Third, the selection of rare earth permanent magnet synchronous motor
The stator of the rare earth permanent magnet synchronous motor is a three-phase symmetrical winding, which has the same structure as the three-phase asynchronous motor. NdFeB magnetic steel is adhered to the rotor. Permanent magnet synchronous motors have more and more superior features in terms of energy saving. China's self-developed rare earth permanent magnet synchronous motor has no rotor resistance loss on the rotor during stable operation, which can reduce the total loss by 20% to 30%, thus increasing the efficiency by 4 to 8 percentage points. At around 95%. Secondly, since the magnetic field of the permanent magnet motor is generated by the permanent magnet, the reactive current in the stator is not required, so the power factor of the motor can be made high (0.95-1) by reasonable design, so that the motor can be made. The current in the stator winding is significantly reduced, and the copper loss of the winding is significantly small.
The efficiency change of rare earth permanent magnet synchronous motor under different loads is similar to that of asynchronous motor, but its high efficiency range is the highest at 40%-60% load rate, which is about 94%. The efficiency is 93.5% at a load rate of 70%. In addition, since the rare earth material is not suitable for long-term work in a high temperature environment, the lower the motor temperature, the longer its service life. The rare earth permanent magnet synchronous motor is applied to the spinning frame, and the choice is slightly larger and better, although the procurement cost has increased. However, long-term use of larger motors, the efficiency is 0.5%, and the failure rate is extremely low, and the cost of long-term use is low.
Recommended use:
Load condition small yarn medium yarn large yarn motor
420 spindle 7KW8.5KW10KW18.5KW
456 spindle 8KW10KW11KW18.5KW
480 spindles 8.5KW10.5KW12KW22KW
516 spindle 9KW11KW13KW22KW
The rare earth permanent magnet synchronous motor has an efficiency of 95%, which is about 4-5% lower than that of the textile FX series motor, and 7%-10% lower than the Y series motor.
Although the price of rare earth permanent magnet synchronous motor is relatively high, it can recover more investment than asynchronous motor in more than one year, and long-term use is very cost-effective.
