Test cycle simulation of an electric car with regenerative braking

In the near future electric cars will be ubiquitous thanks to their wider functionalities and to their much lower tailpipe emissions to the environment. However, at present, there are still problems concerning the storage of energy for long range operation. It is therefore important to employ strategies to preserve the State of Charge (SoC) of batteries as much as possible. The first important strategy is related to the driving style in order to minimize frequent acceleration-braking sequences. Once this condition has been met, the next strategy could be the partial recharge of battery during braking, recovering the kinetic energy of the car mass. This paper presents the simulation of a simple mechanical quarter-car model whose wheel is driven by a Permanent Magnet Synchronous Motor (PMSM) motor. The focus is on the electric control of the motor and on the energy recovery. The PMSM could accelerate and brake the car in all conditions, but this solution depletes the battery also in braking. There is a better strategy that use a combination of regenerative braking (battery recharge) and dissipative mechanical braking. In order to produce meaningful results, the simulations follow the class 3 time-speed data points of the Worldwide Harmonized Light vehicles Test Cycles (WLTC) developed for Pure Electric Vehicles (PEV).