US Patent 7835165 Power converting apparatus

In a power converting apparatus in which two three-phase converters (1), (2) are operated parallel to one another, the three-phase converters (1), (2) are controlled by using d- and q-axis voltage commands. DC current sensors (26), (27) detect individual output DC currents (26a), (27a) of the three-phase converters (1), (2), and a d-axis voltage command vdr for each of the three-phase converters (1), (2) is corrected in a manner that reduces a difference between the output DC currents (26a), (27a). In this way, an output imbalance between the two three-phase converters (1), (2) is corrected while decreasing limitations on arrangement of the DC current sensors (26), (27).