Distributed Power Distribution Grid Harmonic Filtering Method

In recent years, with China's sustained and rapid load growth, a number of provinces are facing the power supply situation. It caused great economic losses, and restricts the development of the economy. Moreover, the increasing of the supply of fossil fuels, the higher demand of human survival environment for their own, and the technical innovation of new small generators efficiency improvements caused the reflection of the traditional power system, which bring forward the distributed generation technology (DG).Incorporating distributed generators will make the Distribution from a type of radiation into the network throughout Power and co-adjacent users, which will bring a series of operation problems. Voltage regulation, protection configuration, and over-voltage, power quality, and so on technical issues need to be reconsidered. This paper is from harmonics perspective to analyze the influence of the distributed generator connected to the distribution network. Distributed generators connected to system always through power electronics converters, which may inject harmonic currents to the distribution system and influence the power quality. Furthermore, this paper analyzes how the location and output of distributed generators affect the distribution of harmonic voltage and current in the power grid.Base on the above analysis, the mathematical model of the maximum and least penetration level are brought forward. Meanwhile, Numerical algorithms are described in sufficient detail, together with test results of a Hangzhou distribution network by using the harmonic analysis function of distribution system analysis tool PSS/ADEPT.Finally, the influence of harmonic resonance on the harmonic distribution of the power grid is studied. For harmonic suppression, a multi-objective passive power filter mathematical optimization model is established, which is solved using Multi-objective Genetic Algorithms. The results showed the installation of filter devices having substantial improvement on the harmonic injection to the system by the distributed generators. This also shows that the multi-objective model is a certain realistic guiding significance.