Detection of voltage variations due to distributed energy resources

With the use of distributed renewable energy resources in the building low-voltage distribution network, voltage fluctuations are of rising concerns. This paper aims to make use of a computational algorithm to identify voltage fluctuations by the use wavelet-based transform. The continuous wavelet transform (CWT) using the complex Morlet wavelet (CMW) is adopted to detect the voltage fluctuations presented in a voltage waveform. A modified complex Morlet wavelet (CMW) is introduced accordingly. A frequency detection algorithm is developed from the wavelet scalogram and ridges. A waveform reconstruction algorithm based on the continuous wavelet transform (CWT) is used to estimate the variation of voltage amplitudes, locations of voltage sags as well as oscillatory transients. Simulation has been used to verify the effectiveness of the approach.