Therefore, thyristor 2 remains gmkrytnym and the engine goes to the natural side: -z characteristic. If now the motor current increases and becomes pav ili exceeds the permissible value, then the polarity of the voltage at the output of the nonlinear bridge will change, the thyristor 17 will close and pulses will be in TC output of the winding 9 of the transformer 10. Extinguishing thyristor 3 will open and the operation of thyristor converter 1 will resume as the switching capacitor 4 with open thyristor 2 is charged through resistor 5. When the converter is running 1, the pulse-shift unit keeps the current of the traction motors within acceptable limits.

Subject invention

A device for controlling a traction electric motor of an electric rolling stock of direct current, comprising a thyristor-pulse converter with power and quenching thyristor, a control system of a thyristor-pulse converter with an automatic current limiting unit for motors, output transformers that generate pulse pulses for controlling power and thyristor converter, speed reference and a current motor current sensor, characterized in that, in order to automatically limit Current t goy ;; when the motor exceeds the permissible value after the output of the traction motors to the natural characteristic, it is equipped with a non-linear bridge, one diagonal of which is connected to the current sensor, and an additional thyristor, the control transition of which is included in another diagonal of the non-linear bridge closing when setting the setpoint to the position corresponding to the maximum speed, the output transformer forming the impulses to control the extinguishing dash Stora converter, provided with an additional winding and said additional thyristor, a contact and a coil connected in series.