POWER CONVERSION UNIT Russian patent published in 2012 - IPC H02M7/48 

FIELD: electrical engineering.

SUBSTANCE: power conversion unit (1a, 1b) comprises a converter (10), which actuates the alternating current motor (5) by transforming the direct current voltage into the alternating current voltage of unrestricted frequency, a switching unit (14a) for disabling alternating current which is connected between the converter (10) and the alternating current motor (5), a detecting element (11, 12, 13) which detects the converter (10) output current, and a control unit (15a, 15b) which switches some elements in the converter (10) on and off and controls the switching unit (14a) on the basis, at least, of the current detected by the detecting element (11, 12, 13). The control unit (15a, 15b) is designed to be able to cut off the fault current by forcing it to pass through zero when the fault current is formed between the converter (10) and the alternating current motor (5).

EFFECT: increased reliability of the device.

2 cl, 6 dwg