A three-phase generator connected in a star generates a phase voltage of Vθ = 2500 Vrms and supplies a delta-connected three-phase load. The three phases of the generator feed 3 equal charges each composed of R = 10 Ω, XC = 4Ω and XL = 10Ω.
a) Calculate the phase, line and load currents
b) Calculate the phase, line and load voltages
c) Calculate the powers of Apparent (S), Real (P) and Reactive (Q)
delivered by the generator
d) Calculate the power factor in each load and the power factor of
the entire system
e) Draw the phasor diagram that shows the "power triangle"
A three-phase generator connected in a star generates a phase voltage of Vθ = 2500 Vrms...
A three-phase generator connected in a star generates a phase voltage of Vθ = 24 KVrms and supplies a three-phase transformer connected in star. The transformation ratio is 115: 1. Each of the three coils of the secondary transformer feed 3 equal charges each composed of them by R = 18Ω, XC = 2Ω and XL = 20Ω. a) Calculate the phase, line and charge currents after the b) Calculate the phase, line and load voltages c) Calculate the Apparent...
A three-phase generator connected in star generates a phase
voltage of Vθ = 220 Vrms and supplies a three-phase load also
connected in star. The three phases of the generator are connected
to the three loads shown Remember that the return of the current of
each charge is through the Neutral.
a) Calculate the phase, line, load and neutral currents
b) Calculate the phase, line and load voltages
c) Calculate the powers of Apparent (S), Real (P) and Reactive (Q)...
Question 2: Three phase circuit. (100p) A wye connected generator supplies a delta connected balanced load through short feeder. seree the load line to neutral voltage as reference voltage phase angle zero. 02.1 Q2.2 Q2.3 Q2.4 Draw the equivalent circuit. 10p Calculate the load line-to-neutral voltages and line-to-line voltages. 20p Calculate the delta load currents and feeder currents. 20p Calculate the supply wye connected generator line-to-neutral voltages. Is the obtained values are acceptable? Calculate the generator real and reactive power...
b) The load connected to a three-phase supply comprises three similar coils connected in star. If the phase currents are 10A and the total active power and power factor absorb by the loads are 3kW and 0.8 lagging, respectively. Find: i. The magnitude of phase and line voltages (4 marks) ii. Total apparent power (1 mark) iii. The impedance of each coil. (2 marks) c) If the coil in Q3(b) are now connected in delta to the same three-phase supply,...
Problem 2:Three phase droult (42 pts) A three-phase wye connected generator ﹃plies two paral el loads through a feeder. tad is matalaeeday connected load and load 2 is a balanced delta connected loed. System data: Generator: Rating S-5oo MVA; Line Voltage: Veu-25KV; Feeder impedance: 7-(0.08 jo 62) O/mile, length-8 miles Generator reactance Xe- 1108: P.-75MW pf c-o.78 (all the power factors are lagging) (a) Draw the one-line diagram and a three-phase equivalent circuit (8pts) (b) Calculate the generator and feeder...
Q3 (3 marks) (4 marks) Two wattmeters are connected in the a and b phases, with the ends of the voltage coils connected in the c phase, of a balanced three phase star- connected lagging load. Draw a circuit diagram showing the three phases, the wattmeters and the load. Draw a phasor diagram of the phase voltages and currents, the voltages across the wattmeter voltage coils, and the angles between the wattmeter voltages and currents. Show that the sum of...
A three-phase 400V, star-connected motor has an output of 50kW, with an efficiency of 90 per cent and a power factor of 0.85. Calculate the line current. Sketch a phasor diagram showing the voltages and the currents. If the motor windings were connected in mesh (delta), What would be the correct voltage of a three-phase supply suitable for the motor?
1. In order to meet an emergency, three single-phase transformers with 12.470/7.200 V are connected in Delta-Wye to form a three-phase transformer which is fed by a 12.470 V transmission line. If the transformer supplies 60 MVA to a load, calculate: (3 marks) a. The turns ratio for each transformer b. The currents in the primary and secondary windings of the transformer c. The primary and secondary transmission line currents 2. A Wye-Delta transformer is connected to a 66 kV...
5. The line to neutral voltages of a Y-connected three phase source are given by, The above three phase source is directly connected to a delta connected balanced three phase resistive load. The resistance in each phase is 10 ohms. Calculate the current phasor 0. Answer- 4. Following three loads are connected in parallel across a single-phase source voltage source: Load 1 absorbs 15 kW and 6.667 kvar; Load 2 absorbs 3 kVA at 0.96PF leading; Load 3 absorbs 15...
A 3-phase Y-connected motor is connected to a three phase Y-connected source with 440V line voltage. It draws a line current of 5A from the source. If the power factor of the motor is 0.8, calculate Active power and Reactive power absorbed by the load Total Apparent power