At the recent EDTA conference in Washington, D.C., Indiana-based Remy International, Inc. said it has an answer for a growing dilemma facing the electric and hybrid vehicle industry.
While Americans are thinking about improving batteries to reduce dependency on foreign oil, at the same time, increased reliance on permanent magnet electric motors stands to set us up for a new dependency on foreign-sourced rare earth metals.
Most of the world’s supply is controlled by China which has been accused of aggressively manipulating it for political and economic gain.
In an effort to fortify America’s advanced-tech transportation future, in May 2010, the U.S. Department of Energy finalized a $60.2 million American Recovery and Reinvestment Act (ARRA) grant for Remy to develop its HVH electric motor technology.
A hybrid version of this motor looks like a fix for the China question, and apparently government investment in this motivated company is paying off.
China now produces about 95-percent of rare earth metals. Last September it was accused of stopping supply of this vital resource to Japan to punish it for detaining one of its ships, thus demonstrating the potentially antagonistic political will of the Chinese government.
While circumstances surrounding that incident were obscured, it remains clear that world supply is threatened. According to a Wharton school publication, in the second half of 2010, China slashed export quotas by 72 percent, then in the first half of 2011 further restricted exports by 35 percent compared to the year prior. The prices for some rare earths have spiked 1,000 percent. It is estimated global demand for these minerals might more than double by 2020 from last year’s 125,000 metric tons.
For now the advanced-tech industry continues to use permanent magnet motors, but should they become prohibitively expensive, Remy says it has an ace up its sleeve.
An American solution
Last week GM-Volt.com was told that Remy’s legal department advised its executives against interviewing with us. This was because in March, Remy International, Inc. filed an S-1 registration statement with the U.S. Securities and Exchange Commission for a $100 million initial public stock offering.
The Remy HVH250 uses its proprietary stator (outer part on lower right). This design can be made with either a permanent magnet or AC-induction rotor. Remy says it has an off-the-shelf EV solution. It has signed with Zap to supply its EVs, AMP to power its converted Chevrolet Equinox, MotoCzysz, and others to supply their electric drive needs.
Not wanting to excite the price one way or the other prior to an estimated summer IPO, Remy told us it will have to wait. It did say what was on public record was fair game however.
And fortunately, we have a complete public recording from Remy’s Global Director of Product Engineering, Andrew Worley. At the the breakout session titled, “Game-Changing Technologies,” he laid out the case for a motor Remy developed that does away with the need for rare earths.
Worley has his PhD in electrical engineering from the University of Leeds in the U.K., where he received his undergraduate degree as well. He earned an MBA from Purdue and a Certificate of Lean Process Development from the University of Michigan. Following is what he said …
“I’d like to start this afternoon’s presentation by presenting a scenario, a question if you like,” Worley said, “and then during my presentation I am going to present what I believe, what we at Remy believe, is a solution to this particular dilemma.”
With a tinge of drama, he set the stage outlining a typical possibility.
“So here’s the scenario, the dilemma: We’re all here involved in hybrid vehicles, electric vehicles in one way or another,” he said, “Just imagine a scenario: You’ve done your market research, you’ve done your engineering, your development, you’re ready for manufacture. You’ve got a couple orders coming in. Life looks good for 20-50-100,000 units a year. But there’s a critical element within all of our products, with most of peoples’ products, which is rare earth.”
He noted that those listening had likely attended an earlier session, titled, “Materials and Rare Earth Metals: Ramping Up For the Future.”
“Many of you here today sat through earlier, I’m sure, talking about rare earth magnets and what the challenges are,” he said, “So it is a challenge, it is a risk.
Worley showed a slide illustrating that Remy has over 100 years experience, 5,500 employees, 23 facilities in 10 countries and produces 17 million units annually. Within Remy Inc., is Remy Electric Motors for which he works.
“We do high output traction motors and generators for hybrid and electric vehicles. We believe we have the highest power density electric motors on the market,” Worley said, “We have proven reliability and durability; we have over 90,000 motors on the road, over a billion miles and very high reliability. We’ve been in this market since 2002 and so no stranger to this technology at all.”
19th century technology reinvented
“So, about this game changing technology. We’re reducing our dependence on rare earth permanent magnets,” he said, “I think most of us are aware rare earth permanent magnet motors are the most popular choice for our applications today because of a high torque density, high efficiency, wide range of constant power; good designs, quiet, have low torque ripple.”
However these motors leave OEMs vulnerable to the rare earth supply question, he said.
“But we keep having this question. And the solution is a technology that’s been around for a long time,” Worley said, “We just think there are some things we can do with that to address some of the perceived disadvantages.”
Remy’s answer is a twist on a motor first developed in the 1880s.
“And the solution is the induction motor. The humble induction motor has been around for a very, very long time, since Nicola Tesla discovered it many, many, many decades ago,” Worley said. “I’m going to talk a little bit about the winding technology we use in our machines. What we call the High Voltage Hairpin, or HVH winding.”
