Hierarchical Multiobjective H-Infinity Robust Control Design for Wireless Power Transfer System Using Genetic Algorithm

In inductive wireless power transfer (IPT) system, parameter perturbation and disturbances not only cause power fluctuation but also worsen system performances. Thus, robust control methods are introduced for improving the performances of uncertain IPT system. In robust control design, robust performance is often considered first. However, the enhancement of robust performance may lead to inferior time-domain performance. To deal with this contradiction, the weighting functions in the robust control design structure shall be chosen wisely. Considering the complex mutual dependence of weighting parameters, the selection of weighting parameters will become a complicated and practically time-consuming problem. Therefore, this brief presents a hierarchical multiobjective optimization method to select weighting parameters of H-infinity controller automatically. The inner level designs the H-infinity controller and guarantees robust performance. The outer level improves the system's time-domain performance and robust performance at the same time with a specially designed objective function using genetic algorithm. An experimental IPT prototype is established for the verification of the proposed optimization method. The optimization results show both good robust performance and fast time response about 5-8ms in different experiment conditions.