Provided is an arrangement for controlling a converter of a power generation system, for example, a wind turbine, the converter being connected to a connection point to a utility grid, the arrangement including: a measurement section adapted to provide measurement values indicative of values of current and voltage at the connection point, a main converter controller adapted to receive the measurement values and to generate a main converter control signal based on the measurement values, an active filter system adapted to receive the measurement values and to generate an active filter control signal based on the measurement values, an addition element adapted to add the main converter control signal and the active filter control signal and to supply the sum signal as a control signal to the converter.

A power generation system (100) including an inverter (140) structured to convert a direct current (DC) power output from an external source (110) to an alternating current (AC) power. The inverter includes at least one phase for converting the DC power to a corresponding phase of AC power. The system also includes an alternator (124) of a generator set (120). The alternator includes at least one phase, each comprising a first winding section and a second winding section coupled in series between a point of common coupling and an output terminal of the phase. A phase of the inverter is connected in parallel with the first winding section of the alternator. The inverter is configured to provide reactive power compensation, power factor correction or acts as an active filter to provide harmoincs damping and the system can be used to buffer and handle grids transients.

A three-phase motor drive system for operation from a three-phase alternating current (AC) power source. The three-phase motor drive system includes a three-phase hybrid active harmonic filter (AHF) having an input operably connected to the three-phase AC power source, the three-phase hybrid active harmonic filter comprising an active harmonic filter operably connected in parallel with the three-phase AC power source and a three-phase AC reactor disposed in series between the input and an output of the hybrid active harmonic filter. The three-phase motor drive system also includes a three-phase variable frequency motor drive configured to provide excitation signals to a three-phase motor; and a three-phase AC motor operably connected to the three-phase variable frequency motor drive, the three-phase AC motor responsive the excitation signals.

A frequency converter and a method in a frequency converter. The frequency converter is adapted to drive an electrical load, wherein the frequency converter comprises a communications interface through which the frequency converter is adapted to receive external requests to change input power of the frequency converter, means adapted to hold one or more conditions for allowing to change the input power of the frequency converter, and processing means adapted to change the input power of the frequency converter upon receipt of the external request in the limits set by the one or more conditions. (FIG. 1)

An electrical power system connectable to a power grid includes a cluster of electrical power subsystems, each of the electrical power subsystems including a power converter electrically coupled to a generator having a generator rotor and a generator stator. Each of the electrical power subsystems defines a stator power path and a converter power path for providing power to the power grid. Each of the electrical power subsystems further includes a transformer. The system further includes a subsystem breaker configured with each of the electrical power subsystems, and a cluster power path extending from each subsystem breaker for connecting the cluster of electrical power subsystems to the power grid. The system further includes a reactive power compensation inverter electrically coupled within the electrical power system, the reactive power compensation inverter operable to increase the reactive power level in the electrical current flowing to the power grid.

A power converter controller for virtual impedance realization is provided that comprises: a sampling circuit configured to sample a real grid interface voltage at terminals of the power converter; a first operation block, which may be a subtractor, for performing a first operation on a reference voltage signal and the sampled real grid interface voltage signal of the power converter to generate a first voltage signal; a second operation block that may consist of a divider for dividing the first voltage signal by an amplification factor to generate a second voltage signal; and third operation block, which may be an adder, for adding the sampled real grid interface voltage signal to the second voltage signal, and a third voltage signal to generate a command voltage signal for realization at the DC-to-AC voltage conversion output, wherein the amplification factor is a real number greater than or equal to 1.

Disclosed techniques for power management include datacenter power management through phase balancing. Power for a datacenter is obtained across a plurality of AC power phases. A power consumption value by loads is determined within the datacenter for each of a plurality of power phases. A power consumption imbalance is calculated between a first phase and a second phase from the plurality of power phases within the datacenter. Phase power balancing is performed by transferring power from the first phase to the second phase from the plurality of power phases within the datacenter. The transferring power is accomplished using current injection. The performing phase power balancing by transferring power from the first phase to the second phase comprises a supply side transfer of power. Performing phase power balancing by transferring power from the first phase to the second phase is accomplished without transferring load power consumption between power phases.

A reactive power control method, a reactive power control device, and a reactive power control system are provided. The device includes: a communication interface, configured to receive a reactive power requirement command; an input interface, configured to acquire an electrical quantity parameter of a preset control point; a strategy calculation module, configured to calculate a target reactive power value meeting the reactive power requirement command based on the electrical quantity parameter, and allocate reactive power to be provided by a regulatable reactive device based on the target reactive power value; and an output interface, configured to send a command for providing the allocated reactive power to the regulatable reactive device.

A wind turbine assembly including a rotor system, a generator, a first converter, a second converter, and a controller system. The first converter includes a first bridge circuit having a plurality of switch members each having a controllable switch. The second converter includes a second bridge circuit having a plurality of switch members each having a controllable switch. The controller system is adapted to provide a drying operation for second converter including short circuiting the second converter with the controllable switches of the second bridge in circuit, and supplying power from the generator through the first converter to the short circuited second converter for drying the second converter.

A control unit for an active filter for reducing resonance in an electric system is provided. The electric system comprises a power source distributing an alternating current to an AC conductor connected to a power consuming unit for distributing the AC to the power consuming unit. The active filter comprises a DC power source and a DC conductor connecting the DC power source to the AC conductor. The control unit comprises: a voltage measurement unit adapter to create a voltage signal on the basis of a measured voltage; a computing unit adapted to compute, using a biquadratic filter, a first compensating current on the basis of the voltage signal for reducing resonance in the electric system and a switching system placed between the DC power source and the DC conductor for creating the calculated first compensating current.