New energy grid-connected power quality management system based on internet of things

Abstract

As a clean and renewable energy source, solar energy has the advantages of inexhaustible, pure and pollution-free. Photovoltaic power generation is different from traditional thermal power generation in that it is more susceptible to external environmental factors. In addition, there are a large number of power electronic devices in the entire system. These various factors will bring a significant shock to the grid power quality after grid connection. The research of grid-connected power quality system is becoming more and more important. A series of researches are carried out around a complete three-phase photovoltaic grid-connected system, which are modeled separately, connected to the distribution network for simulation analysis, and analyzed the power quality impact on the distribution network. Based on the traditional disturbance observation method, this paper proposes a new MPPT algorithm that combines the constant-voltage tracking method with the three-point comparison method (an algorithm derived from the traditional disturbance observation method). This complete three-phase photovoltaic grid-connected system was connected to an IEEE 14-node distribution network, and the impact of grid-connected capacity and grid location on the power quality of different nodes in the distribution network was analyzed. An improved power management scheme is proposed. Finally, the paper analyzes the improvement of power quality by connecting a group of hybrid reactive power compensation device which is composed of static reactive power compensator and shunt capacitor. The results show that the voltage deviation is reduced and the harmonic content is reduced. It can be considered that this measure has achieved the purpose of power quality control to a certain extent.