31.1 : スイング方程式

The Swing Equation is crucial for understanding the dynamics of generating units, such as a three-phase synchronous generator.

It describes rotor motion through Newton's second law, incorporating factors like inertia, angular acceleration, and mechanical and electrical torque.

In steady-state, when mechanical equals electrical torque, rotor acceleration and accelerating torque are zero, maintaining a constant rotor velocity or synchronous speed.

Rotor speed increases when mechanical torque surpasses electrical torque and decreases otherwise.

Measuring rotor position relative to a synchronously rotating reference axis is more convenient than a stationary one.

Also, working with power in per-unit simplifies calculations, as does using the normalized H constant.

The per-unit Swing Equation, a nonlinear second-order differential equation, is essential for transient stability studies.

It accounts for the variable nature of electrical power and rotor speed. For ease of computation, it's rewritten as two first-order differential equations.

The Swing Equation is also used to predict the rotor dynamics of wind turbine generators.