Swing Equation: Know The Definition, Derivation, And Curve!

The variables in the swing equation are rotor angle (δ), moment of inertia (M), mechanical input power (Pm), electrical output power (Pe), and angular acceleration (d2δ/dt2).

The swing equation is derived by applying torque balance on the rotational shaft of the synchronous generator and relating it to electrical power equations through rotor angle and angular speed.

The swing curve provides insights into accelerating, steady, and diverging swing stages during transients. It helps identify critical clearing time of faults ensuring stability.

Factors like fault severity, fault clearing time, line impedances, generator inertias, and load levels influence transient stability studied using a swing equation.

Inertia constant (H) of a generator, which represents stored kinetic energy, can be computed from machine rating and Swing equation variables like Moment of inertia (M).