Battery Cell Connectivity Check Using a Single Switch
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Solution Overview
Problem
Existing rechargeable energy storage systems face challenges in efficiently and reliably detecting faulty connections between cells and control electronics, particularly when the cell voltage is zero, which complicates the detection of bad connections.
Innovation Solution
A rechargeable energy storage system with a single common connection between a terminal of a rechargeable energy storage cell and the monitoring and control circuit, utilizing a controllable switch to check for voltage differences when open and closed, allowing for rapid detection of bad connections by measuring minimal charge current through a filter circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a connection check is performed by measuring voltage differences when switch is open and closed, then faulty connections can be detected, but charge current flows through the cell during switching which may affect cell voltage
Solution Approach 1:
The filter circuit is pre-charged to the input voltage V before the connection check begins. This preliminary charging ensures that when the switch is closed during the connection check, no additional charge current flows through the cell, eliminating the risk of voltage change that could affect detection accuracy.
Solution Approach 2:
A filter circuit is introduced as an intermediary component between the switch and the cell. This filter circuit absorbs the charge current during switching operations, preventing it from flowing through the cell. The filter circuit acts as a buffer that isolates the cell from the transient charging effects during the connection check.
2Reliability
If traditional connection checking methods are used, then faulty connections can be detected, but multiple switches are required which increases device complexity
Solution Approach 1:
A single switch is designed to perform multiple functions: it serves as the primary switching element for the filter circuit and simultaneously acts as the connection check switch. By making the switch multi-functional, the patent eliminates the need for separate switches for different purposes, thereby reducing device complexity while maintaining reliable connection detection capability.
3Measurement precision
If connection checks are performed with multiple switches, then detection accuracy can be maintained, but the system requires more components which increases manufacturing complexity
Solution Approach 1:
The patent combines the filter circuit and connection check functionality into a single integrated system controlled by one switch. The filter circuit is merged with the switching mechanism, and both functions are achieved through a unified design. This merging reduces the number of discrete components, simplifies manufacturing processes, and lowers assembly complexity while preserving measurement precision through the maintained voltage comparison mechanism.
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
Enables reliable connection checks with minimal charge impact on cells, ensuring rapid identification of faulty connections and enhancing system security by preventing overcharging, even at zero cell voltage.
Implementation Method 1
measuring minimal charge current through a filter circuit
Data Source
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AI summary
Connectivity check between cells and control wiring electronics with only one switch A connectivity check for a rechargeable energy storage system comprising a string of rechargeable energy storage cell modules in series is described. Each cell module comprises an individual rechargeable energy storage cell or plurality of rechargeable energy storage cells, a switch for use in a connection check, a monitoring and control circuit adapted for measuring a cell module voltage, a single common connection between a terminal of a rechargeable energy storage cell and the monitoring and control circuit within each module. To perform the connectivity check the switch is opened in one module, a cell voltage is measured in the module to give a first measured value, the switch is closed. The cell voltage is measured again to provide a second measured value, and a determination is made if there is a difference between the first and second measured values which would indicate a bad connection.