Lithium-ion battery packs are widely deployed as power sources in transportation electrification solutions. To ensure safe and reliable operation of battery packs, it is of critical importance to monitor operation status an. ••The operation state of electric scooter is classified by current and s. Global warming, environmental pollution and oil crisis have raised worldwide concerns, and transportation electrification can effectively mitigate their passive influence. The operation safety of battery systems is one of the main issues hindering application and market penetration of E-scooters and EVs. In addition to the built-in fault diagnosis sy. In practical applications, failures seldom occur, and the fault data only account for a small portion of all the operation data. If the variation of measurement is only influenced by random errors. For the systemic fault diagnosis, the operation status of E-scooter is firstly identified to improve the diagnosis accuracy. The diagnostic criterion P is then set to diagnose t.
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If not well balanced, the performance of the battery pack will always be limited by the weakest cell. Battery State of Charge (SOC) is naturally an effective indicator for balancing, yet the SOC estimation cannot always be accurate, which may further induce uncertainties to the balance performance.
How to detect a faulty battery pack?
The systematic faults of battery pack and possible abnormal state can be diagnosed by one coefficient. For the voltage abnormality, an accurate detection and location algorithm of the abnormal cell voltage are attained by combining the data analysis method and the visualization technique.
How to detect abnormal cell voltage in a battery pack?
By applying the designed coefficient, the systematic faults of battery pack and possible abnormal state can be timely diagnosed. 2) The t-SNE technique, The K-means clustering and Z-score methods are exploited to detect and accurately locate the abnormal cell voltage.
What causes abnormality in a battery?
From the detection results and the voltage variation trajectories of cells, it can be concluded that the detected abnormality is a rapid descent of voltage caused by the battery pack that is discharged with a high rate current in a low voltage stage.
The balanced state of the battery pack is defined as the maximal SOC difference of cells in the battery pack. When the battery pack fulfill SOC max -SOC min < 0.05 at time tb, the battery pack is believed to be balanced in this paper. It is worth noting that SOC max -SOC min < 0.05 and the state S0 do not mean the same thing.
Can a switchable indicator be used to evaluate a battery pack?
A novel switchable indicator is proposed to utilize the advantages of voltage and SOC for the consistency evaluation of the battery pack. A balancing algorithm with a specially designed switching logic is used to enable an efficient operation of the battery pack. The rest of this paper is organized as follows.