Implementation aspects and comprehensive assessment of a 16 MVAr static VAr compensator installed for a weak distribution network

Voltage regulation at weak distribution networks and feeders imposes several challenges. The degree of complexities of the overall design and implementation is network and site dependent. In this paper, design and implementation of a thyristor controlled reactor–based static VAr compensator (SVC) system to enhance voltage regulation and avoid voltage instability are presented and discussed. The SVC system is installed for an extremely weak distribution network with long feeders in a remote area in the Kingdom of Saudi Arabia. This work is the first implementation of an SVC system in the utility's distribution network in Kingdom of Saudi Arabia. Principles of operation, overall design assessment, and protection modifications in the installation area are described. Power stage and digital control system are custom designed according to the specific network and operation requirements. The overall system is examined under steady-state and dynamic conditions. Power system at the corresponding area with/without the compensator is simulated using PSCAD/EMTDC software. Field test results are also obtained, and the performance of the system is discussed along with the design considerations required for such installations. The various technical discussions presented in this paper highlight several practical considerations and practices that are valid in similar installations for extremely weak distribution networks around the world.