Research On High Frequency Power Converter And Resonant Gate Driver

The rapid development and wide application of semiconductor technology, micro electronic technology, provides a technical possibility for the power converter to high frequency, miniaturization, high power density and high reliability of the direction of development. However, as the operating frequency(>1MHz) incresing, the driving loss and switching loss of the voltage source driver(Voltage Source Driver, VSD) circuit will increase proportionally, reducing the efficiency of high frequency power converter. In order to solve these problems of traditional VSD circuit, the resonant gate driver(Resonant Gate Driver, RGD) is proposed. The RGD circuit uses the LC resonance principle to recover the driving energy stored on the equivalent input capacitance of the power switch, so as to reduce the high frequency driving loss.This paper first introduces the basic knowledge of MOSFET, the working principle of conventional VSD circuit, the calculation method of each part loss and the defects of VSD circuit.Then, the current resonant driver circuits are divided into two types of inductive current and intermittent, and examples are given to analyze the characteristics of these two types of resonant driving circuits. In this paper, three kinds of resonant driver circuits are used to carry out research, the working principle of the three resonant driver circuits are analyzed in detail, the loss of each part and calculation methods are also analyzed. The feasibility of these three resonant driver circuits is verified by Pspice simulation software. One kind of resonant driving circuit is proposed after the improvement of the original method. The coupling inductance is applied in the circuit, its inductance current is interrupted. By using constant current to drive power MOSFET, the driving loss can be reduced to a greater extent. In order to design the optimal resonant driver circuit, the resonant inductance is optimized by considering the relationship among the driving loss of resonant driver circuit, the switching loss of power switch and bulk diode loss. And then, the driving loss of the three kinds of resonant driver circuits are obtained by using the optimized inductance value. And comparing with the conventional VSD circuit, the result shows that the resonant driver circuits can effectively reduce the driving loss and improves the efficiency of the high frequency power converter.Finally, in order to verify the correctness of the theoretical analysis, in this paper, synchronous Buck circuit is used as the main circuit, and three kinds of resonant driver circuits and a conventional VSD circuit is produced, and carrying on the contrast experiment. The experiment has been completed, and the experimental results and detailed analysis is given.