5th Jul 2023
As part of the ground-breaking research that is underpinning its efforts to develop innovative drive systems for electric vehicles, DG Innovate uses advanced modelling software to simulate heat transfer and the flow of coolant in its motors and associated electronic assemblies. The software, which includes the COMSOL Multiphysics heat transfer module and Ansys Discovery Fluid Analytics, makes it possible for DGI to optimise the geometry of its designs to ensure efficient and reliable cooling even in extreme operating conditions.
Key components of the DGI drive systems, including motor windings and power semiconductors, are fully immersed in insulating oil which circulates continuously to facilitate heat transfer. By working with the simulation software, DGI engineers have been able to refine their designs so that the drives can operate continuously at peak power. This is an important benefit as it allows compact design whilst keeping the temperature of coils and power devices at a lower level, thus helping to maximise operating efficiency. Vehicles using DGI drives, therefore can have greater range for a given battery capacity than vehicles using more conventional drive systems. In many applications, it also means that the drives are smaller and less costly than would otherwise be required.
The adoption of sophisticated modelling techniques using powerful software typifies the effort and attention to detail that DGI is devoting to the development of its drive systems. The ultimate objective of this work is to produce drives that lead the market in terms of efficiency, reliability and performance, whilst, in many respects, being environmentally friendly to manufacture and use.
The company has already made great strides toward achieving these goals by developing highly innovative motors, prototypes of which have already demonstrated outstanding characteristics. The motors feature a unique multiple parallel system architecture which effectively splits the torque-producing elements into a large number of small segments. This provides for improved heat extraction due to power devices being distributed around the whole motor allowing maximum area for heat transfer.
This segmented design results in much enhanced fault tolerance, as the motor will continue to operate with only slightly reduced output if an individual segment fails, and it also allows the motors to be powered by inverters that are more efficient and more cost effective than those used with conventional motors. Typically the compact multi inverters are integrated within the motor assembly to provide an exceptionally compact drive system that is ideal for hub mounting.
