Работа комбинированного устройства управления перетоком активной мощности на изолированную нагрузку

Abstract

At present, the Unified National Energy System of Russia and power systems around the world are witnessing a growth of transit flows both inside power systems and between individual elements; however, the transmission capacity of existing ties lags behind this growth. A combined active power flow control device based on an asynchronized electromechanical frequency converter (AEMFC) can be used as a measure for eliminating overloads. This converter, which is constructed on the basis of an asynchronized synchronous machine, can be used to decrease the power flow through the overloaded power grid element and increase the power flows through weakly loaded power lines. However, the question of how an AEMFC influences the course of transients and power system behavior in emergency modes of its operation is still poorly understood. This research work is aimed at studying that influence and estimating the possibility of improving the quality of transients in a complex inhomogeneous power grid through control by means of an AEMFC. The analysis was performed using the basic principles of the theory of electromechanical transients, mathematical modeling techniques, methods for solving systems of linear and nonlinear equations, and the theory of differential equations. Calculations of electromechanical transients have been carried out taking into account the use of an AEMFC-based power flow control device. The AEMFC control algorithm was proposed, and the effect the AEMFC device with the proposed control algorithm has on the transient stability of machines and load in a complex inhomogeneous electric power system during its operation in an isolated area has been estimated. It has been shown that the combined power flow control device with the proposed control algorithm makes it possible to maintain power supply of loads in the power grid's normal and repair operation modes, also in case of supplying power directly from the combined device.