A method for operating a wind farm having a string (S1-S3) of wind turbines (100-100c) which are electrically connectable with each other and a grid (510, 550) is disclosed. Each wind turbine includes a rotor (106) with rotor blades (108), a power conversion system (118, 210, 238) mechanically connected with the rotor (106), and at least one auxiliary subsystem (105, 109). The method includes operating the wind turbines of the string in an island operating mode in which the wind turbines are not connected with the grid, and the respective at least one auxiliary subsystem is supplied with electric power generated by the power conversion system of the respective wind turbine; detecting that the rotor of one of the wind turbines is exposed to a wind condition at which at least one of the rotor blades is at risk of stalling at the currently generated electric output power; and increasing the electric power generated by the power conversion system of the one of the wind turbines by an electric power amount which is sufficient for suppling the at least one auxiliary subsystem of at least one of the other wind turbines of the string.

In various embodiments of the present disclosure, there is provided a method of controlling active power generation of a wind power plant coupled to a power grid, the wind power plant including a power plant controller for controlling a plurality of wind turbine generators. In an embodiment, the method includes monitoring an operational status of a plant compensation equipment and adjusting a plant reactive power capability when the operational status of the plant compensation equipment indicates a fault in the plant compensation equipment. According to an embodiment, the method includes controlling the wind power plant to curtail the active power generated by the wind power plant by a curtailment amount determined based on the adjusted plant reactive power cap ability. A corresponding wind power plant is further provided.

In various embodiments of the present disclosure, there is provided a method of controlling active power generation of a wind power plant coupled to a power grid, the wind power plant including a power plant controller for controlling a plurality of wind turbine generators. In an embodiment, the method includes monitoring an operational status of a plant compensation equipment and adjusting a plant reactive power capability when the operational status of the plant compensation equipment indicates a fault in the plant compensation equipment. According to an embodiment, the method includes controlling the wind power plant to curtail the active power generated by the wind power plant by a curtailment amount determined based on the adjusted plant reactive power cap ability. A corresponding wind power plant is further provided.

A method and a system sense at least one phase difference between at least two phases of a group of parallel connected three phase AC output terminals (e.g., a first phase AC output terminal, a second phase AC output terminal, or a third phase AC output terminal). The parallel connected AC output terminals may be three parallel connected DC to AC three phase inverters. Features of the parallel connected three phase AC output terminals enable wiring of conductors to one phase of an AC output terminal to be swapped with wiring of conductors of one phase of another phase AC output terminal. A sign of at least one phase difference is verified different from signs of other phase differences thereby the system determining the lateral position of the at least one three phase inverters relative to at least one other of the three phase inverters.

A method and a system sense at least one phase difference between at least two phases of a group of parallel connected three phase AC output terminals (e.g., a first phase AC output terminal, a second phase AC output terminal, or a third phase AC output terminal). The parallel connected AC output terminals may be three parallel connected DC to AC three phase inverters. Features of the parallel connected three phase AC output terminals enable wiring of conductors to one phase of an AC output terminal to be swapped with wiring of conductors of one phase of another phase AC output terminal. A sign of at least one phase difference is verified different from signs of other phase differences thereby the system determining the lateral position of the at least one three phase inverters relative to at least one other of the three phase inverters.

Systems and methods for managing power on an electric power grid including a server for communicating IP-based messages over a network with distributed power consuming devices and/or power supplying devices, the IP-based messages including information including a change in state of the power consuming device(s), a directive for a change in state of the power consuming device(s), a priority message, an alert, a status, an update, a location with respect to the electric power grid, a function, device attributes, and combinations thereof.

Systems and methods for managing power on an electric power grid including a server for communicating IP-based messages over a network with distributed power consuming devices and/or power supplying devices, the IP-based messages including information including a change in state of the power consuming device(s), a directive for a change in state of the power consuming device(s), a priority message, an alert, a status, an update, a location with respect to the electric power grid, a function, device attributes, and combinations thereof.

Provided herein are embodiments of a programmable microgrid control system that includes programming software tools capable of modeling, analyzing and monitoring power system especially AC, DC and hybrid microgrids. The monitoring feature of the software tool allows tools to communicate with a real system to acquire online data of power system assets such as conventional and renewable energy sources, transformers, and electrical loads.

A cascaded H-bridge inverter and a method for handling a fault thereof are provided. An output voltage or an output power of each of N solar panels is detected by a controller. In a case that the output voltage of at least one of the N solar panels is lower than a preset voltage, or that the output power of at least one of the N solar panels is lower than a preset power, the controller controls a corresponding switching device to be switched off, and changes a set value of a voltage across a capacitor in the direct current side. Then, the controller controls a corresponding H-bridge module to perform inverting by taking the set value of the voltage across the capacitor in the direct current side as an input value, so that a total output modulation voltage of the cascaded H-bridge inverter meets a preset condition.

A power adjusting circuit includes a sensor configured to measure a voltage and a current of the first AC output by an inverter, an AC/DC/AC converter configured to receive the first AC output from the inverter, and a controller configured to convert the first AC output to a second AC output having a desired power factor.