Effects of Misalignment on Output Voltage Stability in SS Controlled Wireless Power Transfer Systems with Different Control Strategies

In this paper, a comparison of different control strategies applied to a series-series (SS) compensated wireless power transfer (WPT) system is presented. The aim of the comparison is to find the most suitable strategy which is able to stabilize the system when misalignment conditions occur in the in-air coils of the converter, putting in evidence the main limitations of each tested control strategy. Some preliminary analyses in steady-state conditions are conducted to predict the possible limitations of the control strategies. The closed loop control strategies are designed using the control to output transfer functions of the system, which are used to tune the parameters of a proportional-integrative-derivative (PID) controller. The performances of the system controlled with the different control strategies are evaluated in Simulink environment.