Bifurcation analysis and chaos control in a fourth-order DC–AC H-bridge inverter

There are complex nonlinear phenomena such as bifurcation and chaos in a sinusoidal pulse-width modulated fourth-order H-bridge inverter, which can reduce the stability of this inverter operation and the quality of power supply. Moreover, there are the problems suffering the complicated modeling and difficulty in determining the control coefficients. An exponential time-delay feedback control strategy is proposed in this paper, a feedback term is formed by the difference between the controlled object’s output current and itself delay for a period of time, the feedback term is then fed into the exponential and proportional link to obtain the modulation term, which is applied to the controlled object in a feedback manner. Meanwhile, the range of the feedback proportional coefficient is obtained by analyzing the stability of the exponential time-delay feedback controlled fourth-order H-bridge inverter. The effectiveness and superiority of this strategy have been verified via comparative studies, demonstrating it is successful in improving the nonlinear phenomena of the fourth-order H-bridge inverter. The findings can be used to provide some ideas for the design optimization, dynamic debugging and bifurcation control of the high-order H-bridge inverter, and have good reference value in industrial intelligent control applications.