A Rapid Impedance Acquisition Method for Series-Connected Battery Pack

To address the low efficiency of traditional single-cell measurement, this article proposes a rapid single-input multioutput architecture for synchronous battery impedance acquisition. This configuration enhances measurement throughput and reduces hardware complexity by sharing a single excitation source among multiple series-connected cells. A multiharmonic binary sequence (MHBS) comprising exclusively odd harmonics is designed to ensure a high signal-to-noise ratio (SNR) and resistance to nonlinear interference. Furthermore, an adaptive nonlocal means (ANLM) filter using a Student-t kernel is proposed to effectively suppress noise while preserving spectral details. Experimental results confirm the method outperforms traditional approaches, enabling simultaneous measurement of three cells within 4.7 s with an average normalized root mean square error below 0.78%.