Battery Stack Current Circuit Fault Detection Using Temperature Sensing
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Solution Overview
Problem
Current methods for detecting failures in current measurement circuits of battery systems are inefficient, often requiring complex battery models or additional sensors, which can be costly and computationally intensive, especially for lithium iron phosphate batteries with flat open-circuit voltage curves.
Innovation Solution
A method and system that uses temperature and current measurements to detect failures in current measurement circuits by determining resistive element temperature and ambient temperature, generating a fault signal based on these measurements, and controlling a switch to bring the battery to a safe state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If battery modeling or ESS modeling is used to determine incorrect current measurements, then measurement reliability can be assessed, but the computational cost increases and the system becomes more complex
Solution Approach 1:
The patent extracts the fault detection function from complex battery models and implements it through a dedicated monitoring circuit that measures voltage across the current sensor directly. This separates the measurement reliability assessment from the overall battery management system, reducing computational requirements while maintaining detection capability
Solution Approach 2:
The patent introduces an intermediary monitoring circuit that measures the voltage across the current sensor to detect faults. This intermediary measurement system provides fault detection without requiring complex battery models or extensive computational resources, acting as a mediator between the current sensor and the BMS
2Measurement precision
If a second current sensor is used to determine incorrect measurements, then measurement accuracy improves, but the cost of the energy storage system increases
Solution Approach 1:
The patent creates a virtual copy of the current measurement function by measuring the voltage across the existing current sensor. Instead of adding a physical second sensor, the system uses electrical measurement and comparison to detect faults, providing redundancy without additional sensor hardware
Solution Approach 2:
The patent replaces the mechanical/electrical approach of adding a second physical sensor with an electrical measurement and computational comparison approach. The fault detection is achieved through voltage measurement and algorithmic analysis rather than redundant hardware
3Reliability
If battery modeling is implemented on a resource limited microcontroller, then current measurement validation is achieved, but the computational cost becomes prohibitively high
Solution Approach 1:
The patent extracts the essential fault detection function from complex battery models and implements it through direct voltage measurement across the current sensor. This extraction reduces the computational burden on the microcontroller while maintaining the ability to validate current measurements
Solution Approach 2:
The patent changes the measurement parameter from requiring complex state-of-charge and battery model calculations to simple voltage measurement across the current sensor. This parameter change reduces computational energy consumption while maintaining detection reliability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for reliable detection of current measurement circuit failures without requiring battery models, reducing computational cost and sensor usage, effectively protecting the battery system by opening contactors when a failure is detected.
Implementation Method 1
determining a resistive element temperature of a resistive element... wherein the resistive element is electrically connected between the load and the battery
Data Source
AI summary
Fault detection devices and methods, for detecting a current measurement circuit failure for an energy storage system in an energy storage system, are disclosed. An example device comprising: a temperature measurement module configured to determine a resistive element temperature and an ambient temperature, a current measurement module configured to determine a measured current of a current sensor connected to the energy storage system; a current circuit fault detection module configured to determine a failure condition is met based on the resistive element temperature, the ambient temperature and the measured current and generate a fault signal based on the failure condition; and a switch positioned between the load and the battery, the switch controlled based on the fault signal received from the current circuit fault detection module.