Research on Chaotic SPWM Strategy Based on Fuch Map

The application of chaotic SPWM can have SPSP(spread spectrum) effect on harmonic interference by taking advantage of the continuous spectral characteristics of chaotic signals, thus the higher order harmonics generated by the high frequency action of the switching device tend to be distributed over a wider frequency range, and the spreading effect of chaotic modulation depends on the attribute of the chaotic sequence. That is why it is significant to ensure the pseudo-random variation of the chaotic signal during the operation of the system. To address the problem that the chaotic sequence often falls into the immobile or cyclic state due to the improper selection of the sequence initial value or system parameters when using traditional map functions, the new discrete Fuch map is introduced into the chaotic modulation. It has been shown in the existing literature that the Fuch map does not depend on the initial value of the sequence and the choice of the system parameters, but always can generate chaos phenomenon provided the initial value is not zero. To validate the SPSP effect of chaotic modulation based on Fuch map, a simulated inverter platform is built in Simulink. The simulation results show that the chaotic SPWM based on Fuch map can significantly improve the harmonic interference problem of system, and the spreading spectrum effect is slightly better than that of the conventional Logistic map. The Fuch map can also guarantee that the chaotic sequences would not fall into equilibrium or periodic cyclic states.