The present disclosure relates to a method for controlling a converter, in particular power converter of a wind power installation. The converter has a plurality of, preferably parallel, converter modules. The method includes the following steps: driving a first converter module, such that the converter module generates a first electrical AC current in a first switch position, driving a second converter module, such that the converter module generates a second electrical AC current in a second switch position, superposing the first electrical AC current and the second electrical AC current to form a total current, detecting the total current of the converter, determining a virtual current depending on the first and second switch positions, and changing the first switch position of the first converter module and/or the second switch position of the second converter module depending on the total current and the virtual current.

A method for operating an electric island power network having a renewable energy generation plant, a conventional energy generation plant, an energy store, and an energy consumer, includes: defining first operating parameters for the network for when a frequency and/or voltage of the network is outside defined limits; operating the network using the first operating parameters causing the frequency and voltage of the network to both be within the defined limits; defining second operating parameters for the network after the expiration of a defined time span over which the frequency and voltage have remained within the defined limits, the second operating parameters being defined such that operating the network using the second operating parameters causes the network to operate cost-optimally. If verified that the second operating parameters ensure that the frequency and voltage remain within the defined limits, operation using the second operating parameters is maintained. Otherwise, it is discontinued.

A power conversion device includes a power conversion circuit and a power conversion control circuit. The power conversion control circuit is configured to calculate a positive-phase sequence current command signal based on a positive-phase sequence voltage of the three-phase AC output voltage and a positive-phase sequence current of the three-phase AC output current, calculate a negative-phase sequence current command signal based on the first axis negative-phase sequence current command value, the second axis negative-phase sequence current command value, the first axis negative-phase sequence current value, and the second axis negative-phase sequence current value, and generate the switching control signal based on the positive-phase sequence current command signal and the negative-phase sequence current command signal.

A wind power converting device includes a plurality of grid-side converters, a plurality of generator-side converters and a plurality of DC buses. The grid-side converters are connected with each other in series and electrically coupled to a power grid. The generator-side converters are connected with each other in series and electrically coupled to a generator device. The DC buses are electrically coupled between the grid-side converters and the generator-side converters. The DC buses include a positive DC bus, a negative DC bus and at least one intermediate DC bus between the positive DC bus and the negative DC bus. A cross section area of a conductor of the intermediate DC bus is smaller than 30% of a cross section area of a conductor of the positive DC bus or smaller than 30% of a cross section area of a conductor of the negative DC bus.

Methods and apparatus for reducing peak power consumption of a grid connected power plant having a plurality of wind turbines. In response to determining that a power production value of the power plant is below a power threshold, one method includes: after a first time delay of a first group of one or more wind turbines, control the first group to operate in a power saving mode for a predefined first power saving period; and after a first time delay of a second group of one or more other wind turbines, control the second group to operate in the power saving mode for a predefined second power saving period. The first time delay of the first group is less than the first time delay of the second group and the power saving mode inhibits a power consuming activity for the wind turbines operating in the power saving mode.

An energy storage system converts variable renewable electricity (VRE) to continuous heat at over 1000° C. Intermittent electrical energy heats a solid medium. Heat from the solid medium is delivered continuously on demand. An array of bricks incorporating internal radiation cavities is directly heated by thermal radiation. The cavities facilitate rapid, uniform heating via reradiation. Heat delivery via flowing gas establishes a thermocline which maintains high outlet temperature throughout discharge. Gas flows through structured pathways within the array, delivering heat which may be used for processes including calcination, hydrogen electrolysis, steam generation, and thermal power generation and cogeneration. Groups of thermal storage arrays may be controlled and operated at high temperatures without thermal runaway via deep-discharge sequencing. Forecast-based control enables continuous, year-round heat supply using current and advance information of weather and VRE availability. High-voltage DC power conversion and distribution circuitry improves the efficiency of VRE power transfer into the system.

A system includes a flexible datacenter and a power generation unit that generates power on an intermittent basis. The flexible datacenter is coupled to both the power generation unit and grid power through a local station. By various methods, a control system may detect a transition of the power generation unit into a stand-down mode and selectively direct grid power delivery to always-on systems in the flexible datacenter.

Various embodiments include methods for controlling energy conversion, energy storage, energy transportation, and/or energy consumption of multiple energy installations of an energy system and/or of multiple consumers flexible with regard to their load. The method may include: optimizing values of variables for control by calculation based on a first and a second optimization variable; calculating multiple solutions of the values optimum with regard to the first optimization variable, using a first optimization; ascertaining one of the calculated solutions as optimum with regard to the second optimization variable using a second optimization; and using the optimum calculated solution for controlling the energy system.

A method for attenuating low-frequency oscillations in an electrical power supply grid by means of a feed device which feeds into the electrical power supply grid, in particular a wind power installation, wherein the electrical power supply grid has a grid voltage and a grid frequency, comprising the following steps: picking up a grid signal having the low-frequency oscillations, splitting a total frequency range of the grid signal in which oscillations to be attenuated are to be expected into a plurality of partial frequency ranges, each having a lower and an upper range frequency, performing in each case one frequency analysis of the grid signal for each partial frequency range in order to identify in each case one or more oscillations having an oscillation frequency in the partial frequency range, if present, identifying a low-frequency oscillation to be attenuated as target oscillation depending on the frequency analyses of all of the partial frequency ranges, detecting the target oscillation at least according to frequency and amplitude and optionally according to phase, determining a setpoint attenuation signal depending on the target oscillation detected according to frequency and amplitude and possibly phase for attenuating the detected target oscillation, generating a setpoint feed signal depending on the setpoint attenuation signal and a basic setpoint signal, and generating and feeding in a feed signal depending on the setpoint feed signal (QE).

The system and method described herein provide control for a power generating asset having a double-fed generator connected to an electrical grid. Accordingly, a non-deliverable component and a deliverable component of a total power output of a generator of the power generating asset is determined via a controller. A compensation module of the controller then determines a first control signal based, at least in part, on the non-deliverable component. The first control signal is configured to establish a modified rotor current setpoint. Additionally, a buffer module of the controller then determines a buffer control signal for a DC energy buffer based, at least in part, on the non-deliverable component. The DC energy buffer is operably coupled between a line-side converter and a rotor-side converter of a power converter of the power generating asset. In response to the first control signal and the buffer control signal the non-deliverable component is delivered to the DC energy buffer via the line-side converter, thereby precluding the delivery of the non-deliverable component to or from the electrical grid. The deliverable component of the total power output of the generator is delivered to the electrical grid.