FAULT TOLERANT WIND TURBINE CONVERTER

摘要

A wind turbine is arranged to operate in a fully-functional converter mode and a faulty-converter mode. A plurality of converters are arranged to share electric current in the fully-functional converter mode. The converters are dimensioned not only to operate at nominal active current but to provide an over-current margin to enable reactive current to be produced on top of the nominal active current in the fully-functional converter mode. In the fully-functional converter mode the converters are caused to produce reactive current on top of the nominal active current. In response to a fault of one or more of the converters, operation is changed from the fully-functional converter mode to the faulty-converter mode. In the faulty-converter mode, one or more other converters of the converter system are caused to produce additional active current by using their over-current margin to compensate at least partly for a reduction of active-current production due to the fault of one of the converters, and to reduce the reactive-current production by the other converter correspondingly.

主权项

1. A method of generating and converting electrical energy using a wind turbine, the wind turbine including a generator and an electric-converter system and being configured to operate in a fully-functional converter mode and a faulty-converter mode,
the electric-converter system being configured to, using electric power generated by the generator, produce and convert electric power at a nominal active power to a point of common coupling of the wind turbine to an electrical grid, the electric-converter system including a plurality of converters arranged in parallel and dimensioned to provide a nominal active-current corresponding to the nominal active power, each of the plurality of converters further dimensioned to include an over-current margin to enable an over-current to be produced by the converter in addition to the nominal active-current in the fully-functional converter mode, the method comprising: causing, while operating in the fully-functional converter mode, one or more of the plurality of converters to produce the over-current in addition to the nominal active-current; changing, in response to a fault of at least one faulty converter of the plurality of converters, operation of the wind turbine from the fully-functional converter mode to the faulty-converter mode; and while operating in the faulty-converter mode:
causing at least one non-faulty converter of the plurality of converters to produce additional active-current by using the over-current margin of the at least one non-faulty converter to compensate at least partly for a reduction of active-current production from the at least one faulty converter, andreducing the over-current production of the at least one non-faulty converter correspondingly.