Design Of DC Superposed Pulse Power Supply For Electrostatic Precipitator

Electrostatic precipitator (ESP) technology is widely applied to the field of industrial soot emissions, because it has high collection efficiency, adapts to a wide range, has low operating cost, is safe and reliable, maintains and uses easily, and has no secondary pollution. The high voltage power supply for ESP is an important part of the ESP, the traditional DC power supply for ESP continuously applies high voltage to maintain the breakdown high voltage point. When treating high resistivity dust, spark discharging and back corona phenomenon will be produced, which leads to a substantial decline in collection efficiency. Theory and practice has proved that pulse power supply can improve the breakdown voltage and the peak of electric field strength, reduce the average charged voltage and the average electric field strength, inhibit the occurrence of back corona phenomenon effectively to improve collection efficiency and it also can save energy, reduce the cost of collecting area and the main cost. So pulse power supply has become one of the major trends in ESP power supply in the future.This paper designs a high frequency DC superposed pulse power for ESP, it can realize DC supply, pulse supply and DC superposed pulse supply by different control methods. The power’s main technical index is that DC output voltage is 10 kV-30 kV, rated operating current is 140 mA, the peak value of the pulse voltage is 30 kV, pulse width is in milliseconds to microseconds, pulse repetition frequency is 100 Hz.This paper presents the main DC superposed pulse power circuit topology, focusing on design ideas, methods and simulation of the primary rectifier circuit, high frequency resonant inverter circuit, high frequency high voltage transformer and DC superposed pulse forming circuit. To achieve soft switching technology of switch tubes, this paper theoretically analyses the working principle of LCC resonant converter selected for the inverter circuit and the main circuit in use of mathematical method, describes the design method of LCC resonance parameters and simulation verification. This paper designs control circuit which selects dePIC33F as digital signal controller, and selects PFM and impulse control suitable for the present power by summarizing the control of the current electric dust power. Finally, power supply prototype is finished and the machine commissioning is passing. ESP experiments prove the feasibility of this power supply design and topology control mode.