Application And Research On Frequency Control Technique

The purpose of this thesis is to popularize frequency control technology.The thesis mainly researched speed control technology on the pump and fan.In practice, the motors of pump and fan had greater power consumption and lower operating efficiency, holding a vast space of energy conservation.It not only gained considerable economic benefits, but also improved safety and reliability of the operational equipment.In the face of the shortage situation of world's energy,research and application on frequency conversion technology was full of great practical significance and great social and economic benefits.The thesis reviewed the development and current status of frequency control technology,detailed the basic theory of frequency conversion and energy-saving on mechanical property of the pump and fan.In connection with speed technology about internal feedback, water-resistance, permanent magnet and hydraulic coupling,the thesis presented their principles and performance. According to surveying and researching the speed control methods which the firm used,the work included collection as for operating condition of different speed control methods of motor and gathering the data about transformation of speed technology. By selecting experimental data, generalized the advantages and disadvantages ,scope of application and practical effect. Ultimately,we obtained the results that frequency control technology hold a considerable advantage in comprehensive indicators on safety,reliability and economy.Frequency control technology is the most prominent in terms of security and economic effects.Frequency technology was relatively mature, the problems in the application process been easy to solve,the rate of saving energy been 10%-50%,recovery period of investment been short, it usually recovered the investment cost in two years,the costs of maintenance been low, it been possible that reduced the high initial investment with rapid technological development.The reliability of frequency control was credible relatively.In addition, the frequency control had the widest range,the motor of squirrel cage and wound being available, and the size of the motor capacity, the voltage level being no limit, which is very conducive to the promotion of frequency control.Finally, the harmonic generated by frequency conversion technology were introduced briefly,including analysis on the mechanism,the wide range of harms and the method of suppression.