Power Swing

In last post¬†Load Encroachment on Distance Protection, we observed that low value of Impedance Z arise due to voltage instability or transients associated with electromechanical oscillations of rotors of synchronous machines after a major disturbance like the faults. This can introduce nuisance tripping. Such tripping is known as tripping on Power Swings. In this post … Read more

Effect of Load Encroachment on Distance Protection

For discussing the effect of Load Encroachment on Distance Protection, we make a steady state model of Transmission Line as shown in figure below. In the figure Vi is Sending End voltage and Vj is Receiving End voltage. Power Pij+jQijis flowing in the direction shown in figure. We know that, ¬† Pij – jQij= VixI … Read more