Optimization And Modification Of Electrostatic Precipitator Power Supply

With the cumulatively serious of air pollution,China has issued an increasing stringent emission standard for air pollutants.As the main equipment of flue gas purification,electrostatic precipitator plays a crucial role in the dust control,and the types and characteristics of the power supply affect the dust removal efficiency directly.The traditional electrostatic precipitator uses a DC power supply,but the efficiency is not high,especially when dealing with the high specific resistance dust,for the reason that the dust deposited on the dust collection plate is difficult to release charge,which may give rise to the hazard of anti-corona easily.The pulsed power supply of the electrostatic precipitator,namely,superimposing high-voltage narrow pulse on the DC base voltage slightly when it's lower than the corona voltage,can improve the corona and low voltage corona phenomenon,thus improve the efficiency of dust removal and reduce the energy consumption of the electric precipitator at the same time.In this paper,the structure of high frequency high voltage pulsed power supply was introduced.By comparing the topological structure of several commonly used high frequency switch power converter and analyzing the advantages and disadvantages of all kinds of power converter,the phase-shift full-bridge zero-voltage soft-switching circuit(ZVS-PWM)was chosen finally.The main circuit of the high-voltage pulsed power supply was designed by calculating the relevant parameters of the full-bridge phase-shift zero-voltage soft-switching circuit and getting the corresponding device selection,such as the switch tube,diodes,transistors,etc.In this paper,basing on the DSP30F5016 control system and software system,the characteristics of the controller and the selection of the external components were described in detail,and the sampling circuit and protection circuit parameters were analyzed and calculated.Meanwhile,the small-signal model of the ZVS-PWM converter with phase-shifted full-bridge was presented,and the factors affecting the effective duty ratio were analyzed.The article introduced the phase shift PWM,A/D sampling conversion,timer,input capture and output comparison,and the PWM channel 1 encoding,A/D conversion initialization encoding,stop sampling and start to transform encoding,timer initialization encoding,the preassigned frequency capture encoding,continuous output pulse encoding and gap encoding were collocated simultaneously.Design Explorer software was carried out for the simulation of main circuit of pulsed power supply,and the resulting pulse output verified the correctness of the design and the program.According to the relevant technical indicators,a 30 kW prototype was designed.Results were obtained through the experiments using pulsed power supply and high voltage DC power supply,the pulsed power supply had a 40% improvement in dust removal efficiency,45% improvement in the energy saving rate,and a power factor improvement of about 30%,in comparison with the high voltage direct current power source,which could reduce the interference to the power grid.