Bifurcation behaviour of PWM controlled DC series motor drive

This study presents a detailed investigation on bifurcation of general period-1 behaviour in a pulse width modulation (PWM) controlled dc series motor drive system. Existence of quasi-periodic behaviour and different bifurcation routes are mainly explored for the drive system under voltage mode control. Occurrences of different types of bifurcations are also validated by computing Floquet multipliers. An algorithm is proposed to introduce a new concept for identification of various system parameters to operate the motor drive in stable period-1 mode. The algorithm is based on Newton-Raphson method and results obtained from the proposed algorithm are presented by stability boundary diagram. MATLAB simulations as well as experimental investigations are performed on a 500 W, 220 V, 1800 rpm dc series motor to study the qualitative behaviour of the motor drive system under variations of different control parameters and also to validate the proposed algorithm.