Research on Optimization Method of Maintenance Period for Transmission Line Protection System in Smart Substation
Main Article Content
Abstract
n order to optimize the maintenance periods of transmission line protection system in smart substation, and reduce its operation and maintenance costs, an equipment failure rate model is proposed, considering equipment aging and incomplete maintenance and using Weibull distribution function and the improvement factor of maintenance for the failure rate of equipment. With the method of reliability block diagram, a failure rate model of the protection system is established. According to the different laws of the failure rate for the protection system in stable-operation and deterioration stages, different maintenance periods are adopted in the two stages respectively. An annual average operating cost models of protection system areestablished for the single and dual transmission line protection configurations with three sampling trip modes, i.e. directsampling and directtripping, directsampling and nettripping, netsampling and nettripping, and the maintenance costs of different maintenance grades. The solving method of best maintenance periods of the two stages under the lowest annual average operating cost is studied. Simulations of the two protection configurations under each sampling trip mode are performed to obtain the mean time between failures, reliable operation time and annual operation cost,validating effectiveness of the proposed method.