In this paper the dynamic performance of the wound rotor induction
motor operating with synchronized modulator is considered and analyzed. The
proposed modulator employs a PWM transistor-controlled capacitive network
in rotor circuit with a carrier fiequency proportional to the rotor voltage
frequency. This modulator can reduce the harmonic current components of the
motor and consequently improve the motor power factor. The reduction of
these components is achieved instantaneously with no need for sensing or
computing the harmonics current in motor current, thus simplifying the control
system. Simulated and experimental results obtained from closed loop
O.5KVA prototype confirm the feasibility and features of the proposed system.