Design Of A High-Voltage DC Switching Power-Supply Based On DSP

The traditionary high-voltage DC power-supply, which usually can be got 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 switching power-supply technology is discussed in the paper. The core part includes buck converter, full-bridge inverter, transformer and rectifier. Primary inverter is a full-bridge inverter constructed by LCC-ZVS PWM DC/DC, which increases working frequency. As a result, bulk and weight of the power-supply are largely reduced. Stabilization and efficiency of the power-supply are also greatly improved. BUCK converter chooses and adjusts output voltage. High-voltage insulation is implemented using series of two transformers. Voltage doubling levels are reduced by bi-directional doubler, which also increases the system stability. The driving part is implemented using IR2110/2125 series MOSFET driver. TopSwitch single-chip switch power supply is utilized to produce different DC voltages including 3V DC, ± 5V DC and 15V DC needed by DSP and the driver part. A ball electrostatic model is designed and simulated by Maxwell software. Controlling part of system is based on Digital Signal Processor TMS320LF2407, which protect the system from possible destruction.The power of the power-supply is 100W. The switching frequency is 20kHz. Output of DC high-voltage power-supply which can be chosed by DSP is 25kV, 50kV, 75kV, 100kV. The ripple coefficient is no more than 0.5%. The efficiency of the power-supply system is more than 80%.