Vestas Wind Systems A/s

Mhi Vestas Offshore Wind A/s

Vestas Offshore Wind A/s

Tusitha Abeyasekera

Lars Helle

John Godsk Nielsen

Duy Duc Doan

Søren Andersen

Henrik B Møller

Ove Styhm

Salvador Año-Villalba

Ramon Blasco-Gimenez

Soledad Bernal Pérez

Gert Karmisholt Andersen

Srikanth Narasimalu

Gerner Larsen

Niels Erik Danielsen

Paw Rosenvard

Ravi Kandasamy

Torben Møller Hansen

Per Hagen Nielsen

Tune Pedersen

Allan Holm Jørgensen

Thomas Lundgren Andersen

Voon Hon Wong

Alex Pericleous

Sascha Dominic Erbslöh

Peter C Knudsen

Thomas Lundgren Anderson

Laurids Givskov Jørgensen

Ghada Ali Diaa Hillawi

Salvador AÑO -Villalba

Embodiments herein describe operating wind turbines in an offshore park to provide auxiliary power to a local AC grid or to an onshore grid during a grid malfunction. In one embodiment, the offshore park is coupled via a HVDC link to an onshore grid. When the HVDC link is down, a substation in the park includes a backup generator for creating a weak grid for powering auxiliary systems in a pilot turbine. The wind turbines in the park can switch to an auxiliary control system help power the auxiliary systems in the substation and in other turbines. In another embodiment, the offshore park is AC coupled to an onshore grid using a transformer in the substation. The wind turbines can participate in a brown or black start following a grid fault by switching to operating using the auxiliary control system.

Providing auxiliary power using offshore wind turbines

Operating a renewable energy power plant connected to a power network at a point of interconnection. The plant includes: one or more renewable energy generators connected to a collection point of the renewable energy power plant, and a connecting network connecting the collection point to the point of interconnection. One method includes: receiving one or more measurement signals indicative of measured power characteristics of the renewable energy power plant at the point of interconnection; determining a dynamic short circuit ratio (DSCR) at the point of interconnection based on the one or more measurement signals; determining an equivalent dynamic short circuit ratio (EDSCR) at the collection point based on the determined DSCR at the point of interconnection and one or more components of an impedance of the connecting network; and controlling the one or more renewable energy generators by determining and dispatching active power set points based on the determined EDSCR.

Methods and systems for improving grid stability

Embodiments herein described provide systems and techniques for performing black start operations. For example, one embodiment provides a method for performing black start operations. The method generally includes operating a wind turbine in a wind park in a first mode to provide power to an alternating-current (AC) grid using a control system. The control system may include a reactive power control leg and an active power control leg. The method also includes switching operation of the wind turbine from the first mode to a second mode based on an indication to perform a black start of an electrical grid and by activating a controller with an integral action to thereby increase output power of the wind turbine, the controller being coupled between the reactive power control leg and the active power control leg, and providing power to the electrical grid while operating in the second mode.

Black start restoration

A methodof controlling a wind turbine generator is disclosed. The method comprises operatingthe wind turbine in accordance with a power curve having a knee region and monitoringa temperature of at least one thermal hotspot of the wind turbine generator. The method further comprises initiatinga power boost to temporarily increase an active power generated by the wind turbine generator above a rated power when the wind turbine generator enters the knee region of the power curve and controllingat least one of a magnitude and a duration of the power boost in dependence on the temperature of the at least one thermal hotspot of the wind turbine generator.

Method of controlling a wind turbine generator

The present invention relates to operation of a wind turbine using a power storage unit, such as a rechargeable battery, to power a group of power consuming units during grid loss. The wind turbine comprises a number of power consuming units being grouped into at least a first group and a second group, a first electrical converter for connecting the generator to the electrical grid, and a second electrical converter for connecting the electrical generator to the power storage unit. Upon detecting an occurrence of the grid loss, the generator is operated to ensure sufficient power of the power storage unit to operate the first group of power consuming units.

Operation of a wind turbine during grid loss using a power storage unit

Embodiments herein describe operating a control system for a wind turbine in a first mode and second mode of operation. When in the first mode, the wind turbine provides power to a local AC grid. However, when in the second mode, the wind turbine provides power to a high-voltage direct current (HVDC) link. The control system includes a reactive power control leg and an active power control leg. To switch from the first mode to the second mode, the control system activates a PI controller coupled between the reactive and active power control legs which increases the output voltage of the wind turbine until the magnitude of the voltage activates a diode rectifier and permits the power outputted by the wind turbine to be transmitted along the HVDC link.

