MECHANIK NR 1/20118  How to cite this article: Authors: Adrian Kubiesa, Jakub Paszek, Ryszard Skoberla Title of article: „Nowoczesne systemy hamowania wysokowydajnych miejskich samochodów elektrycznych” (“Modern braking systems for high-efficient urban electric vehicles”) Mechanik, Vol. 91, No. 1 (2018): pages 56–58 DOI: https://doi.org/10.17814/mechanik.2018.1.12 Modern braking systems for high-efficient urban electric vehicles Nowoczesne systemy hamowania wysokowydajnych miejskich samochodów elektrycznych ADRIAN KUBIESA JAKUB PASZEK RYSZARD SKOBERLA * Fast and dynamic development of automotive industry, especially in electric and hybrid drive field, forces on engineers elaboration of new solutions in a car design. An example of this process is a braking system. This paper is an attempt to show how modern braking systems help improve energy efficient by implementation of a regenerative braking and use of electromechanically braking systems. KEYWORDS: braking system, high-efficient vehicles, regenerative braking The continuous search for savings, dynamic development of ecological technologies and development of ways to effectively use resources have been reflected in the automotive industry. Solutions to reduce fuel consumption, reduce resistance, as well as the use of lost energy are being investigated. One of the components that allow the implementation of these postulates is the braking system, whose task is to enable speed reduction by converting the kinetic energy of the vehicle into thermal energy. In conventional brakes, the thermal energy generated as a result of the friction of the friction linings against the side surface of the haulette disc or the inner surface of the brake drum is lost by exchanging heat with the surroundings. Fig. 1 presents executive elements of pop-up brake systems: disc brake and drum haulage. They still form the basis of vehicle braking systems, although drum brakes are less and less frequently encountered. These systems have great potential due to the significant amount of energy wasted in the form of heat emitted on the heating elements that warm up to a high temperature, especially when driving in the urban cycle. Therefore, the research focuses largely on developing ways to recover this energy. Energy losses generated by braking process do not pose a significant problem in conventional drive systems based on drive units using the combustion process of a fuel-air mixture. However, in the case of electric drives, each energy loss is a problem. Electric vehicles have limited capacity of energy storage (accumulators, supercapacitors), and each time the recharge requires time and appropriate conditions. Therefore, in the structures focused on the most effective use of energy, special solutions have been started, the task of which is to:  limit the loss of energy generated during braking,  energy recovery and re-use. For this purpose, KERS (Kinetic Energy Recovery System) systems are increasingly used within modern vehicle structures – both in the form of mechanical and electrical systems. In addition, specialized electronic systems are used, e.g. brake-by-wire, whose task is to choose the right braking strategy to make good use of the vehicle's energy. a) b) Fig. 1. Actuators of conventional braking systems: a) disc brake, b) drum brake Brake energy recovery systems The specificity of city traffic forces frequent stopping or slowing down of the vehicle, and the necessity of speed reduction causes that the accumulated kinetic energy is lost and turns into heat. The engineers, wanting to increase the range of cars, have developed braking energy recovery systems. Their task is to reduce the speed of the car by changing the kinetic energy of moving vehicle into a form of energy that can be collected to re-use it. The stored energy can be used to directly drive wheels or recharge batteries [1–2]. Depending on the method of energy storage, the regenerative braking systems can be divided into electric and mechanical ones. * Adrian Kubiesa (adrikub346@student.polsl.pl), Jakub Paszek (jakupas973@student.polsl.pl), mgr inż. Ryszard Skoberla (ry- szard.skoberla@polsl.pl) – Politechnika Śląska