Spanish practices in reactive power management and voltage control

The need for better reactive power management and voltage control became apparent for the Spanish high voltage power system since the creation of REE in 1985. The REE has launched a research project on analysis, design and implementation of hierarchical and automatic voltage control, in which the current primary generator AVR would be completed by a regional secondary control and, eventually, by an automatic or semi-automatic tertiary national control. Based on off-line optimization studies performed by a specific own adapted OPF/GRE, a complete voltage coordination procedure has been finished and it is being followed by the system operators. In one region, an expert system, called SEGRE, to assist the operator has been developed and is in operation. As a result, except in very special situations, the Spanish high voltage power system does not have voltage problems