Expansion of a Power System using Existing Switchgear

Today´s power system engineer is often faced with expansion of his system with additions usually small, yet sometimes large. With the exception of brand new plants, he must utilize his existing power system equipment and add to it as necessary to increase its power handling capacity. Increased capacity nearly always means increased interrupting duty, and a problem comes with what to do with existing switchgear to prevent exceeding its fault-interrupting capability. A number of system tools or methods are outlined to aid the power system designer with sufficient choice to provide the optimum expansion while utilizing his existing switchgear equipment.