SU922992A1 - Gate-type converter digital control method - Google Patents

Description

The invention relates to the management of thyristor converters.

A known method of digital control of a valve converter, at which measures the duration of a part of the mains voltage period, corrects the frequency of the counting pulses, and generates control pulses when the code of the reference signal coincides with the control code [1].

The disadvantage of this method is its complexity.

The closest to the proposed technical means and the achieved result is a method of digital control valve converter, which measure and encode the duration of the voltage period of the AC network, form the code of the reference period, digital time base for each phase, control code and control signals of the valves [2] .

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The disadvantage of this method is its complexity.

The purpose of the invention is to simplify the method.

This goal is achieved by the fact that the period duration is measured between the transitions of the voltage of each phase from negative to positive values, multiply the codes of the measured and reference periods and get a control code that is compared with time base and, if they coincide, form control signals.

The drawing shows the block diagram of the device.

The device contains the formers 1 of the voltage transition pulses of phases A, B, C of the network through zero from negative to positive values connected to the inputs of the installation of zero blocks of 2 meters, the other inputs of which are connected to control circuit 3, the outputs of blocks 2 are connected to

H 92:

inputs of block 4 comparison of codes and control thyristors, as well as with the control circuit 3. The output of circuit 3 is connected to the input of block 4 for comparing codes and controlling thyristors. five

Let, for example, the binary code of the duration of the reference voltage period of the network be 1000 ... O, · at which it can be taken as one. If the measured period of the network is equal to the reference one, the code of the measured period of the network will be equal to 1000 ... 0. In this case, when multiplying the reference period code by the network period duration code, a control code equal to the reference code (no change) is obtained, which will result in coincidence of control codes and digital time base at times corresponding to 20 coincidence of reference control codes and digital time base for the reference voltage period of the network. If the measured period of the network is greater (or less) than the reference one, the code 25 of its duration will be greater (or less) than unity, i.e. will have the form 100 .. .01, .. (or 011 ... 10). In this case, after multiplying the reference code with the code length pe- zo IRS will receive a greater (or smaller) value of the control code and control code coincidence code and a digital time base will be offset in time by ₃₅

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nor, proportional to the deviation of the magnitude of the period from the reference period, which compensates for the influence of the network's non-synchronization on the operation of the valve converter.

The proposed control method is simple, which leads to simplification and increase of reliability of control systems for valve converters.

Claims (1)

Claim The digital control method of the valve converter, in which the duration of the AC mains voltage period is measured and encoded, forms a reference period code, digital time base for each phase, control code and valve control signals, characterized in that, for the sake of simplicity, the control code is obtained by multiplying the codes of the measured and reference periods, and when the control code coincides with the time base, form control signals for the gates.