Research On Complex Time-delay Correlation Problem Of Wide Area Signals In Power Systems

With the continuous expansion of power grid scale and the rapid development of intelligent technology,the advanced control and protection method based on wide area measurement signal of power system has become a research and application hotspot.Due to the complex communication environment of wide area signal,it will inevitably be affected by the delay correlation problems such as random delay,data packet loss,fouling,noise and chaos,etc.,so the direct application of wide area signal in wide area protection and control system will inevitably lead to the ability of wide area controller to reduce,or even failure.Therefore,this paper mainly focuses on the power wide area signal complex time delay correlation problem.(1)In view of the time-delay correlation problem introduced by wide-area measurement signals in communication,this paper analyzes the causes and characteristics of time-delay correlation factors such as random delay,signal packet loss,noise chaos and data contamination,and studies the influence of these factors on wide-area closed-loop control.(2)Combining CEEMDAN,chaos recognition,SSA decomposition and reconstruction methods,a signal multi-time scale spectrum stratified filtering scheme is proposed.Through smoothing the wide area signals in complex communication scenes,data damage,loss,noise and chaos and other problems existing in the signals are filtered out.The complex delay correlation problem of wide area signals is simplified to a single random delay problem,which effectively guarantees the accuracy of subsequent communication delay prediction and compensation.(3)Analyzed the advantages and disadvantages of different wide-area signals time delay compensation method,put forward a new kind of active predictive compensation scheme,the application of the multi-scale spectrum signal layered filter net,combined with the grey Verhulst prediction method,further active compensation wide-area signals of random time delay problem,make the wide-area signals as close as possible to the ideal correlation without delay.(4)Based on the four-machine two-region model,the simulation verifies the compensation effect of the traditional delay compensation strategy for different types of delay,and analyzes the limitations of its delay processing.Then,a typical complex communication scenario and application environment are simulated in the IEEE39-node system,and five different communication scenarios are constructed to test and verify the effectiveness of the proposed new wide-area signal active predictive compensation scheme.