Battery SOC Estimation During BMS Communication Loss
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Solution Overview
Problem
Existing energy storage systems face instability and require shutdown when a loss of communication occurs in a specific battery assembly, particularly with lithium iron phosphate (LFP) batteries, due to inaccurate SOC estimation in voltage plateau sections, necessitating full charge or discharge before reconnection.
Innovation Solution
A battery control apparatus and method that estimates the state of charge (SOC) of a battery with loss of communication by selecting reference batteries with similar historical patterns, allowing the system to operate stably without shutdown by using the estimated SOC from these reference batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the control apparatus continuously monitors communication status and implements retry mechanisms, then communication reliability is improved, but system complexity and response time increase
Solution Approach 1:
The control apparatus pre-configures multiple communication protocols (first, second, and third protocols) with different characteristics before actual communication needs arise. When communication failure occurs, the system can immediately switch to pre-configured alternative protocols without complex real-time decision-making, thus improving reliability while controlling complexity.
Solution Approach 2:
The system dynamically selects communication protocols based on real-time battery status and communication failure patterns. The control apparatus adapts the communication approach by choosing different protocols (e.g., switching from CAN to LIN or FlexRay) depending on the current situation, making the system flexible without requiring complex permanent architecture.
2Reliability
If the control apparatus implements comprehensive communication monitoring and protocol switching, then communication reliability is improved, but processing time increases
Solution Approach 1:
Multiple communication protocols are pre-configured and ready for immediate use. When a communication failure is detected, the system can switch to an alternative protocol without extensive processing or configuration time, minimizing the time loss while maintaining high reliability through protocol diversity.
Solution Approach 2:
The control apparatus implements a streamlined retry mechanism that quickly attempts communication using alternative protocols without prolonged delays. The system rushes through the protocol switching process by having pre-configured alternatives ready, reducing the time penalty associated with communication recovery.
3Adaptability or versatility
If the control apparatus uses multiple communication protocols, then adaptability to different battery statuses is improved, but device complexity increases
Solution Approach 1:
The control apparatus dynamically selects among multiple communication protocols based on real-time battery status and communication requirements. This dynamic adaptation allows the system to use the most appropriate protocol for each situation (e.g., high-bandwidth protocols when battery is healthy, low-power protocols when battery is degraded) without requiring all protocols to be permanently active, thus balancing adaptability with manageable complexity.
Data Source
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AI summary
According to embodiments of the present invention, an energy storage system may include a plurality of battery management systems (BMSs) provided in correspondence to a plurality of batteries, respectively; and an upper control apparatus configured to collect state information on the plurality of batteries from the plurality of BMSs and to monitor or control the plurality of batteries based on the collected state information. Here, the upper control apparatus may be configured to, upon the state information of the first battery being not received from a first BMS due to a loss of communication, select one or more second batteries among batteries connected in parallel with the first battery based on previously stored history information of batteries and estimate state information of the first battery based on the state information of the one or more second batteries.