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Sequence Impedances of Transmission Lines. Zph. Recall that: Z 012 = A -1 Z abc A. Z 0 =z s +2z m Z 1 =z s -z m Z 2 =z s -z m. Symmetrical components of generator. Symmetrical components of generator. Z1 = synchronous reactance (Xd) transient reactance (Xd’)
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Recall that: Z012 = A-1 ZabcA Z0=zs+2zm Z1=zs-zm Z2=zs-zm
Symmetrical components of generator • Z1 = synchronous reactance (Xd) transient reactance (Xd’) subtransient reactance (Xd’’) • Depends on the analysis required (breaker setting, fault analysis, transient stability studies, steady state analysis) Z2 = Xd’’ Z0 = leakage reactance (Xl)
Symmetrical components of transformer • Although Z0 slightly differ from other two, it is customary to take Z1 = Z2 = Z0 = Xl