Research On Coordination Control Method For Micro Grid Based On The H_∞ Performance Index

Micro grid provides a strong technical support for the large-scale application of renewable energy and distributed energy.With the increase of the type and quantity of distributed generations,and the complexity of the load in micro grid,the operation control of micro gird is especially important.Coordinated control method provides a technological approach for the secure and reliable operation of micro grid system.Through the coordinated control,it can meet the demand of real-time control of the internal power balance of micro grid,can give full play to the flexibility of micro grid transmission,and ensure the stability of the operation.Therefore,it is very important to study the coordinated control of micro grid system.This paper studies the operation control strategies of micro grid.Firstly,the control method of grid connected inverter and the coordinated control strategy of micro grid system are summarized.On this basis,the H_∞ robust control is studied.For micro grid systems may be subjected to a series of disturbances,such as active power and reactive power disturbances,the sensitivity minimization problem of H_∞ robust control is emphatically analyzed.In that cases,it can ensure coordinated operation of micro grid even after interference.Then,based on the improved P-f/Q-dU/dt droop control method,the mathematical model of the micro grid is transformed to the standard model of H_∞ robust control.So the coordination control method for micro grid based on the H_∞ performance index is proposed.This method achieves accurate power distribution of distributed generations.And it can meet the high demand of power and frequency indicators of micro grid system.The distributed generations are operating coordinately,and the overall operation performance achieves its’ optimum.The partial output quantities are selected as feedback so that the method is easy to project realization.Finally,simulation results verify the correctness and feasibility of the proposed method.