MGVCL Exam Paper (30-07-2021 Shift 1)
A fully controlled natural commutated 3-phase bridge rectifier is operating with a firing angle α = 30°, The peak to peak voltage ripple expressed as a ratio of the peak output dc voltage at the output of the converter bridge is
Intern turn winding fault can be easily detect by differential protection relay. Also detect by buchholz relay (gas operated relay), cause buchholz relay is used to detect the internal fault of transformer.
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 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).
EXAMIANS