Battery Current Control Algorithms in an Electric Two Wheeler 2019-26-0112
Various current control algorithms are presented in this paper to prevent vehicle cut-off and increase the range of an electric 2wheeler based on SOC, battery temperature and motor temperature.
At lower SOCs if the current demand is very high there is a possibility of cell voltage hitting the lower threshold voltage leading to cut-off. An algorithm is proposed where current (maximum allowed) derating is done based on reducing SOC, battery voltage and real time throttle demand.
Lithium ion cells operating temperature has an upper cap. Rate of increase of battery temperature mainly depends on current demand by motor while the initial battery temperature also depends on ambient temperature. To prevent the battery temperature from reaching the upper threshold a battery temperature based current (maximum allowed) derating algorithm is used.
As one algorithm affects the other, this leads to Multi Input Single Output (MISO) system configuration. Both the algorithms along with motor fan control based on motor temperature are clubbed. Model developed in Matlab/Simulink is implemented on real vehicle and data is compared/analysed.
Keywords: State of Charge (SOC), Battery Temperature, Multi Input Single Output (MISO) System
Shivaram Venkateswaran, Lokesh Soni
Symposium on International Automotive Technology 2019