The Research And Application Of Energy-saving Frequency Project In Coal-fired Power Station

The high wastage in large power assistant motor is a problem in fire power plants,for these assistant systems are regulated normally by outer damper or regulate valve,however this condition exists large power wastage at a long time,so the high own demand generates.As the electric driving technology especially the high-voltage frequency control technology is developing,how does the Coal-fired power generating units reduce plant service power rate and the coal consumption of electricity supply is imminent.In order to discuss the application of variable-frequency regulating speed technique in modern thermal power plant,this paper mainly focus on the research and design of Unit 1 of Shi Men Electric Power Plant to revamp the draft fan’s variable frequency.The paper researchs the related technology of high voltage frequency conversion,and analyses the different methods of the Y/Δ transformation、high-low-high and high-high variable-frequency regulating speed technique.In final,the MLVERT-D cell-series multi-level voltage PWM source inverter(high-high type)has been selected which is designed by Guangdong Ming yang Dragon Source Power Electronic Company.Aimed at the problems brought by the application of high voltage frequence converter,the corresponding engineering scheme is designed.According to the factual situation of that company,then this paper talked about the design of logical configuration of draft fan variable-frequency operation control strategy.Meanwhile,other problems are discussed after changing the frequency of draft fan,such as an increasing vibration occurs when there is a mechanical resonance frequency,a shape temperature rise in motor coil and the impossibilities to switch between power frequency and variable frequency easily during operation.etc,then the effective solutions to those problems are propose.Compared with the draft fan that not be transformed,the regulation performance of furnace draft can be improved in the A and B draft fans that are both from Unit1,and it could improve the safety promance of boiler equipment.Meanwhile,this technique could obtain great economic benefit and effectively eliminate stall tack phenomena between those two machines.The application of high-voltage frequency conversion technology in A and B the draft fans that are both from Unit 1,Da Tang Shi Men Power Generation Co.Ltd realizes the combination of high-voltage frequency device and decentralized control system in thermal power plant.The production process of power plant could be greatly improved,also the automation level.There is almost no abnormality with the draft fans A and B and they are both in good condition since they have been put into use,which proves the availability and the true value of the research and the design in this paper.