Research on Converter Valve Discharge Localisation Technology Based on IVMD-MUSIC Algorithm

Abstract

Regarding the surface discharge phenomenon of the converter valve, this paper proposes a localisation method based on variational modal decomposition (VMD) and multiple signal classification (MUSIC) to achieve accurate positioning of discharge in the current converter valve. First, a solution for determining the number of modes K in VMD and a new threshold for IMF selection are proposed to enhance the noise removal capability in the valve hall. Second, the improved variational modal decomposition (IVMD) and MUSIC algorithms are combined to accurately identify the discharge phenomenon of the converter valve. This approach addresses the issue of inaccurate localization and failure in conventional methods due to strong noise interference in the converter valve hall. Simulation results indicate that when the signal-to-noise ratio (SNR) is higher than -20 dB, the root mean square error (RMSE) is less than 1.6. Localisation experiments were conducted on three types of discharges—needle-plate, cone-plate and sphere-plate discharges—showing an average angular error of less than 1.8°. Both simulation and experimental results demonstrate that the proposed algorithm exhibits higher localisation accuracy and strong applicability when the SNR is lower than -5 dB. Finally, a partial discharge localisation device was developed based on the proposed algorithm. This device utilises an eight-element cross sensor array and applies the IVMD-MUSIC algorithm for localisation, meeting operational and maintenance requirements and providing convenience for inspection personnel.