Dynamic Improvement of Wireless Power Transfer Systems with Maximum Energy Efficiency Tracking by Sliding Mode Control

A pulsewidth-modulation (PWM)-based sliding mode control (SMC) scheme for improving the dynamic performance of a series-series compensated wireless power transfer system (WPT) with maximum energy efficiency tracking (MEET) is proposed in this paper. In this system, the receiver module comprises a buck-boost converter that is regulated using SMC to emulate the optimal load value, following the maximum energy efficiency point of the WPT system. A hillclimbing- search-based optimization process is applied at the transmitter side of the system such that no communication is required between the controllers of both transmitter and receiver. Compared with the same system using a PI control [12], the proposed system displayed better dynamic performance of the output voltage, input power, and energy efficiency during the MEET search process. This also prevents the load from facing undesirably high overshoot/undershoot during transient.