Question

In: Electrical Engineering

A synchronous generator has parameters as shown in table below. 1. Voltage Rating 30 kV, 3-phase...

A synchronous generator has parameters as shown in table below.

1.

Voltage Rating

30 kV, 3-phase

5.

Frequency

50 Hz

2.

Power Rating

50 MVA

6.

Rotor

Round

3.

Synchronous Reactance,

XS

7 Ω /phase

7.

Connection

STAR

4.

Armature resistance, Ra

1.5 Ω /phase

8.

Excitation Type

Permanent Magnet

  1. An inductive load of 30MW at 0.8 power factor at rated terminal voltage is connected to the synchronous generator to an infinite bus. Determine the excitation voltage per phase and its corresponding power angle. Sketch a phasor diagram for this condition.?
  2. With reference to (a), without losing synchronism, what will be the maximum power the generator will be
    able to deliver? Also, determine the armature current at this condition.?
  3. Turbine torque is reduced until generator output is 15MW while excitation is held constant as in (a) above,
    determine the power angle, armature current, and power factor.?
  4. If now the load has changed to a rated power at rated voltage load, with a leading power factor of 0.8,
    determine the percentage voltage regulation of this generator.?

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