A Comparison Study between Different Decoupling Circuits & Inverter Models in Induction Drives for FOC

Field-oriented control is a technique used to control permanent magnet synchronous and AC induction machines. Implementing this technique in the rotor flux reference frame usually requires a decoupling circuit for independently regulating torque and flux in the induction machines with VSI. In this article, the dynamic behaviors of the different decoupling circuits are investigated with different models of the VSI. Also, the influences of these models on the independent current control in the field-oriented system are identified. The results show that the use of the decoupling circuits in feeding voltage inverters in current mode control has no important effect on the performances of the FOC and by eliminating decoupling circuits, the implementation of a closed-loop control system can be effectively improved.