Research On Coordinated Control And Reactive Power Compensation Control Of Island Microgrid

When the island-type microgrid supplies power to the user independently,it contains a large-scale distributed power source such as a wind turbine,or a frequency change occurs when the high-power load fluctuates;and in actual use,the user There are often a large number of inductive reactive devices in life.which can easily bring negative effects such as power factor reduction and voltage fluctuations to the system.Therefore,in order to improve the stability of voltage and frequency and reduce the influence of reactive power in the actual use of the island microgrnd,this thesis mainly carries out the frequency coordinated control stratesy in the microgrid and uses the static var generator(SVG)to perform no Work compensation is a two-part study.The microgrid in this thesis is an island-type microgrid system includinsg photovoltaic power generation,wind power generation and battery energy storage.The layered control structure is adopted,and the microgrid central controller(MGCC)completes the monitoring and management of the microgrid.task.According to the fluctuation range of the system frequency,their respective control strategies are formulated to complete the stability of the maintenance system frequency and the balance between the source and the load.At the same time,the control strategy is designed for the energy storage battery in the system.and its service life is improved when it can play the role of"shaving the peak and filling the valley".The compensation position,compensation capacity,common lopology and working principle of SVG are analyzed,and the SVG structure combined with the microgrid in this thesis is determined.The SVG uses the improved ip-iq method based on the instantaneous symmetrical component method to detect the reactive current,and the simulation circuit model is built in MATLAB/Simulink to verify the detection effect when the three-phase current is unbalanced.The direct current control method is used to complete the control of the SVG main circuit and the stable control of the DC side capacitor voltage.With the DSP chip as the core,the SVG main circuit,drive circuit and signal acquisition circuit and other hardware circuits are designed.Finally,the actual test of the island microgrid system in this thesis is carried out.According to the test results,the effectiveness of the frequency coordinated control strategy and SVG reactive power compensation is demonstrated,which provides a reference for the practical application of the microgrid system.