Research On Method And Index System Of Comprehensive Evaluation For Relay Protection Operation

Power system relay protection is the patron saint of the safe and stable operation of the power grid,but also an important guarantee to maintain the normal operation of social and economic life.With the increasing demand for power and expansion of the structure of the power grid,the power system imposes increasingly higher requirements on relay protection.The performance of relay protection operation is directly related to the safe operation and economic benefits of the power grid.The operational status and effectiveness of relay protection can be examined in all respects by evaluating the performance of relay protection operation,and it is of great importance in improving the level of relay protection operation.This paper introduces the key performance indicator(KPI)idea and carries out the research on the comprehensive evaluation system of the performance of relay protection operation.The research content is mainly divided into two parts:the establishment of the evaluation index system of relay protection operation and evaluation of the performance of relay protection operation.Firstly this article introduces the key performance indicators in corporate performance management,under the guidance of which established the index system with vision-strategy-tactic three-tier structure.Then,based on the principle of 20-80 principles in the KPI theory and the traditional balance score card,combined with the actual work characteristics of relay protection,a set of strategic indicators was established.Afterwards,each strategy index was decomposed using the fishbone diagram method,and the corresponding set of tactical indicators was formed accordingly.Finally,under the connection of the invisible chain the strategic index set and the tactical index set were inseparable,and together formed a comprehensive,multi-level,and multi-level relay protection evaluation index system.This paper presents a complete set of evaluation methods for the performance of relay protection operation.The method includes three parts:standardization of indicators,calculation of index weight coefficients,and comprehensive evaluation.First of all,in order to eliminate the impact of different dimensions and orders of magnitude of the indicator,the indicator is standardized and a corresponding scoring function is constructed.According to the different attributes of indicators,the indicators are classified,and different methods are used to propose standardized methods for processing and scoring.The proposed standardization method of indicators has decreased the subjectivity of evaluation and improved the scientific rationality of evaluation.Then a set of calculation methods for the weight coefficient of relay protection evaluation indicators was proposed.When calculating the weight coefficient of strategic indicators,the traditional AHP method was improved.The 1-9 scale method,the fractional scale method,and the exponential scale method were used to construct the judgment matrix,and the index-based scale method was determined through comparative analysis.The calculation results were used as the weight coefficient of the strategic indicator.When calculating the weight coefficient of the tactical layer indicators,the concept of dominance degree ratio was proposed based on the comparison of the possible rank of tiangular fuzzy numbers,and the weight coefficients of the tactical layer indicators were calculatedFinally,a fuzzy comprehensive evaluation method was proposed to empirically evaluate the operation status of a grid company's relay protection on the longitudinal time axis using the data of different months of the same year.The operation status of relay protection was expressed in two forms:qualitative and quantitative,and the evaluation results were divided and ranked at different levels,and the final score was given.At the same time,by comparing the comprehensive evaluation results of each single strategic indicator,the weak links that affect the operation level of relay protection were found.The actual case showed that the proposed relay protection operation evaluation index system based on KPI was scientific and reasonable,and the relay protection performance evaluation method with strong operability and universal adaptability could be applied in practical projects.