Control of Bifurcation in a PWM Controlled dc Series Motor Drive

This paper presents a study on bifurcation behavior of a PWM controlled dc series drive to depict the occurrence of different nonlinear behavior including chaos against variation in load torque. In particular, authors have proposed a systematic method to determine amplitude and phase of a sinusoidal signal to be added to the switching surface of a PWM controlled chopper to avoid occurrence of the bifurcation as in many applications bifurcation of period-1 orbit to higher periodic orbit is not desirable. Experimental investigations are also performed on a prototype 500 watt, 220 volt, 1800rpm dc series motor to validate the proposed method.