| Swithing power supply is the necessary electrical equipment in research and industrial applications. In the middle or high power scale applications, the Phase Shifting Full Bridge (PSFB) soft swiching power supply is popular for its relative little energy loss, high efficience and low interference character. In this paper, the improvement of PSFB soft switching DC-DC converter has been discussed, and the intelengance controlling method of the improvement circuit has been fully researched.According to the efficency problems of the traditional PSFB circuit as duty cycle loss and rectifier resonant oscillating phenomenon, an improvement is proposed which adds a snnober and a clamping diode in the auxiliary part that requires fewer capacities and inductance in the same scale of ripples. In the contrast of other improvements, the proposed one offers more efficency and lower cost, and can be proved via simulations in this paper.For the nonlinearity and the discreteness of the improved circuit, the control method has to be improved. In this paper, using Union Rule Configuration (URC) fuzzy theory instead of Intersection Rule Configuration (IRC), an improvenment is proposed to increase the operation speed and decrease the soft requirement at the same time. In the comparasion of the proposed argorithm, common PID and the popular fuzzy PID self adapting argorithm, the common one stabilizes slower, has more overshoot, but easy to realize, and the popular one stabilizes faster, has less overshoot, but hard to be applicated in embedded system, and the proposed one wins in every aspect that can be proved by simulating comparison illustrated in this paper.At last, the whole system is designed in detail including PSFB main borad, DSP mini system with URC fuzzy PID argorithm, isolated MOSFET driver MAX4428, AC EMI-rectifier-filter module, signal sampling and assembling module, and assistant power module. The proposed designation balances the cost, speed, efficency, and robustness.
|
PDF Full Text Request