Development Of7500A Power Supply For DC Circuit Breaker Testing

Because of the better overload and short circuit protection, DC circuit breaker are widely used in households, companies and power grid, Therefore,The DC circuit breaker protection is very important to check. In this paper, basing on soft-switching technology and DSP control technology, we developed a High-frequency switching power supply, which is for DC circuit breaker testing. The main achievements are as follows.The article discusses the PWM converter and soft-switching technology. We compared the zero-voltage soft-switching circuit and zero current soft-switching circuit. According to the main circuit of the phase-shifted full-bridge PWM converter, we propose a zero voltage switch zero current switch DC/DC converter circuit structure and analyze the working process of the converter.The thesis has designed the main circuit topology which we selected, and gave the methods of parameters designing and calculation for main circuit, includes the design of the bridge Rectifier, Inverter bridge, Radiator, high-frequency transformer and output filter Inductor, Capacitor.The specific circuit structure of auxiliary control loop is given in the article. It includes the drive circuit, protection circuit and the voltage, current sampling circuit. The thesis detailed analysis of the control loop works.The thesis completes the design of the control system. It Details the design of the DSP-based control algorithm and introduces the implementation methods of the PLC and touch screen PC software features.On this basis, the Matlab/simulink simulation model is built. The results verify the system is reasonable.According to this research achievement, We have developed a7500A model machine of high-frequency switching power supply and given the specific test waveforms. The model machine which has light weight, small size, current and fast response is operating normally.