Abstract

Study of battery resistance online monitoring system using hilbert-huang transform

Author(s): Guo Chunhua

In batteryÂ’s internal resistance online monitoring system, voltage collected is influenced by charging ripple, load changes,AC frequency interference, etc. It contains high harmonics and other interference. As Hilbert- Huang spectrum has perfect time-frequency characteristics, it can describe frequency varying with time accurately. Hilbert-Huang transform contains two steps: empirical mode decomposition (EMD) and Hilbert transform. Battery voltage collected is implemented EMD and Hilbert transform respectively, in the obtained time-frequency distribution domain, fundamental component which frequency is the same with fed current is preserved, while others are removed, it is the voltage which has the same frequency as fed current. According to the relationship of average power and resistance, the battery resistance can be computed