Research On MAS-based Station Protection Scheme

Smart substation, one of the six core links of strong power grid, should have functions of automatically with real-time online information collection, analysis, and collaborative interaction and other advanced functions, leading to the traditional ladder of protection is difficult to continuously ensure the stable operation of smart substation.Therefore, the new substation-area protection need to improve the traditional relay protection of the inaccurate fault location, long time action, poor adaptive performance and other issues. For this reason, the paper proposes the substation-area protection based on Multi-Agent system to achieve these requirements.Agent, the new branch and research hotspot in the field of distributed artificial intelligence,has been a substantial progress in the study of power system in recent years.According to the definition and characteristics of Agent, the paper forms the Multi-Agent System. Combined with the technological advantages of smart substation station, the paper constructs the substation-area protection based on Multi-Agent System, whose feasibility is verified by simulation. Using the Multi-Agent technology and the electrical quantities information within the station, the paper proposes a method of fault location based on the amount of phase current and the scheme of substation backup protection.The substation-area protection can achieve the real-time sharing station information through the communication network, providing reliable operation of backup protection and breaker failure protection. Its local backup protection and remote backup protection have the same time limit of action, which can cut-off faults quickly and shorten the scope of faults within the station. The substation-area protection can adaptive adjust fixed value of the protection, enhancing its reliability and self-adaptability. Using the principle of the substation-area protection based on MAS, the paper proposes the scheme of the substation-area protection based on Particle Swarm Optimization. On the basis of fault diagnosis principle of PSO, substation topological structure and failure features of circuit breaker,the paper proposes a fault location principle and its evaluation function. The binary particle swarm optimization is introduced to iteratively solve the fault model of the substation-area protection. The substation-area protection can accurately locate the fault location in the case of complete or missing information, also can cut-off multi-point simultaneous failure.