Analysis And Protection Of Satellite Time Synchronization Attack In Power System

All levels of dispatching agencies,centralized control centers,power plants and substations in the power system need a unified and accurate time reference to meet a series of requirements such as accurate detection of system status and dynamic processes,analysis and calculation and control decision-making based on it.The power time synchronization system based on the Global Navigation Satellite System provides a reference clock with an accuracy better than 1us,which ensures the unified time reference of the entire power grid.But the Global Navigation Satellite System does not provide signal integrity(anti-spoofing)protection,so the power time synchronization system is faced with the threat of satellite time synchronization attack.In recent years,production control and information management in power system require more and more time synchronization safety and accuracy.Further,time is gradually becoming the core element of process control and participating in the real time control of power system.Time error or disorder will have a great impact on the stable operation and reliable supply of power system.Therefore,studying the time synchronization security of power systems has important practical significance.Based on the above background,this article develops research along the lines of "what is a satellite time synchronization attack","the harm of an attack" and "how to protect".The main research contents include:(1)Dissect the satellite time synchronization attack of the power system.Firstly,the risk of satellite timing,the actual cases of satellite spoofing and the common attack methods are summarized.Then the concept,realization route and attack model of satellite time synchronization attack are described.Finally,the attack form under the whole scenario of power system is comprehensively analyzed,and the influence of the attack on different timing mechanism system is discussed.(2)Simulation of attack damage.Based on Monte Carlo method,the influence of satellite time synchronization attack on the distributed time synchronization system is simulated and analyzed by taking Foshan lightning positioning system as an example.Taking the metering automation system of South Network as an example,the influence of attack on centralized timing system is simulated and analyzed.(3)The protection method of continuous satellite time synchronization attack based on Kalman and TV regularization is proposed.Based on the combined timing model of Pseudorange/Pseudorange Rate based on Kalman filter,considering the malicious attack component,using the TV regularization optimization to estimate the local clock bias and attack component.Then the compensation model was established to realize the error compensation.Finally,the satellite data analysis tools and regularization tools were used to carry out the simulation verification in Matlab.(4)We propose a satellite time synchronization attack detection scheme with preset time difference value compensation and time continuity.The former detects the validity of the satellite clock after the error compensation of the local crystal oscillator,and the latter detects the threshold value of the cumulative error of the satellite clock.The simulation results verify the impact of the attack on the lightning location system and the metering system,and the effectiveness of the proposed protection and detection methods.The proposed protective measures can improve the anti-spoofing ability of the power time synchronization device,ensure that the power monitoring system operate under a uniform and accurate time reference,and avoid the threat of damage by satellite time synchronization attacks.