For small turbine starts generating power 12.6 kph (3.5 m/s) is the typical cut-in speed. At 36–54 kph (10–15 m/s) produces maximum generation power. At 90 kph (25 m/s) maximum, the turbine is stopped or braked.
The methods often employed in practice to improve system stability are: 1. Increasing System Voltage 2. Reduction in Transfer Reactance 3. Using High Speed Circuit Breaker 4. Automatic Reclosing 5. Transient Stability 6. Turbine Fast Valving 7. Application of Braking Resistors 8. Single Pole Switching:
The V-curves of a synchronous motor show relationship between Armature current (Ia) and Excitation current (If). The Inverted V-curves of a synchronous motor show relationship between power factor (pf) and field excitation (If).
The magnitude of earth fault current for a given fault position within a winding demands upon the winding connections and method of neutral grounding. Earth fault protection for an electric motor is provide by instantaneous relay having a setting of approximately 30% of motor rated current in the residual circuits of two CTs and with ground wire.
EXAMIANS