Research On Resonant Converter For 3KW High Frequency High Voltage Power Supply

Resonant converter has been widely used in high frequency high voltage power supply,which may produce a different DC voltage gain according to changes in the load. Circuit can significantly reduce the adverse effects of high-voltage transformer parasitics when working at the resonance point. A resonant converter is essential for good performance of high voltage power supply.Firstly, universally used topology circuitunder high-voltage situations is contrasted, and its DC gain curves are to be analyzed. Combined with converter workplace and work characteristics of the converter, suitable topology circuit is able to be selected. Secondly, based on the selected series and parallel resonant circuit, the model can be constructed. By using First-Harmonic Analysis of frequency domain analysis circuit is to be modeled, and the parameter values of fomulas of each circuit device are to be obtained. By using Small-Signal Analysis of time domain analysis, a state equation is established, and gives the resolution process and the results of each matrix expressionthe in the state equation. The transfer function of the resonant converter is obtained and the amplitude and phase characteristics of the model is solved by simulation tools, and the stability of the resonant circuit can be analyzed from the perspective of frequency characteristics. The phase shift control is employed in the control scheme. and Zero-Crossing Switch is employed in the switch selection. As to the LCC serial-parallel resanant converter, steady-state analysis is conducted, so are analysis of the operating modal of the circuit and the switching process of the circuit. Then the Generalized Average Method is employed to analyze the circuit. The small signal analysis method is employed to make formulation. and mathematical progressively and the model is set up. The output characteristics of the resonant convert is simulated by using the simulation software and the curves of DC voltage gain and the resonant inductor current at different output voltages and different output power conditions are to be drawn. The control circuit uses frequency phase shifted PWM signal driving and generating a drive signal which is stable and reliable.Through the converter modeling and parameter analyzing and calculating in the circuit, the stability and operation of the system DC converter will be gained. Resonant circuit debugging process is consistent with the theoretical analysis to verify the correctness of the theory, which provides a theoretical support for the optimization of high-voltage power supply system of the main circuit.