Research On Wide-area Control Of Networked Power System Based On Event-triggered Mechanism

In order to adapt to the economic and social development,China is speeding up the construction of cross-region interconnected power grid to achieve large-scale cross-region transmission of electric energy.Wide area measurement system(WAMS)application can achieve the dynamic synchronous acquisition of information in the whole network,laid the foundation for the implementation of networked control in interconnected power systems,but also brings some challenges at the same time.With the gradual popularization and improvement of WAMS and the increase of phasor measurement units(PMU)locations,the proportion of PMU data transmitted in the dispatching data network is increasing.The long-term uninterrupted and high-frequency transmission of PMU results in the influx of massive state and control information into the control center,which brings pressure on the system to collect,store and process information.At the same time,massive information transmission in communication network may also cause network congestion and affect real-time transmission.Under the background of networked power system,this paper introduces event-triggered communication mechanism into wide-area damping control and load frequency control which are the main wide-area control methods.While ensuring the stable operation of the power system,it saves limited communication resources,makes full use of the communication bandwidth of the power system,reduces the operation load of the control center CPU,and designs a reasonable communication and control cooperative strategy to ensure the real-time and accurate transmission of information.This paper mainly consists of the following parts:Firstly,a unified framework including wide-area power system,damping controller and event-triggered communication mechanism is constructed,and a time-delay model is established.An internal dynamic variable is introduced into the event-triggered mechanism,and the dynamic event-triggered mechanism is established to increase the average trigger interval and reduce the trigger times.Then,a joint design method of damping controller and dynamic event trigger mechanism is presented.The wide-area damping controller based on event-triggering mechanism is designed for two-domain four-machine power system to verify the effectiveness of the proposed scheme.Secondly,a resilient communication mechanism is introduced into the derivation of the main conclusions of multi-area power system load frequency control(LFC).And the relationship between the allowed duration of denial-of-service(DoS)attacks and the event-triggered communication mechanism is established,meanwhile,the maximum allowable attack duration is derived.Finally,considering the uncertainty of the model,the time-delay model of based on event-triggering mechanism is established,and the Lyapunov-Krasovskii(L-K)stability analysis method based on Bessel-Legendre integral inequality and convex combination technique is proposed.The joint design algorithm of trigger parameter and guaranteed cost controller is derived.And some simulations are carried out by using the Matlab software.