Problem 4 A synchronous generator rated 480V, 500kVA, 0.9pf, has a synchronous impedance of 160% on...
A 75 MVA, 25 Kv, three-phase, 60 Hz synchronous generator has a synchronous reactance of X= 9 Ω per phase and a negligible resistance. The generator is delivrimg rated power at a 0.8 power factor lagging at the rated terminal voltage to an infinitie bus, as shown in the following figure 1. Figure 1.The synchronous generator connected to infinite bus in single phase. 1) The excitation voltage is E = 26.87 KV, The generator delivring 60 MW. Compute the powe...
A 3-phase 480V, 4-pole, 60Hz, Delta- connected synchronous generator with the OCC shown here has an armature resistance of RA-0015Ω and 400 synchronous reactance ofX, 0.1.2. At full load, the machine supplies 1200A at 0.8PF lagging. Under full-load conditions, the friction and windage losses are 40kW, and the core losses are 30kW. Ignore field 300 200 circuit losses. a) If the generator is operated at full load, how much field current is required to keep the terminal 100 voltage constant...
A 480 V, 60 Hz, 470 kVA, 0.85 PF lagging, 2-pole, Y-connected synchronous generator has a synchronous reactance of XS=0.016 Ω and an armature resistance of RA=0.016 Ω. At rated conditions the core losses are 7 kW. Friction losses and field winding losses are 8 kW. Suppose the machine is connected to an infinite bus (hence the terminal voltage is fixed) and it is running at the rated conditions. a) What is the rotor speed in rpm? b) Calculate the...
Question 5 (Svnchronous machines) a. A synchronous generator connected to an infinite grid has its frequency and terminal b. A six-pole, Y-connected three-phase synchronous machine rated 208 V (line-to- voltage fixed. What is the effect of increasing the excitation current in this case? line), 5500 VA has a synchronous reactance of 8 2 per phase at rated terminal voltage. It is operating as a generator connected to an infinite grid Determine the excitation voltage and the power angle if the...
b) A 1MW, 3300 V, 50 Hz, wye-connected, 3-ф, twenty four-pole, synchronous motor has a synchronous reactance of 3.24 2 per phase. Assume armature resistance is negligible. This machine is connected to an infinite bus-bars at 3300 V. Its field excitation is adjusted to provide P.F-1 at rated load Calculate: 0 the internal generated voltage EA and armature current la at rated conditions (S marks) ii) the maximum power and torqu e that the motor can deliver with its Ir...
Problem #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 (5), 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...
3. A 480 V, 60 Hz, 470 kVA, 0.85 PF lagging, 2-pole, Y-connected synchronous generator has a synchronous reactance of Xs=0.0162 and an armature resistance of RA=0.0.1622. At rated conditions the core losses are 7 kW. Friction losses and field winding losses are 8 kW. Suppose the machine is connected to an infinite bus (hence the terminal voltage is fixed) and it is running at the rated conditions. a) What is the rotor speed in rpm? b) Calculate the phase...
A synchronous generator with a synchronous reactance of XS =j 0.45Ω is connected to a 20 kV infinite bus via a transmission system whose reactance is Xe = j0.1Ω. The generator terminal voltage is adjusted as 20 kV to synchronized with the infinite bus. The generator delivers 400 MW to the infinite bus. a) Compute the armature current. b) Compute the generator's internal voltage (E).
Question 4. (30 Marks) A 480V, Y-connected, 4-pole synchronous motor is drawing 40A at unity power factor from a 480V "infinite" bus. The field current flowing under these conditions is 4A. Its synchronous reactance is 8Ω (neglect Ra). Assume a linear open-circuit characteristic. a) Find the internal voltage and the torque angle for these conditions. b) Draw the Phasor diagram for this condition. On the same axis, use dashed lines to show the Phasor for 0.8 lagging operation while consuming...
S. A three-phase, 4-pole, Y-connected synchronous generator is rated 575V, 200k VA, 60Hz. The generator's synchronous reactance is X-0.Q. Losses are negligible. The generator is comnected to an ideal 575V three- phase 60 Hz bus. Use V, for phase a-to-neutral as the reference angle (a) The generator's input power is 150kW. The generator's field current is adjusted to 10A which caases the generator to operate at unity power factor. What is the generator's phase-a armature current Ia (magnitude and phase)?...