Spotting the Power Quality Events Associated to Utility Distribution Power Network with Solar Energy Power Generation

A method using hybrid combination of Discrete Wavelet transform (DWT), Stockwell transform (ST), Hilbert transform (HT) and entropy formulations to spot the power quality (PQ) events associated with operational and grid disturbance events in a solar test grid (STG) where a solar power plant (SPP) is connected. This PQ spotting technique used the ST, and HT for computing the solar ST PQ detection index (SSPDI) and solar HT PQ detection index (SHPDI) respectively. Solar PQ multiplying factors (SPQMFs) are computed from voltage signal and decomposing voltage signal by application of the DWT. A solar combined PQ detection index (SCPDI) is computed from SSPDI, SHPDI and SPQMFs which effectively spots the PQ disturbances associated with STG during the operational and grid disturbance events such as single phase to ground fault (SPGF), feeder operation, grid outage, load operation and capacitor operation. The SCPDI is differentiated to compute the solar location detection index (SLPDI) which is effective for locating the PQ disturbances in time domain. The proposed technique is validated on IEEE-13 node STG interfaced with a SPP. Performance of designed technique is better compared to the DWT based technique.