Method and system for optimizing broadband impedance characteristic of chained energy storage device

The invention discloses a method and a system for optimizing broadband impedance characteristics of a chained energy storage device, and the method comprises the steps: obtaining the AC side voltage of the chained energy storage device, and setting the frequency of a first frequency interval to be lower than a second frequency interval; extracting a plurality of corresponding frequency components of which the alternating current side voltage amplitudes are greater than a set threshold value; if each frequency component is in the first frequency interval, converting the alternating current side voltage after point resistance filtering to obtain a target value of the alternating current; if a plurality of frequency components in the first frequency interval and the plurality of frequency components in the second frequency interval exist at the same time, subtracting a voltage component in the second frequency interval from the alternating current side voltage after point resistance filtering, and converting to