Disclosed is grid-forming control method for an offshore wind turbine, including the following steps: obtaining a grid voltage and current at a grid connection point of a wind turbine, actual values of active power and reactive power of the wind turbine, and references of the active power, the reactive power and an voltage amplitude; calculating a phase reference of a grid-side converter of the wind turbine; calculating a reference of a modulating voltage at the grid-side converter of the wind turbine in a dq rotating coordinate system; and calculating a reference of a modulating voltage at the grid-side converter in an abc static coordinate system according to the phase reference of the grid-side converter of the wind turbine and the reference of the modulating voltage in the dq rotating coordinate system. The present disclosure can control the voltage amplitude of the grid connection point by the active power of the wind turbine, and can control the voltage frequency at the grid connection point by the reactive power of the wind turbine. Furthermore, the wind turbine controlled by the present disclosure can be kept in reliable synchronous running under conditions of startup, power fluctuation, alternating current (AC) fault and the like.

Disclosed is grid-forming control method for an offshore wind turbine, including the following steps: obtaining a grid voltage and current at a grid connection point of a wind turbine, actual values of active power and reactive power of the wind turbine, and references of the active power, the reactive power and an voltage amplitude; calculating a phase reference of a grid-side converter of the wind turbine; calculating a reference of a modulating voltage at the grid-side converter of the wind turbine in a dq rotating coordinate system; and calculating a reference of a modulating voltage at the grid-side converter in an abc static coordinate system according to the phase reference of the grid-side converter of the wind turbine and the reference of the modulating voltage in the dq rotating coordinate system. The present disclosure can control the voltage amplitude of the grid connection point by the active power of the wind turbine, and can control the voltage frequency at the grid connection point by the reactive power of the wind turbine. Furthermore, the wind turbine controlled by the present disclosure can be kept in reliable synchronous running under conditions of startup, power fluctuation, alternating current (AC) fault and the like.

Disclosed are a method and system for verifying a low-frequency oscillation damping control effect of a governor power system stabilizer (GPSS), relating to the technical field of power systems. The method includes: selecting a wiring working condition for a fault-free disconnection test, and constructing a unit test working condition; performing the fault-free disconnection test on an outgoing line of a power plant, and collecting an electromagnetic power fluctuation recording curve; and comparing low-frequency oscillation damping effects under different GPSS settings, evaluating the effects, and performing a cyclic test. A success rate of the test is increased, safety of the test is improved, and the overall stability and anti-oscillation capacity of the system are improved in the disclosure.

A method for damping oscillations in a power grid is provided. A damping vector (9) targeted at a position of a damping entity (11) and referencing a common reference time frame (4) is generated, based on an identified oscillation in the power grid, the damping vector (9) specifying a frequency, a phase angle and an amplitude. The damping vector (9) is provided to the damping entity (11), and the damping entity (11) reconstructs an oscillation signal corresponding to the oscillation in the power grid, based on the damping vector (9) and applying the common reference time frame (4). The damping entity (11) supplies and/or consumes active and/or reactive power to/from the power grid in accordance with the reconstructed oscillation signal, thus causing damping of the oscillation in the power grid.

The present invention relates to a field coil stable power system for generating and stabilizing electrical output. The system includes a ferromagnetic core, preferably made of iron, that interacts with a field coil. The field coil generates a magnetic field when current flows through it, and this magnetic field interacts with the magnetic field of a permanent magnet, producing attraction or repulsion forces on the ferromagnetic core. The ferromagnetic core absorbs magnetic energy and dissipates the magnetic energy gradually, preventing abrupt changes in current. The system is capable of stabilizing electrical output by balancing fluctuations in current and is applicable to various electronic devices, including audio equipment and medical devices.

A voltage control apparatus includes an inverter and a controller connected to the inverter. The controller executes processing for, when a voltage drop of an output voltage of the inverter is equal to or larger than a threshold because of fluctuation in an AC voltage of a power grid, calculating virtual impedance using variables including an active voltage command value and a reactive voltage command value and an active current command value and a reactive current command value, processing for calculating a virtual active voltage and a virtual reactive voltage by multiplying, by the virtual impedance, each of an active current and a reactive current, and processing for performing voltage control based on the virtual active voltage and the virtual reactive voltage such that each of the active current and the reactive current can approach each of the active current command value and the reactive current command value.

There is disclosed herein an energy storage system for a direct current (DC) transmission system, the energy storage system being configured to be connected to a DC link. The energy storage system comprises a first system terminal, a second system terminal, a first converter connected to the first system terminal, and a second converter connected to the first converter and the second system terminal. The energy storage system further comprises an AC loop device providing an alternating current (AC) path, and a plurality of energy storage devices connected in parallel with the second converter comprising a cell having power electronic switches, and an energy storage element connected to the cell, wherein the cells are individually switchable. The present disclosure further relates to a method for providing energy storage to a DC transmission system.

Systems for microgrid interfacing may include a virtual resource platform (VRP) for integration and management of a plurality of integrated distributed energy resources (IDERs). The VRP may include at least one request-handling interface to process requests for interfacing IDERs, a driver identification engine to retrieve resource metadata attributes and identify compatible drivers, and a standardized application programming interface (API) for cross-platform compatibility. The VRP may further include a predictive energy manager. The predictive energy manager may fetch telemetry data from the IDERs, analyze the data using machine-learning-based models, and may generate energy management analysis products.

The present invention relates to a multichannel test system (100) and to a method for supplying test load devices (61, 62) with electrical power from a supply grid, comprising at least a first test channel (10) and a second test channel (20) which are galvanically separated. At least one switching device (40) is provided for galvanically coupling intermediate circuits (13, 23) of the test channels (10, 20) in a switchable manner to form a common intermediate circuit. For this purpose, in addition to phase-controlled, variably adjustable rectification, uncontrolled, invariable rectification is also provided in a passive operating mode by an active power stage (12, 22) in power converter circuits (16, 26, 36) of the test channels (10, 20, 30).

A model predictive virtual synchronous generator inverter control method considering a frequency-movement direction includes: obtaining a current frequency absolute value based on fundamental frequency of an inverter and a steady-state absolute value based on the fundamental frequency of the inverter; determining a frequency-movement state by comparing the above two absolute values: in a state of deviating from the fundamental frequency or a state of regressing to the fundamental frequency; setting a corresponding prediction output horizon according to the frequency-movement state, and constructing a cost function considering the frequency-movement state; and calculating an optimal virtual power increment value based on the cost function, then calculating an optimal virtual power, inputting the optimal virtual power to a swing equation of a virtual synchronous generator, and performing frequency adjustment according to an output value.