Investigation for Avoiding Nonlinearities in DC-AC Power Converters

A study has been carried out for nonlinear phenomena in DC-AC power converters under this paper. High power DC-AC converters are widely used in HVDC and in AC motor drive applications. There are several sources of undesired nonlinearity in practical power inverters. In addition, their operation is characterized through switching thatgenerates a variety of nonlinear dynamics. DC-AC converters controlled by pulse-width modulation (PWM) have been simulated. These converters are simulated using a software package MATLAB SIMULINK. It is observed that the convertersoperation moves from periodic operation to chaotic operation as the output load to the converter is changed as load considered as bifurcation parameter. The voltage, currentwaveforms and FFT analysis obtained from the circuit simulation have been studied. The bifurcation pathway includes smooth period-doubling bifurcations as well as border collision bifurcations. Simulated results are validated with experimental results. Both are found in good agreement to each other. This knowledge is playing very powerful role for designing practical circuits in power electronics based system.