Effect of STATCOM Location on Distance Protection Relay Operation

Abstract

The presence of FACTS in systems has brought up some difficulties to conventional distance protection to meet basic requirements for protection schemes. This dissertation reviews FACTS concepts, and studies shunt-connected STATCOM and its modelling. Based on the dynamic behaviour of STATCOM in a two-machine system, where a distance protection scheme is applied, performance of the two zone distance protection scheme has been evaluated in EMTDC/PSCAD simulation environment for various contingent conditions. This includes different STATCOM installation locations, various STATCOM voltage settings, various fault locations & types. To overcome the mis-operation of the distance relay when the transmission line is shunt compensated with STATCOM, studies on some communication-aided protection schemes, including PUTT, POTT and DCB, are conducted. These pilot protection schemes have been proven to be effective for fast clearance of the faults on the transmission line and meet the requirements for protections, regardless of STATCOM installation locations.