Multi-Objective Optimization of LCC-S-Compensated IPT System for Improving Misalignment Tolerance

Due to their excellent performance, the inductor-capacitor-capacitor-series (LCC-S)-compensated topologies are extensively used in inductive power transfer (IPT) applications. However, perfect alignment of the system's contactless couplers is difficult, which leads to serious deterioration of the system output characteristics. In this paper, the influence of the coupler misalignment on the performance of the conventional resonant system is studied. To obtain stable output against varying couplings and loads in a certain range, a novel parameter design method based on the multi-objective particle swarm optimization (MOPSO) algorithm is introduced. The multi-objective optimization framework is developed to analyze the Pareto trade-offs between three conflicting performance metrics, namely output current/voltage ripple, reactive power transmission and component stress. Optimization results depict that misalignment tolerances in both constant current output (CCO)-type and constant voltage output (CVO)-type LCC-S-compensated IPT systems are improved, while a wider load range is suitable for a CCO-type system using the method of compensation parameter optimization. Experimental results are highly consistent with the design, achieving a current fluctuation of no more than 10.5% with a load range from 50 omega to 100 omega and a voltage fluctuation of less than 10.4% with a narrow load from 90 omega to 100 omega over 100% of coupling variations (from 0.25 to 0.5).