Control system and method to improve the electrical energy production of a variable speed wind turbine by alternative regulation

摘要

A control system to improve the production of a variable speed wind turbine comprising control devices for a standard regulation tracking a power vs. generator speed curve that also uses an alternative regulation for optimizing the energy production along determinate time periods Tb for compensating previous energy losses at a higher power Pb than the power determined by the standard regulation, the alternative regulation being based on a continuous calculation of the accumulated lost energy ALE as the energy lost with respect to the maximum allowed energy production according to the standard regulation and the fixation of the higher power Pb and a setting of the duration of the time periods Tb being compatible with wind turbine electrical or mechanical limitations. A wind turbine controlled by the method.

主权项

1. A control system for controlling a variable speed wind turbine to improve electrical energy production of said variable speed wind turbine,
said variable speed wind turbine comprising an electrical generator having a generator speed and outputting an electrical power; said control system having a processor that uses a standard regulation that tracks an electrical power versus generator speed curve wherein the electrical power versus generator speed curve has a first sub-nominal zone where the generator speed is kept constant at a coupling value related to mechanical coupling of a drive train of the wind turbine, a second sub-nominal zone where both the generator speed and the electrical power are allowed to increase or decrease with wind speed, a third sub-nominal zone where the generator speed is kept constant at a nominal speed value, and a nominal zone where the electrical power is kept constant at a nominal power value (Pn); wherein said processor further uses: an alternative regulation at an electrical power (Pb) higher than the nominal power (Pn) of said standard regulation, said alternative regulation being used along determinate time periods (Tb); wherein an accumulated lost energy (ALE) is calculated, said accumulated lost energy (ALE) is an integral over a time interval (Ta) of a difference between the nominal power (Pn) and a power produced by the variable speed wind turbine during the time interval (Ta), the calculation of the accumulated lost energy (ALE) is performed by the processor of the control system of the variable speed wind turbine; wherein the higher electrical power (Pb) and the determinate time periods (Tb) are compatible with electrical and mechanical limitations of the variable speed wind turbine, said alternative regulation is activated when the accumulated lost energy (ALE) is higher than a first predetermined value (ALE1), and said alternative regulation is deactivated when the accumulated lost energy (ALE) is less than a second predetermined value (ALE2).