Research on Vibration and Noise of Converter Transformer Based on LCL Converter

The paper introduces a novel converter design that utilizes an LCL filtering structure to mitigate the issues of harmonic generation, which can exacerbate the vibration and noise in converter transformers within high-voltage direct current transmission systems. The paper presents a comprehensive analysis of the vibration and noise reduction capabilities of the converter from both theoretical and experimental viewpoints. Firstly, the paper outlines the topology of the new LCL converter. Following this, a new harmonic model for the LCL converter is established to analyse its harmonic characteristics. Additionally, the paper examines how varying filter capacitor values impact the filtering efficacy and the subsequent reduction in vibration and noise. To validate these findings, a 12-pulse rectification principle prototype experimental platform was constructed. This platform was used to compare the power quality of traditional LCC converters with the new LCL converters, as well as to analyse the vibration and noise characteristics of the converter transformers. The experimental results indicate that the proposed LCL converter not only effectively suppresses harmonics but also significantly reduces the vibration and noise of the converter transformers.