Efficiency Improvement of Electric Motor Drives Using Dynamic Motor Drive Technology

<div class="section abstract"><div class="htmlview paragraph">Tula Technology has developed a novel, patented motor control strategy called Dynamic Motor Drive (DMD®), which reduces the light-load losses of electric motor drives by intermittently pulsing motor torque. Since passenger vehicles frequently operate at light loads, DMD can significantly reduce the energy consumption of electric vehicles, extending their range. DMD is particularly beneficial for rare-earth-free or reduced-rare-earth permanent magnet (PM)-based electric motor drives, and can help make these less expensive, more environmentally friendly motors range-competitive with traditional PM motors.</div><div class="htmlview paragraph">This paper details the efficiency improvement when DMD is applied to a rare-earth-free synchronous reluctance motor (SynRM). We present recent experimental results to show the loss reduction by DMD in a prototype 8-kW three-phase SynRM, and compare them to simulation results. Tula’s models indicate that DMD control, when applied to a 150-kW SynRM driving a Chevrolet Bolt, would reduce energy use by approximately 2.5% over the WLTP driving cycle. A detailed discussion is provided on DMD’s theoretical background, motor design and control techniques to optimize system efficiency with acceptable noise, vibration, and harshness.</div></div>