Method of digital control of m-phase thyristor-pulse d-c converters and apparatus for effecting same

摘要

A method of digital control of m-phase thyristor-pulse converters, in which the duration of the conductive state of the thyristors of each phase of an m-phase thyristor-pulse converter is changed by sending time-shifted and time-constant pulse trains successively from each control channel to the thyristors of respective phases with simultaneous shift of the onset of operation of the thyristors of each phase by (1/m) period of switching the thyristors. Successive connection of each control channel to a respective phase is effected upon achieving the maximum value of the control zone of each control channel. The apparatus for carrying out the proposed method includes a master oscillator connected to a clock counter whose outputs are connected to the inputs of a decoder for decoding the time-constant pulse trains and to the logic inputs of "m" decoders for decoding the time-shifted pulse trains. The data inputs of each of the "m" decoders are connected to the data outputs of a bidirectional counter connected to a control unit, while the ouput of each of the "m" decoders is connected to one of the "m" data inputs of a matching unit whose control inputs are connected to the control outputs of the bidirectional counter. The matching unit includes "m" groups of AND gates, each group comprising "m" AND gates; the output of each AND gate of the 1-th group is connected to the 1-th control output of the bidirectional counter, while the other input of the 1-th AND gate of each group is connected to the output of the decoder for decoding the 1-th time-shifted pulse train, where 1=1,2, . . . m and m is the number of phases of the polyphase thyristor-pulse d-c converter.