Control And Thermal Analysis Of 150kW Power Supply Based On Phase-Shifted Full Bridge

Phase-shifted full-bridge DC-DC circuit has simple structure, easy to control with constant frequency and high frequency, reducing the press and loss of power switches with a resonant circuit constituted by the leakage of transformer and parasitic capacitance of power switches, etc. It is widely used in high power applications. The idea of modular and N+1 redundancy design was proposed in this paper for the need of high power supply in the refining monocrystalline silicon. The 150kW power supply based on Phase-shifted full bridge topology was designed.The operating principle of Phase-shifted full bridge converter without L-C filter circuit, with stray inductance of output, was described in detail. For 150kW switching power supply, the converter proposed had smaller volume of device and less duty cycle loss, compared with traditional phased-shifted full bridge zero-voltage-switching converter. Three-terminal PWM switching model was described in paper. Small-signal model analysis for phase-shifted full bridge converter with three-terminal PWM switching model was proposed in this paper. The control-output, audio attenuation, output impedance and input impedance transfer functions of the converter were calculated.The program control scheme of the 150kW power supply, with digital DSP control scheme, was described in detail, including hardware circuit and implementation scheme of A/D sampling, D/A conversion, SCI module, SPI module, etc. The main program, communications procedures between LCD and DSP,2-ring control algorithm of the power supply was introduced in detail in this paper. With the simulation software of Flotherm, water cooling of the 150kW power supply was designed. The water speed need in cooling-plate of the power unit was calculated with the basic formula of fluid mechanics. The thermal simulation model of power unit with Flotherm was built, and then the simulated and experimental results verified the rationality.Simulated model of the 150kW power supply was built with PSIM. The simulation results verified the rationality. Finally, A experimental prototype of the 150kW power supply based on phase-shifted full-bridge converter without L-C filter circuit, with stray inductance of output, was built and tested. Experimental result and the data from field investigation verified the correctness and superiority.