Rotation speed controller for AC motor drives with frequency converters

Abstract

The paper presents a controller for AC motor drives with frequency converters. It controls output frequency of the converter and in such a way-rotation speed of the motor according to the sensor signals to keep the given value of some parameter of the system, e.g. water pressure in water pump outlet, constant. The suggested controller is based on comparators and an operation amplifier. It can be used for rotation speed control of pumps and fans in heating, ventilating and air conditioning or in flow applications. The controller is simple, cheap and is user friendly.