by Yevgen Barsukov, Senior Applications Engineer, and Dave Freeman, System Engineering Manager, Texas Insruments, Dallas , Power Electronics Technology, Jan 01 2006
Focus:
Digital power control can enhance various aspects of battery management including improved load sharing of system power between battery charging and system operation, improved cell balancing in multi-cell battery packs, prediction of battery runtime, and assessment of battery state-of-health. The article discusses the digital control techniques that can be applied to achieve these benefits. In some cases, the improvements depend on an analysis of a battery's impedance over frequency. A technique for determining battery impedance in system using digital methods is described. The technique involves modulating the duty cycle of a constant-voltage charging signal, using cross-correlation on the battery voltage and input modulation to determine the battery's impulse response, and then using an FFT to calculate the battery's frequency characteristics.
What you’ll learn:
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