Chaotic control of a single-phase H-bridge PV inverter

The inverter is a strong nonlinear system. It generally has sophisticated nonlinear dynamical behaviors, for instance transcritical bifurcation, period doubling bifurcation, etc. It will greatly enhance the harmonic components of the output current, decrease the efficiency rate of the converter, make it oscillate and even collapse. At present, most of chaos control methods has the disadvantages of modeling difficulty, not obvious control effect and not strong stability. Aiming at this, a new chaos suppression method, namely improved cosine delay feedback control ( ICDFC), was proposed. In the method, the difference between the output values of the variable of the controlled object at this time and at the time of one period delay was used as the feedback quantity, and then through the Links of cosine function and feedback control parameters, the controlling signal was achieved. Thereafter, the controlling message directly reacted on the controlled subject in feedback form. In the meantime, the system' s stroboscopic mapping model, was established and the Jacobin matrices and balance points of the controlled object were obtained. At last, the restrictive conditions of the feedback controlling parameter were presented based on the July criterion. To illustrate the superiority of the suggested chaotic control method, a great deal of simulating experiments were unfolded, and compared with the exponential delayed feedback control, which proves that ICDFC can not only suppress the chaotic behavior of the inverter more effectively, but also greatly increase the system operational stable region. © 2023 Chinese Vibration Engineering Society. All rights reserved.