Impact of LCC HVDC Transmission on Distance Protection in IEC 61850 Environment as Applied ...

Impact of LCC HVDC Transmission on Distance Protection in IEC 61850 Environment as Applied to Sumatera-Java 500 kV Interconnection.

Over the years, HVDC transmission link has been known as the better option than its HVAC counterpart to connect geographically far apart power grid reliably and economically, hence interconnecting the island of Sumatera and Java with Line-Commutated Converter (LCC) HVDC link, which represents mature technology would be preferable. As the LCC HVDC is basically employing thyristor to convert from AC to DC and vice versa, it would act as a current source for the AC grid and low in inertia. Therefore, it would possibly contribute insufficient fault current on disturbance condition and could affect the protection system that is relying its performance on current and voltage measurement such as distance protection. To deal with this, the operating performance of distance protection in Java 500 kV AC grid would be investigated. In this case, the dynamic model of the Sumatera-Java 500 kV LCC HVDC transmission link was built in DIgSILENT Power Factory to simulate short circuit and Electro-Magnetic Transient (EMT) response. Furthermore, numerical distance relay is tested in IEC 61850 substation automation standard based environment with OMICRON CMC-256 test set. Static test would represent an ideal scenario while dynamic test using COMTRADE file that is generated from EMT simulation would illustrate condition of the grid when the LCC HVDC link transmits 3 GW of active power from Sumatera to Java. Both results from static and dynamic test are examined and discussed to verify the performance of distance protection. These results show that the LCC HVDC transmission affects performance of distance protection, hence Permissive Over-reach Transfer Trip (POTT) with Weak Infeed (WI) and adaptive scheme with multiple group-setting are discussed as possible solutions.