Modeling and Experimental Research on Active Noise Reduction System of Reactors for Power Equipment

Abstract

As a vital reactive power compensation apparatus in power systems, reactors continuously generate low-frequency electromagnetic noise during operation, which poses persistent threats to the surrounding environment of substations and the physical health of equipment maintenance personnel. Passive vibration isolation schemes suffer from inherent drawbacks such as low sound absorption efficiency in the low-frequency band and large space occupation, making them difficult to satisfy increasingly stringent noise emission standards. To address the above problems, dry-type air-core shunt reactors are taken as the research object. The generation mechanism of electromagnetic vibration and noise is systematically analyzed, and a mathematical model of the acoustic-vibration coupling system is established. On this basis, a multi-channel active noise control system based on the improved FxLMS algorithm is designed. Aiming at the insufficient convergence rate of the traditional FxLMS algorithm under power frequency harmonic conditions, a normalized step-size updating mechanism is introduced, which effectively improves the adaptive tracking performance of the system under variable load operating conditions. An experimental platform with a digital signal processor as the core control unit is built, and systematic tests are carried out under rated operating conditions and different load levels. The experimental results show that the noise reduction of the system reaches 18.6 dB and 14.3 dB at the main noise frequencies of 100 Hz and 200 Hz, respectively, and the comprehensive A-weighted sound pressure level is reduced by 12.7 dB, which verifies the effectiveness and engineering applicability of the proposed scheme.