Fault Tolerant Battery Architecture With Expanded Voltage Range
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional battery cell assemblies experience significant performance reduction when a single cell fails, whether due to short-circuit or open-circuit faults, leading to voltage loss and reduced operational capacity, as the fault affects all connected cells.
Innovation Solution
A battery cell assembly design where each cell unit consists of n cells connected in series, with n≥3, and a voltage range tolerance z% greater than the nominal operational voltage, allowing operational cells to expand their voltage range and compensate for a shorted cell, preventing discharge of neighboring cells and maintaining overall battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If cells are connected in parallel groups within series units, then battery capacity is increased, but a single cell fault causes discharge of all parallel-connected cells and significant performance reduction
Solution Approach 1:
The battery is divided into multiple series-connected string groups, where each group contains series-connected cells. This segmentation isolates faults to individual strings, preventing cross-string discharge paths and maintaining battery functionality when one cell fails.
Solution Approach 2:
The patent changes the electrical connection topology from traditional parallel groups within series units to series-connected string groups. This parameter change in connection configuration eliminates the harmful discharge paths while preserving capacity through increased number of strings.
2Quantity of substance
If strings of series-connected cells are connected in parallel, then battery capacity is increased, but a cell short circuit causes voltage loss and discharge of other parallel strings
Solution Approach 1:
The battery architecture segments cells into independent series strings that are electrically isolated from each other. This segmentation prevents discharge current from flowing between parallel-connected strings when one cell shorts, eliminating the energy loss mechanism.
Solution Approach 2:
The harmful parallel discharge path is extracted/removed from the system by reconfiguring the connection topology. Instead of allowing parallel discharge paths between strings, the design uses series connection of string groups to eliminate this discharge mechanism entirely.
3Quantity of substance
If cells are fully matrixed with parallel row and series column connections, then battery capacity and voltage are optimized, but a cell fault affects the entire row and column
Solution Approach 1:
The full matrix configuration is segmented into independent series string groups without cross-connections. This segmentation isolates faults to individual strings, preventing the fault from affecting entire rows or columns as in the matrix configuration.
Solution Approach 2:
The cross-connecting parallel paths that create the matrix structure are extracted/removed. This elimination of cross-connections prevents fault propagation across rows and columns, isolating failures to single cells or their immediate series neighbors only.
Data Source
AI summary
Provided is a battery cell assembly that continues to operate near normal parameters following a fault in a cell. The battery cell assembly includes a plurality of repeating cell units. Each of the cell units is connected in parallel with another cell unit. Additionally, each of the cell units is connected in series with another cell unit. Each of the cell units includes n cells connected in series, the n cells having a voltage range tolerance of z % greater than a nominal operational voltage range. The n cells comprise a first end cell, a second end cell, and n−2 middle cells interposed between the first end cell and the second end cell. The middle cells are absent a parallel connection. In each of the cell units, n≥3 and z(n−1)≥100. Also provided is a method of compensating for a voltage loss from a shorted cell.