Concept explainers
A three-phase line with an impedance of
Load 1: Absorbs a total of 150 kW and 120 kvar.
Load 2: Delta connected with an impedance of
Load 3: 120 kVA at 0.6 PF leading.
If the line-to-neutral voltage at the load end of the line is 2000 v (rms), determine the magnitude of the line-to-line voltage at the source end of the line.
Trending nowThis is a popular solution!
Chapter 2 Solutions
EBK POWER SYSTEM ANALYSIS AND DESIGN
- Two balanced three-phase loads that are connected in parallel are fed by a three-phase line having a series impedance of (0.4j2.7) per phase. One of the loads absorbs 560 kVA at 0.707 power factor lagging, and the other 132 kW at unity power factor. The line-to-line voltage at the load end of the line is 2203V. Compute (a) the line-to-line voltage at the source end of the line. (b) the total real and reactive power losses in the three-phase line, and (c) the total three-phase real and reactive power supplied at the sending end of the line. Check that the total three-phase complex power delivered by the source equals the total three-phase comp lex power absorbed by the line and loads.arrow_forwardExercise 1: A three-phase 3Φ transmission line has an impedance of 0.62+j35.06Ω/phase and supplies a three-phase load of 100MW with a power factor (fp) of 0.8 lagging at 200kV. Taking 100MVA and 215kV as a base, we ask: a-) Calculate the impedance of the line in p.u;b-) Calculate the current consumed by the load in p.u;c-) Calculate the load voltage in p.u; PLEASE, TYPE, HAND WRITING GETS UNDERSTANDING.arrow_forwardA balanced three-phase distribution line has an impedance of 1+j8 Ω/ϕ. This line is used to supply three balanced three-phase loads that are connected in parallel. The three loads are L1=120 kVA at 0.96 pf leading, L2=180 kVA at 0.80 pf lagging, and L3=100.8 kW and 15.6 kVAR (magnetizing). The magnitude of the line voltage at the terminals of the loads is 24003 V. 1. a) What is the magnitude of the line voltage at the sending end of the line? 2. b) What is the percent efficiency of the distribution line with respect to average power?arrow_forward
- It is powered from a grounded Y-balanced three-phase source. The installations have four balanced three-phase loads: Load 1: 150 kVA Y with pf 0.8 (+), Load 2: 100 kW ∆ with pf 1.0, Load 3: 120 kW Y with pf 0.6 (-), Load 4: 80 kW and 95 kVAR (inductive - ∆). If the line impedance is 0.02 + j0.05 Ω per phase and the line voltage across the loads is 480 V, find the magnitude of the line and phase voltages at the source. Draw the phasor diagram of the voltages.arrow_forward1. A 69-kV, three-phase short transmission line is 16 km long. The line has a per phase series impedance of 0.125+j0.4375 Ω per km. Determine the sending end voltage, voltage regulation, the sending end power, and the transmission efficiency when the line delivers (a) 70 MVA, 0.8 lagging power factor at 64 kV. (b) 120 MW, unity power factor at 64 kV. Use lineperf program to verify your results. 2. A three-phase, 765-kV, 60-Hz transposed line is composed of four ACSR, l,431,000-cmil, 45/7 Bobolink conductors per phase with flat horizontal spacing of 14 m. The conductors have a diameter of 3.625 cm and a GMR of 1.439 cm. The bundle spacing is 45 cm. The line is 400 km long, and for the purpose of this problem, a lossless line is assumed. (a) Determine the transmission line surge impedance Zc, phase constant ß, Wavelength, the surge impedance loading SIL, and the ABCD constant. b) The line delivers 2000 MVA at 0.8 lagging power factor at 735 kV. Determine the sending end quantities and…arrow_forwardThe phase voltage at the terminals of a balanced three-phase Yconnected load is 2400 V. The load has an impedance of 16 + j12 Ω/ϕ and is fed from a line having an impedance of 0.10 + j0.80 Ω/ϕ. The Yconnected source at the sending end of the line has a phase sequence of acb and an internal impedance of 0.02 + j0.16 Ω/ϕ. Use the a-phase voltage at the load as the reference and calculate (a) the line currents IaA, IbB, and IcC; (b) the line voltages at the source, Vab, Vbc, and Vca; and (c) the internal phase-to-neutral voltages at the source, Va ′n, Vb′n, and Vc′n.arrow_forward
- A 3-phase Y-connected load draws power from a 3-phase Y-connected source. The source voltage, ?=440∠0º?_rms and the load impedance, Z_y=(30+j15) Ω. The line impedance, Z_line= (1+j1)Ω and the system operates at 60 Hz. d) Calculate the total active or real power consumed by the load. e) Calculate the total line loss i.e. the total activepower lost due to line. f) Determine the power efficiency of the system.arrow_forwardThe following three-phase loads are connected to a short transmission line with impedance per wire of 4 + j7 ohms: Load 1: Resistive load drawing 80 A, Load 2: Capacitor drawing 60 A, Load 3: Inductive load drawing 50 A at 80 % power factor. What is the sending end power factor for a receiving end voltage of 34.5 kV? a. 96 % b. 97 % c. 98 % d. 99 %arrow_forwardA short 3-phase transmission line connected to a 33kV, 50 Hz generating station at the sending end is required to supply a load of 10 MW at 0·8 lagging power factor at 30 kV at the receiving end. If the minimum transmission efficiency is to be limited to 96%, estimate the per phase value of resistance and inductance of the line. [2·4 Ω; 0·028 H]arrow_forward
- A load of 135 MW at a power factor of 0.6 lagging can be delivered by a 3-phase transmission line. The voltage at the receiving end is to be maintained at 57 kV and the loss in the transmission is 6.5% of the power delivered. (Consider the line to be a short transmission line) Find A) Single phase Power delivered B) Per phase voltage C) Current flowing through the transmission line D) 3 Phase Losses in the transmission line E) Per phase resistance of the transmission linearrow_forwardA three-phase line feeds two balanced three-phase loads connected in parallel. The first Y load consumes a total of 630,000 W at 0.6 power factor lagging. The second in Δ it has an impedance per phase of 46.08 – j 13.44 Ω. The line-to-line voltage at the end of the loads corresponds to 6920 Vrms, negative sequence. Find the total line current and power total complex absorbed by the two-charge system.arrow_forwardIn a balanced abc sequential, three-phase star-star connected system, the total power on the line is 650W. If VAN117/15 degrees Vrms, the load's power factor is 0.88(forward) and the line impedance is 1+j2ohm, what is the load impedance value? a)5+j1.78ohm b) 5-j1.78ohm c) 7-j3.08ohm d) 7+j3.78ohmarrow_forward
- Power System Analysis and Design (MindTap Course ...Electrical EngineeringISBN:9781305632134Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. SarmaPublisher:Cengage Learning