The LCL resonant structure of inductively coupled power transfer system receiver has many constraints of parameters. The traditional design method needs repeated iterations

which is very complicated. To solve this problem

a non-linear programming method is proposed to solve parameters of the unity power factor on critical conduction mode in LCL resonant converter

which can transform the complicated resonant structure parameters design problem into a general non-linear programming problem. This method can make all the components of the resonant structure satisfy the constraints under any condition so that each component works at a relatively close load level. The stress of voltage and current in the resonant structure is distributed to each component in a balanced way. Finally

an example is given to verify the proposed method

and a prototype with a rated output power of 2. 1 kW is built. The feasibility and correctness of the method are verified by experiments.