Production and testing of the battery management system

Baterijski paket i sustav upravljanja baterijskim paketom (eng. BMS) obuhvaćaju široko područje znanosti i tehnike. U ovome je radu naglasak stavljen na izradu i testiranje sustava upravljanja baterijskim paketom prvenstveno s elektrotehničkog gledišta. Početno su promotreni dijelovi baterijskog paketa, s naglaskom na baterijsku ćeliju i njene strujno-naponske karakteristike. Potom je promotren BMS odnosno zahtjevi koji se pred njega stavljaju, podsustavi koji ga ostvaruju te arhitektura i izvedba. U simulacijskom dijelu rada je u fokus stavljena dorada postojećeg BMS-a za dani baterijski paketa. Doradom je obuhvaćeno modeliranje baterijske ćelije modelima prvog i drugog reda te implementacija PI obzervera za procjenu stanja napunjenosti (SOC). U svrhu određivanja parametara modela provedeno je snimanje strujne i naponske karakteristike baterijske ćelije pri impulsnom opterećenju u punom rasponu od 0 do 100 % SOC-a. Rezultati dobiveni simulacijom u području od 20% do 100% SOC-a imaju grešku manju od 2 % što je vrlo dobro. Na kraju rada prikazana je izrađena pločica glavnog modula BMS-a te predloženi programski kod za PI obzerver.The development of the battery pack and the battery pack management system (BMS) cover a wide range of scientific fields. In this paper, the emphasis is placed on the development and testing of the battery pack management system from an electrical point of view. Firstly, parts of the battery pack were studied, with an emphasis on the battery cell and its current-voltage characteristics. Then the BMS was observed, the requirements that are placed before it, the subsystems that realize it, the architecture and performance. In the simulation part of the work, the focus is on customizing the existing BMS for the given battery pack. The customization includes the modeling of the battery cell with first and second order models and the implementation of a PI observer for estimating the state of charge (SOC). Measurements of the current and voltage characteristics at pulse load across the full range of SOC were conducted in order to determine the model parameters. The results obtained by the simulation from 20% to 100% SOC have an error of less than 2% which is very good. At the end of the paper, the printed circuit board of the main module of the BMS and the proposed code for the PI observer are shown