Research On Power Quality Analysis And Reactive Power Compensation On Wind Power Grid

The traditional energy sources are drying up,and the wind power industry is developing rapidly.The new installed capacity and cumulative installed capacity continue to soar.This project is based on the "Analysis and Countermeasure Study on the Impact of Wind Power Integration on Distribution Network Power Quality and Network Loss after the Grid Integration of Wind Power Company" of Shandong Electric Power Company.It analyzes the power quality of wind power after grid connection,and carries out the problems caused by the grid connection.The strategy study will lay a solid foundation for the project to continue to study the impact of network loss in the future.The quality of power after wind power is connected to the grid is a very critical issue in the power system,which affects the safety and stability of the entire power system.If not handled properly,it will have a huge impact on the production and life of society.Therefore,it is of great significance to study power quality and reactive power compensation.The content of the paper includes the following sections:(1)The related definition of power quality is introduced.Starting from the three indicators of voltage deviation,voltage fluctuation and harmonic voltage,the concept and formula are introduced.The causes of the damage and the harm caused to the power grid are analyzed separately.The current state of power quality standards of our country is summarized.(2)Briefly compare the advantages and disadvantages of various wind turbines,and select double-fed induction generators for key analysis and introduction.The structure of doubly-fed induction wind generators is analysed,including mechanical models,electrical models,and power electronics converters.It also describes the analysis of the protection aids used,such as crowbar protection,low-pass filters,and so on.(3)Analyze the model construction and control strategy of the PWM inverter in the wind turbine,and use the vector control strategy to complete the grid connection function on the rotor side and the grid side.The simulation model of the PWM converter was built on the PSCAD platform to lay the foundation for the overall system of wind power generation.(4)Set up a wind power grid integration system model in the PSCAD software platform,performed theoretical analysis and simulation on basic wind,gusts,gradient winds,and random winds,simulate changes in wind speed,and investigate wind power grid-connected systems under changing wind speed conditions.Single-phase faults and three-phase faults were simulated,and the related outputs of wind farms in the event of faults were observed and analyzed,and the impact of faults on grid-connected wind power was explored.(5)Introduce the reactive power compensations,analyze the basic working principle and use premise of SVC and STATCOM,set up the two simulation models in PSCAD,and add it to the previously established wind power grid-connected system.Through comparative analysis,we understand the effect of SVC and STATCOM on power quality control,and verify that the installation of reactive power compensation devices is feasible for the improvement of power quality.