Loads, Za, Zb and Zc are connected to a balanced three-phase four-wire 50 Hz 400 V (line) supply in star configuration. Za: 8Q Zb: 8+j6 Q Zc: 4-j6 Q Calculate: (i) The line currents and their symmetrical components. (ii) The current flowing in the neutral conductor. Draw phasor diagrams for the 3 sets of sequence components of current. If loads Zb and Z remain unchanged, calculate: (i) The new impedance for Za to eliminate the neutral current at the "star" connected load. (ii) The total active power dissipated in the loads with the new impedance calculated in part c)(i). Explain why the symmetrical components technique is used in power systems analysis.

Loads, Za, Zb and Zc are connected to a balanced three-phase four-wire 50 Hz 400 V (line) supply in star configuration. Za: 8Q Zb: 8+j6 Q Zc: 4-j6 Q Calculate: (i) The line currents and their symmetrical components. (ii) The current flowing in the neutral conductor. Draw phasor diagrams for the 3 sets of sequence components of current. If loads Zb and Z remain unchanged, calculate: (i) The new impedance for Za to eliminate the neutral current at the "star" connected load. (ii) The total active power dissipated in the loads with the new impedance calculated in part c)(i). Explain why the symmetrical components technique is used in power systems analysis.

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

Chapter4: Transmission Line Parameters

Section: Chapter Questions

Problem 4.22MCQ: In a three-phase line, in order to avoid unequal phase inductances due to unbalanced flux linkages,...

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