What is the synchronous motor
Synchronous motor is a kind of AC motor. Main generator, but also can be used for motor, generally used for large power, production machinery speed does not requireadjustment, such as large water pump, air compressor and fan etc.. In recent years,as the development of permanent magnetic materials and electronic technology, micro synchronous motor has been applied more and more widely.
One of the characteristics of synchronous motor is strictly constant frequencies between F1 n speed and the stator current of stable operation, i.e.;
Rev N and rotating magnetic field of the synchronous motor speed N0 the same."Synchronous" the name of the resulting.
Http://210.40.32.1/gzjpkc/djtd/9.htm
Principle of synchronous motor:
Http://info.elec.cc/Article/jczs/qt/200507/358.html
Synchronous motor excitation current is on the run, if there is no excitation, isasynchronous motor. Excitation and DC system on the rotor, its rotation speed and the polarity and the stator is consistent, if the excitation problem, the motor will be out of step, adjustment is not over, triggering protection "excitation fault" motor trip
Said the white point, current flows through the excitation current is synchronous motor rotor (in the current, the rotor is equivalent to an electromagnet, a N pole and S pole),in normal operation, the current is generated by an external DC voltage on the rotor.The DC voltage is supplied by the DC motor, it is mostly by the silicon controlled rectifier to supply. We normally think of as the excitation device of silicon controlled rectifier system.
Rotation speed of the rotating magnetic field of stator rotor asynchronous machinespeed and the rotation of the motor is generated is not the same, there is a difference(asynchronous). We call slip. The slip ratio and the stator rotating magnetic field generated by the rotation speed is called slip.
The difference between synchronous machine and asynchronous machine is that:from the supply side, the asynchronous machine stator side voltage in just add (orvoltage on the rotor), and synchronous machine in the stator and rotor are coupled with the voltage. That is to say the asynchronous machine is unilateral excitation,synchronous machine is the bilateral excitation. From the aspects of asynchronousmachine speed, rotational speed is only related to the size of load (of course have a certain range), and synchronous machine speed is only related to the grid frequency.From the structure, structure of synchronous motor with rotor is not the same as.Rotor asynchronous machine is Xi steel sheet and aluminum (or Xi steel sheet andcoil), and the synchronous machine is composed of a plurality of magnets and coils(there are salient pole are not the same). Of course, there are many differences, such as process requirements, design issues and so on, I'm not full, please discuss.