According to a Remy white paper on the design:
In contrast to conventional roundwire windings, the HVH™ stator winding uses precision-formed rectangular wires. Multiple layers of interlocking “hairpins” produce a superior slot fill (up to 73 percent vs. 40 percent for typical round-wire windings),” the paper says, “This patented design also creates a shorter end turn space than round-wire stators, thereby reducing heat and improving the motor’s torque and power density, and lends itself to robust construction at the critical connections between the conductors. Combined, the high slot fill and shorter end turn space reduce the winding resistance causing less heat generation. The HVH™ windings are well-suited to liquid cooling that further enhances performance and reliability.
This design can be used with either a permanent magnet rotor or AC-induction rotor.
Worley contrasted traditional concentrated stator windings with Remy’s innovation.
“A concentrated winding is great in some applications – doesn’t make a very good induction machine,” Worley said, “Our [HVH] winding has low loss, and we use oil cooling which is good for not only a permanent magnet machine, but also an induction machine. So we’re seeing some of what we already have in our permanent magnet motors translates very nicely over into induction machines.”
He then addressed what he called misconceptions about induction motors.
“The first one is they can’t deliver the same performance,” Worley said. “Well, I’ve just shown here. I’ll explain the graph (see below). It’s quite busy; the dotted lines represent continuous performance from three different machine technologies. The solid lines represent peak performance, so that’s performance for up to 60 seconds. The red lines – the dotted and the solid ones – represent the varied permanent magnet motors.”
Dotted lines show continuous performance between a permanent magnet motor (red line) and Remy’s AC-induction motors (black=aluminum rotor, yellow=copper rotor). Solid lines represent peak performance of the same. Increasing system voltage (purple arrow) improves the AC-induction motors’ torque and efficiency.
Permanent magnet motors usually outperform induction motors, he said, but not in this case.
“You can see that typically they sit above the black and the yellow lines. The black line would be an induction machine [with HVH winding] with an aluminum rotor, the yellow line being an induction machine with a copper rotor [and HVH winding],” Worley said, “What I’d like to point out to you is over towards the left you can see the induction machines can deliver comparable performance to the permanent magnet machines and of course that’s dependent on a bunch of things including the cooling and electromagnetic design.”
He described how Remy further improved on Nicola Tesla’s design.
“As you move up in speed for the same system voltage, the induction machines deliver less performance than the permanent magnet machines, but that’s the purpose of the purple arrow,” Worley said, “If you increase the system voltage you can get more torque at higher speeds. Now an advantage of induction machines over the PM is you can increase the system voltage. With PM it’s always a concern because of back EMF [electromotive force].”
Worley said his demonstration showed proof that EVs and hybrids do not need rare earths.
“And the message from this slide really is by working together to develop a system with the OEMs and everybody involved in developing the system we can actually get to the same performance; equivalent performance,” he said, “The next point I’d just like to talk about is efficiency. In general induction machines are believed to not have such good efficiency as the permanent magnet machines. What I’ve shown in this slide is efficiency beginning from the three different motor technologies. I think what’s interesting is at high speed where many of our applications operate and where people tend to be very concerned about efficiency, induction machines are equivalent or in some cases slightly better than the permanent magnet machines in terms of their efficiency.”
It’s a win-win, Worley said.
“So using the same battery, inverter, cooling system and stator, at full load at a high speed we’re getting equivalent or better efficiency on this,” he said, “So, my conclusion here, the message here, is induction machines can provide a viable alternative. And I think the important thing here is: all of this simulation, all of the results I put up on the screen are based on taking an existing permanent magnet motor, removing the rotor, and inserting an induction rotor. So there’s a minimal disruption to the topology of the vehicle, minimal disruption to the systems integration, and build that’s already been done.”
Some may remember the Remy name as Delco Remy, as it was called while a GM division. The now independent company’s HVH permanent magnet motors are extremely efficient. If needed, they can be made into a hybrid AC-induction design and remain competitive.
Worley finished by explaining that Remy is positive rare earth supply need not be a concern.
“So in conclusion, we believe we have an option here. I think like everybody in the room, I very much hope that the rare earth dilemma turns out to be something we don’t have to worry about, but always of course you worry about,” Worley said, “It’s the things you don’t think about that bite you. So here at Remy we have developed what we believe is an option where we can reduce our dependency on rare earth materials, and give maximum benefits to our customers.”
Prior to its IPO, Remy has taken a conservative stance by not talking to the press. Behind the scenes, its senior management is obviously quite bullish. Its motors could be made for electric or hybrid trucks, autos, and motorcycles. They were represented as a home-grown solution that helps America’s energy independence from antagonistic suppliers with no down side.
This entry was posted on Monday, May 2nd, 2011 at 5:55 am and is filed under General. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.