Search 4,000 EV News articles

Friday, May 8, 2009

F1 KERS explained

The 2009 FIA Formula One World Championship this year has the biggest number of rule changes in the history the sport. The front and rear wings have been significantly changed in size and height to reduce the aerodynamic effect on cars following each other. Many of the aerodynamic 'extras' added by teams last season around the side pods will be banned and after 11 years of grooved tires slicks will make a return. The aerodynamic changes include a first in F1, driver adjustable front wing flaps.

Although no-one in Formula One will publicly admit it, the sport has been under pressure from the increasingly successful NASCAR where constant passing and photo finishes are the weekly norm. The close racing in NASCAR has won huge race day crowds, global TV audiences and with that enormous financial success. All the changes being made to F1 this year are in an effort to increase over taking and to reclaim the recently questionable status of formula one as the ultimate automotive research and development series in the world.

The rule change we're most interested in are those concerning the introduction of the Kinetic Energy Recovery System (KERS) that will eventually make every future Formula One race car a hybrid. KERS is not mandatory in 2009 but will be in 2010 and as a result some teams who have no chance of challenging for the world championship have opted not to use KERS immediately. To remain competitive in 2009 the usual race winning teams will all be running KERS this weekend and for the full season.

The FIA rules governing KERS are fairly simple but very restrictive. From this season teams are allowed to use KERS to draw 60 Kw of energy from the rear axle on the car, which can be stored up to a total of 400kJ (111 watt hour) of energy per lap, to be reused in the form of a 'boost' button. In effect the system uses regeneration to collect and store energy during braking which allows the drivers to use 60 Kw (82 hp) for 6.6 seconds per lap. The teams are free to choose between either mechanical or electric hybrid systems. Of the ten teams in Formula One all bar one have chosen the electric hybrid system with only Williams pioneering a flywheel mechanical system.

In fact half the teams on the grid, including front runners Ferrari and Renault, have opted to use the Electric KERS system developed by Italian Auto electrical supplier Magnetti Marelli. The system itself is fairly conventional, using a single 60 Kw liquid cooled brushless direct current (BLDC) motor / generator unit, which operates at around 120 degrees C. The motor is attached to the front of the 2.4 liter V8 and driven by a reduction gear off the crankshaft.

Also included in the system is a KERS control unit, separate from the Microsoft supplied FIA engine control unit, with a similar operating temperature to the motor. This is mounted low in the side pod for cooling. The battery pack is mounted at the bottom of the fuel cell and in the case of Ferrari is supplied by French Li-ion battery maker Saft.

The teams that will run the Magnetti Marelli system in 2009 include the previously mentioned Ferrari plus the team they supply motors to, Toro Rosso. Renault will run the Magnetti Marelli system along with their satellite team Red Bull Racing. Honda / Brawn may have possibly run Ferrari engines in 2009 in which case they would have also used the Magnetti Marelli KERS system but the most likely engine deal now is with Mercedes. Brawn will be supplied engines alongside McLaren and Force India and will use the McLaren / Mercedes in-house developed KERS system.

McLaren Mercedes have been working on their in-house KERS for almost two years. McLaren actually developed a KERS system in 1999. Mario Illien created a system for Mercedes in 1999 that used hydraulic fluid pressure to recover energy lost in braking. It would have provided a 45bhp power boost for four seconds but could have been used many times per lap. The system developed by McLaren in conjunction with Mercedes for the 2009 season is an electrical based hybrid system.

BMW started KERS development with Forschung und Technik GmbH, which is a 100% BMW owned research and technology arm, in mid-2007 and have announced their system 'race ready'. BMW tested a range of different solutions and analyzed electric, mechanical, hydraulic and even pneumatic systems. After several months of research, it was clear that only an electric system would deliver the required energy, while at the same time combining maximum safety and, above all, the lowest possible weight. In the BMW KERS system the batteries are housed in the side pods for cooling and the control unit is fitted in the right hand side pod.

Williams have decided to take on the task of being the only team in the field to develop a flywheel system and to do so without the resources of a major manufacturer behind them. Williams will run Toyota engines but more on Toyota in a moment. They acquired of a minority shareholding in Automotive Hybrid Power Limited, a company developing high-energy composite flywheels for use in energy recovery systems. The Williams Hybrid Power system will use a flywheel spinning at up to 40,000 rpm. It has been reported that the flywheel systems is still being bench tested and has not been track tested as yet. This may result in Williams not debuting their KERS until Round 7 of the 2009 world championship which takes place in Turkey in early June.

