Research And Implementation Of The Portable Digital Test Power Supply

With the development of science and technology, the universal application of thevarious power electronic devices make people’s lives more and more convenient.However, the daily maintenance and overhaul of equipment has already become animportant foundation to guarantee the devices work normal and stable, and theapplication of the test power supply makes it much easier. Portable digital test powersupply is popular for its many advantages such as small size, light weight, highefficience, simple operation and convenient carrying character.Firstly, the principles and process of the phase-shift full-bridge ZVZCS PWMconverter are analyzed,and on the basis of which, according to the modeling methodof BUCK circuit,the small signal model of the phase-shift full-bridge ZVZCS PWMconverter is built, and discusses some key issues of the circuit topology, the outervoltage loop and inner current loop are designed. According to the technical index,the thesis designs and selects the key parameters of the main circuit, and then themain circuit was simulated.The results show that the leading arm can realize ZVS andthe lagging arm can realize ZCS, which has confirmed the rationality of the design.In order to make test power supply can output moer stable voltage and morestable current, the thesis uses double-loop control which consists of outer voltage loopand inner current loop. Because of the PI control algorithm, the system dynamicperformance is further enhanced. The control circuit uses TMS320F2812as the corecontroller, the paper designs hardware and software, which consists of DSP minimumsystem, Voltage sampling circuit, current sampling circuit,PWM driver circuit,auxilia--ry circuit, overvoltage protection circuit, over-current protection circuit, over tempe--rature protection circuit and control procedures. Finally a portable digital test powersupply prototype is produced, and debugging is made after power supply installation.The experimental results and the prototype pictures are given, which verifies the corr--ectness of the thethesis and also meets the design requirements.