2) A three-phase synchronous generator is rated 16 kV and 200 MVA, has negligible losses and...

2)

A three-phase synchronous generator is rated 16 kV and 200 MVA, has negligible losses and has reactance of 1.65 pu. The generator is operated on an infinite bus of 15 kV voltage and delivers 100 MVA at 0.8 Power Factor, lagging.

a)Determine the internal voltage (E_i), the power angle (δ), and the line current of the machine.

b)If the field current of the machine is reduced by 10%, while the mechanical power input to the machine is maintained constant, determine the new value of the power angle (δ) and reactive power delivered to the system.

c)The prime mover is next adjusted without changing the excitation so that the machine delivers zero reactive power to the system. Determine the new power angle (δ) and the real power being delivered to the system.

d)What is the maximum reactive power that the machine can deliver if the level of excitation is maintained as in part b?

Expert Solution

Manojponduru answered 1 year ago

A three-phase synchronous generator is rated 16 kV and 200 MVA, has negligible losses and has...

A three-phase synchronous generator is rated 16 kV and 200 MVA, has negligible losses and has reactance of 1.65 pu. The generator is operated on an infinite bus of 15 kV voltage and delivers 100 MVA at 0.8 Power Factor, lagging. a)Determine the internal voltage (E_i), the power angle (δ), and the line current of the machine. b)If the field current of the machine is reduced by 10%, while the mechanical power input to the machine is maintained constant, determine...

Diesel Generator A I MVA diesel three-phase generator is rated at 4.16 kV, 60 Hz, and...

Diesel Generator A I MVA diesel three-phase generator is rated at 4.16 kV, 60 Hz, and connected as Y its neutral is kept floating. It is directly tied to three loads, one consuming 50% of its capacity, and each of the other two consuming 25% of its capacity. A three-phase to ground fault could occur at any of the loads. Draw a one-line diagram of this system, then describe what type of faults could occur in the generator and diesel...

A 45-MVA, 13.8 kV synchronous machine is operating as a synchronous condenser, as discussed in Appendix...

A 45-MVA, 13.8 kV synchronous machine is operating as a synchronous condenser, as discussed in Appendix D (section D.4.1). It’s short-circuit ratio is 1.68 and the field current at rated voltage, no load is 490 A. Assume the generator to be connected directly to an 13.8 kV source a. What is the saturated synchronous reactance of the generator in per unit and in ohms per phase? The generator field current is adjusted to 260 A. b. Draw a phasor diagram,...

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 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...

6.9 A3 ϕ, 11 kV, 60 Hz, 25 MVA, Y-connected cylindrical-rotor synchronous machine generator has Ra...

6.9 A3 ϕ, 11 kV, 60 Hz, 25 MVA, Y-connected cylindrical-rotor synchronous machine generator has Ra = 0.45 Ω per phase and Xs = 4.5 Ω per phase. The generator delivers the rated load at 11 kV and 0.85 lagging power factor. Determine the excitation voltage, Ef, for this operating condition. 6.11 The synchronous machine in Problem 6.9 is operated as a synchronous motor and it is drawing rated MVA at 0.85 lagging power factor. Determine the excitation voltage, Ef,...

A three phase, 60 Hz, 480 V, Y-connected, two-pole synchronous generator has a synchronous reactance of...

A three phase, 60 Hz, 480 V, Y-connected, two-pole synchronous generator has a synchronous reactance of 0.95 Ω per phase. Its armature resistance is negligible. Its combined friction and windage losses are 1.3 kW and its core losses are 0.95 kW. The field current is constant at no-load. Its full load armature current is 55 A at 0.9PF lagging. Assume phase voltage is a reference. Determine following: a) Its terminal voltage when it is loaded with the rated current at...

A 1-MW, three-phase, star connected, 3.3-kV, 24-pole, 50-Hz synchronous motor has a synchronous reactance of 3.24...

A 1-MW, three-phase, star connected, 3.3-kV, 24-pole, 50-Hz synchronous motor has a synchronous reactance of 3.24 ohms per phase. The armature resistance may be ignored. This motor is energized from 3.3-kV infinite bus bars. The field excitation is adjusted until unity power factor at rated load is achieved. Compute the maximum power and torque that the motor can deliver with the excitation remaining unchanged

A 3-phase, 5 kVA, 208 V, 4-pole, 60 Hz, star-connected synchronous generator has negligible stator winding...

A 3-phase, 5 kVA, 208 V, 4-pole, 60 Hz, star-connected synchronous generator has negligible stator winding resistance and a synchronous reactance of 8 Ω per phase at the rated terminal voltage. The generator is connected in parallel to a 3-phase, 208 V, 60 Hz infinite bus. All losses may be neglected. a) Determine the excitation voltage and the power angle when the machine is delivering rated apparent power at 0.8 PF lagging. b) If the field excitation is increased by...

8. Three 6.6 kV, 12 MVA, 3-phase alternators are connected to a common bus bars. Each...

8. Three 6.6 kV, 12 MVA, 3-phase alternators are connected to a common bus bars. Each has reactance to positive sequence current of 15%. The reactance to negative and zero sequence current are 75% and 30% of the positive sequence value. If an earth fault occurs on one of bus bar, determine the fault current when one of the alternator neutral is earthed through a resistance of 0.25 ohm and the others are isolated. 9. Four identical alternators each rated...

Present the single-phase equivalent circuit of a synchronous generator.

Question