Wind turbine power conversion system

摘要

The invention refers to a multilevel topology power converter (I) for electrical adaption of a low voltage alternating current (LVAC) of an electrical wind power generator (1) and a medium voltage (MV) transmission level for a transmission link to each other, the power converter (I) comprising for each phase:
a switching unit (9) for adapting the low voltage (LV) and the medium voltage (MV) to each other, the switching unit (9) being controlled by a controller (15), whereby the controlled switching unit (9) separately switches n+1 terminal potentials along terminals of an electrical series of n>1 capacitors C1 . . . Cn (7);a current converter (5) for providing or using a direct current (DC) through the plurality of n>1 capacitors C1 . . . Cn (7) connected in series.

主权项

1. Multilevel topology power converter for electrical adaption of a low voltage alternating current of an electrical wind power generator and a medium voltage transmission level for a transmission link to each other, the power converter comprising for each phase:
a switching unit for adapting the low voltage and the medium voltage to each other; a current converter for providing a direct current towards or from a plurality of n>1 capacitors C1 . . . Cn electrically connected in series; and a control system configured to:
control the switching unit to switch the n+1 terminal potentials along terminals of the series of the n>1 capacitors C1 . . . Cn, to thereby provide a DC to AC inverter; andprovide a dual mode operation of the converter based on a status of the electrical wind power generator, by dynamically switching between:
a grid-connected control mode during a grid-connected mode of the electrical wind power generator, wherein the control system controls a grid-side current; anda stand-alone control mode in a stand-alone status of the converter electrical wind power generator, wherein the control system:
increases capacitances of the capacitors C1 . . . Cn to increase a stiffness of the series of the capacitors C1 . . . Cn; andactively controls a load angle.