On computation of the transformation coefficient in the computer simulation of electric-power systems of arbitrary configurations

Abstract

We consider the possibility of computing the transient processes in an electric-power system of an arbitrary topology according to an algorithm taking into account the transformation coefficients of the transformers contained in the system under investigation. This problem arises when computing the dynamic modes since the structure of an electric-power system may be different at different time points. The key problem of calculating an electric-power system of an arbitrary configuration is the use in the system of elements such as transformers as the voltage levels in a part of the system are not known in advance. The problem can be solved by matching the transformer tree, which affects the voltage level of the branch for every branch of the scheme. This method is similar to the method of matching the trees of the key to every branch. When forming the matrices of the nodal conductances and driving currents, a topological list based on the principle of the element-by-element contribution is used. The main advantages of the method based on the topological list are that it does not require observation of the order of the line numeration and its high algorithmic level, which ensures minimization of the computational effort required for computerized derivation of the equations. To determine the transformation coefficient for a branch, it is necessary to pass into the depth on any of the arms of the transformer tree to the last leaf cell, subquentially multiplying the transformation coefficients of the enumerated transfomers. The complete transformer tree can be used to verify that the transformers are correctly connected to the circuit. From the point of view of trends in the development of information technologies, the approach in question allows not only automation of individual subject phases of the design, but also consideration of simulation of the interaction of electrical equipment in an electric-power system, generation of systems of scheduling, economic planning, determination of risks of equipment failure, etc.