Compact Medium-Voltage Converters To Enable Advanced Grid Architectures & Operations
As we trend toward more renewables and distributed energy resources (DERs), the design of the electric distribution system itself imposes physical limitations. These system constraints could lead to issues like overloaded power lines and faults that propagate freely.
But what if we could restructure the underlying system to support greater renewable integration and system resilience? To that end, a National Renewable Energy Laboratory (NREL)–led project is working on a new type of grid device enabled by silicon carbide (SiC) switches and other medium voltage (MV) power electronics that could segment sections of the grid, providing advanced control for flexibility and resilience for our power systems.
The project team is first designing a megawatt-scale prototype converter that provides native “back-to-back” conversion — AC to AC power — at distribution voltages (i.e., not requiring transformers to step down voltage to levels typically used in electronic power conversion). By using MV SiC-based power modules, the converters could be 1/5th the size and 1/10th the weight of alternate equivalent systems, which are trailer-sized and include heavy transformers. Then the team will connect the power converter into NREL’s MV testbed to validate new grid control approaches that the prototype enables.
The project is named “Grid Application Development, Testbed, and Analysis for MV SiC (GADTAMS)” and is funded by the Department of Energy’s Advanced Manufacturing Office.
The NREL-led GADTAMS project is developing and demonstrating smaller and lighter alternatives for direct medium-voltage connections on the grid, which could enable new resilient grid architectures.
“With back-to-back converters between feeders, we can go one step higher in providing resilience across the distribution system,” said Akanksha Singh, a project lead at NREL.
“This technology wasn’t necessary before because we didn’t have so many distributed energy resources on the system, but now we have feeders that are becoming saturated with PV; apart from storage, these feeders don’t have anywhere to inject that excess power,” Singh said. “A new approach to grid interconnection could enable advanced forms of power sharing and provide much-enhanced grid resilience.”
A future grid that features such converters would have the capability to control the flow of power between sections of the grid, shunting excess load or DER-based generation to feeder sections or adjacent circuits as needed, adding new versatility to power distribution. Networked microgrids could protect against the propagation of faults from one microgrid to the next while still allowing controlled power dispatch between the two systems and the macrogrid as well.
During outage recovery, microgrids could be formed that then stabilize neighboring microgrid systems, as envisioned in NREL’s autonomous energy systems research. In general, the two sides of the converter do not need to be synchronized in frequency or even exact voltage level at all — a major shift from the modern power system. But prior to proving any of these applications, NREL and others will first need to build the necessary controls.
“We are developing very novel controls for upcoming grid architectures,” Singh said. “We have local controls on inverters, and we have hierarchical controls that coordinate between grid partitions. With regard to grid support, these controls can do it all: dynamic stability, frequency support, black start, fault ride-through and protection.”
Unlike anything currently available, the NREL testbed provides an environment to validate medium-voltage grid solutions with real power hardware-in-the-loop and real-time grid simulation. For this project, NREL and partners are interested in the full range of use cases for back-to-back SiC converters and have teamed with utility Southern California Edison to inform on utility applications, as well as industry partners General Atomics and Eaton to seek out a commercial path for the technology.
The SiC converter is being built in two halves by project partners Ohio State University and Florida State University. The three-phase converter prototype will be rated for 330 kW and will implement a full thermal and electrical design appropriate for utility use. Traditionally, the same AC-to-AC conversion process requires stepping-down the voltage to low-voltage levels where conventional power electronics can be used, which results in heavy and expensive transformer equipment. The MV SiC option takes advantage of the superior voltage ratings of devices to minimize weight, cost, and size, which makes the technology far more practical and economical for system-wide deployment.
Still, the converter technology is only one aspect of fulfilling flexible interconnections. This framework currently lacks the standardization that exists for so many other recent grid innovations. At NREL, the project team hopes to collect baseline operational data to jumpstart the conversation around how to integrate MV converters in future grids.
