Study of Northern Province Medium Voltage Network Interconnection with the Sri Lankan Power Grid

Abstract

Interconnection of power systems will strengthen the power grid due to its inertia addition. However, interconnection of long distanced large loads and generating plants causes problems like voltage drops, line overloading, power fluctuation and difficulties in black start up. The literature survey resulted that the Flexible AC Transmission System is a proven technology as solution. In Sri Lanka, the Jaffna Peninsula MV network is planned to be re-connected to the main grid network in 2013. This paper discusses about reliable and efficient operation of the Sri Lankan power grid as whole after this interconnection. In this study the present, 2016 predicted Sri Lankan transmission network and Northern MV networks were modelled. Growth rate of the Jaffna Peninsula was calculated using the 2007 to 2011 recorded historical data. Simulated results on load flow and fault analysis were similar to the operational data, thus validated the modelled network. In Sri Lankan power system, the longest transmission line will interconnect the loads and generators at Northern Province with main grid. Solutions to the problems related to this interconnection were studied with an optimally placed Static VAr Compensator. This study has proven better performance in reducing overloading, improving voltage profile and easy black start up.