METHOD OF CURRENT COMMUTATION BY KEYS OF TWO-WAY CONDUCTION OF MATRIX CONVERTERS (VARIANTS) Russian patent published in 2004 - IPC

FIELD: conversion equipment, adjustable A C motor drives.

SUBSTANCE: in method of current commutation by key of two-way conduction each key comprises two halves of matrix converter controlled separately and conducting in opposite directions. Number of input phases of matrix converter is equal or greater than three which makes it possible to carry out safe step-by-step commutation of current by keys of matrix converter without use of information on polarity of load current or unambiguous relation of voltages in supply network at moment of start of step-by-step switching over. Usage of given method in three-phase matrix converter with vector pulse duration modulation provides for synthesis of spatial vectors of output voltage and input current in process of each cycle of vector pulse-duration modulation from zero and nonzero stationary vectors with splitting of period of network voltage into six intervals which boundaries are moments of change of polarity of input phase voltages. Special method of formation of zero vectors and their alternation with nonzero vectors makes it feasible to reach safe current commutations even when curves of network voltage are markedly distorted. All switchings of keys in matrix of converters are functionally advantageous and do not cause any additional dynamic losses.

EFFECT: removal of short-circuit currents and prevented commutation between keys.

5 cl, 12 dwg