New Double Switching Clamping Sequences Based ADPWM Algorithm for Direct Torque Control of Induction Motor Drives

This paper presents a new space vector based advanced pulse width modulation algorithm for direct torque controlled induction motor drive operating at near rated speeds (high modulation regions). The proposed ADPWM algorithm uses a special category of DPWM sequences (0121, 7212) termed as double switching clamping sequences as they clamp one of the phases to either of the buses, switches one of the remaining two phases twice in every switching cycle. The proposed algorithm utilizes these sequences in every sector and it is based on the fact that changing the zero state at any spatial angle γ, different ADPWM methods can be generated which further can be classified into either continual clamping split clamping methods. Though the results of the proposed DTC are in par with CSVPWM based DTC, significant reduction in line current distortion is a substantial feature to be considered.