Research On Methods Of High-power Soft-switching Used For Electrostatic Precipitator Power Supply

With the further deepening of reform and opening up, rapid development of theeconomy, China’s demand for coal, oil and other fossil fuels is growing, but it alsobrings more severe dust pollution, resulting in frequent fog and haze. Because of itssuperior dust effects, electrostatic precipitators with a core of high-power high-voltageand high-frequency dust power supply have been widely used in air pollution control athome and abroad. The high-power high-voltage and high-frequency dust power supplywith application of soft-switching topology can significantly improve itself efficiencyplays an increasingly important role in environmental protection. With the furtherdevelopment of environmental pollution control standards to improve and switchingpower supply technology, it has become an important area of research.Firstly, this paper demonstrates the advantages of ESP dust terms of power, startingfrom the properties of dust power supply and also introduces the working principle ofelectrostatic precipitator, electrical characteristics as well as conventional electrostaticprecipitator power supply. It has analyzed high-power high-frequency electrostaticprecipitator main circuit topology and described the impact of high frequency circuits indetail. It established of a high-power high-frequency high-voltage dust power supplypower transformers circuit model containing distribution parameters. In order toeliminate the bad impact of high-frequency and distribution parameters, it comes to theintroduction of soft-switch technology in the design of high-power high-frequencyelectrostatic precipitator.It introduced soft switch works principle and classification. The principles of LCseries resonant converter (SRC) and LC parallel resonant converter (PRC) to achievesoft switching works were given specifically. It has used Saber simulation software forthe simulation and discussed the advantages and disadvantages of the electrostaticprecipitator power supply applications. LCC series-parallel resonant converter (SPRC)continuous current mode was analyzed in ESP. Because it can not achieve the full effectof the soft switch, the paper used discontinuous current mode to design dust powersupply.The principles of LCC series-parallel resonant converter with discontinuouscurrent mode were given specifically, this way could achieve a zero current turnfull-time switch and zero current/zero voltage soft switching off effect, come to reduce the switching losses and improve efficiency purposes. Based on discontinuous currentmode circuit model, it used time-domain state law to analysis series-parallel resonantconverter operating mode and mathematical description of the characteristics of theconverter, and deduced analytical expressions. It has study of the impact of theconverter output voltage regulation characteristics and series-parallel capacitance ratioof converter efficiency characteristics under discontinuous current mode in-depth firstly,providing a theoretical basis for the design of dust power supply. It has built asimulation model and verified LCC series-parallel resonant principle underdiscontinuous current mode. Based on the simulation works, it has analyzed its outputvoltage regulation, efficiency characteristics. At the same time, it has been verified alow power experimentsFinally, it used TI’s DSP chip TMS320F28035to build a72kV and30kWprototype and described each part of the prototype design in detail. A brief introductionof power control strategy of the high-frequency high-power high-voltage electrostaticdust removal applications was given. And the prototype experimental of the electrostaticprecipitator simulation experiment results show that the accuracy and feasibility of thedesign of the proposed method.