Here’s How Car and ABB System Designers Prepared
LONDON, England, March 24, 2004. . . Power and automation technology supplier ABB could be taking its place in the record books in early June this year, when its drives and motors equipment will be used to power the British challenger to the world electric-land-speed record.
The attempt, on the Chott-el-Jerid salt flats in Tunisia, is scheduled to begin on June 9th.An ABB industrial drive and two 50 horsepower AC motors will be used to drive the ABB e=motion electric car to speeds in excess of the current world record of 245.523 mph held by the White Lightning team from the U.S.
Based on the data from development and testing, the car could also set another first – if it becomes the first-ever electrically powered vehicle to break the 300 mph limit.Already Gone 146 mph -- With its motors producing a combined output of more than 500bhp, i.e., the horsepower produced at the motor shaft), ABB’s system has already helped propel the ABB e=motion car to 146 mph during testing, unofficially breaking the 139 mph U.K. record for the fastest speed travelled by an electric vehicle, and equalling the first-ever land-speed record set by Sir Malcolm Campbell’s petrol-driven car in 1924.The vehicle’s designers, Mark Newby and Colin Fallows, will attempt to set the new world record between June 9 and June 11.How Does the Car Work?
– Logically! -- When building the car, Newby and Fallows set a goal of using only equipment that could be sourced easily off-the-shelf from any supplier, both to reduce the cost of the project and to add to the prestige of the challenge.
ABB’s system uses a standard inverter from ABB’s ACS800 motor drives line to convert the 600V DC output from the car’s four packs of lead-acid batteries into AC power for the two motors; the motors are commonly supplied by ABB for use in machine tool and a host of other applications.To qualify as an official world record under FIA rules, the car must perform two recorded runs at better than 252 mph over a distance of one kilometer (.622 mile), requiring the motors to reach speeds in excess of 6,000 rpm.To put this into context, in ordinary use, the motors would normally run at between 1,000 and 3,000 rpm.
So, to prevent overheating during the world-record attempt, each motor has been adapted to include a forced-ventilation system that’s comprised of a 24V DC fan, to help keep the motors within their maximum operating temperature of 180ºC (356ºF). PT100 sensors fitted to each motor winding provide real-time information about the motor operating temperature and also serve to protect the motors from overheating.
As further protection, the team will also use nitrogen to bring down the motor temperature, after the car has made its first run during the land-speed-record attempt.Immediate, High Torque Critical To Start And Acceleration -- A major consideration in designing the drive system for the car was the ability for the car to accelerate quickly to achieve maximum speed within the permitted distance. For this reason, ABB’s drive system also features ABB’s Direct Torque Control (DTC) drive technology, which provides excellent control of motor torque, with full motor torque available, even at zero speed.
“Other challengers to the record commonly use gear-driven systems in their cars to achieve the fastest possible acceleration, whereas the technology we’ve supplied steadily controls torque across the whole speed range,” says Frank Griffith, one of the team at ABB who helped to develop the car’s power system.
“Although a geared vehicle can achieve 100 mph in a few seconds, its rate of acceleration falls away much more quickly compared to our system; this one will continue to accelerate even past the 300 mph mark, provided sufficient battery power is available.”The system’s ability was proven during the car’s first test run at the Bruntingthorpe airfield in Leicestershire, U.K., in Summer 2003, when the car unofficially beat the existing British electric-land-speed record within one-third of the distance travelled by the current official title holder. “The car used by the Bluebird team, which holds the current British electric-land-speed record, reached a top speed of 139 mph over a distance of two miles.
In its first-ever test run, ABB e=motion easily reached 146 mph within just over 900 metres (1,000 yards). In fact, the only reason we had to stop the car was because we ran out of road!” says Newby. “With this sort of performance, we’re convinced that our car can beat easily the existing world electric-land- speed record.”Design Challenges in Building the Car -- For Newby and Fallows, finding a company that could supply the equipment needed to power the car proved a frustrating struggle that would last 18 months.Before contacting ABB, they initially approached two leading drives manufacturers, neither of which was able to provide the technology needed.
