Method, system and computer-readable media for measuring impedance of an energy storage device

摘要

Real-time battery impedance spectrum is acquired using a one-time record. Fast Summation Transformation (FST) is a parallel method of acquiring a real-time battery impedance spectrum using a one-time record that enables battery diagnostics. An excitation current to a battery is a sum of equal amplitude sine waves of frequencies that are octave harmonics spread over a range of interest. A sample frequency is also octave and harmonically related to all frequencies in the sum. A time profile of this sampled signal has a duration that is a few periods of the lowest frequency. A voltage response of the battery, average deleted, is an impedance of the battery in a time domain. Since the excitation frequencies are known and octave and harmonically related, a simple algorithm, FST, processes the time profile by rectifying relative to sine and cosine of each frequency. Another algorithm yields real and imaginary components for each frequency.

主权项

1. A method of measuring impedance of an energy storage device, comprising:
generating an excitation time record comprising a summation of one or more sinusoidal signals with a frequency step factor of octave harmonics therebetween; stimulating an energy storage device with the excitation time record; during the stimulating, capturing a response time record at a sampling frequency, the response time record indicative of a response of the energy storage device to the excitation time record; and rectifying the response time record relative to a sine and a cosine for at least one of the one or more sinusoidal signals to determine at least one of an in-phase component and a quadrature component of an impedance of the energy storage device.