“This is a new application that doesn’t exist anywhere yet. We need standards that apply to how the converters can integrate with regular system operation, like starting up, syncing to the grid, etc.,” Singh said. “We are using IEEE Standards 1547 and 2030.8 as a base, interpreting their rules to implement new controls on MV systems. We are trying to merge the two to understand what will apply to this new approach.”
An entirely new grid architecture and operational flexibility could seem far-out for now, but NREL and partners are showing that these options are viable in the near-term and that NREL has the capability to prepare these solutions for real systems. Learn more about how NREL can validate advanced energy systems at scale.
Article courtesy of NREL.
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Despite the warnings, BYD continues introducing new discounts. On Wednesday, BYD’s luxury off-road brand began offering over 50% Huawei’s smart driving tech.
BYD introduces new discounts on smart driving tech
After BYD cut prices again in May, the China Automobile Manufacturers Association (CAMA) warned that the ultra-low prices are “triggering a new round of price war panic.”
Although they didn’t single out BYD, it was pretty obvious. BYD slashed prices across 22 of its vehicles by up to 34%, triggering several automakers to follow suit in China.
BYD’s cheapest EV, the Seagull, typically starts at about $10,000 (66,800 yuan). After the price cuts, the Seagull is listed at under $8,000 (55,800 yuan).
It doesn’t look like China’s EV leader plans to slow down anytime soon. Fang Cheng Bao, BYD’s luxury off-road brand, introduced new discounts on Huawei’s smart driving tech on Wednesday.
The limited-time offer cuts the price of Huawei’s Qiankun Intelligent Driving High-end Function Package to just 12,000 yuan ($1,700).
Buyers who order the smart driving tech in July will save over 50% compared to its typical price of 32,000 yuan ($4,500).
Earlier this year, Fang Chang Bao launched the Tai 3, its most affordable vehicle, starting at 139,800 yuan ($19,300). The Tai 3 is about the size of the Tesla Model Y, but costs about half as much.
The Tai 3 will spearhead a new sub-brand of electric SUVs following the more premium Bao 8 and Bao 5 hybrid SUVs.
BYD’s luxury off-road brand sold 18,903 vehicles last month, up 50% from May and 605% compared to last year. Fang Cheng Bao has now sold over 10,000 vehicles for three consecutive months.
The Chinese EV giant sold 382,585 vehicles in total in June, an increase of 12% from last year. In the first half of the year, BYD’s cumulative sales reached over 2.1 million, a YOY increase of 33%.
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Every year, it seems like there’s a new headline about the world’s lightest electric bike. Each year, engineers manage to shave a few more grams off of an exotically designed frame built with even more exotic materials. And each year, the continuously lower weight is balanced by continuously higher prices – often exorbitantly high. But now Dahon has bucked that trend, offering us an incredibly lightweight electric bike at a price that normal e-bike riders can afford. Meet the Dahon K-Feather.
To put things in perspective, some of the previous lightest electric bicycles have included the 11.8 kg (26 lb) LeMond Prolog at US $4,500, the 11.75 kg (12.59 lb) Trek Domane+ SLR at US $8,999, and the 10 kg (22 lb) Hummingbird Flax folding e-bike at US $6,050.
So with that in mind, please allow me to introduce you to the new Dahon K-Feather. This is a 12 kg (26.5 kg) folding electric bike priced at an incredibly reasonable US $1,199 in North America or €1,499 in Europe.
Sure, it’s not the absolute lightest folding e-bike we’ve ever seen, but it’s 90% of the way there and at a quarter of the price. Plus, it comes from Dahon, which is one of the most respected names in the folding bike world and is largely credited with paving the way for the booming folding bike industry we see today. Since the 1980s, Dahon’s innovative designs have been imitated around the world, yet the folding bike maker has continued to innovate and stay several steps ahead of competing brands.
The K-feather achieves its extra low weight through the combination of a novel frame design employing Dahon’s patented frame designs, including the company’s DELTECH technology and “super down tube,” which help improve rigidity and robustness while reducing weight.
The electrical system on the K-Feather is also a featherweight, keeping the e-bike largely in the last-mile category. While the battery claims a maximum range of up to 24.8 miles (40 km), real-world riding and hilly terrain could reduce that range. Still, clever designs like a system that automatically shuts off the extra motor power when detecting a downhill segment help to eke out more range from the small 24V and 5Ah battery.
