Home Articles Upload in the future

Upload in the future

electric charging station

By Joseph A. Thomsen, Vice President, MCU16 Business Unit

With many countries aiming to ban the sale of new vehicles with gasoline and diesel engines from 2030, the development of electric vehicles (EVs) is set to grow enormously. This is driving the need for more efficient and cost-effective electric vehicle designs, with longer range and lower cost, to help consumers make the switch. However, the global impact of electric vehicles in the world is underestimated. People tend to think that the transition is as easy as swapping gasoline engines and tanks for batteries and electric motors, but the reality is much more complex.

Emerging Powertrain Technologies

New power MOSFET technologies are a key part of this shift to electric operation for EV traction inverters to support higher efficiency and higher voltages. There is much talk about the use of new WBG technologies, such as silicon carbide (SiC) and gallium nitride (GaN), for the powertrain of electric vehicles. New SiC designs are emerging to meet the growing high-power needs of electric vehicles. GaN technology is growing, but it still needs to build confidence to prove its reliability and lower prices to penetrate the EV inverter market. Both SiC and GaN are more expensive than traditional solutions, but offer compelling features such as higher efficiency due to lower switching losses, as well as smaller system size and weight, due to higher switching frequencies and lower refrigeration systems. Designs with these new technologies can be more complicated to ensure safe and robust operation. It is likely that there will be a long transition from silicon power devices to emerging technologies, with silicon power continuing to be engineered into the most cost sensitive applications.

Increased voltages in on-board chargers

In the future there will be a tremendous technological battle over on-board chargers (OBCs), used to recharge the high-voltage traction battery from the grid while the vehicle is parked. There is a big boost from 400V to 800V systems, which favors SiC technology, but GaN's higher switching speed makes the charger more efficient. In the end, it is likely that both technologies will succeed in different parts of the world and that both will coexist. What is certain is that electric vehicle charging voltages will continue to rise. New technology developed for high-power charging stations will be carried over to on-board chargers to speed up charge times.

Leverage data center designs

The data center industry brings a wealth of experience in power system design. Designers can take advantage of topologies developed for hyperscale data centers, add security and functional protection, and devise a good 48V to 400V or 800V DC-DC converter or charger for the power train. The biggest difference between designing for a data center and powering an electric vehicle is that the data center approach using dsPIC33 devices uses a digital control loop instead of analog filters and a feedback loop. This allows for a platform design in the digital domain, sensing the output voltage and current, converting it to digital, and adjusting the PWM to drive all power FETs with low latency feedback loops. It is that data center expertise that helps manage the complexity of increased power in electric vehicles. Pairing a digital signal controller with high-speed switching GaN devices requires 250MHz performance, and our dsPIC33 controller roadmaps are designed to meet that need in the near future. In addition, the dsPIC33 offering includes multicore drivers to separate compact control algorithms from the rest of the software required for VE applications. Aspects such as automotive requirements, functional safety, abstraction layers, drivers, and Autosar quickly lead to memory requirements greater than 1 MB, with a clear advantage for multicore devices using one core for the control loop and another core for automotive and maintenance functions. These requirements lead to more complex driver chips, with associated software tools and the right level of ASIL security support, to support EV system designers.

Charging infrastructure

The broader implication of the growing popularity of electric vehicles is much more than the cars themselves. The entire infrastructure of the electricity grid will have to change. We'll see more sustainable energy and local microgrids develop in many places where you can't just double the amount of electricity from providers, so consumers will generate something at home through solar or other means.

With vast amounts of power moving to enable fast charging, business models may be introduced that we haven't thought of yet. Perhaps instead of every home having fast-charging capability, we'll see rapid battery swapping, leaving more time to fully charge the "backup" battery.

Or maybe, in the long run, charging will be more ubiquitous and there will be less need for batteries. In Korea and Sweden there are already inductive coils on the roads to charge a vehicle while driving. This reduces battery size requirements and power requirements and reduces the need for chargers.

Conclusion

With electric vehicles set to become the dominant transportation trend over the next decade, technology providers are paying close attention to the system architectures used by developers. Flexible devices that deliver the performance needed for the next generation will be critical to enabling innovation as the EV market expands. But close attention also needs to be paid to innovation in infrastructure design, both in on-road and integrated charging, to avoid the range limitations that consumers fear today.