Mathematical model of an asynchronous generator for assessing the state of an electrical power system

The study is aimed at determining criteria for a mathematical model of an asynchronous generator used to assess the state of an electrical power system. The relevance of the study is predicated on the current inadequacy of measuring instruments for electrical distribution networks, resulting in low measurement redundancy. Mathematical data processing methods, including tasks of measurement verification and state assessment, are developed to support technical measures for increasing the volume of information. The paper considers the problem of choosing a mathematical model for an asynchronous generator widely used in assessing the state of an electric power system at wind turbine power plants. In this paper, PQ and RX mathematical models of an asynchronous generator are used. Quality studies of the obtained active power of the asynchronous generator depending on the generator model are carried out and recommendations concerning the choice of model presented. The selected mathematical model should provide the opportunity to solve the problem of measurement verification, causing no loss in the node observability. The recommendations are based on an analysis of the Jacobi matrix, with the structure determined by the measurement elements. The calculations were performed on an IEEE 30-node test circuit using simulated load schedules and generation of wind farm data. Based on the research results, the following recommendations were developed. In the case of asynchronous generator measurement where the active power belongs to a group with low redundancy, the RX model is appropriate for authenticating measurements of the asynchronous generator active power and its flow in the line leaving this node. In the case of critical active power measurement, the PQ model should be used to ensure the observability of this node.

electric power system, state estimation, induction generator, mathematical model, Jacobi matrix analysis, reliability problem