A study on occurance of a nonlinear phenomenon: Chaos in a DC chopper drive

Power electronics has been a part of interdisciplinary platforms in 21
^st
century due to its wide range of applications. Due to the nonlinear characteristics of the semiconductor switches and their nonlinear switching patterns, the system as a whole becomes a nonlinear one. This paper aims at a study on existence of a nonlinear phenomenon called chaos in a chopper fed DC drive. A study is made on how these chaotic phenomena occur in a voltage fed separately excited DC motor due to the variation in different bifurcation parameters associated with the circuit. The state variable models are derived and the phase-portrait is constructed to do the stability analysis of the system. A buck chopper is used to vary the voltage applied across a dc motor which is separately excited. The simulation is done in MATLAB-Simulink and various phase portraits are plotted by varying the bifurcation parameters.