This paper enumerates the most possible causes of short-circuit faults on 10kV bus in transformer substation,discusses the hazards of the short-circuit current on 10kV bus to switch cabinet and main transformer,the necessity and three methods to shorten the clearing time of fault are put forward.

It is also found the proportion of motor load has great impact on the critical clearing time.

The transient angle stability margin and critical clearing time are computed by FASTEST under different proportion of dynamic electric load model using in Henan Power Grid.

Two applications, calculating the critical clearing time and contingency ranking, are presented based on the approximated index.

Estimation of critical clearing time of constant speed wind turbines;

The mechanism of this phenomenon in OMIB is studied with equal area criterion (EAC), PEBS direct method and stability region analysis, respectively This phenomenon takes on periodicity when the damping of the generator is ignored and the index of critical clearing time (CCT) is invalidated in this case The analytical expressio.

When the influence of load model on transient stability is being assessed,factors which effect the stability limit,such as the maximum power transfer,critical clearing time etc.

A new nonlinear transformation is put forward in this paper,by which there is no poly value problem when the critical clearance time is determined; the general form of the movement equations in terms of Taylor.

A theorem to determine the critical clearance time is derived.

Critical clearing time (CCT) is one of the most important stable indices in power system transient stability analysis.

The formulae for SMIS are derived and verified by case simulation,the solution of critical clearing time (CCT) of three-phase short fault in MMS is theoretically discussed.