Power factor improvement using fuzzy logic control of an AC synchronous motor

The paper presents the design, implementation, and evaluation of a fuzzy logic (FL) controller to manipulate an alternating current (AC) synchronous motor´s delivered reactive power (VAr), thereby improving the power factor (PF) of an industrial plant. The FL controller mimics the action that would be carried out by a human operator when adjusting the synchronous motor to deliver the necessary VAr to achieve the desired PF value. The controller provides flexibility with its nonlinear gain characteristic and adaptive operation. The FL controller performs adequately under all test conditions. The FL controller was observed to perform successfully under both rapidly and slowly changing load conditions. The FL controller performance was highly satisfactory in tracking and improving the plant PF to achieve the set point in a reasonable time frame and motivated by the proportional integral derivative (PID) concept. The FL controller in conjunction with a synchronous motor represents an innovative new approach to the problem of PF improvement in industrial plants.