Voltage Sag Location Based on Wavelet Transform Using Modulus Maximum Principle

Voltage sag location based on wavelet transform utilizes the modulus maximum principle to achieve accurate detection of sag start and end times. In power systems, voltage sags represent a common electrical issue that may lead to equipment malfunction or power outages. To ensure stable operation of power systems, precise detection and location of voltage sags is crucial. In this research, we employ wavelet transform for processing voltage signals and apply the modulus maximum principle to determine the exact start and end moments of sags. Through wavelet decomposition of voltage signals, we can break them down into different frequency components, enabling better analysis of voltage sag characteristics. The implementation typically involves using MATLAB's wavelet toolbox functions like 'cwt' for continuous wavelet transform or 'dwt' for discrete wavelet transform, followed by modulus maximum detection algorithms to identify singularity points in the signal. By applying the modulus maximum principle, we can precisely locate the start and end points of voltage sags, thereby achieving accurate detection and positioning. This method enhances the power system's responsiveness to voltage sags, ultimately improving equipment protection and ensuring power supply reliability. The algorithm workflow generally includes signal acquisition, wavelet coefficient calculation, modulus maximum extraction, and threshold-based sag event identification.