A New Double Narrow Pulse High-Voltage Power-Supply For Wastewater Treatment By Discharge

Wastewater Treatment by high-voltage discharge is the novelty method of wastewater treatment technology which has been widely developed in home and abroad. Pulse power supply is important part of the technology, and it's also a bottleneck of development of the technology. Unipolar pulse discharge will lead to charge accumulate to reactor. With the charge not releasing, the tail voltage will be formed. It will strengthen electric field which is formed by later pulse power supply, then make gap sparking discharge and induce injection of energy difficulty. Bipolar pulse power can avoid spark discharge efficiently, so a new double short pulse power-supply based on DSP is designed.The power-supply system is composed of a positive and a negative DC high-voltage power-supply and a RSGS (rotating spark-gap switch). The RSGS is used to control charge and discharge of pulse forming capacitances. In this power-supply system the full-bridge inverter is used to increase frequency, so the bulk and weight of the power-supply will be reduced obviously. In the inverter, the application of the soft-switching has two advantages. The first is reducing loss of switch, then frequency of power-supply can be heightened much more. The second is solving EMC problem of power-switching circuit. The controlling core of this power-supply is a DSP chip, TMS320LF2407. The ability of processing data of DSP is very strong so that it can control BUCK DC-DC circuit and full-bridge inverter (fixed frequency) and rotating speed regulation of motor only by the chip based on the feedback information of interior parameter of the load. In addition, EMC problem of the power supply is solved.The power-supply system has been applied to discharge in water for dye wastewater treatment. The power of this power-supply is 800W; output of DC high-voltage power-supply is from 0 to 50KV; rise time of the double short pulse is from 50nS to 100nS; pulse width is from 200nS to 500nS. These parameters are very satisfied with the demands of wastewater treatment by discharge...