Voltage sensors are indispensable components of energy storage systems and play an important role in ensuring system safety, improving efficiency, extending battery life and optimizing system management.
Voltage sensors are used, for example, to measure the voltage at various key points in the energy storage system, such as the input and output voltages of the battery pack, inverter, charging equipment, and the system as a whole. This helps to keep track of the system's operating status in real time and ensures that voltage levels are maintained within safe and efficient limits.
Battery health (SOH) can be indirectly assessed by continuously monitoring voltage changes in the battery pack. Abnormal voltage can be a sign of battery aging, performance degradation, or individual cell failure, and detecting these issues in a timely manner can help prevent system failure and extend battery life.
Voltage sensors can also detect abnormal voltage fluctuations in circuits, such as over- or under-voltage conditions, which can be a precursor to system failure. Once an abnormality is detected, the system can quickly take action, such as sounding an alarm or activating a protection mechanism, to avoid equipment damage or safety incidents.
Accurate voltage data is essential for the efficient operation of an energy storage system. Based on the information provided by the voltage sensor, the control system can dynamically adjust the charging and discharging strategy, power distribution and energy management to improve the overall efficiency and stability of the system.
Typically, voltage sensors are integrated with the BMS to provide the necessary voltage data to help the BMS evaluate and maintain the battery condition. When the sensor's measurement data is sent to the BMS, it is used to calculate the state of charge (SOC) of the battery and make charging and discharging decisions accordingly. This is essential to ensure balanced charging and discharging of the battery pack, avoid overcharging and overdischarging, and optimize energy use.
Selection of storage voltage sensors
For voltage sensors used in energy storage products, compared to voltage sensors in other electronic products, although all can detect and monitor voltage levels and convert voltage signals into signals that can be used for control and monitoring. However, in contrast, voltage sensors in energy storage products can be more demanding, even to industrial grade.
Voltage sensors in energy storage systems often require higher measurement accuracy and long-term stability, as small changes in battery voltage may reflect the state of health of the battery or system operation, which is critical for battery management and system safety. And energy storage systems may face wider voltage ranges, especially in large-scale energy storage applications, requiring voltage sensors with wider dynamic measurement ranges.
Care also needs to be taken to select output signal types that are compatible with the system (e.g. analog voltage, current outputs or digital communications such as CAN, Modbus, etc.) to ensure seamless integration with battery management systems and other control devices. When considering system energy consumption, low power sensors are preferred. At the same time, for high power applications, good thermal design is a must.
In addition, durability and environmental adaptability, long-term reliability, accuracy, safety and the ability to integrate with complex systems are all requirements for applications in energy storage systems.
In the current market, high-end sensors are still dominated by foreign companies, such as Switzerland's LEM, Sensirion, etc. LEM's products, for example, offer a wide range of voltage sensors, such as the HV series (high-voltage applications), LV series (low-voltage applications), etc. These sensors use optimized Hall effect or fluxgate technology, and are suitable for high-precision, wide-range, fast response and strong isolation capabilities. for use in a variety of high-voltage and precision measurement applications, including energy storage systems.
There are also a number of related sensor companies in China, such as Park Ace, CoreTech, TPS Tepson, KaiBu Electronics, etc., which can provide the corresponding voltage sensors.
Summary
Voltage sensors play a multi-faceted role in energy storage systems, from ensuring battery safety, optimizing performance to improving economic efficiency, all without this key component. As energy storage technology continues to advance, the functionality and accuracy of voltage sensors will be further enhanced to meet the needs of increasingly complex applications.