OPTIMAL DISTRIBUTION OF REACTIVE POWER AMONG POWER UNITS CONNECTED TO DISTRIBUTION DEVICES OF VARIOUS VOLTAGE CLASSES

Abstract

This paper examines the features of in-station optimization of reactive power operating modes at power plants whose power units are connected to distribution devices of two different voltage classes with autotransformers. For such power plants, a methodology and mathematical model have been developed for the comprehensive optimization of distribution of reactive load among power units and reactive power flow through autotransformers. The proposed methodology and mathematical model incorporate the technical and economic characteristics, the maximum and minimum constraints, active power losses in generators, block transformers, auxiliary transformers, and autotransformers, as well as the power supply schemes for the auxiliary needs of the power plant. A detailed description of the implementation algorithm for the comprehensive optimization of distribution of reactive load among power units connected to distribution devices of two different voltage classes, as well as reactive power flow through autotransformers are provided. Its application enables the determination of the optimal value of reactive power for each of the parallel-operating power units and reactive power flow through autotransformers to ensure the minimum level of active power losses of a power plant as a whole. Calculations of the in-station active power losses at a power plant with generators possessing a nominal capacity of 200 MW connected to 220 kV and 330 kV distribution devices with 220/330 kV autotransformers have been conducted. The obtained results confirm the economic efficiency of the developed methodology. References 10, figures 2.