10. A 3-phase, salient pole synchronous motor operates at rated voltage on infinite busbars. If t...
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...
(Question 1): (4pts) A three-phase, 2300-V, 60-Hz, 10-pole, A-connected cylindrical rotor synchronous motor has a synchronous reactance of 4.0 82/phase. The armature resistance may be neglected. It is connected to 2300-V source and drives a system with its excitation set to give a PF of 0.9-leading when the power is 500-kW. (a) Sketch the phasor diagram of this motor. (b) Calculate the armature current. (c) Calculate the excitation voltage and torque angle. (d) If the load torque is increased by...
A 1500 kW, unity pf, 3-phase, Y-connected, 2300 V-(line), 30 pole, 60 Hz synchronous motor has a synchronous reactance of 1.95 22/phase. For this problem all losses may be neglected. a. Compute the max. torque in Nm which this motor can deliver if it is supplied with power from an infinite bus, and if its field excitation is constant at the value which would result in unity (1.0) pf at rated load. b. Now, suppose that the motor is supplied...
A three-phase, Y-connected, 6.9-kV, 8-pole, 60-Hz, synchronous motor has a synchronous impedance of 0.01+j6 Ω/phase. The motor is energized at its rated voltage and frequency, and draws a line current of 100 A. The motor rotates a load, while operating at a lagging power factor of 0.9. Calculate the torque developed by the motor: (a) considering the armature resistance (b) neglecting the armature resistance
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 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.
Electric Machines - Synchronous Motors
4. A 150 kVA, 460-V, four pole, 60 Hz, three phase, Y-connected synchronous motor operatingat rated load has a synchronous reactance of 1.20 ohms/phase, determine: Excitation voltage Power angle Pull-out torque Draw a phasor diagram a. b. c. d.
4. A 150 kVA, 460-V, four pole, 60 Hz, three phase, Y-connected synchronous motor operatingat rated load has a synchronous reactance of 1.20 ohms/phase, determine: Excitation voltage Power angle Pull-out torque Draw a phasor diagram a....
A 4-pole, 60Hz, three-phase synchronous motor with a synchronous reactance of 0.5 Ω is working at half load with torque of 20 N-m. Assume ?? = 120∠00 ? (phase voltage). When working at the full load, the equivalent field voltage is Ef = 100 V (phase voltage). a) Draw the per-phase equivalent circuit and label the parameters (5 Points) b) Determine the power consumed by the half load (5 Points) c) Calculate the armature current and active power consumed, at full...
A three-phase synchronous generator with rated data VM = 20 kV, SM = 100 MVA, n = 500 rpm is driven by a turbine that can provide a maximum of 1.6 MNm. Synchronous reactance, XS = 3Ω / phase. The armature resistance (Ra ) is neglected. In open circuit mode (P = 0), an excitation current of 300 A is required to obtain rated voltage (VM ). The machine should be phased into a strong grid, 3x20 kV, 50 Hz....
2.3 (20 points) A separately-excited de motor is mechanically coupled to a three-phase, 4-pole, 30-kVA, 460-V, round-rotor synchronous generator. The de motor is connected to a constant 230-V de supply The ac generator is connected to a 460 V, fixed-voltage, fixed-frequency, three-phase supply. The synchronous reactance of the synchronous generator is 513 Ω/phase. The armature resistance of the de motor is 30 m2. The 4-pole de machine is rated 30 kW at 230 V. All unspecified losses are to be...