This exception report was triggered when the wind turbine reactive power output was unable to meet its reactive power setpoint. While this can cause compliance issues, the more serious effects are:
1. Additional loading on the medium voltage reticulation system (the medium voltage distribution network may have been sized to carry the full wind farm load under the assumed operating conditions of unity power factor at the wind turbine terminals). If multiple wind turbines are failing to meet their reactive power targets then in extreme cases this can overload the medium voltage reticulation and cause cable joint failures, resulting in significant downtime and lost production.
Wind farm MV cable joint failures can occur due to overloading if the wind turbines are not operating within their intended reactive power limits.
2. Additional loading on the substation reactive power compensation system (if installed) in order to maintain compliance at the point of common coupling.
3. Increased real power losses (lost revenue) due to sub-optimal load flow conditions on the wind farm.
A turbine manufacturer is not likely to alert a wind farm owner to such problems because it may cost the OEM to fix the problem and doesn’t have an immediate effect on availability. Because reactive power issues don’t often affect availability, they can go unnoticed for long periods of time. SCADA Miner regulalry performs checks of reactive power at the turbine terminals as well as the point of common coupling and generates exception reports if conditions require attention.