AC-AC DIRECT POWER CONVERTER

摘要

Provided is an AC-AC direct power converter which can actively reduce a higher harmonic of a power source. A matrix converter main circuit (2) includes an LC filter (6) connected to an AC power source (4) and converts an AC output of the 3-phase AC power source (4) into other AC output.  A diode bridge rectification circuit (22) and a PWM converter unit (38) are connected between the output side of the matrix converter main circuit (2) and the input side of the LC filter (6).  A clamp circuit (24) is connected between the output side of the rectification circuit (22) and the input side of the PWM converter unit (38).  Control is performed as follows.  Current of the AC power source (4) is detected by current detection units (44R, 44S, 44T).  The maximum or the minimum output signal of power frequency component removers (46R, 46S, 46T) is detected by a current comparator (54).  The output signals of comparators (50R, 50S, 50T) are selected by a selection switch (52).  A switching element of the converter unit (38) is selected according to the output signal of the comparators.