Can EVs Charge While Driving?

As EVs become more prevalent, EV Transformation is becoming increasingly critical. This refers to the holistic design and real-world deployment of the entire energy ecosystem, from power generation and storage through to charging and reuse.

However, realizing EV Transformation requires overcoming major challenges: insufficient charging infrastructure, lengthy charging times, and the complexity of managing electricity supply and demand.

Today, EV drivers planning long-distance trips often need to research charging station locations in advance and endure extended wait times. Expanding the charging network requires enormous investment, and installation in rural or low-density areas remains particularly slow.

• DRIVEN BASE: Innovation in Energy and Lifestyle by EVs | DENSO

DWPT has emerged as a technology with the potential to solve these challenges. By embedding transmitter units beneath road surfaces, it enables automatic charging of EV batteries both when stationary and while moving. If commercialized, driving continuously over a powered lane could eliminate the need for lengthy stops at charging stations, unlocking what might be called unlimited range.

Beyond advancing charging technology, DWPT is expected to bring broader transformation to public infrastructure and economic systems. On the infrastructure side, locally generating and consuming renewable energy along roadways could help distribute load across power grids. Economically, such infrastructure investment could catalyze entirely new service models.

And as EVs and roads begin exchanging real-time data, tracking vehicle location and monitoring power consumption, the technology could also drive significant improvements in traffic and energy management. Together, these capabilities could dramatically increase vehicle utilization by enabling truly unlimited range.

Against this backdrop, DENSO has been actively pursuing the development and validation of DWPT. In September 2024, the team completed a technical feasibility demonstration, successfully completing a 50-hour continuous drive using the technology.

The demonstration project was spearheaded by DENSO's Advanced Testing & Evaluation Division. As detailed in the article linked below, this division plays a vital role in DENSO's technology development, turning engineers' concepts into a tangible reality, incorporating a manufacturing perspective from the earliest planning stages, and running agile development processes.

• DRIVEN BASE: Driving Society-Wide Adoption of Advanced Technologies | DENSO

While DWPT holds tremendous promise, making it practical involves significant technical challenges. One of the most prominent challenges is that implementation does not involve the vehicle-mounted equipment alone. Power must continue to be delivered even as system characteristics fluctuate depending on the positional relationship with infrastructure-side equipment, making the overall system highly advanced and complex.
To overcome these challenges, members of the Advanced Testing & Evaluation Division led three initiatives:

1. Building a component test bench capable of accurately measuring the complex, mutually dependent characteristics between the vehicle-side and infrastructure-side equipment.

2. Preparing for successful driving tests by ensuring the safe installation of the heavy-duty wireless receiver coil, providing specialized driver training for extended operation, and establishing standardized testing protocols.

3. Developing a demonstration application and sensor data acquisition system featuring an intuitive UI to help stakeholders and government bodies immediately grasp the technology's value.

Tatsuma Yoshida led the component test bench, Hironobu Ueda oversaw preparations for the driving test, and Takumi Fujiwara and Tetsushi Matsushima developed the intuitive UI—all from the Advanced Testing & Evaluation Division. They worked in close coordination with Masaki Kanesaki of the Research and Development Division as part of a project involving over 70 contributors.

How was the foundational infrastructure built to validate these three critical areas?

First, let’s look at the development of the component test bench. Typically, test bench evaluations involve mounting vehicle components—such as conventional engines or electric motors—onto a fixed platform to measure performance, durability, and energy efficiency, ranging from exhaust flow for engines to power conversion for motors, under controlled conditions. However, since no precedent existed for a DWPT test bench, the team had to design and build one from scratch. Yoshida explains:

"To continuously improve safety and performance throughout development, we needed a test bench that could replicate the dynamic conditions of an actual moving vehicle from the earliest demonstration phase, and accurately capture how power transfer characteristics shift in that environment. Because of the highly specialized nature of the setup, nothing like it existed anywhere, and we had no choice but to build it ourselves. We combined DENSO's advanced expertise and core technical skills in mechanical design, electrical design, and assembly with lessons from our internal evaluation facilities and production lines to create something entirely new."

The greatest challenge was designing and building the test bench itself. The team constructed a 22-meter-long structure simulating travel at 20 km/h, engineered so as not to interfere with the characteristics of the prototype under test. A critical constraint that emerged early in the design process was the need to safely propel a 370 kg vehicle at 20 km/h, demanding robust, safety-first engineering for the movement of a significant load at speed.

For a team accustomed to building benches roughly one to two meters long, this was uncharted territory. Yoshida consulted with internal production line design teams and external manufacturers, then developed a structural design that met all required safety standards. The team modeled risk scenarios for a 370 kg object traveling at 20 km/h and specified safety equipment rated to handle the resulting forces.

To improve development efficiency, the team used 1D CAE*¹ and an internally developed Design-VR*² tool, ultimately trimming one month off the originally planned nine-month construction schedule.

*¹ 1D CAE: A design support tool that models a product as functional blocks and enables analysis and evaluation of design parameter variations.

