Method and apparatus for controlling the supply of power to an induction motor to maintain high efficiency under varying load conditions

摘要

An energy-saving induction motor control apparatus maintains the operation of a motor at an optimum power factor irrespective of changes in motor load, by generating a power factor compensation value which is varied in accordance with the motor supply voltage. The motor supply voltage is controlled such as to reduce any difference between the optimum power factor value and a measured power factor value, thereby ensuring that stable operation with minimum energy consumption are achieved over a wide range of motor load values.