|英文要約||Title: An Innovative Project for New Energy Venture Technologies / An Innovative Project for New Energy Venture Technologies (Fuel Cells, Storage Battery) / Development of The IoT (Internet of Things) Platform That Enables Monitoring Li-ion Battery Systems (FY2017-FY2017) Final Report
Abstract: A high-functional BMS (Battery Management System) is necessary to improve the performance of a Li-ion battery system that is set in an EV (Electric Vehicle), a forklift and various instruments. Nowadays, technical requirements for BMS are not only high accuracy but also network function to transmit data of Li-ion battery systems to a storage server, and to update BMS settings by remote control. We named the IoT (Internet Of Things) platform for Li-ion battery systems “Li-ion BatteryMonitoring Platform (LiB-MP)” and have been trying the achievement of this platform. LiB-MP provides us various benefits. For example, it reduces the cost when we reuse Li-ion batteries by omitting the process that is called “grading” to check characteristics of each battery, and we can estimate SOH (State Of Health) and the other parameters of Li-ion battery systems that based on LiB-MP’s “Big Data” analysis with a high degree of accuracy. In this research and development, we developed BMS that had a high-precision measurement system for cell voltages and SOC, BM IoT (IoT device for Monitoring Batteries) that sent or received data and control commands through wireless network, and software running on the host server that stored data of Li-ion battery systems. Our technical target were +/- 2mV voltage measurement accuracy, +/- 2% SOC estimation accuracy, sending data of the battery system that had 10 and more Li-ion battery cells to the host server, BM IoT having data-backup storage that was 512kB or over, and updating BMS settings via wireless network, i.e. OTA(Over The Air) updating. In order to achieve these goals, we prototyped BMS and BM IoT hardwares for two times, and we developed embedded and server-side software to store data from BMS in the database during this development period. Finally we achieved these five goals by means of developing calibration system for voltage measurement, new algorithm for SOC calculation, the BM IoT hardware that had a LTE wireless module, a flash memory and a SD card slot, and the tool chain to update BMS settings through a network. We got a lot of knowhow and other technical challenges to be solved for mass production throughout this development process, so we will continue efforts to achieve further improvements.