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A detailed component performance, ratings, and cost study was conducted on series and parallel hybrid electric vehicle (HEV) configurations for several battery pack and main electric traction motor voltages while meeting stringent Partnership for a New Generation of Vehicles (PNGV) power delivery requirements. A computer simulation calculated maximum current and voltage for each component as well as power and fuel consumption. These values defined the peak power ratings for each HEV drive system's electric components: batteries, battery cables, boost converter, generator, rectifier, motor, and inverter. To identify a superior configuration or voltage level, life cycle costs were calculated based on the components required to execute simulated drive schedules. These life cycle costs include the initial manufacturing cost of components, fuel cost, and battery replacement cost over the vehicle life.

Oak Ridge National Laboratory's (ORNL) computer code PMM_IDT (Permanent Magnet Motor Interactive Design Tool) was used to study the sensitivity to changes in design parameters at constant power output and scaling laws for similar designs with different rated power outputs. The base design used was a radial-gap motor with 30 kW of net output characteristic of the PNGV “Series” vehicles. Sensitivity parameters studied were active length, magnet and air gap thicknesses, and number of magnets. Power output variation approaches considered were active length, stator external diameter, and rotor external diameter. The impact on efficiency, cost, weight, specific power, cooling requirements, drive current and voltage requirements, and demagnetization margins are presented. Common constraints in this study are: Hollow rotor, trapezoidal back emf - 212 V maximum - and double layer winding leading to an even number of turns per slot

Visual Computing Systems (VCS) and Oak Ridge National Laboratory (ORNL) are partnered in a research effort to design and build a power inverter for use with an automotive accessory permanent magnet (PM) motor provided by VCS. The inverter is designed so it can fit within the volume of the housing, which is integrated with the motor. Moreover, a modular design for both the inverter and motor is employed for easily expanding the power capability to other applications. A simple back electromotive force (EMF) based position detection scheme is implemented with a digital signal processor (DSP) to eliminate the need for position sensors. Issues related to position detection errors are addressed and correction methods are suggested and implemented in DSP software. Finally, since the motor has very low inductance because of its core-less stator structure, the influences of the low inductance on the motor current ripple are analyzed.