“Finding a company that could supply the necessary technology to drive the car was the biggest single technical hurdle we faced in building the car,” says Fallows, who designed the car. “Of the companies we originally approached, none could provide either the technology or expertise that justified a world- record attempt of this magnitude. In fact, one suggested a water-cooled drive solution which resulted in us extending the nose of the vehicle by some 1.5 meters (five feet) -- at great expense.”Electrical Design Team Excels -- The answer came in November 2002, when they approached ABB and found that the company was able to provide a solution that met their needs perfectly.
“We initially approached ABB because we were aware of its profile in the world of electrical engineering,” says Fallows. “Its solution proved extremely compact and means our car does not even need to be the 10 meters (33 feet) that it is!” The drive system developed for the ABB e=motion car is the work of members of ABB’s drives application engineering team, Frank Griffith, Steve Malpass and John Schofield. For this team, one of the biggest challenges was the need to simulate the vehicle dynamics and performance likely to be experienced during the land-speed- record attempt without the car actually having run. “We initially had to develop our system without physically testing the car on a track,” says Frank Griffith.
“Likely performance was modeled and calculated using a set of estimated conditions involving factors such as rolling resistance, drag and battery discharge rate. Much of this information either did not exist or else had to be extrapolated from data found on the Internet, such as when we were trying to obtain figures for potential tire resistance at 300 mph. Not only that, but we only had a limited amount of space available for installing our system in the car, so we had to ensure that whatever we came up with was also compact.”To help fine-tune the system’s performance, ABB used data from the two independent four-channel data loggers incorporated within the drive.
During testing performed at the Bruntingthorpe airstrip, the data loggers were used to collect a range of data on drive and motor status, which was uploaded to a PC for analysis using ABB’s Drives Window tool. “The data loggers enabled us to improve the performance of our system in the same way as Formula One teams do with their cars,” explains Steve Malpass. “One of the data loggers was set to a rapid sampling rate of 1 sample per millisecond to record all the actual events as they happened.
“By setting the other logger to a slower rate, we were able to record information on trends that occurred throughout the test runs, which provided us with an overall picture of how the car was faring.”Using the data loggers proved invaluable in helping to trace the cause of higher-than-expected torque, which occurred during several of the test runs at Bruntingthorpe. “The acceleration data collected during the test runs indicated much higher torque than we’d expected,” explains Griffith. “After examining all of the mechanical and electrical factors, we were relieved to find that this was actually due to the track being on a two-inch incline, something which we hadn’t noticed previously!” The ABB e=motion team already is being seen as the favorite for 2004, to break the existing record.
“Throughout the development of the car, we have constantly been able to call upon ABB’s expertise and have been unbelievably impressed by what Frank, Steve and John have come up with,” says Newby. “Based on what we’ve seen so far, we are 100% confident that ABB will be joining us in the record books, when we break the world speed record.”Power With Potential – Speed Gains Gallop --With several weeks still to go until the attempt, Newby and Fallows are already planning their next attempt to take their car even faster. “Since 1972, the world electric-land-speed record has shot from 152 mph to the current official record of 248 mph, an increase of 96 mph,” says Newby. “In this same period, the record for petrol fuel cars has only risen by 6 mph.
There is obviously fantastic potential for electrically powered vehicles, and we aim to be the ones to set the limits to beat for future challengers.”ABB Inc., Automation Technologies, Automation Products, Drives, is the world's largest manufacturer of electric motors and drives. In the USA, an integrated channel of sales representatives, distributors, and system integrators allow ABB, New Berlin, Wisconsin, to supply a complete line of energy-efficient electric drives, motors and engineered drive systems to a wide range of industrial and commercial customers.
Products manufactured include AC and DC variable speed drives for electric motors from 1/8th through 135,000 HP, and application-specific drive system solutions to meet diverse customer needs ( www.abb-drives.com ).ABB ( www.abb.com ) is a leader in power and automation technologies that enable utility and industry customers to improve performance while lowering environmental impact.
The ABB Group of companies operates in around 100 countries and employs about 115,000 people. The company's U.S. operations employ about 9,000 in manufacturing and other facilities in 40 states.