*² Design-VR: A VR-based design support tool that overlays full-scale CAD models in real space for team review, helping align everyone on the expected outcome and allowing engineers to experience the assembly process before fabrication begins, preventing costly rework.

Successfully completing the 50-hour continuous drive evaluation required work on two parallel fronts: vehicle modification and drive testing.

On the vehicle modification side, a wireless receiver coil needed to be mounted on the vehicle to capture energy transmitted from the underground infrastructure. To maximize power transfer efficiency, the coil needed to be large, and safely mounting an approximately 130 kg component to the underside of a production vehicle was a task without precedent. Existing equipment couldn't handle the job, so the team built a dedicated workspace using a customized mobile lifting platform, enabling the work to be carried out safely.

On the drive testing side, long-duration testing was essential to verify both the stability of the DWPT system and the core value proposition of truly continuous driving. The evaluation came with unique operational challenges, as Ueda explains:

"The 50-hour continuous evaluation required simultaneously running two vehicles (one equipped with DWPT and one without) and collecting comparative range data throughout. Driving at 10 km/h around a roughly 180-meter loop, completing nearly 50 laps an hour, is relentlessly monotonous. Keeping drivers alert and focused for that duration was one of our biggest challenges."

To address this, the team selected highly skilled drivers who held internal driving qualifications and adopted a two-person-per-vehicle setup, with one driver and one safety observer rotating every hour across 24-hour day-and-night shifts. A pre-test training session aligned all participants on the route, target speed, and safety checkpoints, ensuring consistent, high-quality data collection from start to finish.

The third focus in advancing demonstrations of DWPT was an intuitive demonstration enabled by an intuitive user interface (UI).

Achieving large-scale deployment of DWPT will require buy-in not only from the automotive industry but from a wide range of stakeholders across industrial sectors and at national and local government levels. In the limited time available in any given meeting or presentation, the technology's value needs to land immediately and leave a lasting impression.

To meet this need, the Advanced Testing & Evaluation Division developed a demonstration application designed to communicate the appeal and excitement of the technology in a vivid, tangible way — prioritizing visual impact and hands-on experience over charts and data readouts. Fujiwara, who led the effort, reflects on what went into it:

"To help a broad audience well beyond the automotive industry grasp the technology intuitively, I felt we needed to move far beyond the conventional waveform readouts and data graphs from measurement instruments. We needed a new way to engage people's senses — by having them actually ride in the DWPT-equipped vehicle and experience the technology firsthand.

We implemented visual interactions and audio feedback triggered when the vehicle passes over a transmitter coil, a display that conveys the tangible sensation of receiving power, and a UI designed to intuitively communicate the key technological milestones on the road to making unlimited range a reality. The goal was to let stakeholders feel genuine excitement, build real understanding, and walk away truly convinced — in real time, in a way that documents and videos simply cannot achieve.

Having so many stakeholders experience the demo firsthand also gave us invaluable feedback that we channeled directly into improving the UI design, refining the control logic, and raising the overall quality of the application."
— Fujiwara

Supporting the demonstration was a sensor data acquisition system designed to provide real-time data for effective visualization. To ensure zero interference with the vehicle’s onboard communication systems, the team implemented a non-intrusive data-reading method. This was paired with an independent communication architecture capable of processing the precise data frequency and volume required from multiple added sensors. By developing a custom, compact, and cost-effective measurement circuit, the team met all technical specifications while overcoming tight space constraints within the vehicle.

Tetsushi Matsushima, who built the sensor data acquisition system, reflects on what made the project work:

"There were plenty of technical hurdles along the way, but I believe the reason this demonstration succeeded is that we were able to bring together the core technologies from the Research and Development Division and the deep, accumulated expertise of the Advanced Testing & Evaluation Division. Even when a project has little precedent and requires navigating uncharted territory, I believe we can contribute to real-world technology deployment by drawing on and building from the knowledge our division has developed over the years."

This demonstration project has given DENSO a much stronger platform to showcase the real-world potential of DWPT. Building on this achievement, Masaki Kanesaki of the Research and Development Division says the team is now aiming to move into the next phase: pilot shipments to vehicle manufacturers and partner companies.

"The Advanced Testing & Evaluation Division takes on requests from teams across the company, and even under heavy workloads, they bring real initiative and drive enormous momentum — I'm genuinely grateful for everything they contribute. The next phase means moving from our private test tracks to public roads. That will require bringing our prototypes up to DENSO product quality standards and shifting to faster development cycles, which in turn demands more efficient test benches, more refined vehicle modification processes, and a wider range of driving test scenarios. Stakeholder engagement will also intensify, and we'll need to tailor our demonstrations to new features as they're added and to the specific needs of each audience. As the project grows in scale and complexity, the full-spectrum capabilities of the Advanced Testing & Evaluation Division will be more critical than ever."
— Kanesaki

Looking ahead, the systems developed through this demonstration are also being evaluated for standardization, with the goal of applying them to other programs across the business. Going forward, DENSO will continue to bring together the technological depth of the Research and Development Division and the hands-on expertise of the Advanced Testing & Evaluation Division, combining mechanics, electronics, and software to drive the large-scale deployment of DWPT.