That only leaves Toyota, the company who started the move to hybrids beginning in 1998. Toyota have decided not to race with KERS in Melbourne and it is possible that Toyota will not use a KERS system at any time during the 2009 race season.

It is already known that the Cologne based team will contest the season opening Australian grand prix without the energy re-use technology, despite the TF109 being fitted with a functioning KERS during testing. Toyota have been quoted as saying they think KERS is 'primative' and not relevant to road car Hybrid systems. Toyota say they have already had success with a more advanced hybrid system in their Supra HV-R with which they won the Tokashi 24 hour race by 9 laps over second place. The technical difference between the two systems is enormous. While KERS is limited to 60kw for 6.6 seconds per lap and can only be used on the rear axle, the Toyota HV-R system has a 150 kw electric motor on the rear axle plus two 10 kw wheel motors on the front wheels. As 70% of all braking effort is on the front wheels the Toyota system can collect a lot more energy per lap.

The FIA rules will grant Toyota their wish of four wheel regeneration but they will have to wait until 2013. The KERS regulations will allow the energy storage limit to be doubled to 800kj (222 wh) by 2011, and KERS will be allowed on both axles with up to 200kW and 1.6MJ (444 wh) of energy storage per lap from 2013.

Toyota have admitted they came very close to following Honda out of Formula One at the end of last year and there have been reports that Toyota have ambitions to race their Hybrid at Le Mans. With Hybrid rules being introduced to Le Mans this year and flywheel systems being banned, if the regulations allow four wheel hybrid systems then that may prove too tempting. Toyota last raced in Le Mans in 1999 and placed second and may now hope a hybrid race car will take them to victory. The Peugeot team are taking advantage of the new Le Mans hybrid rules and have incorporated the Magnetti Marelli hybrid system into their 908 HY V12 diesel sports prototype. The Peugeot will have 60kw (80 hp) for up to 20 seconds per lap.


The KERS system adds an extra 30kg (66 lb) weight to the car which effects weight distribution and tire wear. The minimum weight of 605kg stipulated for the cars in the regulations includes the driver. The difference between the actual weight and minimum weight is leveled out by positioning ballast around the car to optimum effect. Traditionally, this means that a heavier driver has been at a disadvantage as he has had less ballast to balance out the car. Using KERS will further reduce - by the weight of the system - the amount of ballast available. In order to prevent F1 from becoming even more of a jockeys' competition some teams such as BMW are pushing for an increase of the minimum weight in the future. Many drivers have reported putting extra effort into reducing their weight, although it must be said they are all very light to start with.

The drivers will be kept especially bust in the cockpit this year learning how best to use the new systems. With KERS having only 111 watt hours of energy storage capacity and all of the energy coming from the rear axle under braking, there may be more than a few exciting moments where mid way through a heavy braking zone, as the battery becomes full, the rear brake balance will suddenly change perhaps resulting in the odd spin or two. An added distraction is the driver adjustable front wing which many have speculated will be used at the exact same time as the KERS boost button to momentarily reduce drag during a passing maneuver.


Most Formula One cars in 2009 will be wearing “High Voltage” warning stickers for the first time. Insulated gloves and color-coding will help keep F1 marshals safe from the dangers of new KERS technology while Puma have developed a new insulated shoe for drivers. The cars will also carry a KERS status warning light so it should be clear to a marshal who walks up to the car that if the status light is in the wrong state, he shouldn’t touch the car.

In July 2008 a mechanic received a powerful shock after touching the steering wheel and side pod of a BMW F1 car fitted with the KERS prototype. After six weeks of investigation, the team determined that the shock was due to a high-frequency AC voltage between the two contact points, the cause of which was traced back to the KERS control unit and a sporadic capacitive coupling from the high-voltage network to the 12-volt network. The voltage ran through the wiring of the 12-volt network to the steering wheel and through the carbon chassis back to the control unit.

The analysis, in addition to identifying the problem and pointing to solutions, resulted in other recommendations for the development of electric KERS systems. Among the measures arrived at are changes in the design of the control unit to avoid capacitive coupling effects, extended monitoring functions for high frequencies and a conductive connection of the chassis components to avoid any electric potential.

The Electric Future

The FIA must be congratulated for being the first motorsport sanctioning body in the world to introduce hybrid systems to a professional racing series. It did take them a while to wake up to the fact that having teams spending so much time in wind tunnels that the winning teams had to own one or two of their own had become increasing irrelevant to any kind of road car application. Now with the emphasis squarely on putting the best and brightest to work on developing electric hybrid technology we can most definitely look forward to seeing what effect the red hot competition of Formula One racing can do for EV technology.

Blog Widget by LinkWithin

No comments:

Post a Comment