Research On On-line Verification And Automatic Identification Of Operation Mode Of Regional Power Grid

With the gradual complexity of the grid structure and the rapid growth of the scale of the grid,the operation of the grid is gradually diversified and operation adjustments have become more frequent.This change also greatly increases the workload of the relay protection device,and puts forward higher requirements on the rationality and accuracy of the relay protection setting.Therefore,by analyzing the current operation mode of the power grid,it is of great significance to study how the fixed value is adjusted accordingly with the switching of the operation mode.At the same time,in order to ensure that the fixed value meets the "four characteristics" requirements,it is necessary to conduct more in-depth research and improvement on the existing relay protection online verification technology.This article first studies and analyzes the functional modules of the existing online protection setting check and early warning system,and on this basis,further develops the "operation mode identification and setting zone automatic switching" function,so as to solve the current grid operation mode When a change occurs,the fixed value of the line protection cannot be switched synchronously.At the same time,combined with the engineering example of Bijie Power Grid,comprehensive sub-item verification of its protection setting is carried out,and corresponding verification report is generated to analyze the rationality and correctness of its setting.The function module of "recognition of operation mode and automatic switching of fixed value zone" is a method combined with graph theory.First,the topology model of the power grid is analyzed,and the position of the circuit breaker and the switching state of the power grid are searched and judged by the graphical search method.Identification of the operation mode of the power grid.After the identification of the operating mode is completed,the logical discriminant expression method is used to logically match the set value area with the operating mode.Once the operating mode changes,the line will automatically switch to the corresponding correct set value area,and then pass through the trust system after the switch is completed.Read the field setting value and compare it with the currently recognized protection setting value to ensure that the setting value is switched in the correct area.The comprehensive sub-item verification of the protection setting is mainly divided into the following aspects: protection setting sub-item horizontal time sequence online verification,protection setting sub-item vertical sequence online verification,protection setting sub-item sensitivity online verification,protection fixed value sub-item quickaction online verification,protection fixed value sub-item vertical protection scope online verification,overall plan verification.