Research On Distributed Generation Control Method Based On Communication Network

The emergence of distributed generation system not only saves investment in power transmission and improves the reliability of power supply network but also provides convenience for residents in remote areas or residents of commercial areas.The future development trend of China's power grid industry will be to go with large power supply by the main distributed power generation,supplemented by a variety of distributed generation and coexistence of various forms.But as more and more distributed generation access to the main power grid,some problems also follow.For example,large-scale distributed power accessed to enhance the overall system complexity and unpredictability,for the secondary equipment and communication facilities provide a new requirement.So the distributed power supply brings convenience to people's lives,but also inevitably brings new challenges to the use of energy in human society.Therefore,at the same time the rapid development of distributed generation it is also necessary to improve the technical level of the distributed remote monitoring system.The smooth switching between the main power grid and the distributed power supply is the premise of the distributed power supply for the large power grid to supplement and protect the security of the power grid,and is the basis of ensuring the distributed power supply to maximize its own advantages.This paper is from the perspective of switching control,the two operating modes of distributed grid as a switching control system of the two subsystems,combined with networked control system(NCS)knowledge on the distributed power supply remote monitoring problem analysis and research.For the issues inherent in the network control order to fit the actual engineering,this paper based on the consideration of the limited communication network,the handoff delay and subsystem instability are considered on the stability of the system and the controller design problem.The main contents of this paper are as follows:(1)Establishment of mathematical model for distributed power network.Firstly,this paper introduces the existing mainstream distributed power supply,analyzes the structural characteristics of wind energy,solar energy,fuel cell and the influence of grid connection.Then the structure and problems of distributed power remote control are introduced.Finally,the state space model of the two modes is derived by the topology of the distributed power grid and the topology relationship of the islanding mode,which lays the foundation for the next work.(2)Switching control of distributed generation under the influence of limited communication and switching delay.On the basis of the existing communication control technology,the NCS and the switching control system are combined to form a new kind of network switching control system(NSCS).When the network is introduced,in the actual situation due to network bandwidth constraints,limited communication and switching delay inevitably exist distributed power,their presence will affect the stability of the system,for this part of the work,this paper is based on the average dwell time(ADT),method for processing communication sequence,Lyapunov stability theory and linear matrix inequality(LMI)method to design concepts to analyze the system controller and the finite time stability conditions.(3)Switching control of distributed power supply under the condition of unstable subsystem.Subsystem instability is an important factor for instability of industrial system,in order to better fit the actual project,In this part,based on the average dwell time and the total dwell time,the switching control strategy is designed to study the stability of the system under the condition of unstable subsystems.Finally,two examples are given to verify the effectiveness of the proposed method.Through the operation of distributed power grid mode and islanding mode as a special class of switched systems,combining the research results of the network switching control system with the remote switching control of distributed power supply,provides theoretical support for the realization of wide area distributed power supply remote interconnection and the smooth and stable switching between grid mode and islanding mode.