Design Of High Voltage High Power LCC Resonant Converter Used For Electrostatic Precipitator

With the rapid development of the economy,the environmental problems are becoming more serious and the standards for pollutant emissions are also increasingly rigorous.Electrostatic precipitator is widely used in dust removal areas,such as thermal power plant,cement plant and industrial furnace.Electrostatic precipitator power supply plays a key role of dust removal.The conventional 50Hz thyristor based power supply is unable to satisfy the needs of higher dust removal efficiency and energy saving for its insurmountable drawbacks.The high frequency power supply has the advantages of small volume,low loss,small output voltage ripple,wide range of voltage regulation and flexible control mode,and is becoming the development trend of electrostatic precipitator power supply.LCC resonant converter is one of the most frequently used topologies for high frequency power supply,which combines the advantages of LC series resonant converter and LC parallel resonant converter and overcomes their disadvantages.In this paper,the working principle and circuit characteristics of LCC resonant converter operating in discontinuous current mode are analyzed in detail.The optimal design of the parameters of the resonant converter is proposed,and the simulation and experimental verification for research results are presented.Firstly,the working process of two kinds of operating modes under the discontinuous current mode is concretely described,the state equation of the circuit is established by time domain analysis,and the expressions of state variables of the circuit are obtained.The dynamic analysis of output voltage,resonant current,frequency and load of the circuit are deeply analyzed based on the expressions.The influence of the ratio of the shunt capacitor and the series capacitor on the circuit is studied and the control strategy of constant voltage and constant current output is researched.The parameters design method of LCC resonant converter is discussed,and the optimal design of the resonance parameters is proposed according to the design objective by theoretical analysis and curve drawing.The simulation results show that the theoretical analysis is correct and the parameters design is reasonable.Finally,the experiment tests of the theory is carried out based on lkW power LCC resonant converter,the experimental results verify the validity of the theoretical analysis in this paper.