Analysis And Research On Power Quality Problems Of Distribution Network With Distributed Generation

As the scale of the power grid continues to expand,the drawbacks of the centralized single power supply form become more and more obvious.With the encouragement of energy saving and emission reduction policies,distributed generation technology is booming,and its proportion in the distribution network is increasing.However,distributed renewable energy generation is mainly in the form of photovoltaic and wind power,which has the characteristics of large output fluctuation and needs to go through power electronic devices such as converters when connected to the grid.Therefore,the power quality in distribution network will present new characteristics.Research on the power quality of distribution networks with distributed generation is extremely necessary.The power quality problem of distribution network with distributed generation mainly includes two aspects: the effect of distributed generation on distribution network and the impact of non-ideal power in the actual distribution network on distributed power sources.Which results in the power quality characteristics of the distribution network are more complex and variable.Firstly,this paper introduces the typical structure and operation control of distribution network with distributed power supply,and discusses the system structure,working principle,mathematical model and control characteristics of distributed generators.Based on the PSCAD software,the operating state of the distribution network with distributed generation is simulated and analyzed,which provides theoretical support for studying the complex power quality in the distribution network.Since there are many types of distributed power sources and different grid-connected modes,the power quality of each power supply output also has its own characteristics.Based on the principle,the formation mechanism of the output power quality problems of distributed power sources such as micro gas turbines,wind power generation and photovoltaic power generation is analyzed.According to different grid-connected interfaces,and then further study the influence mechanism of DC-type and AC-type distributed generators on voltage deviation,voltage fluctuation and harmonic distortion of distribution network.Through simulation analysis of the differences between various types of distributed power access locations and access capacities,and the changes in power quality in distribution networks,the influencing factors and propagation characteristics of power quality problems in distributed power distribution networks are studied in depth.The power quality of the actual distribution network is not ideal,so the output characteristics of distributed generation will be affected by the access point,which makes the power quality of distribution network more complex.In this paper,the influence mechanism of background harmonics and three-phase unbalance on the output of power supply is studied,and the influence factors and propagation characteristics of power supply on power quality of distribution network under non-ideal conditions are further analyzed by simulation.This paper studies the interaction mechanism between distributed generators and distribution network power quality.In this paper,the relationship between the various parts of distribution network with distributed generation is studied,and the power quality problems are analyzed from various angles and aspects.It provides an effective theoretical basis for the monitoring,management and evaluation of power quality problems in distribution networks with distributed generation.