Critical clearing angle

Critical clearing angle.

The critical clearing angle , is the maximum allowable change in the power angle δ before clearing the fault, without loss of synchronism.

The time corresponding to this angle is called critical clearing time, .It can be defined as the maximum time delay that can be allowed to clear a fault without loss of synchronism.

Methods of improving the transient stability limit of a power system.

(i).Reduction in system transfer reactance

(ii).Increase of system voltage and use AVR

(iii).Use of high speed excitation systems

(iv). Use of high speed reclosing breakers

Numerical integration methods of power system stability

·                    Point by point method or step by step method

·                    Euler method

·                    Modified Euler method

·                    Runge-Kutta method(R-K method)