Power System Dynamics

Abstract

A power system is continuously subjected to a variety of disturbances. These may vary from minor events like small and random load changes to major events like faults and line tripping. It is desirable that a power system should be stable (i.e., settle to an acceptable steady state condition) without exceeding equipment ratings. Consequently, the dynamic behavior of a power system has an important bearing on satisfactory system operation. The dynamic behavior of the power system can be described by a set of differential equations. With modeling simplifications they are usually formulated as differential algebraic equations (DAEs) as follows:

$$\dot x = f\left( {x,y,u,t} \right)$$

(12.1)

$$0 = g\left( {x,y,u,t} \right)$$

(12.2)

where:

• x represents states of the system

• y represents variables which are algebraically dependent on x

• u represents inputs

• t represents time