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 line

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 line

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter3: Power Transformers

Section: Chapter Questions

Problem 3.49P: Consider the single-Line diagram of a power system shown in Figure 3.42 with equipment ratings...

See similar textbooks

Similar questions

Problem 1 - Series en Parallel AC networks [19] Look at the circuit in Figure 1 and determine the following: (a) Total Admittance. (b) Total Impedance. (c) Total Current (l:). (d) Current (I1) through impedance Z2. (e) Current (12) through impedance Z3. (f) Current (I3) through impedance Z4. (g) Is this an inductive or capacitive circuit? A. B Zs 220V;50HZ Figure 1 (h) Voltage across Z1. (i) Voltage across A and B. G) Voltage across Zs. Z1 = 3 + j5 ohm Z2 = 10 + jo ohm Z3 = 5 + j15 ohm Z4 = 10 – j30 ohm Zs = 20 – j30 ohm Admittance and Impedance in rectangular notation. All currents and voltage in polar notation. Take voltage as reference.
In the following network, the voltage magnitudes at all buses are equal to 1 p.u., the voltage phase angles are very small, and the line resistances are negligible. All the line reactances are equal to j1 p.u. (1) (2. P₂ = 0.1 p.u. P3 = 0.2 p.u. The voltage phase angle 83 in radian at bus 3 is (Assume one of the generator bus as slack bus and sin-¹ (0.1) = 0.1 rad) (a) -0.1 (b) -0.2 (c) 0.1 (d) 0
Three single-phase distribution transformers, each rated for 18 kVA, 20000/220 volts, are connected in a Dy three-phase bank. For convenience, at the factory, the OCT and the SCT were per- formed as per standards with the whole three-phase bank already connected and the measured values were as follows: Vline 381.051V, line 1.78436A, P30 = 372.414 W. Vline = 5656.85 V, Iline = 1.55885 A, P30 = 2160 W. Three phase bank of single phase transformer on a utility pole. 37.5 K (a) Find the single phase equivalent circuit referred to the low volt- age side. (b) Find the transformer regulation at the rated load and voltage and a power factor of 0.45 lagging (Neglect the excitation current). (c) Using the "load" model, what is the approximate transformer- bank's efficiency, n, under these conditions of load? (a) R2 X=2 Rsc=mXsc = mS (b) Vreg= (c) n = %
One advantages of load balancing is that each phase conductor carries the ? current value
Figure below shows the one line diagram of a 3-o system. By selecting a common base of 100 MVA and 22 KV on the generator side, draw an impedance diagram showing all impedances including the load impedance in per unit. The data are given as follows: G: 100 MVA, 22 KV, X= 0.18 pu 22/220 KV, X= 0.1 pu TR1: 50 MVA, TR2: 40 MVA, 220/11 KV, X=0.06 pu Load 1: 50 MVA, 0.8 pf lag Load 2: 50 MVA, 0.8 pf lead If volt at bus 4 equal 11 KV constant value : calculate i) volt at bus 1 ii) EMF (Eg) of generator ii) Transmission line current TR1 TR2 ZTL=j80 2 G1 3. 4 Load 1 Load 2
Question 1) A 154 kV transmission line has a length of 100 km. The line and the conductors are given in Figure 1. The line is operated at f= 50 Hz. For both old and new lines calculate; a. GMD and GMR. b. Inductance of the line in Henries (H). c. Series Impedance (Z) of the line in Ohms. d. *Compare the results for both lines and comment on the results. e. *If the distance between the two neighbouring conductors is increase from 13 meters to 15 meters what would be the parameters in part a.,b. and c. comment on the results. New Line's Conductors 13 m 13 m Old Line's Conductors d r = 2 cm d = 40 cm r = 2 cm Figure 1
Figure Q2 (a) shows the spacing of a double circuit 3-phase overhead line. The phase sequence is RYB and the line is completely transposed. i) Critically assess the significance of transposition in a 3-phase overhead line. ii) Calculate the inductance per phase for 500 meter length of line using Table 2(a) data for the Figure Q2(a). Table 2(a) GMR of the line Distance a-b' 0.01m 6.6m Distance a-a' 8.5m Figure Q2(a)
OS: (A A 100 KVaurge travehs on an overhead line of surge impedance 40 a The line is conmected to a cable of surge impedance 50 Q through a resistance R. Find () the valur of R that it aboerbs masimum energy, and (2) voltage and current transmitted into cable? Explain in detailh the folloming phrase "The rate of rie of restriking voltage will become high if the fault ocurrs near the bus har of the station?
Consider a single-phase electric system shown in Figure 3.33. Transformers are rated as follows: XY15MVA,13.8/138kV, leakage reactance 10 YZ15MVA,138/69kV, leakage reactance 8 With the base in circuit Y chosen as 15MVA,138kV determine the per-unit impedance of the 500 resistive load in circuit Z, referred to circuits Z, Y, and X. Neglecting magnetizing currents, transformer resistances, and line impedances, draw the impedance diagram in per unit.
Consider the single-Line diagram of a power system shown in Figure 3.42 with equipment ratings given: Generator G1: 50MVA,13.2kV,x=0.15p.u. Generator G2: 20MVA,13.8kV,x=0.15p.u. Three-phase -Y transformer T1: 80MVA,13.2/165YkV,X=0.1p.u. Three-phase Y- transformer T2: 40MVA,165Y/13.8kV,X=0.1p.u. Load: 40MVA,0.8PFlagging,operatingat150kV Choose a base of 100 MVA for the system and 132-kV base in the transmission-line circuit. Let the load be modeled as a parallel combination of resistance and inductance. Neglect transformer phase shifts. Draw a per-phase equivalent circuit of the system showing all impedances in per unit.
2. The one-line diagram of a three-phase power system is as shown in the figure below. Impedances are marked in per unit on a 100-MVA, 400-kV base. The load at bus 2 is S2 = 15.93 MW-j33.4 Mvar, and at bus 3 is S3 = 77 MW +j14 Mvar. It is required to hold the voltage at bus 3 at 4006 0 kV. Working in per unit, determine the voltage at buses 2 and 1. V3 j0.5 pu V₂ S₂ j0.4 pu S3
1. The one-line diagram of an unloaded power system is shown below. Reactances of the two sections of transmission line are shown on the diagram. The generators and transformers are rated as follows: Generator 1: 20 MVA, 13.8 kV, X = 0.20 p.u Generator 2: 30 MVA, 18 kV, X = 0.20 p.u Generator 3: 30 MVA, 20 kV, X = 0.20 p.u Transformer T1: 25 MVA, 220Y/13.8A kV, X = 10% Transformer T2: Three single-phase units each rated 10 MVA, 127/18 kV, X = 10% HT sides connected in wye LT sides connected in delta Transformer T3: 35 MVA, 220Y/22Y kV, X = 10% j80 2 j100 0 Line 1 Line 2 T T2 Draw the impedance diagram with all reactances marked in per unit. Choose a base of 50 MVA, 13.8 kV in the circuit of generator 1. 2. For the electric power system shown in the figure below, draw the impedance diagram with all impedance marked in per unit. Choose 100 MVA, 20-kV as base in the generator 1 circuit. The three-phase power and line-line ratings are given below: G1: 90 MVA, 20kV,X = 9% T1:80 MVA, 20/200…