Research on Power Fluctuation Control of Photovoltaic Generator Sets Considering the Harmonic Distortion Rate

Harmonics in the power grid mainly come from photovoltaic (PV) equipment, and the impact of the harmonic distortion rate (THD) is ignored by conventional power fluctuation control methods, which results in a slow response to the output power of the generator sets and poor power fluctuation control. In this paper, a power fluctuation control method for PV generator sets that accounts for THD is proposed. The dynamic equations of each part of the system on axis d and q are calculated based on the topological structure of the PV generator set and its operating characteristics and consequently a PV generator system (genset system) model is established. Based on this model and THD on the non-harmonic source nodes, the weighted harmonics is determined using an entropy weights model and combined with the motor characteristics, the power fluctuation control of PV generator sets is realized by a proportional integral control method. The experimental results show that the proposed method provides faster power response and better power fluctuation control.