1, the electromagnetic torque of the synchronous motor is the interaction between the stator rotating magnetic field generated by the power supply voltage and the main magnetic field of the rotor;
2, the stator rotating magnetic field and the rotor main magnetic field axis of the magnetic angle called angle;
3, the power angle is zero, the electromagnetic torque is zero, the greater the angle of the larger torque, the greater the stator current, as if you pull the car, the greater the elongation of the rope, the greater the pulling force;
4, of course, the power angle close to 90 degrees, the maximum torque, current maximum;
5, when the power angle is greater than 90 degrees, the torque begins to decrease, enter the unstable operation area, then soon will be out of step, equal to pulling the car, pull the rope broken the same!
6, the amount of physical angle related to the power angle are:
1) Electromagnetic torque
2) stator current;
3) Output power (related to speed);
7, when the power angle increases from zero to 90 degrees, the current, torque, and power are monotonically increasing functions. In a nutshell, the current, torque and power increase as the power angle increases.
8, as long as the detection of synchronous motor current size, you know the size of the power angle, the size of the torque!
9, for example, you detect the synchronous motor current is rated current, then needless to say the power angle is the rated power angle, the torque is the rated torque!
10, for synchronous motor, frequency start from zero HZ start, the current increases from zero, when the current increases to the rated current, the power angle is the rated power angle, the torque is the rated torque, this time the minimum power, with the When the speed increases to the rated speed, the power reaches the rated power!
11, as long as the control current is rated current, the power angle is the rated power angle, the torque is the rated torque!
12, in the case of a certain current, but also can increase the voltage, increase the magnetic field, increase torque, which is the second way torque control!