5.1 A full-pitched coil in a 6-pole machine has a mechanical angle span of (a) 30°...
A three-phase, 5 kVA, 208 V, four-pole, 60 Hz, wye-connected synchronous machine has negligible stator winding resistance and a synchronous reactance of 8 Wper phase. It is operated in parallel with a three-phase, 208 V, 60 Hz power supply.Determine the excitation voltage and the power angle when the machine is delivering rated kVA at 0.8 pf lagging. Draw the phasor diagram
1. Machine Overview. Please answer the following questions. Note: this is to test your comprehension of the basic concepts covered in class. For a DC Machine and Synchronous Machine: Name the two winding types for synchronous and de machines a. Identify which type of winding is used to control torque b. Of the winding types, which is wound on the stator? c. DC Machine: Synchronous Machine: nsidering the combined air gap MMF for the following machines, indicate which has rotating...
Q1 Consider a 24 slot machine. This machine is designed to have 4-poles a) If the phase winding 5/6 pitched, draw winding diagram of phase A. b) What is the mechanical angle between the poles of a phase? c) What is the electrical angle between the poles of a phase? d) Calculate the number of coils per phase. e) Each coil has 10 turns. What is the number of turns per phase? f) The phase A current is 5 A....
A 3-phase, 7 kVA, 400 V, 2-pole, star-connected synchronous machine has negligible armature resistance and Xs-60/phase at rated terminal voltage The machine first runs as a generator in parallel with 3-phase, 400 V, 50 Hz power supply 111 Determine the generated voltage and torque angle of the machine operating as a generator, delivering rated kVA at 0 9 pf lagging Draw and label the corresponding phasor diagram for this condition 1 12 If the field excitation is increased by 18%...
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 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...
please solve the multiple choices [17-18-19-20] (a) What kind of rotor construction is used in this machine? Cylindrical or salient pole rotor? Why? (b) The field current and the mechanical input power are adjusted so that the machine delivers 15 k W at 0.9 lagging power factor. Is it a generator or motor? Draw the per- phase equivalent circuit of machine. (c) Determine the excitation voltage and the power angle (degree) Problem 1. (10 Points) A 3-phase, 20 kVA, 460...
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 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...
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...