Dynamics and Control of Electric Transmission and Microgrids

10Analysis of Subsynchronous Resonance

10.1 Introduction

Chapters and primarily dealt with the stability of relative motion between the rotors of different synchronous generators (angular stability). These transients are much slower than the electro‐magnetic transients associated with the electrical network and generator stator fluxes. For the study of these electro‐mechanical transients, the fast transients may be neglected, that is, the differential equations associated with the stator fluxes and the states of the network (in the ‐ frame) are converted into algebraic equations by neglecting the time‐derivative terms of these quantities. In these slow‐transient studies, the rotating system of the turbine‐generator is assumed to be a single rigid body. Therefore, the inertia constant considered in these studies is the cumulative inertia of the turbine‐generator system.

Another class of dynamic phenomena in a power system involves the relatively faster transient interactions between (i) turbine‐generator systems, (ii) the electrical network, and (iii) power‐electronic systems and their controllers (HVDC, FACTS, renewable energy/storage interfaces, generator excitation systems). The ...