Disturbance detection using Wavelet Transform for power quality application

Although capacitors provide voltage support and correct displacement power factor on power distribution lines, capacitor switching transients are the second most common power quality events, after voltage sags. Capacitor switching transients can disrupt loads that are sensitive to overvoltage sub-cycle transients, including adjustable speed drives, data communication systems and process controls. The voltage transients can also travel long distances, in some cases becoming magnified on low voltage busses. This paper introduces voltage disturbance detection technique using Wavelet Transform (WT) during transient operations. Feasibility of the proposed disturbance detection approach is evaluated by digital time domain simulation using PSCAD/EMTDC and MatLab software packages.