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.

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 and method for wireless power energy distribution in which power is allocated for both real-time use as well as subsequent distributed energy storage including host objects that achieve enhanced features as enabled by the availability of wireless power. Embodiments range from stationary to mobile host objects such as reusable packaging system including direct impact on a transport vehicle moving a reusable container within a reusable packaging system.

The present invention discloses a fiducial node DC voltage based DC voltage droop control method with dead-band for HVDC grids. Two levels of DC voltage control e.g. primary and secondary DC voltage regulation are introduced to realize load sharing and DC voltage control in HVDC grids. In the process of primary DC voltage regulation, the power flow regulation ability of the entire HVDC grids can be significantly improved, and the DC voltage and stability of the HVDC grids will be quickly controlled and guaranteed for the benefit of droop characteristic. Secondary DC voltage regulation is achieved by by introducing the load-DC voltage controller. In the process of secondary DC voltage regulation, the burden of accommodating power imbalance by the DC voltage fiducial node will be alleviated, thus improving the ability to resist disturbances of the entire HVDC grids.

A grid connection power conversion device having isolated operation function for connecting a distributed power supply to a commercial power system is provided which comprises an inverter for converting DC power to AC power, a capacitor connected between the inverter and the commercial power system, a commercial voltage amplitude detection circuitry, an amplitude adjustment circuitry to increase an amplitude of an output voltage from the inverter stepwise from a given value to match the amplitude of the commercial system voltage, and a start-up control circuitry to control the grid connection power conversion device so that after the amplitude adjustment circuitry adjusts the amplitude of the output voltage from the inverter, after the start-up, to match the amplitude of the commercial system voltage detected by the commercial voltage amplitude detection circuitry, the start-up control circuitry connects the inverter to the commercial power system to start grid-connected operation.

Various implementations described herein are directed to systems and methods for managing a plurality of loads connected to a plurality of power sources using a switching apparatus. Apparatuses described herein may include multi-throw switches designed for fast and efficient switching of loads. Methods described herein may include selecting one or more loads from a group of loads to connect to one or more alternative power sources, and selecting one or more loads to connect to a main (e.g. utility) electrical grid.

A power transmission system includes: a power transmitter connected to a power supply; a plurality of power receivers respectively connected to a plurality of loads; a power transmission line connecting the power transmitter and the plurality of power receivers; and a controller. The controller acquires information on optimum power for maximizing transmission efficiency in the power transmission line and information on power demands requested by the loads, and routes transmission power from the power transmitter selectively to the plurality of power receivers. The transmission power is equal to or smaller than the optimum power. When a total power demand is larger than the optimum power, the controller requests another controller to supply supplementary power. When the total power demand is smaller than the optimum power, the controller notifies the other controller that surplus power is available.

The present invention discloses a modular intelligent combined wind power converter and a control method thereof. The modular intelligent combined wind power converter comprises separate bridge arm power units, wherein a plurality of the bridge arm power units are connected in parallel to form a high-capacity bridge arm power module, three bridge arm power modules form a three-phase full-controlled bridge power module, and the three-phase full-controlled bridge power module comprises an electric reactor, a capacitor, a fuse and a circuit breaker to form a basic converter module, and the basic converter module forms a high-capacity wind power converter through a modular intelligent combination method.

The present application provides a method and a system for controlling continuous high voltage ride-through and low voltage ride-through of a permanent magnet direct-driven wind turbine. The method includes: determining a transient time period during which the wind turbine is transitioned from a high voltage ride-through state to a low voltage ride-through state; controlling the wind turbine to provide, during the transient time period, a gradually increasing active current to the point of common coupling; and controlling the wind turbine to provide, during the transient time period, a reactive current to the point of common coupling according to an operation state of the wind turbine before the high voltage ride-through state.