Design And Application Of Fan Control In Power Plant Based On Frequency Conversion Technology

In accordance with the energy conservation plan of the 12 th Five-Year Plan,the state will vigorously promote energy conservation technologies,and focus on energy conservation and consumption reduction.In thermal power plants,high-voltage auxiliary machines are usually high-power power equipment,with high power consumption,and are the main users of power consumption in the plant,which is prone to energy waste.In recent years,high voltage converters have been widely used in high-power auxiliary machines of thermal power plants,and have achieved good energy-saving results.This paper analyzes the operating situation of 3 × 100 MW fan chopper feed-in speed control,summarizes the problems of low power factor,resonance,susceptibility to disturbance,and narrow applicable range,and designs the high voltage frequency control for the first and second fan of the new 300 MW circulating fluidized unit.According to the process requirements,combined with fan parameters,complete the design of the primary and secondary fan frequency control bypass scheme,cooling scheme,technical parameters,point directory,and DCS operation interface;Combined with the study of the characteristics of the inverter,the QF split control of the power switch,the control of the fan inlet guide and the exit valve,the frequency converter start,stop,frequency converter cut,frequency converter automatically adjust the control logic,and the chain protection logic related to the safe operation of the unit are designed.The DCS platform is used to complete the logical configuration and realize the high efficiency,stability and automation of the frequency conversion control.In view of the problem that when the frequency is cut by the inverter,the wind door tracking to the fixed opening degree will cause the large fluctuation of the furnace pressure,study the running data,draw the wind door opening curve,and design the wind door opening automatically.With the help of the research results of this paper,it can effectively reduce the running power consumption of the fan,and can realize the chain protection control related to the operation of the unit,such as frequency changer start-up,shutdown,frequency frequency changer cutting,and frequency changer.It can effectively reduce the effect of switching to power frequency on the stable operation of generator set under frequency converter failure.It can effectively improve the automation control level of the generating units,ensure the safe and stable operation of the generating units,reduce the energy consumption of the generating units,and enhance the core competitiveness of the power generation enterprises.