Method and apparatus for determining the complex impedance of an electrical component

摘要

The invention provides a method and apparatus for determining the complex impedance of an electrical component. The method comprises the steps of applying an input signal to the component comprising a plurality of discrete frequencies simultaneously, and determining the complex impedance of the component at each of the frequencies using a discrete demodulation technique on two complex impedance related parameters at each of the discrete frequencies. This method is particularly useful in electrically noisy environments and can be used to determine the impedance and equivalent circuit parameters for a battery. It can also be applied to battery system interconnects to enable battery system currents to be determined.