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The power system stability is classified into the following types.
1. Rotor angle stability.
2. Voltage stability.
3. Frequency stability.
Rotor angle stability is due to the disturbances in the generator, whereas voltage and frequency
stability are mainly due to the disturbances in the load.
10.5.1 Rotor Angle Stability
Rotor angle stability refers to the ability of synchronous machines in an interconnected power sys-
tem to remain in synchronism after being subjected to disturbance. It is the ability to maintain or
restore the equilibrium between mechanical torque and electromagnetic torque of each synchro-
nous machine in the ...