Energy Function of a General Multimachine System with an SMES

摘要

To provide dynamic power-flow control that improve electric-power-system stability, superconducting magnetic energy storage (SMES) can be applied. In order to assess the influence of an SMES on the system's dynamic behaviour using direct methods, pro per energy functions for this device are needed. Besides transient-stability assessment the energy functions can be applied to determinate the device's control strategy. In this paper the energy functions for a series connection and for a parallel connection of SMES into the general multimachine system have been developed. For both series and parallel connections various energy functions were proposed according to the control strategy applied. The energy functions were constructed as additional terms that can be added to any existing structure-preserving energy function. Tests within a single-machine infiniite-bus system and an IEEE 9-bus 3-machine system proved the correctness of the proposed energy functions. The application of new energy functions was demonstrated on the problem of transient-stability assessment.