On Speed Stability

Abstract

Distributed energy resources, such as wind turbine generators, often employ induction generators. When such a generator is subjected to a nearby fault, its rotor may accelerate and reach high steady-state speed far from that corresponding to the frequency of the system. This is the generator counterpart to induction motor stalling, which is classified as voltage stability. The phenomenon is a matter of stability, but it is not covered by current definitions of power system stability. We denote this type of stability as speed stability and propose a definition, which also includes induction motor stalling.

Transient Stability Improvement of a FSIG Based Grid Connected wind Farm with the help of a SVC and aSTATCOM: A Comparison

“…So voltage stability in a power system is achieved when there exists equilibrium between the load demand and load supply [6]- [8].…”

“…(b) Rotor angle stability-when all the synchronous machines in a power system runs in synchronism with each other even after being subjected to a disturbance, the power system is said to possess rotor angle stability [6]- [8].…”

“…So a power system which is capable of maintaining a constant system frequency during such conditions is said to possess frequency stability [6]- [8].…”

“…But if a power system is interconnected with a FSIG based wind farm another concept called 'rotor speed stability' in addition to the above concepts comes into picture [6]- [8].…”

“…(d) The 'rotor speed stability' of a FSIG based wind farm is defined as the ability of FSIG based wind generators to maintain a fixed mechanical speed which is near to the speed corresponding to the actual power system frequency even if it is subjected to a disturbance [6]- [8].…”