We have presented a simplified V/f control method of
induction motor based on steady-state relation of vector
control theory. The system has few tuning parameters,
comparing with speed sensorless vector control method. The
stability of the proposed system was discussed in detail by
deriving a linear model in motoring and regenerating modes
by root loci. When the cut-off frequency of low pass filter is
selected as 1 2 1 c c ω =ω = in order to simplify the control
system because there is only one tuning parameter for control
system, the stable region is large. It is remarkable point that
the low pass filter can not be removed to stabilize the system.
By comparing simulation results with experimental results, the
effectiveness of proposed method is verified. In addition, a
compensating algorithm about output voltage of inverter is
introduced for experimental system. The compensation is
useful to improve the speed accuracy at low speed.