Controlling power exchange from self-commutated converters

Embodiments herein describe operating a first wind turbine using an auxiliary control system when a high-voltage link coupling a wind park to a grid is not functioning. When using the auxiliary control system, the first wind turbine provides power to a local AC grid which can be used to power auxiliary system in a second wind turbine while the second wind turbine is shutdown. However, when the high-voltage link is functional, the first and second wind turbines provide power to the high-voltage link using a primary control system.

Providing auxiliary power when a high-voltage link is non-functional

A method, converter arrangement, and controller are disclosed for connecting an output of a converter with an electrical grid to control inrush currents into a grid filter assembly connected with the output of the converter, the electrical grid carrying an alternating current (AC) signal having one or more phases. The method includes determining a voltage of the AC signal and operating, after pre-charging a direct current (DC) link of the converter to a predetermined voltage, the converter using open-loop voltage control to produce an AC output signal that substantially matches the AC signal of the electrical grid. The open-loop voltage control is based on the determined voltage of the AC signal. The method further includes closing, after a predetermined amount of time of operating the converter using the open-loop voltage control, a switching device to thereby connect the output of the converter with the electrical grid.

Controlled inrush current for converter-connected grid filter

A wind turbine generatorsupplies three-phase a.c. current of variable voltage and variable frequency to two pairs of rectifiersandwhich generate respective d.c. outputs connected to positive, negative and neutral d.c. conductors. The outputs from each pair of rectifiers are connected together, and the outputs from the two pairs are connected in series to create a high-voltage d.c. output. Invertersthen convert the d.c. power to a.c. at a fixed frequency and voltage suitable for connection to the mains grid. To reduce the effect of common-mode noise, a capacitor is connected between the 1 neutral conductorand earth, and a respective filter circuitis connected between each of the a.c. outputs of the invertersand earth. To reduce the effect of voltage surges during lightning, a surge protection device is also connected between the neutral d.c. conductorand earth. Any imbalance in the current in the positive and negative conductorsis compensated by detecting the presence of current flowing in the neutral conductor. Power supplied to auxiliary circuits from the output of one of the inverters, e.g., of the wind turbine is measured, and any resulting imbalance between the current in the positive and negative conductors is compensated. In the event of an earth-leakage fault in the conductors connecting the a.c. outputs of the inverters to the grid, when isolated, isolation detection relaysare provided.

Converters for wind turbine generators

A wind turbine converter system with a rectifier and an inverter and a converter controller has at least first and second converter strings. The converter system is controlled by a master-converter controller and a slave-converter controller. The master-converter controller controls the first converter string and the slave-converter controller controls the second converter string. The master-converter controller receives commands from a superordinate wind turbine controller, provides the slave-converter controller with string-control commands on the basis of the superordinate control commands, and controls the conversion operation of the first converter string on the basis of the superordinate control command. The slave-converter controller receives the string-control commands from the master-converter controller and controls the conversion operation of the second converter string on the basis of the string-control commands received. The first and the second converter strings can be arranged in a bipolar configuration giving access to a neutral point. Fault detection can be performed based on current through the neutral. The system is capable of fault ride-through. Also, in case of failure of the master-converter controller, a redundant unit takes its place.

Wind-turbine converter control for modular string converters

A heat sink for cooling at least one power semiconductor module, and that includes a basin for containing a cooling liquid. The basin has a contact rim for receiving the base plate and that includes a surface that is sloped inwards to the basin.

Heat sink for cooling of power semiconductor modules

A heat exchanger assembly for cooling a heat-generating component, such as a generator or power electronics module, within a wind turbine nacelle comprises a thermoelectric element, such as a Peltier element, having a first section arranged in a first region of relatively high temperature in contact with the heat-generating component or in the vicinity thereof, and a second section arranged in a second region of a relatively low temperature. The thermoelectric element is configured to transfer heat from the first region of relatively high temperature to the second region of relatively low temperature with consumption of electrical energy. A source of electrical energy is provided for the thermoelectric element, and a control unit may be provided for controlling the energy supply in order to control the temperature of the component or surface area cooled by the thermoelectric element. A further cooling element including a so-called heat pipe may be provided to enhance cooling efficiency.

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Aarhus N, Denmark

Tusitha Abeyasekera