A 3-phase, star-connected synchronous motor takes current of 116 A at 0.80 lagging pf with 500...
- A 3-phase, star-connected synchronous motor takes current of 116 A at 0.80 lagging pf with 500 V applied. At this current, the total armature copper loss is 1,200 W. The synchronous reactance per phase of the motor is 0.30 ohm. Calculate (a) the gross mechanical power developed and (b) the core and friction losses if the full-load efficiency is 95%.
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A 3-phase, star-connected synchronous motor takes current of
116 A at 0.80 lagging pf with 500...
A 208 V, star-connected, 3-phase synchronous motor has a synchronous reactance of 4 ohms/phase and negligible...
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.
Q3- A synchronous motor's parameters are 220-volt,50 hp, 4-pole, 60Hz, 0.8 pf lagging. The synchronous reactance...
Q3- A synchronous motor's parameters are 220-volt,50 hp, 4-pole, 60Hz, 0.8 pf lagging. The synchronous reactance is 2.4ohm.The armature resistance is negligible. The motor is Y-connected.The motor's friction & windage losses are 1400W and its core loss is 1000W.The motor is supplying power to a 25hp load connected to the shaft, at an initial pf of 0.80 lagging. Calculate: (a)the input power and the efficiency (b)the line and phase currents (c)the internal voltage Ea There has been a change in...
2) A 480 V, 60 Hz, 400 hp 0.8 PF-lagging eight-pole A-connected synchronous motor has a...
2) A 480 V, 60 Hz, 400 hp 0.8 PF-lagging eight-pole A-connected synchronous motor has a synchronous reactance of 0.6 and negligible armature resistance. Ignore the mechanical and core losses. The magnitude of the internal machine voltage is 480 V when the field current is 4 A. Assume magnetic linearity. Initially, the motor operates at the rated conditions. a) Find the speed of this motor. b) Find the armature and field currents. c) What is the developed torque? What is...
A 480-V, 50-Hz, Y-connected, 6-pole synchronous generator has a synchronous reactance of 1 Ohm. Its full...
A 480-V, 50-Hz, Y-connected, 6-pole synchronous generator has a synchronous reactance of 1 Ohm. Its full load armature current is 60 A at 0.8 pf lagging. Under full load conditions, the friction and windage losses are 1.5 kW, and core losses are 1 kW at 50 Hz. Ignore armature copper losses. The field has been adjusted so that the terminal voltage is 480 V at no load. a.What is the speed of rotation of this gen? b.What is the generator...
Question 4 (10 marks) A) A 10-kVA, 415-V, three phase, Y -connected synchronous generator has a...
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...
4. A 3-phase, 340 V, Induction motor is supplied with 60 A at .85 pf lagging....
4. A 3-phase, 340 V, Induction motor is supplied with
60 A at .85 pf lagging. Its stator and rotor copper
losses are 4000 W and 800 W respectively, while its core losses are
2000 W, and its Friction, Windage
and Stray losses are a combined 750 W. Determine:
a. Draw a diagram depicting the energy flow in the motor (Similar
to the one we had drawn in class)
b The air gap power
c. The mechanical power developed
d....
A 480-V, 60-Hz, A-connected, four-pole synchronous generator has a synchronous reactance of 0.1 ohm and an...
A 480-V, 60-Hz, A-connected, four-pole synchronous generator has a synchronous reactance of 0.1 ohm and an armature resistance of 0.0 15 ohm. At full load, the machine supplies 1200 A at 0.8 PF lagging. Under full-load conditions, the friction and windage losses are 40 kW, and the core losses are 30 kW. Ignore any field circuit losses c) How much power is the generator now supplying? How much power is supplied to the generator by the prime mover? What is...
A 3-phase, 400 V synchronous motor is operating in parallel with a 3-phase balanced load of...
A 3-phase, 400 V synchronous motor is operating in parallel with a 3-phase balanced load of 400 kW at 0.80 pf lagging. In order to improve the pf to 0.9 lagging the excitation of the motor is increased. If the mechanical load on the motor including losses amount to 80 kW, calculate the current taken by the motor from the supply.
3. A 480 V, 60 Hz, 470 kVA, 0.85 PF lagging, 2-pole, Y-connected synchronous generator has...
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...
QUESTION 4 A three-phase Y-connected, 500 kVA, 3.2 kV, 0.85 PF-lagging, six-pole, 60 Hz synchronous generator...
QUESTION 4 A three-phase Y-connected, 500 kVA, 3.2 kV, 0.85 PF-lagging, six-pole, 60 Hz synchronous generator has a synchronous reactance of 15 ohm and an armature resistance of 0.8 ohm. What are the electrical losses in this generator at the rated conditions? Attach File Browse My Computer Browse Content Collection QUESTION 5 If phase current of a Delta-connected three-phase system is equal to 1pu, then the line current of the same system is equal to 3 pu. Click Save and...
Q3- A synchronous motor's parameters are 220-volt,50 hp, 4-pole, 60Hz, 0.8 pf lagging. The synchronous reactance is 2.4ohm.The armature resistance is negligible. The motor is Y-connected.The motor's friction & windage losses are 1400W and its core loss is 1000W.The motor is supplying power to a 25hp load connected to the shaft, at an initial pf of 0.80 lagging. Calculate: (a)the input power and the efficiency (b)the line and phase currents (c)the internal voltage Ea There has been a change in...
2) A 480 V, 60 Hz, 400 hp 0.8 PF-lagging eight-pole A-connected synchronous motor has a synchronous reactance of 0.6 and negligible armature resistance. Ignore the mechanical and core losses. The magnitude of the internal machine voltage is 480 V when the field current is 4 A. Assume magnetic linearity. Initially, the motor operates at the rated conditions. a) Find the speed of this motor. b) Find the armature and field currents. c) What is the developed torque? What 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...
4. A 3-phase, 340 V, Induction motor is supplied with
60 A at .85 pf lagging. Its stator and rotor copper
losses are 4000 W and 800 W respectively, while its core losses are
2000 W, and its Friction, Windage
and Stray losses are a combined 750 W. Determine:
a. Draw a diagram depicting the energy flow in the motor (Similar
to the one we had drawn in class)
b The air gap power
c. The mechanical power developed
d....
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...
QUESTION 4 A three-phase Y-connected, 500 kVA, 3.2 kV, 0.85 PF-lagging, six-pole, 60 Hz synchronous generator has a synchronous reactance of 15 ohm and an armature resistance of 0.8 ohm. What are the electrical losses in this generator at the rated conditions? Attach File Browse My Computer Browse Content Collection QUESTION 5 If phase current of a Delta-connected three-phase system is equal to 1pu, then the line current of the same system is equal to 3 pu. Click Save and...
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