Research On Power Stabilization And Reactive Power Compensation Control Strategy Based On Microgrid

The energy structure of today’s world is changing,and the destruction of the natural environment is becoming more and more serious.Therefore,in some regions rich in wind and solar energy,renewable energy has been widely used because of its economy,universality,reproducibility and pollution-free nature.In order to give full play to the role and benefit of distributed power supply,the micro-grid emerges at the right moment and develops rapidly.As an important supplement to large power grids and a bridge between distributed generation and power grids,microgrids are playing an increasingly important role in promoting the development of renewable energy,the country’s energy transformation and power system reform.However,photovoltaic power generation and wind power generation are greatly affected by topography,climate and environment,and there are some problems such as volatility,intermittency and unpredictability.The microgrid composed of distributed power sources such as wind power generation and photovoltaic power generation is prone to produce large power fluctuations,resulting in abnormal or damaged load in the microgrid.In addition,because the micro grid contains a large number of inductive and capacitive impact loads,it will produce a certain amount of reactive load,which will cause serious harm if not solved in time.In this paper,with the distribution of wind power and photovoltaic power microcontroller source of micro power grid as the research object,through to take the battery energy storage device of the Static Synchronous Compensator(STATCOM)(hereinafter referred to as the STATCOM/BESS)in-depth study,using the STATCOM/BESS to micro power grid to calm and active power and reactive power compensation,and analyzes its control strategy,give full play to the device in the micro grid two-way adjustment.The main research contents and achievements are as follows:This paper studies the grid-connection problem of Distributed Generation(DG)commonly used in micro grid,and analyzes the principle and characteristics of wind power Generation,photovoltaic power Generation and other current main DG,and builds mathematical models of each DG to study the influence of grid-connection on power quality of microgrid.The working principle of STATCOM/BESS is analyzed,and the output power expression of statcom/bess is derived.It is theoretically proved that STATCOM/BESS can smooth the active power fluctuation of the micro grid and compensate the reactive power generated by a large number of inductive or capacitive impact loads in the micro grid.The balance control strategy of SoC is studied when multiple battery energy storage units are connected in parallel on the dc side of STATCOM/BESS.This paper adopts a method of SoC equilibrium control based on fuzzy theory.On the basis of the double closed-loop control method,the reference voltage is adjusted within a certain range by adding the fuzzy control link of SoC,so as to change the output current of the battery energy storage unit,and finally achieve the balance of the remaining power,while maintaining the output voltage stability of the energy storage system.Finally,the SoC equilibrium control strategy simulation model was established by MATLAB/simulink for verification,and the simulation results showed the effectiveness of the method.Aiming at the problem of active power fluctuation and reactive power compensation in the microgrid,based on the original control strategy,a power coordination control strategy suitable for the microgrid is proposed,which comprehensively considers the output power of distributed micro-sources such as photovoltaic and wind power generation in the microgrid.Various factors such as load power consumption,STATCOM / BESS current limit and battery SoC.The simulation model is established in MATLAB / Simulink for verification.The simulation results show that the control strategy can effectively smooth the active power fluctuation of the microgrid and compensate the reactive power demand,thereby ensuring the stable operation of the microgrid and the normal operation of the microgrid load.