SVPWM Variable Structure Control of Induction Motor Drives

This paper presents a new proposal of speed vector control of induction motors based on robust adaptive VSC (variable structure control) law and its experimental validation. The presented control scheme incorporates the SVPWM (space vector pulse width modulation) instead of the traditional current hysteresis comparator. The SVPWM improves the quality of the stator currents, reducing the harmonics, while maintains the main characteristics that is usual in this kind of algorithm, like the fast response and good rejection to uncertainties and measurement noises. This regulator is also compared with the PI (proportional integral) controller designed in the frequency domain, in order to prove the good performance of the proposed controller. The two controllers have been tested using various simulation and real experiments, taking into account the parameter uncertainties and measurement noise in the loop signal, in the rotor speed and in the stator current. This work shows that the VSC regulator is more efficient than the traditional PI controller in both adverse conditions and suitable conditions. Finally, some practical recommendations for real experiment implementations are also given.