The design of control and protection system of 900 MVAr SVC in Holeta substation in Ethiopia

A 900 MVAr Static Var Compensator system have been installed in the Holeta substation in Ethiopia which was designed and manufactured by NR Electric. In order to strengthen the role of SVC in controlling reactive power, the paper presents a new design of control and protection System. There are three sets of 300 MVAr capacity SVC when the whole system works in the independent mode. They can also work as one set of 900 MVAr reactive compensation in the coordinate mode. The Whole system contains fifteen branches and eight control units. Every two SCUs are backup for each other in one single set of 300 MVAr SVC. The two CCUs control the whole system alternately when it is in the coordinate mode. The 900 MVAr SVC control system has implemented some advanced strategy such as POD function and Voltage control strategy with reserve power. FAT and Control Logic Tests have been completed to verify that the system works perfectly. RTDS system is used to verify the control logic in the Control Logic Tests. The results prove that the control logic of new design of large capacity SVC works well.