Dynamic reactive power optimization method based on the transformer dummy node model

Abstract

This paper proposes a dynamic reactive power optimization method based on the transformer dummy node model. Compared to the method based on the traditional equivalent n circuit, the proposed method adds the voltage at the dummy node as a variable, together with the voltage at the other side of the transformer, to express the voltage change on the two sides of the transformer. So the turn ratio of transformer is removed from variables, and the power flow equations of transformer branches do not contain turn ratio and its square, both the dimension of power flow equations and the number of non-zero elements in the Jacobian and Hessian matrix reduce, which decreases the calculative amount and accelerates the solution process. The test results of IEEE4, 14, 30 bus systems show that the proposed method obtains the same optimal solution with the traditional method but converges more quickly. With higher computational efficiency, the proposed method is suitable for the practical application of power systems.