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Energy storage systems (ESS) are critical for grid stability as renewable energy adoption accelerates, but safety concerns have emerged due to fire hazards in lithium-ion batteries. Korea Electric Power Corporation (KEPCO) has developed an innovative solution called the Battery Intelligence Management System (BiMS), which provides real-time monitoring and diagnostics to prevent battery failures while extending operational lifespan. The modern world has thrived on the foundation of a stable electricity supply. However, as global efforts to combat climate change and achieve carbon neutrality accelerate, renewable energy sources such as solar and wind power are expanding rapidly. While this shift is essential for a sustainable future, it introduces new challenges to power grid stability due to the inherent variability of renewable generation. To maintain grid stability, electricity generation and consumption must be constantly adjusted in real-time to keep frequency fluctuations within acceptable limits. This is where energy storage systems (ESS) play a critical role. By storing excess electricity and discharging it when needed, ESS helps bridge the gap between variable renewable generation and consistent energy demand. Compared to conventional grid-balancing solutions, ESS offers several advantages, including shorter construction times and rapid response capabilities. These benefits, combined with advances in battery technology, have fueled the rapid growth of the global ESS market.
KEPCO’s Pioneering Efforts in ESS Deployment
Korea Electric Power Corporation (KEPCO) has been a leader in ESS deployment. In 2014, it became the first in the world to integrate a 24-MW frequency regulation ESS (FR-ESS) into a national power grid for commercial operation. Since then, KEPCO has expanded its ESS capacity, reaching a total of 376 MW, demonstrating its commitment to advancing energy storage technologies and adapting to the evolving energy landscape. However, as ESS adoption surged, a critical issue emerged—fire hazards linked to lithium-ion batteries. Since the introduction of ESS in Korea, at least 52 fire incidents have been reported, leading to significant concerns about the safety of ESS installations. Due to these risks, KEPCO was forced to suspend its FR-ESS operations, while the government launched multiple investigations to determine the root causes of these fires. Despite extensive research and recommendations for preventive measures, a definitive solution remained elusive.
Development of the Battery Intelligence Management System
To address the safety concerns, KEPCO took proactive steps to develop an innovative monitoring and diagnostic system. Instead of relying solely on battery manufacturers to resolve safety issues, KEPCO sought to empower ESS operators with real-time insights into battery health and performance. The goal was not only to enhance safety but also to extend battery lifespan and optimize ESS operation for long-term sustainability. One of the primary causes of ESS fires is thermal runaway, a phenomenon where excessive heat generated within a battery cell leads to a chain reaction, potentially resulting in catastrophic failure. Thermal runaway can be triggered by several factors, including internal short circuits, overcharging, and cooling system malfunctions. Given these risks, KEPCO needed a solution that could detect early warning signs, predict potential failures, and enable preemptive actions before critical failures occur. In 2020, alongside its plan to deploy an additional 1 GW of grid-stabilization ESS (KEPCO Grid-ESS, or KG-ESS), KEPCO initiated the development of the Battery Intelligence Management System (BiMS). This system was designed to move beyond traditional manufacturer-driven diagnostics, providing operators with a comprehensive and real-time battery monitoring system. The key objectives of BiMS were:
How BiMS Works
BiMS is an advanced monitoring and diagnostic system that continuously analyzes lithium-ion battery voltage, current, and temperature data. By leveraging real-time data acquisition and predictive analytics, it enables precise assessment of battery health and enhances overall ESS reliability. The internal state of a battery is often a “black box,” meaning its condition cannot be directly observed until it is physically opened for inspection. To address this challenge, the BiMS operates in KEPCO’s MW-scale KG-ESS installations, where it performs three core functions:
By integrating these capabilities, BiMS helps operators monitor battery status in real-time, detect early signs of failure, and extend battery lifespan—ensuring safer and more reliable ESS operations.
System Architecture and Data Processing
BiMS is designed to function independently of existing ESS automatic control systems, ensuring zero interference with core ESS operations. The system integrates with ESS infrastructure via Modbus communication (Figure 1), gathering real-time data from up to 150,000 battery cells (for a 56-MW ESS). The collected data is stored on dedicated servers, where BiMS applies sophisticated analytical models that account for site-specific environmental conditions. The results are visualized in an intuitive interface, providing operators with actionable insights into battery health and performance trends. By leveraging BiMS, operators can:
