Turning control manner of alternating current - alternating current direct conversion device and alternating current - alternating current direct conversion device

摘要

PPROBLEM TO BE SOLVED: To increase the degree of freedom of commutation by increasing the three step commutation pattern having a small number of times of switching in a matrix converter including a plurality of bi-directional switches for AC-AC conversion which is inserted into an electric path connecting an AC power supply and a load. PSOLUTION: A three step commutation pattern includes a first step of extracting such a pattern as the control of a third step is identical and the control of a fourth step is identical from a commutation pattern where power supply short circuit fault and load current open circuit fault do not occur in a four step commutation method, and then performing the first control (switch S1b is off) and the second control (switch S2b is on) of an extracted pattern simultaneously, a second step of performing the third control (switch S2b is off) of an extracted pattern, and a third step of performing the fourth control (switch S2b is on) of an extracted pattern, wherein the commutation pattern is selected according to the magnitude of the power supply voltage and the polarity of the load current. PCOPYRIGHT: (C)2010,JPO&INPIT