Series compensation for extended utilization of power transmission systems

Series compensation is an efficient and cost effective means for improving the transmission capability of power grids. It minimizes the number of transmission lines needed for a certain power transmission capacity of an inter-connector. With series capacitors, the capability of already existing power lines can be increased considerably, thereby decreasing the need for building new lines in cases where the need for power transmission in a system is growing. Installing series compensation is typically also less costly as well as less time consuming than building new lines. The paper presents some basic mechanisms for series compensation in power grids, fixed as well as thyristor-controlled, some salient design features as well as operational experience from a few cases for improving interregional power transfer in a cost-effective and environmentally friendly way.