Study On A Constant Current High-voltage Charging Power-supply Based On DSP

The traditional high-voltage DC power-supply, which usually be gotten by boosting 220V 50Hz AC voltage with transformer and then converting voltage with rectifier filter, has big bulk and weight, high ripple coefficient of output voltage, low stabilization and efficiency. The design of a high-frequency high-voltage power-supply using soft switching power-supply technology is discussed in this paper. The core part includes full-bridge inverter, transformer and rectifier. Primary inverter is a full-bridge inverter constructed by ZVS PWM DC/DC, which insures the system working at high frequency.The main use of transformer for high frequency is to transform energy ,electric insulating, voltage changing and impedance changing as magnetic coupling. The capability of the transformer affect the safety of the device of the power switching. In the paper, the factors that affect the capability of the transformer is analyzed, which including that the principle of the magnetic material selecting, the principle of the shape of the magnetic core, the kinds of the magnetic core and the calculation of the design for the transformer.DSP is the core of the power supply ,The paper adopted TMS320LF2407 made by TI company to realize phase shift full-bridge soft switch, it is also used to adjust the voltage of output and protect the system when current is overflow .The control method is decided by software, it can be modified according to the need of the custom.The power of the power-supply is 3000W.The switching frequency is 20kHz. Output DC voltage of power-supply is 2.4kV and can be changed by DSP. The ripple coefficient is no more than 0.5%. The efficiency of the power-supply system is more than 80%.