10th Aug 2023
DG Innovate, a frontrunner in the development of electric vehicle drive technology, has announced that its unique Pareta® drive systems are proving to be an ideal complement for hydrogen fuel cell technology in hybrid vehicles. While hydrogen fuel cells are, in principle, an attractive and environmentally friendly power source for vehicles, their thermal characteristics mean that deploying them safely and cost-effectively in EV applications is often challenging. DGI’s Pareta® technology provides the answer.
In operation, hydrogen fuel cells generate a significant amount of heat, which means that each cell must have a good supply of oxygen not only to function but also to keep it cool. This is most easily and safely achieved if the cells are arranged as thermally managed modules, with each module made up of a small number of cells. This architecture is a perfect match for Pareta® drives, which can directly accept multiple DC supplies from multiple fuel cell modules. This contrasts sharply with conventional drive systems that require a single high voltage, high current supply.
The essential features of Pareta® drives are that they divide the torque-producing elements of the motor into multiple segments – 24 in a typical medium power motor – and that each segment is fed from its own inverter, which is usually integrated within the motor. When used with fuel cells, each inverter/motor segment can be powered, at low voltage and low current, from its own fuel cell module. This arrangement brings multiple benefits.
Lower voltages and currents mean increased safety and lower cost per kW for the semiconductors used in the inverters. Effective thermal management is easier to achieve, and crucially, the segmented architecture is inherently fault tolerant. If an individual segment fails, either because of a drive fault or a problem with the associated fuel cell module, the drive will continue to operate normally, albeit with marginally reduced power output. In comparison, with conventional drive architecture, a single fault almost invariably leads to complete failure of the drive.
“Many of the benefits that Pareta® technology provides, such as very high efficiency, exceptional power density and low EMI, are important irrespective of the power source,” said Martin Boughtwood, Chief Technical Officer of DG Innovate. “Where fuel cells are used, however, there is the big additional benefit of the excellent match between a segmented drive system and a segmented power source. We are confident that this synergy between the drive and supply technologies in hybrid fuel cell EVs will reduce costs, improve overall performance and deliver enhanced safety.”
Pareta® drive systems have already demonstrated their reliability, efficiency and performance in demanding applications when supplied from conventional batteries.
