Multi-level Inverter fed Induction Motor Drive

In this book, PIDTC along with SVM technique is used for two-level inverter. PIDTC of IM suffers from stator flux ripple under steady state is more while operating at and above modulation index 0.5, thereby, causing the deterioration of the harmonic spectrum of output current wave-forms. The conventional PI controllers are tuned for specific operating point and do not operate satisfactorily when the operating point changes, which results in the inferior dynamic performance while operating in a wide range of speed and load applications. Hence, the improvement of the IM drive can be mainly classified into two parts such as ripple performance and dynamic performance. Ripple performance of the IM mainly depends on the Duty ratio control technique, whereas the dynamic performance depends on the type of the controllers. Dynamic and steady-state performances of IM can be improved when PI-controllers and hybrid duty ratios are controlled with T2FC in three-dimensional control. A three and five-level inverter fed direct torque controlled IM drive along with T2FLC are also developed to further improve the IM performance and balanced capacitor voltages without need of an extra controllers.