KERS has been in F1 since 2009, the system recovers energy under braking and allows the driver a boost in engine power each lap. However the FIA imposed strict limits on the amount of energy that can be recovered and discharged each lap. Which has often raised the question how do they control this usage and ensure teams are sticking to the rules? This sensor from Isabellenhütte Heusler has been introduced by the FIA this year to ensure exactly this.
Within the current rules KERS energy usage is covered by article 5.2.3, which states “The maximum power, in or out, of any KERS must not exceed 60kW. Energy released from the KERS may not exceed 400kJ in any one lap.” Although the FIA have the cars electronics controlled and monitored by the Standard ECU (SECU), this requires a method to control the energy passing in and out of the KERS.
For 2012 a new homologated sensor is fitted to all cars running KERS (Marussia and HRT did not run KERS) as part of the FIA SECU Package. Isabellenhütte’s IVT-F “integrated current sensor” controls the quantity of power supplied by KERS and aims to ensure that teams will not use KERS to break the rules. It took just two months to develop the modules and they are specifically designed for use in Formula 1.
As the current levels in F1 KERS are so high, a special inline measurement device is hard to develop. A Shunt based measurement system has been used. A shunt is simply a very accurate resistor, placed in series with the circuit being measured. The current passing through the Shunt is smaller than the main circuit in proportionally to their relative resistance. Even small workshop electrical Multi-meters use this method to measure current.
The sensor fits in the power cabling between the MGU and the Power Control Hardware.
Being able to measure the current accurate provides an input to the SECU, As the SECU Data channels are available to the teams and the FIA both parties can use the data for their own purposes. The teams use it to maximise their use of KERS and the FIA use it to ensure teams do not over use KERS.
With the current KERS formula continuing into next year and completely new Energy Recovery Systems being introduced the year after, Isabellenhütte have commented “We are already working on sensors for the 2013 and 2014 Formula 1 seasons.”
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