Research on setting calculation of transformer protection based on model

The protection based on model has the advantage of operating properly under the condition of energization without load and can provide a better protection instead of the differential protection. Prior to its practical application, there must be a method to compute its pickup value. But up to now no method is presented, in many articles the pickup value is made according to the test data obtained from the laboratory transformer, obviously the pickup value may be smaller, and it is not reliable to prevent the protection from misoperation. In this paper, the factors that influence the performance of the protection are analyzed, and a feasible method for computing the pickup value is presented. The conclusion is supported by the test data.