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,...
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...
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 3-phase, 100 MVA, 11 kV, 60 Hz, 200 rpm synchronous generator has synchronous reactance of 12 2 and negligible stator resistance. a. The generator is connected to an infinite bus and delivers 80 MW at 0.8 leading power factor. Determine the power angle and excitation voltage EA. Draw the phasor diagram. b. The field current of the generator is now slowly reduced until the generator reaches its static stability limit (5=0). For this condition, determine the power angle, excitation...
A 208 V, star-connected, 3-phase synchronous motor has a synchronous reactance of 4 ohms/phase and negligible armature winding resistance. At a certain load, the motor takes 7.2 kW at 0.8 pf lagging. If the power developed by the motor remains the same while the excitation voltage is increased by 50% by raising the field excitation, determine (a) the new armature current and (b) the new power factor.
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
A 1500-kVA, 6.6 kV, 50 Hz, 6-pole, three-phase, star-connected synchronous generator has a resistance 0.5Q/phase and a synchronous reactance of 5Q/phase. The generator is supplying its rated power at its rated voltage and at a power factor lagging. The rotational loss is 2 kW. Calculate: (a) the power developed, (b) the power angle, (c) the voltage regulation, and (d) the shaft torque. A 1500-kVA, 6.6 kV, 50 Hz, 6-pole, three-phase, star-connected synchronous generator has a resistance 0.50/phase and a synchronous...
A 2200Vrms (line-to-line), 30Hz, Y-connected, 3-phase synchronous motor has a synchronous reactance of 10Ω per phase. The motor draws 163kW at a power angle of 15°. Determine: a) The excitation voltage per phase. b) The supply current and the supply power factor. c) Draw the phasor diagram for the above condition. d) Suppose the mechanical load is now disconnected, with all the losses are negligible. Determine the new supply current and the supply power factor.
In a synchronous generator, at 0.8 lagging power factor, an excitation voltage per phase of 240 V gives a rated terminal voltage V. If the power factor of load increases to unity, the excitation voltage per phase required to produce a terminal voltage of V must be a. 260 V b. 250 V c. 240 V d. 225 V
Be detailed please A three-phase y-connected 2300 V, 60 Hz round-rotor synchronous motor has a synchronous reactance of 2 ohms/ phase and negligible armature resistance. 2. If the motor takes a line current of 350 A operating at a leading pf of 0.8. calculate the armature voltage and the power angle. If the motor is operating on load with a load angle of-20%, and the excitation is adjusted so that the armature voltage is equal in magnitude to the terminal...
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...