IMBALANCING VOLTAGE COMPENSATION CIRCUIT OF 3 PHASE INVERTER AND ITS METHOD

摘要

PURPOSE: Unbalanced voltage compensation circuit and method are provided to easily calculate a compensation value by compensating voltage unbalance at a DC link end using offset voltage. CONSTITUTION: A first subtractor(710) outputs u-phase instruction voltage. A second subtractor(720) outputs w-phase instruction voltage. A third subtractor(730) outputs difference between lower side DC link voltage and upper side DC link voltage. A multiplier(740) outputs offset voltage by multiplying a specific ratio to the output of the third subtractor. A first adder(750) outputs u-phase offset compensation instruction voltage by adding the u-phase instruction voltage and the offset voltage.