New components arise to handle more power

The desire for faster charging times and better driving performance and an increase in automated driving features in electric vehicles are creating the need for more power.

Delivering the juice inside an EV requires higher voltages — and multivoltage vehicle architectures.

"As EVs become more mainstream, you're going to have more than one voltage layer in the vehicle, which means you're going to have to convert power back and forth," said John Romain, senior manager of advanced development at Yazaki North America, the U.S. unit of the Japanese supplier of wire harnesses and related power components. "You're going to have to manage how much power you have available in those layers to make sure everything functions properly for the customer and everything is safe."

Different voltages require the ability to partition out power management across different components, he says — which is where Yazaki technologies come into play.

Yazaki is developing components to support higher vehicle voltages: a battery busbar module; a high-voltage junction box, which controls how current flows from inlet to battery and from battery to motor; a DC/DC converter, which reduces 400 volts to 12 volts; and an on-board charger, which interfaces with a plug.

For 48 volts, Yazaki uses a bidirectional DC/DC converter and an electric semiconductor relay. For 12 volts, Yazaki relies on power distribution through a battery-mounted power management module.

"If you have a high-voltage system, a 48-volt system and a 12-volt system, you really do need all of these components in order to provide certain functions," Romain said.

In addition to 12-volt layers, more EVs are going to integrate 48-volt layers to handle high-power features such as HVAC. A high-voltage layer on top of that could handle the battery and propulsion system and other high-energy systems.

As more of these features go into an EV, there is more heat and a greater risk of thermal runaway — which leads to a depletion of the vehicle's battery range. EV developers are focusing in part on thermal management, but part of the solution, Romain said, comes from better power management.