Decouple control scheme for three phase PWM converter under inductances unbalanced conditions

In three-phase PWM converter, the active and reactive currents are coupled in the synchronous frame. To avoid the deterioration of these coupling amounts, decouple control strategy is essential. However, under the conditions of unbalanced inductances, decoupling effects will be affected. Therefore, this paper proposes a novel decouple control scheme for the PWM converter. A mathematical model was built in the synchronous frame considering the imbalance in three-phase inductance. Coupling amounts induced by inductances imbalance are taken into account in the proposed decoupling strategy based on the traditional vector control method. Through analysis, a more rapid dynamic response can be obtained using this measure compared with PIR method and dual dq method. To validate the effectiveness of the proposed strategy, experiment tests on a three-phase PWM system are carried out. The results demonstrate that the proposed strategy can realize effective decoupling, and eliminate the negative influence caused by inductances imbalance with fast dynamic response.