Adaptive load shedding scheme for transmission line overloading problem in TNB

Building new infrastructures such as power plants, substations and transmission lines to meet rapid demand growth has becoming more challenging than ever. This is mainly due to economic factor but more importantly is public acceptance. Consequently, transmission grid operation is stressed to the limit and poses significant risks such as transmission line overloading. The overloading problem mostly occurs at congested load areas connection with low rating transmission lines. This paper describes a newly implemented adaptive load shedding scheme to minimize the amount of load loss and its duration due to transmission line overloading. The transmission line overloading detection is based on dynamic line rating and conductor temperature calculation. Quasi-optimum quantum method is used to determine the quantum of load to be shed based on the pre-determined priority of distribution feeders and real time loading. The scheme consists of distributed automation processors, control intelligent electronic devices, synchrophasors and ambient and line temperature sensors.