Researchers Use Wireless Technology to Speed Transition to Electric Vehicles

Jun 28, 2011

By UCLA Samueli Newsroom

By Judy Lin

For Engineering Professor Rajit Gadh, knowledge is power. In particular, that’s electric power and finding new ways to harness, store and deliver it as growing numbers of American drivers give up their gas-guzzlers for electric vehicles.

While the benefits of clean-energy, petroleum-free electric vehicles (EVs) like the Nissan Leaf and Chevy Volt are clear to a nation dependent on foreign oil, making this large-scale transition poses a whole new set of problems.

EV charging station signTake the seemingly simple matter of charging EV batteries, said Gadh, director of the UCLA Smart Grid Energy Research Center (SMERC) at the UCLA Henry Samueli School of Engineering and Applied Science.

Suppose you’re a UCLA employee and proud owner of a new EV. You drive to campus, pull into a parking structure, plug into a charging station and leave your car for the several hours required for a complete recharge — about 5 kilowatts of power, enough to run a typical home.

Now fast-forward to the day when you’re one of 50 EV owners who pull into the same parking lot at about the same time. Problem one is having enough charging stations for everyone, given that one station costs several thousand dollars to install and the rapidly advancing technology requires regular upgrades. Problem two is power capacity.

“That’s 50 EVs consuming 5 kilowatts each,” Gadh said, a huge load that could well blow a campus transformer, or, scaled up to citywide proportions, could blow out the whole power grid.

Engineering Professor Rajit Gadh with the insides of an electric golf cart reconfigured to work like the battery of a Nissan Leaf.

So Gadh and graduate student researchers at SMERC are exploring other possibilities. What if all the EVs could plug in at the same time and a software program could schedule the aggregate battery charges? What if EVs could not only draw power from the electric grid but feed it back in — helping stabilize our power supply?

Getting car and equipment manufacturers, utility companies and consumers onto the same grid — a 21st-century “smart” grid — could well change the entire ecosystem of technology. Underpinning SMERC’s work is its UCLA-based parent organization, the Wireless Internet for Mobile Enterprise Consortium (WINMEC). Also under Gadh’s direction, this university/industry/government collaboration is supported by funding from the U.S. Department of Energy and the L.A. Department of Water and Power. Both are racing to fulfill federal and state mandates requiring utilities to find ways to incorporate renewable energy into California’s electric grid.

To incorporate EVs into this larger energy picture, Gadh envisions wireless computer networks connected to vast “cloud computing” resources in a sophisticated system that keeps everything from EVs to the utility companies running smoothly.

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The first step is to track precisely how — and how well — today’s EVs and existing charging stations work. “There’s a lot of information that exists inside electric vehicles that did not exist inside traditional vehicles,” said Gadh, “because EVs have been designed as a fundamentally new product, not just an incremental change from the previous [combustion engine vehicle].”

A visit to SMERC, four floors up in the Engineering IV Building, reveals a tangle of technology, all organized around data collection. On one end of the lab, a steel shelf is spread with the innards of an electric golf cart engine — the pieces retrofitted to function much like the battery of a Nissan Leaf — that is connected to an EV charger and wireless sensors that track everything that’s going on. On a nearby table sits a baseball-size rubber plug of an EV charging station that’s been reconfigured to collect information while it’s at work.

An EV charger has been rewired with sensors so researchers can precisely track the device’s activity.
“The beauty of electricity is that you cannot hide it,” Gadh said. “It has to flow through wires. So we can monitor it from the outside. We can know how much [the battery] is consuming and for how long. We can know exactly how the charger is behaving.”

Data from these and scores of similar contraptions spread about the lab are wirelessly transmitted to computers, where it is stored, analyzed and mined for the next breakthrough idea.

One concept the team is already developing, said Gadh, is “an intelligent software program able to manage the charging function in such a way that it benefits the EV owner, the utility company and even the specific facility where the charger is located.”

This imaginative software could be accessed by EV owners from their cell phones to indicate whether they want a full or partial battery recharge, for example, or how much they would pay for electric power, costing more during peak periods and less at night. The program would determine when to start the charge, thanks to daily rates that could be wirelessly supplied by the utility company.

Individual charging facilities could better manage power consumption by adding input of their own. UCLA, for example, could provide data factoring in the day’s power requirements for the campus area near each charging station.

Input from these three sources — the EV owner, the utility company and the charging facility — could, Gadh said, be “put into a master program that balances them all out” by combining data with “smart” sensors and switches.

Concepts like this, he said, “would potentially work anywhere and at any scale, from UCLA to all of L.A.”

Another intriguing idea being explored at UCLA is the “vehicle-to-grid” potential of EVs. More than mere energy users, EVs could become energy-storage devices that could deliver power back to the electric company during emergencies, especially grueling-hot days when demand for power peaks. To avert blackouts, the utility companies could offer to purchase a chunk of energy from UCLA, which might pull this power from the batteries of a bank of EVs connected to campus charging stations. Then, as the city’s power crisis cools down, the EVs would be automatically recharged.

Gadh and his team are already preparing to test some of these concepts in their “Living Lab.” In Parking Structure 9, they have installed two EV charging stations connected to devices that collect and wirelessly transmit data about electricity usage back to the lab. A staff member in Engineering has volunteered to have his Nissan Leaf become their first test vehicle.

“The idea,” said Gadh, “it to do some simulations and see how the EVs will behave, how people will behave and how the utilities will behave.” From this, the researchers can get a better idea of the types of interfaces and infrastructures needed to best serve everyone involved.

Ultimately, all of this research could make a difference in whether EVs take off in a big way or quietly disappear. “If these issues are not solved,” Gadh said, “then there’s a risk of … the world losing interest in EVs.”

On August 3, Gadh and his colleagues from SMERC, along with WINMEC, will showcase their research at the UCLA Electric Vehicle-Smart Grid (EV-SG) Living Lab Demo and EV-SG Consortium. The event has drawn so much interest from colleagues in industry, government and research that it’s already fully booked, but a second showcase workshop is being planned for about two months from now.

For more information about the consortium and Gadh’s research, visit the SMERC website.

Main Image: Engineering Professor Rajit Gadh with the insides of an electric golf cart reconfigured to work like the battery of a Nissan Leaf. Inset Image: An EV charger has been rewired with sensors so researchers can precisely track the device’s activity.

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