Signal quality is the keyissue for maintaining effective power transmission in electrical networks. Inmost cases, a high voltage (HV) is transmitted in power systems to decreasepower loss. Power quality disturbances are monitored by observing the noisedegradation of HV signals. Increased oscillations and high-frequency componentsof power signals exhibit nonstationary signal characteristics. In this study, acomparative analysis of empirical mode decomposition (EMD) and variational modedecomposition (VMD) was conducted on noisy discharge signals. These techniqueswere used for adaptive signal decomposition in the time domain, facilitatingthe evaluation of deeper characteristics of the investigated signal. The HVdischarges were obtained using 0.4/40 kV and 8 kVA transformers in alaboratory, and all the current and voltage signal waveforms were recordedusing high-frequency current and high-voltage probes. The results demonstratedistinct calculations of EMD and VMD techniques in terms of signaldecomposition and extracting intrinsic mode functions (IMFs), which define low-and high-frequency components.