In the figure, each transmission line of the three-phase system has an impedance of 0.2 / 90° Q. In the balanced supply, VAN = 240 / 30° V, in the load Z1 = 4/30° Q, Z2 = 5 / 24.5° Q, Z3 = 7/ 15° Q. Calculate: a) The currents in the load and in the neutral b) The stresses at the load level c) The total average power supplied to the load leul .ff

In the figure, each transmission line of the three-phase system has an impedance of 0.2 / 90° Q. In the balanced supply, VAN = 240 / 30° V, in the load Z1 = 4/30° Q, Z2 = 5 / 24.5° Q, Z3 = 7/ 15° Q. Calculate: a) The currents in the load and in the neutral b) The stresses at the load level c) The total average power supplied to the load leul .ff

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

Chapter5: Transmission Lines: Steady-state Operation

Section: Chapter Questions

Problem 5.7P

See similar textbooks

Similar questions

A balanced three-phase load is connected to a 4.16-kV, three-phase, fourwire, grounded-wye dedicated distribution feeder. The load can be mode led by an impedance of ZL=(4.7+j9)/phase, wye-connected. The impedance of the phase conductors is (0.3+j1). Determine the following by using the phase A to neutral voltage as a reference and assume positive phase sequence: (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.
A three-phase line, which has an impedance of (2+j4) per phase, feeds two balanced three-phase loads that are connected in parallel. One of the loads is Y-connected with an impedance of (30+j40) per phase, and the other is -connected with an impedance of (60j45) per phase. The line is energized at the sending end from a 60-Hz, three-phase, balanced voltage source of 1203V (rms. line-to-line). Determine (a) the current, real power. and reactive power delivered by the sending-end source: (b) the line-to-line voltage at the load: (C) the current per phase in each load: and (d) the total three-phase real and reactive powers absorbed by each load and by the line. Check that the total three- phase complex power delivered by the source equals the total three-phase power absorbed by the line and loads.
A three-phase line with an impedance of (0.2+j1.0)/ phase feeds three balanced three-phase loads connected in parallel. Load 1: Absorbs a total of 150 kW and 120 kvar. Load 2: Delta connected with an impedance of (150j48)/phase. 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.
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.
Two three-phase generators supply a three-phase load through separate three-phase lines. The load absorbs 30 kW at 0.8 power factor lagging. The line impedance is (1.4+j1.6) per phase between generator G1 and the load, and (0.8+j1) per phase between generator G2 and the load. If generator G1 supplies 15 kW at 0.8 poir factor lagging, with a terminal voltage of 460 V line-to-line, determine (a) the voltage at the load terminals. (b) the voltage at the terminals of generator G2, and (c) the real and reactive power supplied by generator G2. Assume balanced operation.
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) No
Figure 2.33 gives the general -Y transformation. (a) Show that the general transformation reduces to that given in Figure 2.16 for a balanced three-phase load. (b) Determine the impedances of the equivalent Y for the following impedances: ZAB=j10,ZBC=j20, and ZCA=j25. ZAB=ZAZB+ZBAC+ZCZAZCZA=ZABZCAZAB+ZBC+ZCAZBC=ZAZB+ZBAC+ZCZAZAZB=ZABZBCZAB+ZBC+ZCAZCA=ZAZB+ZBAC+ZCZAZBZA=ZCAZBCZAB+ZBC+ZCA
In a balanced three-phase Y-connected system with a positive-sequence source, the line-to-line voltages are 3 times the line-to-neutral voltages and lend by 30. (a) True (b) False
Question-2) The parameters of a three-phase transmission line are given as Z = (12.84 + j72, 76)Ω and y = j5, 83x10^-4 mho. At the end of the line, a power of 55 MVA with a power factor of 0.8 is drawn under 132 kV voltage. Accordingly, calculate the line head voltage, active and reactive power values per line, and voltage regulation of the line using the nominal π circuit.7-) Since 55 MVA power is drawn from the end of the line under the conditions mentioned above, calculate the line head voltage (phase-phase voltage) and enter it in the box below. (The value will be entered in kiloVolts. Only the amplitude value of the voltage will be entered. The phase value will NOT be entered!!! Two digits after the comma will be sufficient. )8-) Since 55 MVA power is drawn from the end of the line under the conditions mentioned above, calculate the active power value per line and enter it in the box below. (The value will be entered in MegaWatt. It will be sufficient to take two digits after…
Consider the configuration from Problem 1, except that each phase of the transmission line has an impedance of ݆1.5 Ω. a. Determine the line currents. b. Determine the line‐neutral voltage for each branch of the 3Φ load. c. Determine the complex power consumed by the 3Φ load. d. Determine the complex power produced by the 3Φ source. e. Determine the power consumed by the transmission line. f. Determine the load power factor, and the power factor observed by the source. problem 1 : Each leg of a symmetric, Y‐connected, 3Φ load has an impedance of 10∠36.87° Ω, and is connected to A 60 Hz, balanced, positive‐sequence, Y‐connected 3Φ voltage source with Vrms .3Φ source via an ideal transmission line (that is, the connection from the source to the load has zero impedance).
4. What are the values of the line voltages? 5. What are the values of the line currents? 6. What is the value of the total power drawn by three-phase load? 7. If a capacitor is part of the impedance Z, suggest the specifications (radii and length) of a cylindrical capacitor, which has to be installed in a space of 2.5 m3. Support your suggestion properly.
Suppose a completely transposed 60-Hz three-phase line has flat horizontal phase spacing with 10 m between adjacent conductors. The conductors are 1,590,000 cmil ACSR with 54/3 stranding. Line length is 200 km. Assume the line voltage is 345 kV, at 60 Hz. i) Calculate the inductance in H/m. ii) The inductive reactance in ohm/m.