A Tapped Winding Interior Permanent Magnet Synchronous Machine for Medium-Duty Delivery Trucks

Medium-duty delivery trucks in city traffic require high torque at low speeds and low torque during mid- and high-speed operations. The design of a three-phase machine that suits such requirements results in a high inverter power rating and dc bus voltage. This article proposes a tapped winding topology of the interior permanent magnet synchronous machine (IPMSM), which is derived by reconfiguration of winding turns of a conventional three-phase IPMSM designed for similar applications. It is demonstrated using simulation results that for a 74.5 kW three-phase IPMSM designed for a delivery truck, the proposed topology requires 10% lesser inverter kVA rating compared with a three-phase drive. Moreover, considering equal per-phase current rating of the inverters in both the cases, the proposed drive demands 55% lesser dc bus voltage than the three-phase drive. The proposed concepts of design and control of the tapped winding IPMSM are experimentally validated on a 3.5 kW IPMSM prototype, and the significant advantages of the proposed drive are compared with the simulation results of the conceptual 74.5 kW IPMSM drive based on the generalized mathematical model presented in this article. A comparative analysis with the existing topologies is also provided.