Dynamic Ripple Tracking Method in DC Distribution Network

In response to the urgent need for dynamic ripple monitoring and energy metering in direct current (DC) distribution networks, this paper proposes a dynamic ripple tracking method for DC grids. Firstly, considering the dynamic characteristics of ripples, a Taylor series is introduced to establish a dynamic ripple representation model. Simultaneously, the frequency-domain information of ripples is analyzed using the Fast Fourier Transform (FFT) for single-frequency data, and an iterative interpolation and polynomial fitting correction method is applied for frequency estimation. Secondly, offline matrix calculations based on rough frequency estimation, correction of discrete Fourier transform results, and least squares are used to obtain accurate ripple parameter values. Finally, through simulations under dynamic conditions such as frequency ramp changes, amplitude variations, and simultaneous oscillations in frequency, accurate measurement of dynamic ripples is achieved.