Why is AC motor control more difficult than DC?
Motor control, generally refers to speed regulation".AC motors are different from the mechanical characteristics of direct current motors,The mechanical characteristics of the DC motor are 1 slightly downward inclined "straight lines", the relationship between its speed and torque (characteristic) is relatively "hard", and it can easily change its speed by changing the power supply voltage of the motor;
In addition, the DC variable voltage is easy to realize and the communication is troublesome. Therefore, the AC speed regulation uses frequency conversion speed regulation more frequently, but the frequency conversion speed regulation system is more complex than the DC voltage regulation speed regulation.
The mechanical characteristics of AC motor (curve) as 1 tilt of the toilet, the mechanical characteristics of "soft", and "inflection point" (or there is a negative resistance region), the operating condition of the motor once in the negative resistance region will lose control".
