How to Bring Vehicle Power Distribution into a Digital Future

As the automotive industry moves inexorably toward creating software-defined vehicles with the advanced features consumers expect, the journey is not always easy. Breaking from traditional approaches and embracing new technologies requires a careful balance between realizing immediate value through incremental changes and maintaining a vision for the future of vehicle architectures. This balance is especially important in power distribution and electrical centers.

For decades, automotive power distribution has been rooted in electromechanical analog devices, and those devices have performed reliably. But the next generation of vehicles will have more automated driving features, more electrification, more shared mobility and more connectivity — and those capabilities require that every circuit in the vehicle can be monitored and supports diagnostics.

That means going digital: collecting data in microseconds to capture shifts in performance in near real time, leading to better predictive maintenance. Only through digital technologies will OEMs be able to capitalize on the benefits of next-generation vehicle architectures such as Aptiv’s Smart Vehicle Architecture™ and reduce the number, weight and length of wires in a vehicle.

While embracing smart electrical centers to enable that digital capability might seem like a no-brainer, cultural resistance to change is not unusual. The cost of switching all circuits at once to smart fuses can seem daunting, and engineers may have already invested a lot of time and effort into the legacy infrastructure. Company politics can be a factor, as different groups — such as those managing data or communications — suddenly have more say in a design process that traditionally has been owned by the wiring group.

Digital transformation

The most straightforward way to overcome these obstacles is to show real value early on. Instead of trying to replace all circuits, start by identifying relay-fuse combinations where using a smart electrical center could save material costs. That is, focus on those places where the change can lead to downsizing or removing a wire or device. For example, Aptiv recently demonstrated to a major OEM that it could eliminate one of three traditional electrical centers in one of its vehicles to save 2 kg in weight and reduce the overall cost by $40.

In addition, every relay-fuse combination that is converted into a solid-state smart fuse saves 2 Watts of power dissipation – which improves gas mileage for internal combustion engines and conserves battery life in battery electric vehicles. In the above example, we converted 29 relays, which resulted in about 58 Watts of power savings.

The cost and power savings are a critical factor at this early stage in the process. The benefits of digital data produced by smart electrical centers are too far removed from the user experience for the consumer to seek them out, so cost savings show value more quickly.

The next step toward success is to use a scalable architecture. Even though only some circuits may see value today, others could see benefits in the future, so it is important to have an architecture that can expand — and having that scalability keeps the effort focused on the long-term vision of evolving the vehicle architecture.

Because this change brings together groups that traditionally have been separate, it is important to get buy-in, both from a high-level executive in the organization who can champion the initiative and from the owners of the devices receiving the output from the electrical center.

Smart electrical centers include a software component, so they will encounter some of the same challenges facing the industry overall as it moves to software-defined vehicles. Software has more frequent design iterations and more frequent testing. Specialized test benches utilizing hardware-in-the-loop are needed to ensure that the software and hardware work together as expected. While a software developer’s approach may seem foreign to those who have focused on power distribution, it is rapidly becoming an integral part of development throughout the vehicle.

A change from analog to digital is not always easy, but there are many precedents where going digital has resulted in a massive increase in value. Consider airplanes, when they went from all-mechanical operation to flying by wire. The hydraulics necessary to guide the plane are still there, but the digital controls layered on top provide a much smoother experience for pilots. Likewise, as vehicle architectures embrace digital technologies, we will see new levels of functionality.