The voltage between the system and generator must be small enough to ensure minor current in the armature winding of generator, avoiding the impact to the coupling shaft.
发电机电压与系统电压之差必须足够小，避免合闸时发电机电枢绕组电流过大，对发电机联轴系统产生冲击。
2
As the mainstream generator in the future, brushless doubly-fed machine has many advantage, but it's also high order, nonlinear, strong coupling and multivariate dynamical system.