Research On Damping Control Method Of Wide Area Power System Based On Integrated Cyber-physical System

With the widely application of information and communication technology in the grid,the cyber-physical power system(CPPS)will facilitate the low frequency oscillation control of wide-area power system.The wide area measurement system constructs by phasor measurement units which let the power grid more observable.Wide application of wide area measurement system of laid the hardware and software foundation for low-frequency oscillation monitoring and closed-loop control in the power system.Data synchronous acquisition and transmission across the network will bring several problems to the information system and the physical power system,such as massive data processing and transmission,network congestion,network induced delay,data loss etc.In order to damp low-frequency of wide area interconnected power grid oscillation effectively,it is necessary to overcome the adverse effects brought by communication network.This thesis makes a deep study on wide area damping control in cyber physical power system through network control.The main works of this thesis are as follows:First of all,this thesis analyzes the characteristics of the wide area monitoring and control system,proposes a four layer structure model of cyber physical power system and introduces each part' s function.Then makes characteristics analysis on communication network which is closely connected to the power system and the information system,finds that the communication network affects both the physical and information world.To reduce its adverse effects,it discusses the suitable communication network technology,communication protocol,network topology of cyber physical power system.Later,based on the small signal model of power system,this thesis analyzes the mechanism of low frequency in power system.Based on the massive synchronous measurement operation data in power system,a wide area damping controller of cyber physical power system is designed,which adopts variable forgetting factor least squares method to on-line identify the physical model,and the improved generalized predictive control algorithm uses the identification model to decide control instruction.Then a delay compensation mechanism is established to compensate for the adverse effects caused by system delay.The simulation is performed to test the controller performance.Finally,to compensate the adverse effects of information system packet loss and disorder in the physical system,it establishes a communication compensation mechanism,and establishes a co-simulation platform of cyber physical power system using MATLAB and OPNET software to analysis the interaction of power system and information system.Through co-simulation analysis,it shows that the wide area damping controller with communication compensation mechanism still can effectively suppress the low-frequency oscillation of interconnected power systems,even though there are some unfavorable factors exist between the physical system and information system.