Vitesco Technologies reduces emissions in high-voltage hybrid vehicles with electrical catalyst heating; new DC/DC converter
Vitesco Technologies, a leading international supplier of advanced powertrain technologies and electrification solutions, is now making electrical catalyst heating available in high-voltage hybrid vehicles as well. With a new DC/DC converter, the heating discs of the electrically heated EMICAT catalyst (earlier post) can now also be supplied with electricity in high-voltage vehicles. It is already in use in vehicles with a pure combustion engine or in mild hybrids.
EMICAT heated catalyst and the new DC/DC converter.
For Vitesco Technologies, the novel use of heating technology in the high-voltage sector is an extension of its existing product range. The e-catalyst enables lowest emissions in real operation—something that is becoming increasingly important in light of forthcoming regulations such as Euro 7.
The challenge of plug-in hybrids: CO2 efficiency and low cold engine start emissions. Hybrid vehicles utilize their potential for CO2 savings by shutting off the combustion engine as often as possible and using electric power instead. This results in longer operating pauses in the combustion engine during which the vehicle does not emit CO2.
During these phases, the engine cools down. If it is required and restarted, the exhaust flow is also cold at first—possibly too cold to convert pollutant gases in the catalyst.
In other words, the cold start is actually the rule, especially with efficiently-driven hybrids. From the perspective of emission reduction, this is a challenge, as the greatest share of the emissions in a cycle can be generated during cold start situations.—Rolf Brück, head of Catalysts and Filters at Vitesco Technologies
This form of exhaust gas aftertreatment has so far not been available for high-voltage hybrids—such as plug-in hybrids—because the heating disc cannot be supplied directly from the high-voltage system at 200-450 V. The newly-developed DC/DC converter now generates the low voltage and power for the heating disc from the high voltage of the drive system.
The compact unit is based on state-of-the-art printed circuit board technology and the latest components with small dimensions, and enables a high degree of efficiency of 95%.
The system solution, consisting of heating disc and DC/DC converter, upgrades exhaust-gas aftertreatment systems for even stricter emission standards worldwide in the future.
The converter is designed in such a way that it can even supply multi-flow exhaust systems with multiple heating discs via separate outputs.—Alexander Reich, head of Product Management High Voltage Electronics at Vitesco Technologies
The likely start of production is 2023. In the medium-term, the DC/DC converter technology has the potential to supply other high-power consumers in the vehicle. Possible examples include electric roll stabilization or the electric steering assistance, Reich added.