Research On New Power-frequency Constant-current Source Of Electrostatic Precipitator

Electrostatic Precipitator plays an extremely important role in industrial dust control because of its advantages such as higher efficiency, lower energy consumption, greater amount of processing gas and so on. With growing awareness of environment protection and energy-saving and increasing national standards for air pollutant emissions, China's traditional electrostatic precipitators can not meet the new requirements for energy conservation and emission reduction.As a core component of electrostatic precipitator, electrostatic precipitation power directly influences the dust removal efficiency and performance. This paper presents a new power frequency constant-current electrostatic precipitation power supply. It will partly reform the traditional power supply, namely: replace the thyristor phase controlled voltage regulator by high frequency IGBT inverter and retain the frequency transformer and rectifier. By combining the high frequency PWM control and the power frequency boost rectifier, the performance of the electrostatic precipitator will be improved and the existing dust removal equipment can also be made full use of, the enterprise transformation cost can be reduced.Based on the electrostatic precipitator's principle and characteristics, the single pole modulation was used in the new constant-current electrostatic precipitation power supply. After analyzing the new power supply's work principle, author established the mathematical model using the state space average method, and then designed the PI controller according to the poles configuration method. To further improve the performance of the power system, variable parameter PI controller was adopted. To compensation and suppression the transformer DC bias, appropriate measures were taken. The results of MATLAB simulation verified the new power frequency constant-current electrostatic precipitation power supply was correct in theory.A prototype with the maximum output power of 2KW was designed and built to verify the rationality and validity of the theoretical analysis. In the prototype, the digital closed-loop control method was used through TMS320F240 controller. Finally, to prove the feasibility of the new constant-current power supply, the transformer harmonic losses of the two sources were compared by the simulation software MATLAB. And through comparing transformer temperature of two kinds of sources, experiment result further verified the new power frequency constant-current electrostatic precipitation power supply was feasible.