Study on electricity saving fuzzy controller of asynchronous motors based on fuzzy logic

A kind of electricity saving fuzzy controller (ESFC) has been developed based on fuzzy logic principle in order to save energy and obtain greater electricity efficiency for asynchronous motors during their operation and a set of fuzzy rules are set up to control the input power by adjusting the stator voltage and frequency of asynchronous motors according to the stator current and its derivative without measurement of motor shaft speeds. Much more attention is paid to the analysis of control methods, the design of sampling circuits, the definition of the mathematical model of overload and the discussion of all factors to interfere with its operational reliability. In addition, the hardware block diagram of ESFC dominated by a single-chip microcomputer is also introduced in the paper. The controller has been tested and applied to an underground flameproof magnetic starter. It has been proved that the controller is stable and reliable and is of great applied value in the mining industry