Reactive power and current formulations for wind farms Spanish grid code

Reactive powers and currents supplied by wind generators are studied in this paper to verify new Spanish grid code requirements. Two approaches are used for that study. One approach is based on the well known Emanuel´s theory included in the IEEE Standard 1459-2000. Reactive powers and currents are expressed by Emanuel for the fundamental-frequency, positive-sequence voltages and currents. Second approach was recently formulated by Czarnecki in his CPC theory. With both theories is possible to decompose reactive powers and currents into a component obtained with balanced voltages (or due to the load reactances) and another component due to the unbalances. This last component is zero when voltage supply and/or loads are balanced. This decomposition of reactive powers and currents gives up more information than other theories about the reactive phenomena and thus can be an excellent tool to verify reactive grid code requirements at wind farms.