Improved H∞ Control for Input-Series–Output-Series Multichannel Inductive Power Transfer System Considering Parameter Inconsistency and Load Perturbation

To achieve stable output and enhance the robustness of input-series–output-series multichannel inductive power transfer system under parameter inconsistency and load perturbation, an improved H_∞ robust control is proposed in this article. First, the control effect of multichannel system is analyzed, which transfers the controller design into single system with uncertainty. Then, a linear model is established based on generalized state space averaged method and the influence of parameter inconsistency and load perturbation is analyzed. After that, the uncertain model is obtained via frequency-domain analysis, generating a numerical solution of weighting function to describe the uncertainty of parameter inconsistency and load perturbation. Based on the proposed weighting function, the improved H_∞ robust controller is designed and the dynamic performance and robustness of the close-loop system is analyzed. Finally, a down-scale prototype with three channels is built to verify the effectiveness of the proposed method. The experimental results show that the system obtains good dynamic performance and strong robustness against parameter inconsistency and load perturbation. When load changes between 60 and 80 Ω, the settling time is less than 4.7 ms with the overshoot being less than 7.3%. Even against large load perturbations, the settling time is still less than 8 ms.