SU1255476A1 - Device for pulsed control of direct current in vehicle - Google Patents

Description

The invention relates to transport, in particular, to devices for pulsed regulation of the excitation current of a vehicle traction motor.

The purpose of the invention is to increase reliability.

FIG. 1 is an electrical block diagram of the device; in fig. 2 - time diagrams of currents and voltages at the electrical device.

The device contains a thyristor converter 1, supplying the traction motor 2 from the power source 3 through an inductive-capacitive filter 4. The converter I includes the main thyristors 5 and 6, the node 7 forced switching, auxiliary thyristors 8 and 9, shunt resistors 10 and II reverse diode | 1 12 and 13. Block 14 control unit; 1 is input to the sensor 15 1 of the first motor, and Biii- moves to the formers of 16-19 main and auxiliary pulses and to the generators 20 and 21 of the sawtooth voltage. The outputs of the drivers 16 and 19 are connected to the main thyristors 5 and 6, and the generator 17 and 18 - to the inputs of the node 7 forced switching. The outputs of the generators 21 and 20 are connected to the inputs of the comparison units 22 and 23, the outputs of which are connected to the additional formers 24 and 25, the node.pochechen, the outputs to the thyristors 8 and 9. The generator 26 of pulses is connected to the input of the And 27 element, to friend | a) to the input of which, as well as to the inputs of the counter 28 and the register 29 of the memory of the undercarriage. The sensor 15 of the current of the motor, the output of the AND element 27 is connected to another input of the counter 28. The counter is; through a digital-to-analog conversion. 30 is connected to the inputs of the comparison units 22 and 23.

The time diagrams (Fig. 2) show curves a, b of the voltage of the shapers of shapers 16 and 17, the curve in is the current of 5, the curves r, g are the voltage of the shapers of shapers 18 and 19, the curve of f is GOK thyristor 6, curve l - motor current 2, curve h - voltage of sensor 15, curve and - voltage of the heater 26, curve k - voltage of the H 27 element, curve l - voltage at the output and transformer .l: 30, curves m, n the voltage of the generators 20 and 21, curves n, p e a rp pa output bblokov 22 and 23.

The device works in a smooth way.

From the outputs of the control unit 14, the formers 16 and 17 receive pulses of unlocking (curve a) and latching (cr. B) of the main thyristor 5 of the first phase, through which phase current ii flows (curve and), and from other outputs through the drivers 18 and 19, shifted by 180 ° - unlock pulses (curve r) n lock

PIA (curve e), respectively, of the main thyristor 6 of the second phase, through which the phase current ij (curve e) of the motor 2 flows.

After the adjustment of the voltage of the engine 2 is completed, the current of the core to (curve g) will decrease and the engine 2 will tend to achieve a natural characteristic. To illustrate the operation of the device in FIG. Figure 2 conventionally shows a decrease over several periods of correction of the core current relative to its nominal value.

The output pulses (curve C) of the current sensor 15, whose frequency is proportional to the magnitude of the current core, are filled at the logic element AND 27 with high frequency pulses (the curve and, received by P1I.MI from the output of the pulse generator 26. At the output of the And 27 element, voltage values (curve k), to which, first of all, stacked in a time interval equal to the duration of the output pulse of the current sensor 15, is reverse to the current magnitude of the core in this gap and equal to the output code

counter 28. The writing of this code from the outputs of the counter 28 into the memory register 29, as well as resetting and resetting the counter 28, takes place on the falling edge of the output pulse of the current sensor 15.

Thus, the code, inversely proportional to the current value of the core, is updated at the output of the register 29 with the frequency of the output pulses of the current sensor 15. This code is converted by a N / A digital-to-analog converter 30 in a straight line (curve), directly proportional to the magnitude of the current of the motor core, which is achieved by selecting the appropriate field of the digital-to-analog converter 30.

The voltage pulses from the control unit 14 are fed to the inputs of the generator 20 1111. | A voltage form, the output of which produces sawtooth voltage pulses (curve). Voltage pulses from the control unit 14 are also fed to the inputs of the sawtooth voltage generator 21, and pulses of the filament voltage are formed at its output (curve g). The slope and amplitude of the impulses of the sawtooth voltage are proportional to the current setpoint of the core. As a result of the comparison of the voltage values in the block 22 and the block 23 of comparison (curves l, m and l, n), the output pulses are produced at the output of the blocks of comparison, respectively (curves n, p, on the front

the fronts of which are formed with the help of formers 24 and 25 of control pulses, respectively, of the thyristor unlocking pulses 8 and 9. Their locking is

dits respectively pulses lock the main thyristors 5 and 6.

Thus, the proposed device provides for the formation of control pulses without first isolating the magnitude of the current mismatch with respect to the setpoint when controlling

A two-phase thyristor-pulse converter with additional regulating thyristors connected in parallel to the field winding, which simplifies the algorithm for determining the magnitude of the control action, improves the control accuracy, and consequently, the quality of the controlled current.

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Claims (1)

DEVICE FOR PULSE REGULATION OF EXCITATION OF DC TRACTION MOTOR OF DC, containing thyristor converter connected to power supply through inductance-capacitive filter, including main and auxiliary thyristors, forced switching unit and reverse diodes, control unit connected to voltage generators and outputs connected to voltage generators and outputs and auxiliary pulses, the outputs of which are connected respectively to the main thyristors and inputs of the forced switching, and the input is with a current sensor of the traction motor, the comparison units connected by the outputs through additional shapers to auxiliary thyristors, one input to the outputs of the corresponding sawtooth generators, and other inputs to the output of the digital-to-analog converter, the input of which is connected to the output of the memory register connected by one input to the outputs of the meter, one of the inputs of which is connected to the current sensor of the traction electrodvigatel § §, characterized in that, in order to increase reliability and, it is equipped with an And element and a pulse generator connected to one of its inputs, while the other input of the And element and the other input of the memory register are connected to the current sensor of the traction motor, and the output of the And element is connected to another input of the counter. SU ,,,, 1255476