ABSTRACT
This chapter describes many of the pitfalls that exist in applying conventional relaying practices and the extremes to which we have gone to circumvent these problems. It also describes several types of relaying systems that have been designed with the series capacitor application in mind. The simplicity of the phase-comparison protective relaying system encourages its consideration for series-compensated transmission line applications. Generally, the most severe problems occur with the relaying associated with the adjacent line. Series compensation of a network will affect the distance protection on both the compensated line and adjacent lines connected to bus bars at which a voltage reversal can occur. The basic phase-comparison system is a scheme in which a single-phase filter voltage is developed at each transmission line terminal that is dependent on the symmetrical component content of the phase currents. Communications equipment is keyed during the positive half-cycle.
