A PMSM drive design with inverter-stage soft-switching hysteresis current control and space vector modulation for two-level operation of a Very Sparse Matrix Converter

Discussed in this paper is a 3-phase adjustable speed AC drive (ASD) system employing a Very Sparse Matrix Converter (VSMC) feeding a Permanent Magnet Synchronous Motor (PMSM). Such a system may be used in many conventional applications (e.g. traction, pumping, mills, kilns) and has substantial benefits for sustainable system applications such as building HVAC (heating, ventilation and air conditioning) where ventilation using a variable speed drive can greatly reduce net energy input. The VSMC is a bidirectional converter, with no dc-link energy storage element, consisting of 12 IGBTs (or other power devices), capable of drawing sinusoidal current from the supply. Hysteresis current control (HCC) may be employed so that a near-sinusoidal AC output current can be obtained while satisfying the torque load or speed load requirements. In conventional ASDs hard-switching can produce undesirable harmonics and losses. However, in this paper a new HCC-based space vector modulation (SVM) technique employing soft-switching is applied to the inverter stage of a VSMC with careful selection of a zero voltage vector (ZVV). As discussed in this paper, vector selection depends on the location of the current error vector instead of motor back emf prediction with no need for current derivatives. A simulation of a 3-phase VSMC drive and 40 kW PMSM is presented to verify the validity of the proposed new switching technique using the MATLAB SIMULINK package.