Adding a speed observer, a slip frequency calculator and a torque current component limiter to the SFO vector control system, a speed sensor-less vector control system based on stator flux orientation is formed.

• 在矢量控制系统中采用定子磁场定向,并进一步加入了转速估计、转速调节闭环、转差计算和常用的转矩电流限幅等重要环节,构成了一种无速度传感器矢量控制变频调速系统。