The DCoffset component of the threephase shortcircuit curren

The DC-offset component of the three-phase short-circuit current of an unloaded synchronous machine is different in the three phases and its exponential decay is dictated by ______. Fill in the Blank. Even though the fault current is not symmetrical and not strictly periodic, the RMS asymmetrical fault current is computed as the RMS AC fault current times an \"asymmetry factor, \" which is a function of_____. Fill in the Blank. The series sequence impedance matrix of a completely transposed three-phase line is____, with its no diagonal elements equal to_____. Fill in the Blanks. In an unbalanced three-phase system, line-to-neutral voltage______ have a zero-sequence component, whereas line-to-line voltages____ have a zero-sequence component Fill in the Blanks. For a power system, modeled by its positive-sequence network, both bus-admittance matrix and bus-impedance matrix are symmetric. (a) True (b) False Balanced three-phase systems with positive sequence do not have zero-sequence and negative-sequence components. (a) True (b) False In a delta-connected three-phase system, line currents have no zero-sequence component, (a) True (b) False

Solution

(a) e^-t/Ta

(b) X/R ;reactance/resistance

(c) Symmetrical, equal to zero

(d) Star, Delta

(e) (a) True

(f) (a) True

(g) (a) True