Research On Coordinated Control Of Stand-Alone Microgrid System With Hybrid Energy Storage

Scientific and effective coordinated control strategy is an important link to ensure the security,stability and economic operation of stand-alone microgrid system.With the continuous improvement of renewable energy permeability in stand-alone microgrid,the randomness and intermittence of its output power lead to the increasing regulation pressure of conventional controllable units,the increasing risk of microgrid operation,and the difficulty of improving the operation economy.At the same time,the research on optimal power allocation of hybrid energy storage system and multi-time scale coordinated control of independent microgrid system with hybrid energy storage is not perfect,and there is room for further study.In this paper,the coordinated control strategy of stand-alone microgrid with hybrid energy storage is studied.The main research contents are as follows:1.Based on the analysis of typical topology and control architecture of stand-alone microgrid with hybrid energy storage,the mathematical model of micro-source units(wind power unit,photovoltaic unit,diesel power gemeration unit,hybrid energy storage unit)and the analysis of underlying control strategy are presented in detail,which lays a foundation for the research of coordinated control strategy.2.How to realize the optimal allocation of power instructions in hybrid energy storage system is a key problem for coordinated control of stand-alone microgrid with hybrid energy storage.On the basis of introducing the basic principle of Kalman filtering algorithm,this paper deeply analyses the characteristics of R and H parameters of Kalman filtering equation,and proposes a hybrid energy storage power optimal allocation strategy based on adaptive Kalman R parameters.Aiming at the inherent defect of low capacity configuration of power-type energy storage system,which makes its state of charge easy to exceed the limit,a fast recovery strategy of power-type energy storage state based on Kalman H parameter reconstruction is proposed to realize the optimal allocation of mixed energy storage power and the optimal management of energy.3.Based on the analysis of the multi-time-scale characteristics and the multi-time-scale coordinated control strategy framework of the stand-alone microgrid with hybrid energy storage,a multi-time-scale coordinated control strategy of the microgrid system with hybrid energy storage based on Kalman filter is proposed.The strategy consists of day-ahead,day-time and real-time time time scale control strategies.On the day-ahead and day-in-day time scales,a two-stage modified optimal dispatching strategy for microgrid is proposed.In real-time time time scale,considering the physical constraints such as operating power and power climbing of diesel generating units,a power coordination control strategy based on adaptive Kalman filter is proposed to realize the reasonable distribution of unbalanced net load power and realize the stable and economic operation of independent microgrid on multi-time scale.