Novel stator voltage oriented V/F control method capable of high performance at low speed

A novel stator voltage oriented V/F control method for induction motor is presented in this paper to improve the low speed performance and speed precision. The control scheme was based on the popular constant volts per hertz (V/F) method and adopted a novel voltage boost method to compensate the stator resistor voltage drop keeping the magnitude of the stator flux constant. A novel slip frequency compensation strategy, based on the equivalent circuit of induction motor, was also introduced. This method reduced the steady-state speed error to almost zero. Different from conventional V/F methods, all the compensation and regulation were based on stator voltage oriented synchronous rotation frame transformation, which avoided complicated vector calculation and were simple to implement. The experimental results show that, by adopting the proposed method, the speed can be accurately controlled down to 0.3Hz with rated load torque and the speed accuracy is improved in various speeds and loads.