Protection Reviews

pro-single-protection

Delivery of statewide reviews of the transmission and sub-transmission time graded Distance and Overcurrent/Earth Fault protection on the Sabah Electricity network performed following the upgrade of the Teluk Salut 120MW open cycle power station to a 200MW combined cycle plant plus the commissioning of the Sepangar Bay Power Corporation 2 x 35MW gas turbines, the commissioning of the new 132kV and 33kV networks of the Northern Grid and the reconfiguration of the power system to facilitate transmission of power to the east coast grid (ECG) load centres, from the more economical west coast grid (WCG) gas fired plant across the Sabah 275kV state interconnector.

Macros were developed in the CAPE (Computer Aided Protection Engineering) application to automate the application of faults on the network to investigate the performance of the protection schemes on all 275kV, 132kV, 66 and 33kV feeders on the statewide system. Protection performance was evaluated in terms of operating times to safe guard against plant damage and system instability, coordination for secure clearance of faults and reach/cover for reliability. Grading of the protection schemes considered the coordination between primary and local or remote backup schemes, grading with CB Fail schemes and between Overcurrent and earth fault elements. The adequacy of backup protection schemes was investigated to ensure provision for protection element failure, CB Failure and substation battery failure.