Field Oriented Modeling and Control of Six Phase, Open-Delta Winding, Interior Permanent Magnet Synchronous Machines considering Current Unbalance and Zero Sequence Currents

摘要

Industrial and academic interest on multiphase electric machines have been steadily increasing due to the advantages they provide compared to their three phase counterparts. They offer higher efficiency and better fault tolerance. The power is distributed across a larger number of machine phases and inverter legs, which allows the use of semiconductor devices with lower ratings. These advantages are especially benecifial for electric and hybrid vehicle applications. Increasing the battery pack voltage of an electric vehicle increases the cost and complexity, while decreasing the energy density of the battery pack. Therefore, electric vehicle system design may benefit on the vehicle level from a more complex drivetrain with higher dc link voltage utilization. H bridge inverters as well as multiphase machines provide increased dc-link voltage utilization compared to three phase inverters and machines. A low voltage, high power drivetrain is designed for an electric vehicle using an asymmetrical six phase, open-delta interior permanent magnet synchronous machine (IPMSM) and an H Bridge inverter. Field oriented modeling and control of such a system is investigated in this paper. The sources of unbalance and zero sequence current components are explored.