Research And Application Of High-voltage Electrostatic Precipitator Power System

Electrostatic precipitator(ESP)is an essential tool for industrial dust removal.In order to ensure enough charged particles and avoid flashover,arc and reverse corona,a suitable ESP power must be used.Armed with this,the key technology of the ESP power system is studied in this paper.The achieved results can provide the theoretical basis for the development of the equipment and the operation of the engineering.Alternate conduction PWM control method which is appropriate for DC-DC switching power is proposed.Compared with the traditional PWM control,the proposed control method can not only make the power loss and junction temperature similarity and uniform,but also reduce the switching loss by about 50% in the same output power.This is convenient for the design and selection of the heater,and can also improve the conversion efficiency of the ESP power;the alternate working frequency can make the ESP power adaptable to the transformer with different working frequencies,and reduce the cost of the industrial site update while improving the efficiency of the transformer.The current hysteresis control is utilized to realize the alternate conduction PWM control method.The simulation system is built to study and analyze the key technical problems of the hysteresis control,such as the operating state of the inverter under the current hysteresis control and the analysis of the voltage regulation under three typical operating conditions.The mathematical relationship between parameters such as IGBT switching frequency,width of hysteresis loop and inductor is discussed and derived.The power loss and junction temperature are calculated and compared with different voltage under the current hysteresis control.The average switching loss is reduced by about 30% if the output voltage rises from 70 k V to 90 k V.The obtained data verify that the control is an adaptive current control method.This adaptive control method can not only make the system more stable but also make the width of the hysteresis loop larger,the switching frequency of the IGBT module is reduced,then the switching loss is reduced too,this can reduces the serious switching loss when the output power of the hard switching power system increases.This control method can provide a theoretical basis for the operation of the future equipment.In view of the problem of current overshoot and ringing,the simulation system which considering the distribution parameters of the transformer is established.A distributed parameter model of three capacitance is proposed,and the two port network method is used to extract parameters of this model.The distribution parameters of the transformer are measured and calculated by the resonance method.Finally,the current overshoot problem is addressed by using the three capacitance distribution parameter model.The work can provide reference for the optimal design of the transformer.The paper is involved in the development and application of the ESP power system with capacity of 200 k VA,The theories and methods have been verified by simulation and engineering practice,and have been applied in an ESP field.The measured data show that the ESP using the power system can enhance the charge capacity of the dust particles,improve the reaction ability of the ESP under extreme conditions significantly,and promote the average corona power and the dust removal efficiency evidently.The work obtains the expected effect.