220kV Relay State Research Evaluation And Decision-Making Methods To Protect The Device Status

With the development of science and technology, power grid structure is increasingly complex, and the grid distribution range is more and more wide, meanwhile the maintenance workload and the cost are increasingly too. In addition, with the comprehensive use of microcomputer relay protection and the improving of the device self-checking, if continue to adopt the traditional fault maintenance and preventive maintenance strategies, it certainly will cause the waste of manpower, material and financial resources. The state overhaul strategy arises at the moment, and become an important means to optimize the power grid equipment management and as a technical support. Based on this, this paper has carried on a thorough research on the state overhaul of the relay protection technology, and the completed work are listed as follow:First, this paper briefly expounds the existing equipment maintenance method and its shortcomings, which lead to the necessity of the state overhaul.Secondly, discuss from two aspects which are the microcomputer protection self-checking and the secondary loop monitoring. The main contain is the monitoring of the relay protection status, the typical fault distribution curve, the failure rate function of protection of the overall system, the Weibull distributed function, and the Weibull distribute model based on Marquardt method.Again, analyzing equipment failure distribution function’s characteristics, drawing forth the data requirements of state estimation method, and for all different needs, discuss its effect and importance. The paper study the state estimation method based on fuzzy theory, including the comprehensive evaluation index weight distribution methods, membership function, fuzzy method. Research discuss the equipment failure rate calculation method, as well as the parameter determination method of the function.Finally, the paper give the evaluation of the status of the device and two examples based on evaluating the state of the failure rate calculation.Then, discourse the definition of the military age of equipment maintenance cycle and build the maximum detection period calculation. Establishing the equipment reliability evaluation model and analyzing the importance of preventive maintenance. Discussing the impact of hiding fault and propose the decision-making method for a single set equipment’s best preventive maintenance cycle.Finally, the paper established equipment condition repairing space model by using state space method, which can automatically estimate the condition of equipment and make the repairing strategy.