Electrification specialist Equipmake has brought to market a next-generation inverter that can deliver a step change in EV powertrain performance.
The silicon carbide-based (SiC) HPI-800 inverter has such efficiency gains that it has the potential to reduce the size of an EV’s battery by around 10%.
SiC inverters are also smaller and lighter enabling further benefits in packaging as well.
Inverters play an important role in an EV powertrain as they convert DC charge from the battery to AC to drive the electric motor. There are also time switching changes to adjust the frequency of the AC charge to control the speed of the motor, much like a fuel injection and ignition system does in a combustion engine.
“The faster and more efficient the inverter is, the more efficient the vehicle is as a whole and the greater the amount of driving range that can be extracted from the battery,” said Equipmake.
A traditional and cheaper alternative to SiC’s are insulated-gate bipolar transistors (IGBTs) that switch current at up to 20kHz. But Equipmake’s new HPI-800 can double the switch current at up to 40kHz.
SiC inverters are yet to be adopted by the mass market as they have been deemed too expensive but Equipmake’s managing director Ian Foley believes this is about to change.
“The upfront cost of a SiC inverter is more than recouped by the benefits in additional performance. In a typical high performance EV sports saloon, the associated efficiencies can reduce the size of the battery by at least 10% – or around 40-50kg. While they can be twice as expensive as IGBT versions, they can reduce battery size by such a large amount that the cost saving more than pays for the inverter itself. At the same time, the increase in efficiency and performance the technology can bring to an EV will enhance its natural appeal to customers.”
Mr. Foley added: “HPI-800 offers huge potential benefits for all types of EV powertrain, just in terms of reducing the size of the battery required. Factor in its compactness and light weight, and OEMs have even more reason to choose SiC for their next inverter.”
Equipmake forecasts that SiCs will overtake traditional IGBT units by 2024, and by 2030, 95% of all BEVs will use silicon carbide.
In terms of its dimensions, the HPI-800 measures 494mm long, 287mm wide and 94mm high. It weighs 12.7kg and delivers a maximum continuous power output of up to 400kW, depending on the motor.
The HPI-800 inverter is available now and can be bought in production runs from tens to thousands of units.
The inverter will be on display at the Future Propulsion Conference in Solihull on March 2nd-3rd.
Equipmake recently began in-service trials of its technology with Jewel E double-decker buses from Go-Ahead.