Grid-connection of distributed photovoltaic generation method based on the power quality health status of distribution system

Distributed photovoltaic (PV) generation is fluctuant power source. Power quality is easily influenced by grid-connection of it and may occasionally exceed the standards' limits. In order to solve this problem, this paper presents a PV grid-connection method based on the power quality health status of the distribution system. The method relies on the health condition of total harmonics distortion of the current, voltage deviation and voltage fluctuation. The establishments of the membership functions which represent the health condition of these power quality items are based on the grid-connected PV system. Then, fuzzy set theory is used to make clear the power quality health status of the distribution system. Case study shows the reliability of the presented method.