SU699502A1 - Device for regulating converter voltage - Google Patents

Description

one

The invention relates to the field of electrical engineering, in particular, to the transformation of the vocational technique, and can be used, for example, in systems of smooth interstage regulation of the voltage of traction motors.

The closest in technical essence to the proposed invention is a device for regulating the voltage of the converter, containing a transformer with a sectioned secondary winding, and a voltage control unit, the output of which is connected to the control electrodes of the thyristors of the converter, and a current sensor ij.

A disadvantage of the known device is that due to the inconsistency of the angle of regulation of the angle of natural commutation, it is possible to break the power contacts under current, which reduces the reliability of the device in the case.

The circuit of the invention is to increase the reliability of the converter and the quality of regulation.

This goal is achieved by the fact that the device is equipped with a logic unit that has two pulse-width formers, the first of which is connected to the current sensor output, and its output is connected to the second, Memory circuit, one of the inputs of which is connected to the output of the first the former, and the other through the Inhibit circuit, to the output of the second imager, the output, circuits of the Memory being connected to the input of the control unit, and its output through the One-Vibrator connected to the second input of the indicated AND circuit, and the Prohibition circuit, respectively .

Switching on the logic unit between the current sensor and the control unit and the connection of its elements between each other provides a position in which the transition of the power controller from one control step to another is allowed only if the phase of the control pulses corresponds to the natural switching angle of the thyristors

queue increases the reliability and quality of regulation.

FIG. 1 shows a block diagram of the device, containing its converter 1 voltage regulating unit 2, current sensor 3, pulse shapers 4.5, Single Vibrator 6, circuit 7; schema Memory 8 Barring scheme 9.

FIG. Figures 2 and 3 show timing diagrams that explain the principle of operation of the device when the phase of the control pulses coincides with and does not coincide with the angle of natural commutation.

The device works as follows.

The control pulses from the output of the control block 2 switch the thyristors of the converter and simultaneously start the one-shot 6, at the output of which pulses form, the phase of which corresponds to the phase of the control switches of the thyristors

During the switching of the thyristors At the output of the current sensor 3, a square-shaped signal appears, the duration of which is determined by the moment when the switching ends. This signal is fed to the input of the first shaper 4 given pulse duration.

When the output coincides: the signals of the one-shot 6 (Fig. 3.6) and the pulse width generator 4 (Fig. 3 4), the Memory 8 circuit is switched through the And 7 circuit to its output state (Fig. 3.8) It has a signal that permits the transition of the power controller to the next stage of regulation.

At the same time, the signal from the output of a single vibrator 6 prohibits the passage of a signal from the output of the second pulse shaper 5 (Fig. 3.6) through the Inhibit circuit, 9 to the switching of the Memory 8 circuit to a state when there is no signal at its output.

If the phase of the control pulses does not correspond to the natural switching angle (Fig. 2), the signal from the output of the one-shot 6 (Fig. 2.6) coincides with the output signal of the pulse width generator 5 (Fig. 2.5), resulting in the output of the Inhibit 9 circuit (Fig .2 9) a signal appears that switches memory circuit 8 to a state where there is no signal at its output and thereby blocking the start of the control unit 2.

Thus, the resolution of the transition of the power controller is provided only if the phase of the control pulses corresponds to the natural switching angle of the converter thyristors.

Claims (1)

1. USSR author's certificate in application number 2051251/07 Cl. G05 F1 / 14, 1974. "Q