Hybrid Electric Vehicles, 2nd Edition

10Electric Machines and Drives in HEVs

10.1 Introduction

Advances in electric machines, along with progress in power electronics, are the key enablers for electric, hybrid electric, and plug‐in hybrid electric vehicles (HEVs). Induction machines, permanent magnet (PM) synchronous machines, PM brushless DC machines, and switched reluctance machines (SRMs) have all been considered in various types of vehicle powertrain applications [1–20]. Brushed DC motors, once popular for traction applications such as in streetcars, are no longer considered a proper choice due to the bulky construction, low efficiency, need for maintenance of the brush and commutator, high electromagnetic interference (EMI), low reliability, and limited speed range.

When using electric motors for powertrain applications, there are a few possible configurations. Today’s electric motors, combined with inverters and associated controllers, have a wide speed range for constant torque operations, and an extended speed range for constant power operations, which make the design of the powertrain much easier. Depending on the configuration of the hybrid powertrain, the design and selection of electric motor drives can also be different. For example, for series hybrid vehicles, the powertrain motor needs to be able to provide the required torque and speed for all driving conditions. Hence, the size of the motor will be fairly large, usually rated at 100 kW or more for passenger cars. A PM motor or an induction motor ...