Problem 1. (25 points) A 200-hp 440-V 0.8-PF-leading љс0nnected synchronous motor has an armature resistance of 0.6 Ω and a synchronous reactance of 8.0 Ω. Its efficiency at full load is 90 percent....
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...
Problem 3:A 480 V, 50 kW, 60 Hz, 3-φ synchronous motor has a synchronous reactance of Xs = 4.56 Ω and an armature-to-field mutual inductance, Laf = 150 mH. The motor is operating at rated speed and terminal voltage and at an output power of 35kW. Neglecting losses in the motor, calculate the magnitude and phase angle of the line-to-neutral generated voltage Eaf and field current I if the motor is operating at (a) 0.9 power factor lagging (b) unity...
Problem 7 (Chapter 5: Three-Phase Synchronous Motors) A 440 V, 124 HP, 4 poles, 50 Hz, 0.9 leading Power Factor, A-connected synchronous motor has an armature resistance of 0.05 12, and a synchronous reactance of 1.5 12. This motor is operating at its rated conditions with an efficiency of 92 %. 1. Calculate the electrical input power. 2. Find the RMS phase and line currents. 3. What is the reactive power consumed by or supplied by this motor? 4. Calculate...
Problem 3) [15 marks] A 200-V, 100-hp, 0.6 PF leading, Y-connected, 50 Hz synchronous motor has a synchronous reactance of2.0 Ω and negligible resistance. Its mechanical losses and core losses are 1 .0 Kw and 0.5 KW, respectively. The shaft is supplying a 20-hp load at 0.6 PF leading. a) Sketch the phasor diagram of the machine and find the values of IA, I, and EA. b) The load is now increased to 40 hp. Repeat part (a) and find...
Problem 3:A 480 V, 50 kW, 60 Hz, 3-φ synchronous motor has a synchronous reactance of Xs = 4.56 Ω and an armature-to-field mutual inductance, Laf = 150 mH. The motor is operating at rated speed and terminal voltage and at an output power of 35kW. Neglecting losses in the motor, calculate the magnitude and phase angle of the line-to-neutral generated voltage Eaf and field current I if the motor is operating at (a) 0.9 power factor lagging (b) unity...
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...
A 480-V 100-kW 0.85-PF leading 50-Hz six-pole Y-connected synchronous motor has a synchronous reactance of 1.5 and a negligible armature resistance. The rotational losses are also to be ignored. This motor is to be operated over a continuous range of speeds from 300 to 1000 r/min, where the speed changes are to be accomplished by controlling the system frequency with a solid-state drive. (a) Over what range must the input frequency be varied to provide this speed control range? 6-6....
Q3) A 400-V, 3-phase, 50-HZ, 4-pole Y-connected synchronous machine is operated as a motor and draws 27A at 0.77 PF leading. The motor armature resistance is 0.50/Phase and synchronous reactance is j12Ω /phase. The rotational loss is 200 watts. The field winding has a resistance of 0.4Ω and is supplied by 50V DC sources. Determine the following: a) Real and reactive power drawn by the motor b) The power developed c) The torque angle d) The shaft torque e) Efficiency...
500 hp, 600 V, 0.8 pf leading, 6-pole, delta-connected synchronous motor has XS = 1.2 ohm and RA = 0 ohm. Assume motor is lossless. (a) Calculate EA and IA for 400 hp, 0.85 leading pf load. (b) What is the torque? (c) If |EA| is increased by 20% for the 400 hp load, what are the new values of IA and power factor?
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...