Rancang Bangun Kontrol Pi pada Konverter Bidirectional untuk Pengisian dan Pelepasan Baterai

Abstract

The increasing demand for renewable energy has driven the need for reliable energy storage and power management systems. However, solar cells exhibit unstable output due to environmental dependencies, necessitating bidirectional converters to manage battery charging and discharging. This research designs and implements a synchronous buck-boost bidirectional DC-DC converter with Proportional-Integral (PI) control using an STM32 microcontroller. The PI controller parameters were optimized through trial-and-error, yielding Kp = 2 and Ki = 0.01. Experimental results demonstrate that the system successfully maintains DC-BUS voltage stability at 18V across various weather conditions, including clear skies with voltage ripple below 2%, cloudy conditions with instantaneous standby mode execution, and rainy conditions with automatic battery discharging and safety protection at 10.8V. Hardware measurements show boost mode efficiency of 93.29– 97.86%, buck mode efficiency of 92.68–98.16%, voltage sensor error below 0.91%, and current sensor error below 4%. The implemented bidirectional converter effectively functions as an Energy Management System (EMS), successfully managing bidirectional power flow and protecting battery integrity through intelligent control and automatic safety mechanisms. This design provides a practical solution for integrating renewable energy sources with battery storage in distributed generation systems.