Control Characteristics And Magnetic Integration Techniques For Class E Converter

Due to the simplicity and high efficiency, Class E converters have a bright future, especially in the high switching frequency application. At present, Class E converters are concerned and applied in lighting, high-frequency induction heating and radio frequency fields. Class E converter is detailly studied in this thesis. Basic principle and control characteristics of the Class E converter are presented. There are more magnetic components in Class E converter with transformer, so IM (Integrated Magnetic) technology is introduced into it in order to reduce the magnetic core size and improve the power density.In order to design the Class E converter properly, the quantitative relationships are analyzed in detail and the influence of parameters on the circuit performance is discussed. Then, in order to realize the ZVS (Zero Voltage Switching) and steady output, graphic and computer programming methods are presented to analyze the control method on variable input and variable load condition.A prototype of 21W is built in the lab to verify the correctness of the design procedure and the validity of the control method. Experimental results show the validity of theoretical analysis.The influence of magnetizing inductance on the Class E converter is analyzed. Two IM methods of the Class E converter with transformer are presented in this thesis. Several structures of IM transformer with leakage inductor is simulated by Ansoft. The equivalent circuits of two kinds of IM transformers are derived. The equivalent circuits'parameters can be solved directly using the relationship of the ports'impedance. Then the design of IM is finished.Finally, with the same given specification, two prototypes rated 21W with discrete magnetic and integrated magnetic are built in the lab, respectively to verify the theoretical analysis. Compared to the discrete magnetic, the core volume and weight can be reduced by nearly 50 percent with the independent winding integrated magnetic, and also the efficiency is improved slightly.