Abstract

The double fuzzy control is proposed for the MPPT (Maximum Power Point Tracking) of grid-connected photovoltaic generation system, which combines asymmetric fuzzy MPPT and fuzzy PID together. The conventional method such as perturbation-observation is replaced by the asymmetric fuzzy control in the reference voltage setting section and the general PID control is replaced by the fuzzy PID control in the actual-reference voltage deviation elimination section. Four MPPT performance indexes are proposed: tracing time when environment changes slowly, power output of photovoltaic array, steady-state power fluctuation, and power output of photovoltaic array when environment changes greatly. Four cases are designed and five control methods are respectively simulated in the environment of MATLAB / Simulink. The comparison of the indexes of MPPT performance and the waveform of output power verifies that, the proposed double fuzzy control method is better than the traditional methods.

Index Terms

photovoltaic; electric power generation; maximum power point tracking; fuzzy control; asymmetric fuzzy MPPT; fuzzy PID.

Cite this paper:

Xingpeng Li, Qingjun Shi, and Quanyuan Jiang, “Application of double fuzzy control in MPPT of grid-connected photovoltaic generation system,” Electric Power Automation Equipment, vol. 32, no.8, pp. 113-117, Aug. 2012.