Author:
Sivaguru Noopuran, Senior Product Manager, NexGen Power Systems
Date
08/01/2022
PDF
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Figure 1: Global EV passenger car sales could make up roughly half of all cars sold by 2030
The rising popularity of EVs in recent times is not merely due to consumer demand, but because of the collective effort by the governments across the world to implement more sustainable and safer ways of mobility. In 2021, we saw an indication of the rapid adoption of electric vehicles with the number of EV (BEV, PHEV) shipments exceeding 6 million units. Some experts are estimating that global EV passenger car sales could make up roughly half of all cars sold by 2030 (Figure 1).
While EV technologies and solutions have advanced significantly over the past couple of decades, there are still a few challenges that can quickly become roadblocks:
1. Range anxiety–the first EVs range was too small for people to consider
2. Performance– Early EVs just couldn’t match the power and performance of gasoline-powered vehicles.
3. Cost– EVs were/are still expensive.
Today, we do see car makers address some of these challenges, but the dream of a car that needs to be charged only once a month, is affordable for most, and doesn’t compromise on performance is still elusive. Here are some of the considerations manufacturers must keep in mind as they address these challenges:
Range – Efficiency Is Key
• Delivering higher energy from the existing battery requires higher efficiency of power systems with minimum losses
Performance – Watch Your Weight
• Reducing the weight requires:
o Smaller/lighter batteries with higher power density modules to deliver the same performance.
o Smaller cables that carry lower current based on higher voltage (800V) batteries.
Cost – Turn Efficiency into Savings
• Battery efficiency has a direct impact on cost. For example, a 0.1% increase in the efficiency of the powertrain can save up to $500 in battery costs.
Significantly improving range, performance, and cost essentially comes down to the limitations of power devices and systems. There are several power conversion systems in an electric vehicle. Figure 2 presents an overview of the 3 key power conversion systems in an electric vehicle along with some high-level requirements:
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Figure 2: Key power conversion systems in an EV
Reinventing Automotive Power Electronics
Making real improvements to EV range, performance, and cost will take a new breed of power conversion systems. The silicon-based power technology that enabled consumer and industrial electronics in past decades is no longer sufficient for today’s advanced needs. Modern EVs require more advanced power semiconductor technology.
NexGen has developed a Vertical GaN technology which can form the basis of a scalable, software-configurable power platform for the next generation of automotive power systems. The technology is based on three separate advances;
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Figure 3: NexGen Power Platform
1) Vertical GaN - GaN on GaN Power Semiconductors
NexGen Vertical GaN devices are made of Gallium Nitride (GaN) grown vertically on a GaN wafer. This construction decouples the breakdown voltage from the device area, creating high voltage, avalanche-rated devices carrying large current densities while still operating at very high frequencies. Vertical GaN systems deliver:
NexGen Vertical GaN-enabled power supplies can also lower costs by reducing passive components like inductors and capacitors. The resulting power systems are not only lighter and smaller, but they are also more robust and efficient. Figure 4 summarizes the advantages of NexGen Vertical GaN over competing technologies.
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Figure 4: NexGen Vertical GaN Outperforms Si-based & Newer Technologies
2) 1+ MHz Digital Powertrain Controller
Merlinis NexGen’s digital power systems controller for Power Factor Correction (PFC) and DC-DC LLC. This is the world’s first digital powertrain controller running at 1+MHz. Merlin runs proprietary software enabling NexGen Vertical GaN-based Power Systems with the highest efficiency. Some of the key features of Merlin include:
• Discrete time control for MHz switching of FETs
• Intelligent EMI control through spread spectrum
• Programmable, on-demand power for low-load management
• Metrology for predictive maintenance capability
• Low standby power
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Figure 5: Merlin Power Engine
3) Planar magnetics
The third key element in the platform concerns the magnetics and thermal design.
Planar magnetics eliminate wire-wound designs enabling:
• 10x lower leakage current than current magnetic solutions
• Reduction of noise sources with predictable parasitic effects
• Excellent repeatability in manufacturing
Efficiency in thermal design is also achieved through advanced thermal impedance management and thermal throttling.
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Figure 6: Planar magnetics eliminate wire-wound designs
Benefits of EV Power Systems with Vertical GaN-based Power Systems:
Now that we have seen how NexGen’s power platform enables software configurable, scalable, and highly efficient, small form-factor power systems, let us look at its benefits for the three critical EV power applications:
Making a Global Impact
With state-of-the-art power systems based on the innovative Vertical GaN devices in EV power conversion systems and inverters, you can achieve improvements in all three major areas—range, performance, and cost.
The overall efficiency improvements also present a significant opportunity for a greater global impact. An average electric vehicle requires 30 kilowatt-hours (kWh) to travel 100 miles. Assuming a typical vehicle drives an average of 13,500 miles in a year, this amounts to 4,050 kWh of energy consumption in one year. An estimated 150 million electric vehicles are expected to be sold from 2025 to 2030. Assuming an average 11-year ownership of a car, the electricity consumption of these new vehicles is estimated to be approximately 6.6 trillion kWh. A 1% efficiency improvement in the overall electric vehicle power electronics of these cars amounts to 66 billion kWh of energy savings. This is equivalent to the carbon sequestered by one-third of all U.S. national forests.
Summary
Electrification of vehicles is growing at a skyrocketing rate; however, it comes with the challenges of drive range, performance, and vehicle cost. To address these challenges, major improvements are needed in the three key power systems in an EV: on-board chargers, DC-DC converters, and inverters. With NexGen Vertical GaN technology at the core of this platform, coupled with Merlin Power Engine digital powertrain controller and innovations in thermals with planar magnetics – NexGen Power Systems can effectively and efficiently accommodate the automotive needs of tomorrow.
