Efficiency-Oriented Design and Control of Multilevel Power Converter–Fed Electrical Machines for Grid-Connected and Industrial Applications

Abstract

The trend toward using grid-connected and industrialized electric drive packages requires better efficiency, more valuable power quality, and full adherence to grid standards. The natural benefits of multilevel power converter fed electrical machines include: less harmonic distortion, less voltage stress and more power scalability. Nonetheless, traditional methods of control are mainly aimed at dynamic executing and do not take into account the integrated loss optimization and therefore, have low efficiency in different operating environments. With a proposal based on efficiency-oriented design and control framework of multilevel converter fed electrical machines is put in this paper which explicitly considers converter as well as machine losses. Loss modelling approach is developed in a comprehensive manner with semiconductor conduction and switching losses as well as machine copper, core and mechanical losses. According to this model, the loss-aware control strategy is developed that dynamically optimises the existing references without affecting the accuracy of torque and grid power quality. Experiments of simulation show that overall efficiency and total losses and grid current harmonic distortion were reduced in comparisons to more than traditional control schemes and the schemes are therefore feasible in the field of industrial automation and grid-connected drive applications.