Systems and methods for controlling operation of a power converter based on grid conditions are provided. In particular, a first gating voltage can be applied to a switching element of a power converter associated with a wind-driven power generation system. The first gating voltage can be greater than a threshold voltage for the switching element. A grid event associated with an electrical grid coupled to the power generation system can be detected. A second gating voltage can be applied to the gate of the switching element during the detected grid event. The second gating voltage can be greater than the first gating voltage.

A method for compensating the output power of wind turbine generator set includes acquiring the average values of the first ambient temperature of environments where the wind turbine generator set is located in various periods; collecting the output power of the wind turbine generator set at the end time of various periods; compensating the set output power collected at the end time of current period according to difference value between the average value of the first ambient temperature in the current period and that in the previous period so as to guarantee the stability of the set output power if the average value of the first ambient temperature in the current period and the average value of the first ambient temperature in the previous period both are higher than a preset temperature threshold value.

A method is disclosed for controlling a wind turbine generator to provide power above a rated level. The wind turbine includes one or more electrical components that conduct current from the internal generator to supply the external grid. The control method calculates the maximum current that the electrical components can carry at the ambient temperature. The calculated current is combined with a measurement of the voltage and an estimate of reactive power in the system to give a maximum power at which the wind turbine can operate without the maximum allowable current being exceeded for the electrical components. The electrical components may be housed in the main electrical panel of the wind turbine.

A method of setting a reference DC-link voltage of a wind-turbine converter system is provided. At least at least one DC voltage demand from at least one generator-side inverter and at least one DC voltage demand are received from at least one grid-side inverter. A generator-side DC voltage demand value on the basis of the at least one DC voltage demand received from the at least one generator-side inverter. Also a grid-side DC voltage demand value is determined on the basis of the at least one DC voltage demand received from the at least one grid-side inverter. The highest DC voltage demand value out of the generator-side and grid-side DC voltage demand values is chosen. This chosen value corresponds to the set reference DC-link voltage.

The invention relates to a method for controlling power generation of a VSM wind turbine. The wind turbine comprises a machine side converter, a line side converter, a DC link, and an electric storage device electrically connected to the DC link. The method comprises determining a first power control signal to the machine side converter, determining a second power control signal for controlling a desired output power of the line side converter based on a storage device voltage error, and a power production reference, and determining a charging current reference for controlling charging and discharging of the electric storage device based on a DC-link voltage error.

The present invention relates to a connection system for connecting a power generator to a DC electrical power system, with a controllable voltage source unit functionally connected in series with the power generator to receive AC electrical power from the power generator, and to generate an AC electrical power output accordingly, and a rectifier arranged to receive AC electrical power output from said voltage source unit and to rectify the AC electrical power output to a DC electrical power to be provided to the DC electrical power system. The invention also relates to method for connecting a power generator to a DC electrical power system.

System and methods for optimizing operation of a wind turbine are disclosed. In one aspect, the method also includes determining, via a converter controller of a power converter, a tap position of a tap changer configured between the power grid and a primary winding of a transformer. Another step includes calculating, via the converter controller, a primary voltage of the primary winding as a function of the tap position. The method also includes implementing, via the converter controller, a control action if the primary voltage or a measured secondary voltage of a secondary winding of the transformer is outside of a predetermined voltage range.

The invention is directed to a wind generator, comprising a wind turbine which is mounted so that it is rotatable about a horizontal or approximately horizontal rotational axis and which has one or more blades or other wind-guiding surfaces for converting flow energy of the wind into rotational energy, and at least one generator, coupled to the hub or shaft of the wind turbine or to the output shaft of a gear connected thereto, for converting the rotational energy into electrical energy, wherein the center of gravity of the wind turbine, together with the hub and rotor shaft and rotatable parts coupled thereto which rotate about the same rotational axis, is translationally movable in a direction completely or predominantly in parallel to the rotational axis of the wind turbine.

A lubricant cooler, a cooling and lubricating system of a speed-up gear box, a wind power unit and a low-temperature starting method of the wind power unit. The lubricant cooler includes a radiating plate and a one-way valve arranged on a lubricant conveying pipeline, wherein the radiating plate and the one-way valve are arranged in parallel, and the one-way valve and/or the lubricant conveying pipeline in communication with the one-way valve are integrated on the radiating plate. The lubricant cooler can solve the problem that, when the wind power unit is started at a low temperature, the cooling and lubricating system of the speed-up gear box causes the shut-down of the wind power unit because the lubricant blocks the radiating plate.

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.