Subsynchronous oscillation analysis of multimachine power system with HVDC transmission and series compensation

This paper extends the complex torque coefficient approach to subsynchronous oscillation (SSO) analysis in multimachine power systems with HVDC transmission and series compensation (SC). A linearized model of the whole system for SSO study is derived, based on which a new version of the SSO analysis program SOFRESP is developed. While using sparse calculation skill, the program also adopts the technique of generator-network interface and DC-AC interface, which make it convenient to apply to large power systems. At the end of this paper, the SSO problem of an example power system is investigated using SOFRESP and some conclusions are proposed