Q：What is the rated capacity, rated voltage, and rated current of a synchronous generator?
A：The rated capacity refers to the maximum output power of the generator for long-term safe operation.
The rated voltage is the highest voltage that the generator can operate safely for a long time, and the rated voltage of the generator refers to the line voltage.
The rated current is the maximum operating current of the generator during normal continuous operation.
Q：What is force ratio? What are the forward and backward phases of force ratio?
A：The power factor of an AC motor, also known as the force ratio, is equal to the ratio of active power to apparent power.
The so-called phase advancement of force rate refers to the operating state of sending out active power and absorbing reactive power; The late phase of force rate refers to the operation of both active and reactive power generation.
Q：What is the physical process of regulating active power? What should be noted when adjusting active load?
A：Let's talk about the process of adjusting active power based on the power angle of the motor. At this point, it is assumed that the excitation current of the generator remains constant, and the voltage of the system also remains constant.
(1) Load increase process: When the steam valve is opened wide, the main torque on the rotor shaft of the generator increases. At this time, because the electrical power has not yet started to change, that is, the magnitude of the resistance torque has not changed, the rotor needs to accelerate, so that the angle between the rotor and the stator is opened up slightly. According to the power angle characteristics of the motor itself, as the power angle increases, the output power of the motor increases. That is to say, with more load, will the rotor accelerate continuously? Normally, it is not possible because the motor carries more load, which increases the resistance torque. When the resistance torque is balanced with the main torque, the rotor speed stabilizes, and at this point, the output of the generator increases to a new value.
(2) Load reduction process: When the small steam valve is closed, the main torque on the generator rotor shaft decreases, causing the rotor to decelerate and the power angle to decrease. When the power angle decreases, the electromagnetic power decreases, and the corresponding resistance torque also decreases. When the resistance torque decreases to the same size as the new main torque, a new balance is reached, and the motor carries less load.
Post time: May-21-2024