Foreword: New Security Challenges Amid the Explosive Growth of Energy Storage
On November 5th, the "High-Quality Development of New Energy Strage to Promote Global Energy Transition" sub-forum of the 8th Hongqiao International Economic Forum was held in Shanghai. It was learned at the forum that by September 2025, China's installed capacity of new energy storage has historically exceeded 100 million kilowatts, becoming an important component of the new power system.
However, with the surge in installed capacity and the expansion of project scale, the safe operation of energy storage systems has become the lifeline for the industry's continued healthy development. In particular, the concentration of high-energy-density batteries in the battery compartment makes risks such as electrical insulation failures and DC arcing a "sword of Damocles" hanging overhead. Against this backdrop, what protective measures are needed for modern energy storage systems? This will be discussed below. CHIPSENSE current sensors will involved in it.
For cabinet-type lithium battery energy storage systems are a complex systems engineering project. Besides selecting safer cell materials (such as lithium iron phosphate) and structural design, comprehensive protection is typically implemented from multiple dimensions, including electrical safety, thermal management, mechanical structure, fire safety, and monitoring and early warning. The following are common core safety measures:
1. Electrical Safety
Insulation Monitoring: Real-time monitoring of insulation resistance to prevent leakage and short-circuit risks (e.g., using fluxgate sensors or high-precision insulation detection devices).
Over-current/Over-voltage Protection: Configuration of a BMS (Battery Management System) to monitor battery voltage and current in real time and trigger circuit breaker protection.
Grounding Protection: Ensuring reliable system grounding to prevent static electricity buildup and electric shock risks.
2. Thermal Management
Active/Passive Cooling: Utilizes liquid cooling, air cooling, or phase change materials to control battery temperature within a safe range (typically 15°C–35°C).
Temperature Equalization: Monitors individual cell temperature differences via BMS to prevent localized overheating.
3. Mechanical Structure
Fire-Resistant Materials: The cabinet is constructed from flame-retardant or fire-resistant materials (e.g., steel plate with fire-retardant coating).
Explosion-Proof Design: Equipped with explosion-proof valves and pressure relief channels to prevent thermal runaway-induced explosions.
Seismic and Impact Resistance: The structural design meets seismic standards to prevent mechanical damage.
4. Fire Safety
Gas Suppression: It will be Equipped with a heptafluoropropane or perfluorohexanone fire suppression system for rapid initial fire suppression.
Smoke/Temperature Alarm: Installed smoke and heat detectors, linked to fire suppression and power cut-off mechanisms.
Isolation Design: Fireproof partitions are installed between battery modules to prevent the spread of fire.
5. Monitoring and Early Warning
Multi-Parameter Monitoring: Real-time monitoring of voltage, current, temperature, and gases (such as CO and VOCs), with early warning of anomalies.
Remote Monitoring: Real-time data upload via a cloud platform, supporting remote fault diagnosis and early warning.
6. Operation and Maintenance Management
Regular Inspections: Check electrical connections, insulation condition, heat dissipation system, etc.
Emergency Response Plans: Develop emergency response procedures for fires, electrical leaks, etc., and conduct regular drills.
CHIPSENSE FR2V series is a current sensor based on fluxgate technology, capable of measuring minute leakage currents in DC systems with high precision. The entire series boasts a typical accuracy of ±0.5%, a typical gain error of only ±0.5%, and extremely high zero-point stability (typical ±20mV) and extremely low temperature drift (±1.5mV/K). This ensures that readings are virtually unaffected by ambient temperature within the operating temperature range, effectively distinguishing genuine leakage signals from temperature drift noise and avoiding false alarms. The series offers a wide measurement range, covering ±10mA to ±300mA, meeting the needs of energy storage systems of various sizes. It features a 500ms response time, suitable for real-time protection. It also boasts an isolation withstand voltage of up to 3kV AC/1min (CHIPSENSE current sensors compliant with IEC60664-1), with electrical clearances and creepage distances both reaching 7.2mm. This ensures that even in the event of a transient high-voltage surge in a 1500V DC energy storage system, the sensor can establish a reliable safety barrier between the primary and secondary sides.
