Motor V/F curve
In Fig. 4-15, the curve l is the Uf curve of the low frequency compensation when the motor drags the LXT905LC dynamic constant torque load, and the curve 2 is the Uf curve without the low frequency compensation when the motor drags the constant torque load; the curve 3 is the motor When the load of the water pump fan is dragged, the Uf curve of the low frequency compensation is performed; the curve 4 is the sand mill curve without the low frequency compensation when the motor drags the load of the water pump fan.
It can also be seen from Fig. 4-15 that since the motor can not work above the rated voltage, the inverter increases above the basic frequency fi, the output voltage U does not change, and maintains the rated voltage, so the Uf curve changes. It becomes a horizontal straight line, which will cause the magnetic flux to be west according to equation (4-4). As the increase is reduced, the torque is also reduced, the motor becomes a constant power speed regulation, and the constant torque speed regulation (U equals the fixed value) is taken as an example to draw more magnetic flux. The variation curve is shown in Figure 4-16.
In Figure 4-16, curve 2 is the Uf curve without low frequency compensation when the motor drags the constant torque load, curve 1 is the magnetic flux change curve corresponding to curve 2, and the constant magnetic flux is lower than the basic frequency ^ (pme Corresponding to the constant torque speed control mode. When the factory is higher than the basic frequency fi, the magnetic flux is west. The reciprocal change function is corresponding to constant power speed regulation; the curve 4 is when the motor drags the square torque load, there is no low frequency compensation. The U factory curve, curve 3 is the flux change fluff corresponding to curve 4, when it is lower than the basic frequency fi, it corresponds to the square torque speed control mode, and when it is higher than the basic frequency fi, the reciprocal change function in the magnetic flux, Corresponding to constant power speed regulation.
Connecting Terminals,Micro Connecting Terminal,Aluminum Connecting Terminals,Connecting Copper Terminal
Taixing Longyi Terminals Co.,Ltd. , https://www.longyicopperterminals.com