Broadband Signal Measurement Method in the Background of Power Electronics in Substation Area of Distribution Network

Abstract

With the development and application of power electronic devices in distribution stations, the power grid has frequent broadband oscillations, with characteristics such as a wide frequency range and multiple modal components, etc. However, the existing signal estimation methods cannot provide accurate parameter information due to ignoring the dynamic changes and failing to reduce the interference. Therefore, this paper proposes a broadband signal analysis method considering fundamental wave dynamics and reducing interference to achieve high-precision identification of signal parameters and provide data for applications such as wide-frequency oscillation analysis and improving power quality issues. Firstly, the variational modal decomposition extracts the waveform information of various components and the corresponding frequencies. Secondly, correct the centre frequencies and make them filter frequencies. Finally, based on the least square method, parameter estimation of broadband signals is achieved. The performance of the algorithm is verified under the situations of frequency ramp change, frequency dynamic modulation, noise, etc. The simulation results show that the proposed algorithm can estimate the parameter information of broadband signal accurately and keep the total vector error less than 3%.

Keywords

• Broadband oscillation
• parameter estimation
• variational mode decomposition (VMD)
• fundamental wave dynamics