Provided is a method of controlling a converter, in particular of a wind turbine, the converter including a first converter portion connected to a generator, a DC-link, and a second converter portion connected to a utility grid. The method including: controlling the first converter portion and the second converter portion by a first control signal and a second control signal, respectively, both being derived based on a requested power signal, in particular requested active power signal, and a generator rotational speed, wherein the first control signal indicates substantially constant generator torque for rotational speed variations of the generator rotational speed above a frequency threshold.

A load control method and a load control apparatus for a wind turbine generator system are provided, and the load control method includes: obtaining feature parameters of the wind turbine generator system for load prediction; obtaining a load estimation value of the wind turbine generator system by inputting the obtained feature parameters into a virtual load sensor; adjusting a control strategy of the wind turbine generator system based on the obtained load estimation value. A controller and a computer readable storage medium storing a computer program are further included. With the load control method and apparatus for the wind turbine generator system, a trained virtual load sensor can be used to realize real-time monitoring of the load of the on-site wind turbine generator system, and a reference for adjusting the control strategy can be provided according to the load.

A method for operating a power system connected to a power grid includes providing an active filter in the converter power path. Further, the method includes determining a change in attenuation of harmonics of the power system over a predetermined frequency spectrum that is needed to comply with one or more grid code requirements of the power grid. Thus, the method includes actively controlling, via a controller, the active filter to provide the change to the attenuation of the harmonics of the power system so as to mitigate the harmonics of the power system.

Provided is a method and system of positive and negative sequence rotor currents control for DFIGs under a single dq-PI control structure, comprising: adjusting the negative sequence rotor current reference

[00001]$\stackrel{.fwdarw.}{I}{\overline{{}_r}}_{\_ref-\ast }$

according to the negative sequence stator terminal voltage to obtain a reference adjustment value

[00002]$\stackrel{.fwdarw.}{I}{\overline{{}_r}}_{\_com-\ast }$

; converting the reference adjustment value to the forward-rotating dq coordinate system and superimposing it with the positive sequence rotor current reference as the input of a PI-regulator-based current feedback controller to uniformly control the positive and negative sequence rotor current; determining the output voltage reference of the rotor-side converter by the PI-regulator-based current feedback controller, according to which, the switching signal of the rotor-side converter can be determined through the SPWM function, controlling the turn-on and turn-off of the bridge arms of the rotor-side converter to form the output voltage. It realizes the control of the positive and negative rotor currents under the single dq-PI control structure, retaining the good control performance of the control structure for the positive sequence rotor current, and enabling the control of the negative sequence rotor current under unbalancing conditions, with a control structure with lower order and lower complexity compared to the existing control structures for realizing the DFIG positive and negative sequence current control.

A method and associated system for providing grid-forming (GFM) control of an inverter-based resource (IBR) connected to an electrical grid include monitoring the electrical grid for grid events that cause a change in one or both of grid frequency and angle. Via a controller, an active power response of the IBR to the grid event is controlled by changing an angle of the IBR voltage relative to grid voltage in a manner so as to mimic an active power response of an IBR having a certain desired impedance that may similar to or different from a hardware impedance of the IBR itself.

A method and apparatus for operating a converter system of a wind turbine for exchanging electrical power with an electrical supply grid at a grid connection point are provided. In the method and apparatus, the converter system is operated in a normal operating mode. An overload situation affecting the converter system is detected and operation of the converter system is changed to an overload operating mode when the overload situation is detected. An average switching frequency for generating an output current is reduced in the overload operating mode of the converter system in comparison with the normal operating mode, a higher load is permitted on the converter system, which may be in the form of an increased temperature or an increased output current, in the overload operating mode of the converter system for a predetermined maximum overload period.

A method monitors one or more electric drives of an electromechanical installation, particularly a wind orientation control of a wind turbine. The drive or drives work on a movable machine element of the installation, e.g., on a bearing ring of an azimuth bearing. A plurality of currents, e.g., phase currents of a plurality of phases, and/or a plurality of drives are measured during the operation of the drives at a predetermined sampling rate and are stored as series of measurement values with a predetermined quantity m of measurement values. Statistical characteristic values are calculated from one or more series of measurement values, and one or more pieces of state information and/or one or more state prognoses are/is generated for one or more drives through analysis of the time evolution of the characteristic values and/or through analysis of a relationship of the characteristic values of different motor currents.

An electrical system for a wind turbine having a reduced uptower footprint and method for achieving the same are provided. Accordingly, the electrical system includes a plurality of electrical subsystems having a plurality of electrical subsystem assemblies. At least one electrical subsystem assembly is integrated with the generator housing. Additionally, the electrical subsystem assembly is coupled between the stator or the rotor of the generator and the generator output connection. The electrical system incorporating the electrical subsystem assembly with the generator housing has a reduced uptower footprint relative to a nominal design of an electrical system.

A system and method are provided for controlling a wind turbine to protect the wind turbine from anomalous operations. Accordingly, in response to receiving data indicative of an anomalous operational event of the wind turbine, the controller initiates an enhanced braking mode for the wind turbine. The enhanced braking mode is characterized by operating the generator at a torque setpoint that generates maximum available torque for a given set of operating conditions. Additionally, the torque setpoint is in excess of a nominal torque limit for the generator.

The present disclosure proposes a decomposition-coordination voltage control method for wind power to be transmitted to a nearby area via flexible DC. The method includes: initializing parameters; sending the parameters to wind power farms; for each of the wind power farms, establishing a voltage control optimization sub-model; solving the voltage control optimization sub-model to obtain a first optimal result; for the control center, establishing a voltage control optimization main model; solving the voltage control optimization main model to obtain a second optimal result; calculating a determination index based on the first optimal result and the second optimal result; and determining whether the determination index is convergent to an admissible value, if no, updating the parameters and returning to establishing the voltage control optimization sub-model.