A method for operating a wind turbine generator connected to a power network to account for recurring voltage faults on the power network caused by automatic reclosure of at least one circuit breaker following a short-circuit. The method comprises: identifying a deviation of voltage level of the power network from a normal operational voltage level of the network; determining that the identified deviation fulfils criteria for automatic reclosure; and operating the wind turbine generator in a recurring fault mode if automatic reclosure criteria are fulfilled. When operating the wind turbine generator in recurring fault mode, the method comprises: monitoring the recovery of the voltage level from the deviation; categorising the recovery of the voltage as one of at least a strong recovery or a weak recovery; and implementing a ride-through protocol according to the category of recovery.

A method for operating a renewable energy power plant comprising a plurality of renewable energy generators. The method comprises: identifying a predetermined condition of the renewable energy power plant, of the grid, or of the connection between the renewable energy power plant and the grid, the predetermined condition indicating a weak grid interconnection between the renewable energy power plant and the grid; and controlling each renewable energy generator in an adaptive active power mode in response to recovery of the grid from a voltage deviation. The adaptive active power mode comprises: determining a thermal capacity of a chopper resistor of the renewable energy generator; calculating, based upon the determined thermal capacity, a limit level of rate of change of active power output that may be implemented by the renewable energy generator; and operating the renewable energy generator to output active power at the calculated rate of change limit level.

A grounding circuit for a backup power source used to power a pitch motor of a pitch system in a wind turbine is provided. The grounding circuit includes one or more switching elements configured to selectively couple the backup power source to a charging circuit based on a state of a first interface element. The grounding circuit further includes one or more switching elements configured to selectively couple the backup power source to ground based on a state of a second interface element. The grounding circuit includes at least one circuit protection device coupled between the backup power source and the charging circuit. When the backup power source is coupled to the charging circuit and subsequently coupled to ground, the at least one circuit protection device is configured to decouple the backup power source from the charging circuit.

A grid power configuration may provide a reliable, efficient, inexpensive and environmentally conscious power source to a site, for example, a remote site such as a well services environment. Grid power may be provided for one or more operations at the site by coupling a main breaker to a switchgear unit coupled to one or more loads. The switchgear unit may be coupled to the main breaker via a main power distribution unit and may also be coupled to one or more loads. At least one of a grid power unit and a switchgear unit may be coupled to the main breaker via the main power distribution unit and may also be coupled to one or more additional loads. A control center may be communicatively coupled to the main breaker or any one or more other components to control one or more operations of the grid power configuration.

The present disclosure provides a programmable controller for monitoring battery performance and usage at a remote pump jack location. The disclosure provides an energy efficient controller and display system which allows the operator to quickly and accurately test batteries in an installation. It uses programmable logic to switch between system modes and decide which battery supplies power to the output. Further it will sense any high voltages at and disable the input from the faulty source. Further, the programmable logic is designed such that the mode selection process is automatic when the system is in operation. The purpose is to elongate battery and connected equipment life by preventing battery failure. The present disclosure also provides an easy and economical method of communicating potential battery failure and status to an operator via cell phone communication.

A method for controlling a wind farm electrical power system is presented. The wind farm electrical power system includes a controller and a plurality of wind turbines electrically connected to an electrical grid through a point of interconnection. Each wind turbine includes a voltage regulator. The method includes receiving, via the controller, one or more electrical signals associated with the point of interconnection for a frequency domain. Further, the method includes estimating, via an estimator of the controller, a voltage sensitivity of the electrical grid using the one or more electrical signals. Moreover, the method includes dynamically controlling a voltage of the wind farm electrical power system at the point of interconnection based on the voltage sensitivity.

A wind park for feeding power into a supply network at a connection point is provided. The wind park includes wind turbines for generating the power, a DC network for transmitting the power to the connection point, an inverter configured to transform electrical DC voltage into an AC voltage for feeding the power into the supply network, at least one DC-DC converter for feeding the power into the DC network. The DC-DC converter includes a switching device and a transformer with primary and secondary sides. The primary side is coupled to the at least one wind turbine via the switching device and the secondary side is coupled to the DC park network via at least one rectifier. The DC-DC converter is configured to apply a DC voltage of changing polarity to the primary side by the switching device to transform a DC voltage of the at least one wind turbine.

A method for operating a renewable energy power plant comprising a plurality of renewable energy generators. The method comprises: identifying a predetermined condition of the renewable energy power plant, of the grid, or of the connection between the renewable energy power plant and the grid, the predetermined condition indicating a weak grid interconnection between the renewable energy power plant and the grid; and controlling each renewable energy generator in an adaptive active power mode in response to recovery of the grid from a voltage deviation. The adaptive active power mode comprises: determining a thermal capacity of a chopper resistor of the renewable energy generator; calculating, based upon the determined thermal capacity, a limit level of rate of change of active power output that may be implemented by the renewable energy generator; and operating the renewable energy generator to output active power at the calculated rate of change limit level.

Embodiments of systems and methods for power demand management are described herein. More specifically, embodiments comprise systems and methods for powering, controlling, and/or operating various types of controllable load for integration with power fluctuations from intermittent power generation plants, such as photovoltaic arrays and wind turbine farms.

Harmonics of a power output of a power plant at a point of common coupling between the power plant and a utility grid, wherein the power plant comprises a plurality of energy production units. The method comprises determining an electrical characteristic at the point of common coupling; determining the electrical characteristic at an output terminal of each of the energy production units and dispatching a control signal to at least one of the energy production units to control the electrical characteristic at an output terminal of the respective energy production units. The control signal is based on the measurement of the electrical characteristic at the point of common coupling and arranged for damping the harmonic of the power output of the power plant at the point of common coupling, wherein the control signal is determined on the basis of a predetermined prioritizing sequence of said electrical characteristic.