Research On The High-frequency Power Supply Control System Of Wet Electrostatic Precipitator

In recent years, with the development of the economy, industrial dust pollution is becoming more and more serious, which leads to the frequent occurrence of fog and haze,and affects human health seriously. So it is very urgent to control the dust. Wet electrostatic precipitator is widely used as a dust collector. The high-frequency power supply is the key part of the wet electrostatic precipitator. It is directly related to the efficiency of dust removal and the safety of equipment. In this paper, with the high frequency power switch loss and the difficulity of control, we have carried out theoretical research and control strategy optimization. The purpose is to improve the efficiency of the high-frequency power supply. On the basis of comprehensive analysis of wet electrostatic precipitator technology, the following research work is carried out:We use the soft switching technique to solve the high frequency power switch loss,which is caused by high-frequency power supply and the distribution parameters of the transformer. Then we design the main circuit of the high frequency power supply, which is based on the LCC series parallel resonant circuit. The soft switch of the switch tube is realized, and it is verified by the simulation.It is difficult to obtain the ideal control effect when the conventional PID control is applied in the high-frequency power supply system with time-varying and nonlinear characteristics. Therefore, this paper introduces the fuzzy self-tuning PID control combined with PID control and fuzzy control in high-frequency power supply control system. At the same time, for flashover performance in wet ESP, the method of judging,treating and controlling the flashover is given, and the optimum flashover rate is used.The simulation model of the system is built with SIMULINK, and the control algorithm is simulated. The simulation results show that the fuzzy self-tuning PID control can effectively improve the dynamic performance of the system, and it has a stronger anti disturbance ability. By changing the voltage value, the flashover control mode come ture.The hardware circuit and software of the control system of the high-frequency power supply based on DSP TMS320F28335 are designed. The hardware circuit includes minimum system circuit, driving circuit, signal acquisition and conditioning circuit,spark detection circuit and over voltage protection circuit. In the CCS4.1.2 environment,we realize the generation of PWM, ADC data sampling, fuzzy self-tuning PID control and protection functions.