Abstract：An equivalent serial resistance (ESR) is one of the key parameters of supercapacitor, which is difficult to accurately measure. The Fast Fourier Transform (FFT) method can accurately measure the ESR of supercapacitors, but it requires a large amount of computation. A new method for measuring ESR of supercapacitor based on the Goertzel algorithm and the alternating current(AC) injection method was proposed. The complex impedance of supercapacitor was obtained by using the AC injection method, and then the phase difference of the input excitation current and the output voltage of supercapacitor was solved by using the Goertzel algorithm. This proposed method only requires calculating the spectral information of a specific frequency point of the excitation signal, which significantly reduces the computational complexity compared to FFT. The experimental results show that the measurement error of the Goertzel algorithm is equivalent to that of the FFT algorithm, both of which can meet the requirement of an error less than 5%. However, the computational complexity of the Goertzel algorithm is much smaller than that of the FFT algorithm.
2025, Vol. 46 
