Novosibirsk State Technical University has developed a demonstration stand for life cycle management of lithium-ion traction batteries, which in many ways surpasses its foreign counterparts.
Ilham Khalikov, a graduate student of the Department of Electrotechnical Complexes at the Faculty of Mechatronics and Automation of NSTU-NETI, proposed his own version of the battery management system for lithium-ion traction batteries, which are used to provide high power and long operating time. The development within the framework of a student startup involves solving a problem such as premature failure of lithium-ion batteries. As a rule, if the battery is used incorrectly, the battery life drops several times, and the loss of 20% of the capacity makes the battery inoperable.
To keep the battery in working condition, a student at NSTU-NETI has developed a mobile cycler stand with 30 charge-discharge channels of 0-10 A each, powered by a conventional three-phase 380V outlet and connected to a PC logger via USB. According to Ilham Khalikov, each channel contains a controlled current source and a linear electronic load on the MOSFET IRFB4615, equipped with current, voltage and temperature sensors. Mode switching is performed by relays, hardware protection is duplicated by LM335/Schmitt trigger hardware, and ten ATmega328P microcontrollers control three channels, store up to 15,000 seconds of profile, and perform standard charge-pause—discharge cycles for traction modules in the range of 12-120 V.
"The stand is a configurable structure of 30 modules that charge and discharge batteries according to specified test programs and record the values of parameters such as charging and discharging currents, battery voltages and temperatures, convert them into data packets that are processed by special software on a PC. Using the obtained data set, during multiple cycles, mathematical transformations can be used to analyze the degradation processes of batteries and obtain a correlation function between a drop in capacity and charge and discharge parameters, which makes it possible to select the optimal operating mode with an increase in battery life," noted Ilham Khalikov.
The developer is confident that the lithium-ion battery cycle control stand will be in demand at enterprises producing R&D batteries, in certification and testing laboratories, technology parks, for electric transport operators and charging infrastructure. The development is made according to the "all in one" type, is compact (2x3x1 m) and is several times cheaper than domestic and foreign analogues — its cost is about three million rubles.