Under long-term charge-discharge cycles and complex operating conditions, the insulation layers of internal circuits and connection terminals in battery packs may deteriorate due to aging, vibration, and moisture, resulting in leakage current to ground. If not detected in time, the leakage current will gradually increase, potentially leading to short circuits, thermal runaway, or even a fire in the entire battery compartment. CHIPSENSE FR2V current sensor provides a solution as follows:
1.DC Leakage Current Monitoring
Energy Storage System Insulation Fault Detection: Based on fluxgate technology, CHIPSENSE FR2V can accurately measure minute leakage currents (e.g., ±10mA) in DC systems, suitable for real-time monitoring of the DC bus insulation status to ground in energy storage cabinets. When insulation resistance decreases (e.g., due to aging, moisture, or mechanical damage), leakage current increases. CHIPSENSE FR2V fluxgate current sensor can promptly detect and output a voltage signal. The output voltage (±5V) is acquired through a BMS or monitoring unit, and a threshold (e.g., 30mA) can be set to trigger protection actions. Alternatively, combined with Ohm's law, it can calculate the insulation resistance values (Riso) of the positive and negative poles to ground in real time for multi-level threshold management:
Early Warning (e.g., Riso < 100 kΩ): Insulation level declines; the system records data trends and prompts planned maintenance.
Alarm (e.g., Riso < 50 kΩ): Insulation has deteriorated; an audible and visual alarm is issued, and the information is reported to the cloud platform.
Fault (e.g., Riso < 10 kΩ): Serious safety risk; the circuit breaker is immediately instructed to trip, achieving millisecond-level protection.
The application of CHIPSENSE FR2V fluxgate current sensor R framework diagram is as follows:
Fault Diagnosis of Battery Stacking Systems
Battery Module Insulation Monitoring: In energy storage cabinets with multiple stacked modules, CHIPSENSE FR2V fluxgate current sensor can detect leakage current between modules or between a module and ground, locating faulty modules. Its operating temperature is -10°C to 70°C, and its storage temperature is -40°C to 85°C, making it suitable for outdoor energy storage cabinet environments. However, prolonged exposure of the sensor to environments >100°C (such as near power devices) is avoided to ensure its lifespan. CHIPSENSE aims to provide customers with long-life, high-quality current sensors. Furthermore, it consumes only 20mA of current, without increasing the system load. Its application framework diagram is as follows:
System Integration and Signal Processing
Output Interface:
Output voltage signal (±5V), directly connectable to PLC, BMS, or data acquisition card (e.g., NI, ADI).
Recommended load resistor: 10kΩ to ensure measurement accuracy.
Mechanical Installation:
Secure with M4 screws, installation torque: 0.9 N·m (±10%).
Primary side via hole: Φ20mm, compatible with standard busbars.
Safety and Compliance
Insulation withstand voltage: 3kV AC/1min, meeting the high-voltage safety requirements of energy storage systems.
Fire-retardant materials: The casing is UL94-V0 flame-retardant, meeting the fire protection standards for energy storage cabinets. All CHIPSENSE current sensors have this requirement.
Risk Warning and Maintenance
Regular calibration: Zero-point drift is checked annually (typically ±20mV) to ensure measurement accuracy.
Environmental adaptability: Avoid installation in vibrating or damp locations, as this may affect sensor performance.
CHIPSENSE FR2V H00 series current sensor, with its high accuracy, low temperature drift, fast response, and strong isolation characteristics, is the preferred solution for DC leakage current monitoring in modern energy storage systems, especially suitable for cabinet-type lithium battery energy storage systems with extremely high safety requirements. Combined with BMS and fire suppression systems, it can construct a multi-layered safety protection network.
As energy storage installations reach gigawatt-level capacity, CHIPSENSE FR2V series leakage current sensors offer more than just the function of a component; their value extends far beyond a single emergency power outage. Long-term accuracy and stability are key to predictive maintenance. By continuously monitoring the historical decay curve of insulation resistance, it helps maintenance teams shift from periodic inspections to condition-based maintenance (CBM), enabling precise decision-making and improving system availability and life-cycle value. CHIPSENSE current sensors will be keep it.
CHIPSENSE is a national high-tech enterprise that focuses on the research and development, production, and application of high-end current and voltage sensors, as well as forward research on sensor chips and cutting-edge sensor technologies. CHIPSENSE is committed to providing customers with independently developed sensors, as well as diversified customized products and solutions.
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