The ultra-lightweight 250W hub motor also offers just 32 Nm of torque, meaning the assist is more of a helpful push than a powerful shove. But with the inclusion of a torque sensor for the pedal assist, that push comes on quickly and reliably, making the bike feel more like a traditional analog bike being pedaled by someone with extra strong legs.
With 16″ dual-wall rims and 14g spokes, this isn’t the heavy fat tire folding e-bikes we’re used to in North America, and the capacity reflects that. The K-Feather is rated to support riders weighing up to 105 kg (231 lb), though the highly adjustable seating position can support a range of rider heights from 145 to 190.5 cm (4’9″ to 6’3″).
Coming in six colorways, the Dahon K-feather folding e-bike is now available in the US and has launched for pre-order in Europe, with shipments there expected in September.
I had a bit of a preview of the K-feather on my last trip to China when I was able to visit Dahon’s headquarters and test ride the bike.
I still can’t believe how light it felt, both underneath me and while folding it up and carrying it around. Be on the lookout for that full experience from my trip, coming soon.
Electrek’s Take
The K-Feather represents a compelling milestone not just for Dahon, but for the entire folding e-bike market. By delivering a truly lightweight, compact, and fully electric folder at an impressively affordable price point, Dahon has made minimalist e-mobility more accessible than ever.
It’s not just a bike for die-hard lightweight e-bike connoisseurs; it’s a real-world solution for commuters, travelers, and apartment dwellers who want the freedom of electric assist without the bulk or the sticker shock. If the goal is to get more people on two wheels, the K-Feather might just be one of the most important steps forward yet.
Coming in at less than half the weight of most folding e-bikes, and still a fraction of most lighter-duty folders, the K-Feather’s modest performance makes it a great urban ride for those who favor compact size and light weight. In fact, I think it might be perfect for my mother-in-law, who needs an e-bike to get to and from the train she takes to work, but also needs it to be light enough to carry up to her second-story apartment. Hmmm, perhaps I should have her do a review for us…
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The Honda Prologue remains a top-selling EV in the US, but it’s Acura’s luxury electric SUV that’s been the surprise hit this year.
Honda Prologue sales rise while Acura’s EV surprises
After delivering the first Prologue models last year, Honda’s electric SUV quickly became a hit. In the second half of 2024, it was the second-best-selling electric SUV in the US, trailing only the Tesla Model Y.
Despite limited inventory due to the new 2025 model year change, Honda sold 2,799 Prologues last month. In the first half of the year, Honda has now sold 16,317 Prologue models in the US. In comparison, Toyota sold just over 9,200 units of its electric SUV, the bZ4X, during the same period.
Toyota’s luxury brand, Lexus, sold only 763 RZ models, its sole electric SUV, for a total of 3,779 units in the first half of the year.
Honda Prologue sales have now held steady, averaging over 2,700 units per month, but it’s Acura’s electric SUV that has been quietly gaining ground in the luxury EV space.
With another 1,318 models sold last month, Acura ZDX sales reached 10,355 in the first half of 2025. Acura’s electric SUV is even outpacing the Cadillac Lyriq, which is based on the same Ultium platform.
Sales are significantly higher than the company expected. Earlier this year, Mike Langel, vice president of national sales for Acura, told Automotive News that the company expected to sell around 1,000 ZDX models a month this year.
A significant reason behind the strong demand is the availability of massive discounts, which can reach nearly $30,000 in some states. The luxury electric SUV is more affordable than a Honda CR-V, with monthly leases starting at just $299.
The Honda Prologue is available to lease for as little as $259 per month. The offer is for 36 months with $2,399 due at signing in California and other ZEV states.
With the Trump administration planning to end the $7,500 federal EV tax credit, many of these savings will soon disappear.
If you’re looking to take advantage of the savings while they’re still available, we can help you get started. You can use our links below to find deals on the Honda Prologue and Acura ZDX in your area.
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