Concept explainers
A balanced three-phase load is connected to a
(a) Line currents for phases A, B, and C.
(b) Line-to-neutral voltages for all three phases at the load.
(c) Apparent. active, and reactive power dissipated per phase, and for all three phases in the load.
(d) Active power losses per phase and for all three phases in the phase conductors.
Trending nowThis is a popular solution!
Chapter 2 Solutions
MindTap Engineering, 1 term (6 months) Printed Access Card for Glover/Overbye/Sarma's Power System Analysis and Design, 6th
- The three-phase source line-to-neutral voltages are given by Ean=100,Ebh=10+240, and Ecn=10240volts. Is the source balanced? (a) Yes (b) Noarrow_forwardThe instantaneous power absorbed by the load in a single-phase ac circuit, for a general R LC load under sinusoidal-steady-state excitation. is (a) Nonzero constant (b) Zero (c) Containing double-frequency componentsarrow_forwardTwo 7970-V:230-V single-phase transformers with impedance with respect to their secondaries of 1.5 + j3 and 2 + j4.5 ohms are connected in parallel to a 7900-V source. Their secondaries are supplying a common load of 30 + j40 ohms. What is the magnitude of the voltage across the load in volts? (2 decimal places)arrow_forward
- Q2) A 13.2-kV single-phase generator supplies power to a load through a transmission line. The load's impedance is Ztoad 500 236.87° ohm , and the transmission line's impedance is Zine = 60 253.1° ohm. To reduce transmission line losses to 0.0103 of its losses without using the transformers design and use two transformers T1 between the generator and the transmission line and T2 between the transmission line and the load.arrow_forwardA three-phase circuit is balanced. The source voltage for the a-phase has a magnitude of 100 volts, and you can assume the phase angle is a reference of 0 degrees. Write the phasor expressions with proper subscript notation for the source voltage for each leg of the three-phase source if it is in a positive phase sequence.arrow_forwardFigure Q2(a) shows a positive sequence three phase circuits. Given a line-to-line voltage at generator, ERY = 415230°V. With assumption that all load impedance are balanced, Zn=Zyb=Zbr= 15 + jl8 2, determine all phase currents at each load and line currents. Include the phasor diagram for all currents in your analysis. R Zry Zyt Figure Q2(a) If the transmission line in three phase circuit at Figure Q2(a) has a impedance of 1+j20 for each phase, determine the phase voltages for each load with using an appropriate analysis. Use phase voltage at generator, ERN as a reference. Then determine the total apparent power, active power and reactive power supplied by the generator.arrow_forward
- (b) A symmetrical delta-connected 415V three-phase supply is feed to an asymmetrical delta- connected load as shown in Figure Q2(b). Assume that it is a RYB sequence. The impedances of the load are ZrY = 50 + j50 N , ZYB = 150 + j0 N and ZBr = 50 –j50 N. jos (i) Determine and draw the phasor diagram of phase currents in the load. (ii) Determine and draw the phasor diagram of line currents in the system.arrow_forwardQ. 2a) The impedance Zi and Z2 are connected in parallel across 200 V, 50 HZ single phase ac supply. Zi carries 2 A at 0.8 lag p.f. If the total current is 5 A at 0.985 lagging p.f. Determine - 1. Value of Z, and Z2 2. Total power and power consumed by Z2.arrow_forwardIf the line-to-line primary voltage and line current is 1.0 at 0 degrees, what is the secondary line- to-line voltage for the following three-phase transformers? Assume a turns ratio of N = 10. Express answer in polar form. a. Delta-to-Delta: b. Delta-to-Wye: c. Wye-to-Delta: d. Wye-to-Wye:arrow_forward
- Consider a 10 kVA, 200/400 V, 50 HZ: single-phase tranformer has the folloving test results:0.C. test: 200 V, 0.6A, 63 W (L.V.side)S.C. test : 20 V, 25A, 85 W (H.V. side)Deternine:i- The eficiengy at 75 % offiull-load at 0.9 leading power factor.ii -The secondary terminal voltage on fill-load at tunity power factonarrow_forward1. Given the circuit below, the phase voltages are given by Van = 20040° Vrms. The source impedance is 5 + j7 per phase and the wire impedance is 8 +j10 per phase. Let the load impedance be Zy = 50 ohms. Find: Van Vin Ven a. II, and Ic b. c. VAN, VBN, and VCN, and VAB, VBC, and VCA Z₂ Z₂ Z₂ Zw Zw Zw B C le Narrow_forwardTwo 7970-V:230-V single-phase transformers with impedance with respect to their secondaries of 1.5 + j3 and 2 + j4.5 ohms are connected in parallel to a 7900-V source. Their secondaries are supplying a common load of 30 + j40 ohms. A. What is the magnitude of the voltage across the load in volts? (2 decimal places) B. What is the magnitude of the total current supplied by the 7900-V source in amperes? (3 decimal places) C. What is the efficiency of the parallel transformers combined in percent? ( 1 decimal place)arrow_forward
- Power System Analysis and Design (MindTap Course ...Electrical EngineeringISBN:9781305632134Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. SarmaPublisher:Cengage Learning