Power Quality Disturbances and Protective Relays on Transmission Lines
Power quality concerns the effect of voltage disturbances on end-user equipment and of current disturbances on network components. Power system protection concerns the detection of faults in the system from measured voltages and currents. However, non-fault voltage and current disturbances may lead to the inadvertent detection of a fault in the same way as voltage disturbances may lead to the tripping of end-user equipment. Starting from the principles (algorithms) of the relays, a quantification approach is developed to assess the disturbance impact on the relays. The quantification is based on the relay response after processing the disturbance signals by relay filters.