Few people realize the technology used in the Mars Ingenuity helicopter’s maiden flight is also used in EVs down on Earth
By The Technical Marketing Team at Rutronik
A fascinating example of electromobility occurred in April 2021: the maiden flight of the Ingenuity helicopter on Mars.The environment here was harsh, with extreme temperatures and low atmospheric pressure.
Although electric vehicles on Earth don’t have to operate in such harsh environments, their power electronics still need to work reliably in difficult conditions.
Terrestrial vehicles also have it tough
There are vehicles on Earth that operate in harsh environments, including pallet/forklift trucks, tractors, and excavators, as well as smaller machines used for automated tasks or passenger transport. Like Ingenuity, they require DC-to-DC (DC-DC) converters to transform the voltage level between the drive battery and 12V or 24V for auxiliary equipment. These converter modules typically operate at outdoor temperatures between –40°C and +75°C and are protected against the ingress of dust and water.
Electronics to automotive quality standards
Advances in power electronics aim to improve efficiency and reduce the size and weight of electric vehicle components. Low-voltage DC-DC converters need to work reliably for decades in the demanding environment of EVs.
Self-driving EVs can be seen as mobile data processors. They are equipped with components such as CPUs, FPGAs, and SoCs, all of which demand low-voltage precision power rails, usually provided by point-of-load (PoL) converters that must ensure the highest level of reliability (e.g., through surface-mount solder connections with wettable flanks).
Further, the operating environment of an EV is susceptible to EMC (electromagnetic compatibility) and switching frequencies in the AM range can be problematic. The converters must, therefore, be kept within limited frequency ranges, restricting the circuitry design.
Vibrations and both physical and thermal shocks also pose challenges. RECOM’s high-efficiency RPX series is designed to withstand them (according to MILSTD-883D). It can also be obtained from Rutronik as a Q-version, meeting the requirements of the automotive industry. The RPX is housed in an ultra-miniaturized, 3mm × 5mm QFN package that is just 1.6mm tall with an over-molded flip chip on a lead frame. The output voltage can be trimmed from 0.8 to 30V, while the input range is 4 to 36V. It additionally provides comprehensive monitoring and control, something that is essential for EV applications.
Chargers for EVs must be small and should have the least possible impact on the environment. This requires a high level of efficiency, not only in the main stage of the AC-DC charger but also in many commonly available AC-DC and DC-DC auxiliary power supplies.
Off-board chargers generally operate in an environment of Overvoltage Category 3 (OVC III). Off-the-shelf AC-DC chargers are, therefore, often not suitable. The RECOM subsidiary Power Control Systems (PCS) specializes in customized products for high kW applications. The power supplies available through Rutronik meet all relevant standards and feature an operating temperature range from –40°C to +85°C. Besides low noise and low ripple, they are characterized by a high level of efficiency.
Regulations for rail electronics
Unlike helicopters on Mars, e-mobility applications on Earth must meet international standards for functionality and safety. An example is the rail sector: DIN standard EN 50155 is the general standard here, while other standards regulate EMC, insulation systems, shock/vibration, fire protection, and electrical safety features. They ensure that power sources operate reliably despite disturbances.
To meet these standards, modular converters require a high level of electrical and environmental protection. The DC-DC converters of RECOM’s RMD family satisfy these requirements. They are available for applications in the range of 150W to 1kW.