Method and system for preventing transformer differential protection maloperation

The invention discloses a method and system for preventing transformer differential protection maloperation, and the method comprises the steps: 1, obtaining the sampling value data of N sampling points based on a current differential current sampling point and N-1 sampling points before the current differential current sampling point; 2, setting the maximum cycle index M, and initializing m to be equal to 1; 3, selecting m pieces of sampling value data with the maximum absolute value in the N pieces of sampling value data as a first data set, and taking the rest data as a second data set; 4, solving an average value of absolute values of all the sampling value data in the second data set, and calculating a ratio of the average value to the maximum absolute value in the sampling value data; step 5, if the ratio is smaller than or equal to a preset threshold value and the current differential current sampling point is the sampling point corresponding to the data in the first data set, determining that m abnorm