Study on robust controller design for inductively coupled power transfer system

In an Inductively Coupled Power Transfer (ICPT) system, there are two approaches, namely terminal control and source control, to obtain constant voltage output. The source control is beneficial to reduce unnecessary power losses and realize optimal operation. However, due to nonlinear characteristic of ICPT system, it is difficult to set up a nonlinear robust controller. This paper presents an extended Generalized State Space Averaging (GSSA) model with detachment of real part and imaginary part to avoid appearance of complex coefficient matrices in the modeling. Because the GSSA model is an approximation model, the paper defines the condition to guarantee stability equivalence between the GSSA approximation model and actual ICPT system and provides proof. Furthermore, the robust controller design method on the basis of the GSSA model is proposed and proven as well. The modeling and controller design method were verified by simulation results.