In a synchronous generator, at 0.8 lagging power factor, an excitation voltage per phase of 240...
A 10MVA 13.8-kV 60-Hz four-pole Y-connected synchronous generator is delivering rated power at unity power factor. a) Draw the equivalent circuit for the analysis of this problem b) Find the synchronous reactance given that the field excitation voltage is 6.89kV (per phase) and leads the terminal voltage by an angle π/4. c) In a special occasion, the generator is operated as a motor (the synchronous reactance is the one derived in (a)). At rated terminal voltage, what is the minimum...
QUESTION 5 A 3-phase, 22 kV (phase), 500 MVA star-connected synchronous generator has a per phase reactance Xg of 1.5 pu and supplies 0.8 pu per phase real power (P) at the rated voltage, with a lagging power factor of 0.6 to the load. Find the actual excitation voltage Vo in kV (line value). 96.392
Q2 (a) A star connected 6.6kV, 8MVA synchronous generator operating at 7MW and a 0.88 lagging power factor is connected to the Grid. The synchronous reactance is 1.5Ω (i) Calculate the phase current, excitation voltage and load angle. [10] (ii) What is the maximum theoretical power at this excitation? Draw a phasor diagram (to scale) and from this estimate the phase current and power factor when operating at this point. 151 Q2 (a) A star connected 6.6kV, 8MVA synchronous generator...
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...
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...
A 2000 V single-phase synchronous generator is being used as a backup generator outside a diagnostic center. When the generator terminals are short-circuited and a field excitation current of 2.5 A is passed, the ammeter between the terminals read 100 A of full load current. If the terminals of the same generator are opened and the voltage across them is measured using a voltmeter, we get the value of 500 V with the same excitation current. The armature resistance is...
Question 4 (10 marks) A) A 10-kVA, 415-V, three phase, Y -connected synchronous generator has a winding resistance of 0.3 Q and a synchronous reactance of 0.6 on a per phase basis. Determine its voltage regulation at full load when the power factor is (a) 75% lagging and (b) 75% leading. B) (10 marks) A 220-V, Y-connected, three-phase, synchronous motor has a synchronous reactance of 4 O/phase and negligible armature winding resistance. At a certain load the motor takes 7.5...
A 60-MVA, 69.3-kV, three-phase synchronous generator has a synchronous reactance of 15 Ω/phase and negligible armature resistance. -a. The generator is delivering rated power at 0.8 power factor lagging at the rated terminal voltage to an infinite bus bar. Determine the magnitude of the generated emfper phase and the power angle δ. -b. If the generated emfis 36 kV per phase, what is the maximum three-phase power that the generator can deliver before losing its synchronism? Winter
Q2) A 13.8-kV, 50-MVA, 0.9-power-factor-lagging, 60-Hz, four-pole Y-connected synchronous generator has a synchronous reactance of 2.5 Ω and an armature resistance of 0.2 Ω At 60 Hz, its friction and windage losses are 1 MW, and its core losses are 1.5 MW. The field circuit has a de voltage of 120 V, and the maximum , is 10 A. The current of the field circuit is adjustable over the range from 0 to 10 A. The OCC of this generator...
A 12 kV, 300 MVA synchronous generator is tested at a field current of 200 A. The open-circuit voltage was found to be 10 kV and the short-circuit current was 7.5 kA. The stator resistance was measured at 0.1 ohms per phase. i) Find the value of the synchronous reactance in per-unit. [ 2 marks ] ii) The synchronous generator is delivering half rated output at a terminal voltage of 5% below rated voltage and a power factor of 0.7...