Research On Microgrid Cooperative Control Based On Active Disturbance Rejection Technology

With the continuous popularity of the concept of green development,concepts such as sustainable development,distributed power generation and micro-grid have gradually come into the public view,among which the concept of micro-grid has been deeply rooted in the hearts of the people.As a controllable unit,the microgrid can be operated in grid-connected or island mode respectively according to the situation.When grid-connected,the frequency and voltage are supported by the large power grid,while when the island is operated,reasonable operation strategies should be adopted to maintain the bus voltage and frequency.For the overall architecture of microgrid,scholars took the lead in using centralized control based on the central processor.Although centralized control can effectively control the master and slave of all units,this method cannot cope with the rapidly increasing number of distributed generation units and will face the problem of "data disaster".Then,in order to cast off the yoke of the centralized control concept,scholars have put forward the distributed control and distributed control,its purpose is to explore a more suitable for micro control mode of network structure,however,whether this kind of method is used to control,micro network need to take further policy,to improve its running state.In this paper,we study the microgrid in island-based mode,starting from droop control,we analyze its control mechanism,and based on this,we introduce the consistency algorithm.The aim of this paper is to improve the operation state of the microgrid island mode by using distributed layered control,so that the reactive power can be divided reasonably,the voltage and frequency can be restored to the rated value,and the optimal economic operation can be achieved.Average consistency algorithm is used for reactive power and optimal economic operation,and tracking consistency algorithm is used for voltage and frequency recovery.At the same time,due to the adoption of the droop control based on the consistency algorithm,the distributed power supply can fully meet its "plug and play" characteristics,and avoid the disadvantages of centralized control based on the central processor.Then,this paper analyzes the PI unit adopted in the existing articles.Active Disturbance Rejection Controller(ADRC)is introduced to optimize the traditional PI unit by introducing advanced controller.At the same time,in order to explore the effectiveness of the proposed control strategy,the corresponding simulation example is built.Finally,based on a single microgrid,this paper analyzes multiple microgrids,studies the microgrids in the group-off-grid mode,and puts forward an operational control strategy in the group-off-grid mode,aiming at discussing the position of each sub-microgrid in the microgrid group and the corresponding control mode.In this paper,the bottom layer of the micro-grid group still uses the distributed layered control framework,aiming to retain their respective "plug and play" characteristics,so as to further improve the operation of the micro-grid group.Then,a simulation example of double micro grid with five distributed power sources is built,and the simulation results show the effectiveness of the proposed control strategy.