Fan control systems use induction motors to provide traction motive force for the entiresystem. Ordinary cage induction motors do not have speed regulation function due to theirown structural factors. In order to provide different air volumes for the units, more than 90%of ordinary fan systems use external adjustable baffiles or gates to achieve air flowregulation by controlling the opening size of the baffles or gates.
During the static adjustment process of the fan system, due to mechanical adjustment,the output operating power of the fan motor is always maintained at full load during theentire operation process, and its output does not decrease as the load decreases, resultingin a long-term unbalanced operating condition between the output and the input, resulting ina large amount of electric energy waste. Since the operating shaft power of the fan is incubic proportion to its actual operating speed, if the variable frequency speed controlmethod is used to replace the conventional damper or valve adjustment mode, the controlsystem dynamically adjusts the fan motor speed according to the auxiliary system airvolume demand, so that the throttling loss caused by other accessory structures of thesystem can be eliminated while meeting the generator air volume demand, and at the sametime, the comprehensive operating efficiency of the fan motor can be improved, so that theentire fan system can operate safely,stably, energy-saving and economically.