Yes, but the impact is minimal. When adjusting the active power of the generator, the reactive power will automatically change in the opposite direction. This phenomenon can be explained by the “power angle characteristics of the generator”. The active power of the generator is proportional to sinδ When the active power is increased and the steam valve is opened, the generator power angle δ increases and sinδ increases. However, the reactive power of the generator is proportional to cosδ. , cosδ decreases instead. So the reactive power decreases.
The active power of the generator is adjusted by the speed regulator, which is obtained by changing the original output power such as the steam valve (thermal power unit) or the opening of the water guide vane (hydroelectric power station). The adjustment of the reactive power of the generator is carried out by the generator excitation regulator by modifyingt the excitation current and adjusting the generator voltage.
Detailed information:
When the generator is connected to a symmetrical load, the armature winding The three-phase current in the motor will produce another rotating magnetic field, called the armature reaction magnetic field. Its speed is exactly equal to the speed of the rotor and the two rotate synchronously.
The armature reaction magnetic field and the excitation magnetic field of the synchronous generator rotor can be approximately considered to be distributed according to the sinusoidal law. The spatial phase difference between them depends on the temporal phase difference between the no-load electromotive force E0 and the armature current I.
The armature reaction magnetic field is also related to the state of charge. When the generator load is inductive, the armature reaction magnetic field acts as ademagnetizer, which will lead to a decrease in generator voltage; when the load is capacitive, the armature reaction magnetic field acts as a magnetizer, which will reduce the generator voltage; the generator output voltage increases.
Baidu Encyclopedia-Electric Motor