公开(公告)号：EP3853991A1

公开(公告)日：2021-07-28

申请号：EP19769712.1

申请日：2019-09-11

Applicant: VESTAS WIND SYSTEMS A/S

Inventor： BIRIS, Ciprian ,  TANGE, Kent ,  ANDERSEN, Gert Karmisholt ,  DOAN, Duy Duc ,  LUND, Torsten ,  MEYER, Lars

IPC: H02M7/5395 ,  H02M7/5387

公开(公告)号：EP3780366A1

公开(公告)日：2021-02-17

申请号：EP20190429.9

申请日：2020-08-11

Applicant: VESTAS WIND SYSTEMS A/S

Inventor： BIRIS, Ciprian ,  GERÇEK, Cem Özgür ,  HELLE, Lars ,  DOAN, Duy Duc ,  PEDERSEN, Tune

IPC: H02M1/32

Abstract: This disclosure proposes a topology that integrates a DC chopper into the Modular Multilevel Converter (MMC) cells of a power converter. The integrated DC chopper may include chopper resistors that may also be advantageously integrated into a heat sink for a power module comprising at least the power transistors of the MMC cell. Embodiments herein also describe a method for using an MMC cell's IGBTs and chopper resistors for providing a safe discharge of both cell capacitors and DC-link capacitors in different operating conditions.

公开(公告)号：EP3512065A1

公开(公告)日：2019-07-17

申请号：EP19150387.9

申请日：2019-01-04

Applicant: VESTAS WIND SYSTEMS A/S

Inventor： BIRIS, Ciprian ,  TANGE, Kent ,  DOAN, Duy Duc ,  LUND, Torsten ,  ANDERSEN, Gert Karmisholt

IPC: H02J3/38 ,  H02M7/5395 ,  H02J3/18 ,  H02M1/08

Abstract: The invention relates to a method for operating a wind turbine. The method comprises monitoring a wind turbine signal for detection of an over voltage of the grid and upon detection of the over voltage, initiate an over-modulation mode wherein the grid side converter is operated with a modulation index being increased in an over-modulation range at least during a sub-period of the over-modulation mode, and upon the detection of the operational condition, initiate a DC-voltage adjustment mode wherein the DC voltage of the DC link is decreased from a second voltage level towards a first voltage level at least during a sub-period of the DC-voltage adjustment mode.

公开(公告)号：EP3464889A1

公开(公告)日：2019-04-10

申请号：EP17727097.2

申请日：2017-05-16

Applicant: Vestas Wind Systems A/S

Inventor： BIRIS, Ciprian ,  ANDERSEN, Gert Karmisholt ,  MERRILD, Uffe C. ,  CHRISTENSEN, Leif Svinth

IPC: F03D7/02 ,  F03D9/25 ,  H02P9/00 ,  H02J3/38 ,  F03D7/04 ,  H02J3/00

公开(公告)号：EP3462559A1

公开(公告)日：2019-04-03

申请号：EP18196816.5

申请日：2018-09-26

Applicant: VESTAS WIND SYSTEMS A/S

Inventor： BIRIS, Ciprian ,  MERRILD, Uffe C. ,  CHRISTENSEN, Leif Svinth ,  KJÆR, Martin Ansbjerg

IPC: H02J3/18 ,  H02J3/38 ,  F03D7/02 ,  H02J3/00

Abstract: The invention relates to a fault ride through method for controlling a wind turbine during a grid fault where the grid voltage drops below a nominal grid voltage. After detection of a grid fault, the total current limit for the power converter output is increased to a total maximum overload current limit. This may allow generation of an increased active current for compensating a reduction in active power. Depending on whether active or reactive current generation is prioritized, an active or reactive current reference is determined initially. The active current reference is determined in a way so that a reduction in active power production due to the grid voltage drop is minimized and based on the condition that the vector-sum of the active output current Iq and the reactive output current Id is limited according to the total maximum overload current limit, and a maximum period of time is determined in which the power converter can be controlled based on the active and reactive current references. Afterwards the power converter is controlled based on the active and reactive current references.