8/9/2019 Electrical Power and Machines- Three Phase-Tutorial

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Tutorial Week 6 :Three Phase

1.1 If V ab = 400 V in a balanced Y-connected three-phase generator, find the phase voltages.

1.2 For the Y-Y circuit of Fig. 12.41, find the line currents, the line voltages, and the loadvoltages.

1.3 btain the line currents in the three-phase circuit belo!.

1.4 " balanced Y-connected load !ith a phase i#pedance of 1$ % &' Ω is connected to a balanced three-phase source !ith a line voltage of 220 V. (alculate the line current I L.

1.5 " balanced Y-Y four-!ire s)ste# has phase voltages

V an = 120 0° , V bn = 120 -120 °V cn = 120 120 ° V

*he load i#pedance per phase is 1' % &1+ Ω , and the line i#pedance per phase is 1 % &2Ω . olve for the line currents and neutral current.

1.6 For the three-phase circuit , I bB = +0 $0 ° " and V BC = 220 10° V.

Find V an , V AB , I AC , and Z .