Reduction of DC link capacitor stress for double three-phase drive unit through shifted control and phase displacement

In automotive industry space is extremely limited. The efficient and fast control of electric motors is a key technology to save energy and space. This paper shows strategies to improve energy consumption of a redundant Voltage Source Inverter (VSI) and an associated double three-phase Permanent Magnet Synchronous Motor (PMSM). Focus is to significantly reduce the DC link power dissipation of the power electronics to extend life time or to reduce the capacity and thus the size required to install the capacitors. In particular, shifted control technique and in addition phase displacement are developed and implemented on a drive unit used in automotive application to control the multi-phase system. Analytical calculations show that these strategies reduce the DC link capacitor effective current value. The conventional three-phase PMSM is compared with the double three-phase PMSM run with the new control strategies.