Provided is a method for feeding electrical power into an electrical supply grid that has a grid voltage and a grid frequency. The grid comprises consumers for consuming electrical power from the grid, and generators for generating electrical power and feeding the electrical power into the grid. A feed management system is provided for managing the feed. The feed management system takes into consideration a power flow stipulation for a power flow in at least one grid segment of the electrical supply grid, an energy provision stipulation for the provision of a quantity of energy at at least one consumption point of the electrical supply grid, and a stability stipulation that specifies at least one stability criterion for the electrical supply grid. The feed management system, depending on the power flow stipulation, the energy provision stipulation and the stability stipulation, selects or adjusts a master controller to support the feed.

Provided is a method for feeding electrical power into an electrical supply grid that has a grid voltage and a grid frequency. The grid comprises consumers for consuming electrical power from the grid, and generators for generating electrical power and feeding the electrical power into the grid. A feed management system is provided for managing the feed. The feed management system takes into consideration a power flow stipulation for a power flow in at least one grid segment of the electrical supply grid, an energy provision stipulation for the provision of a quantity of energy at at least one consumption point of the electrical supply grid, and a stability stipulation that specifies at least one stability criterion for the electrical supply grid. The feed management system, depending on the power flow stipulation, the energy provision stipulation and the stability stipulation, selects or adjusts a master controller to support the feed.

A system of surge suppressor units is connected at multiple locations on a power transmission and distribution grid to provide grid level protection against various disturbances before such disturbances can reach or affect facility level equipment. The surge suppressor units effectively prevent major voltage and current spikes from impacting the grid. In addition, the surge suppressor units include various integration features which provide diagnostic and remote reporting capabilities required by most utility operations. As such, the surge suppressor units protect grid level components from major events such as natural geomagnetic disturbances (solar flares), extreme electrical events (lightning) and human-generated events (EMPs) and cascading failures on the power grid.

A system of surge suppressor units is connected at multiple locations on a power transmission and distribution grid to provide grid level protection against various disturbances before such disturbances can reach or affect facility level equipment. The surge suppressor units effectively prevent major voltage and current spikes from impacting the grid. In addition, the surge suppressor units include various integration features which provide diagnostic and remote reporting capabilities required by most utility operations. As such, the surge suppressor units protect grid level components from major events such as natural geomagnetic disturbances (solar flares), extreme electrical events (lightning) and human-generated events (EMPs) and cascading failures on the power grid.

A system of surge suppressor units is connected at multiple locations on a power transmission and distribution grid to provide grid level protection against various disturbances before such disturbances can reach or affect facility level equipment. The surge suppressor units effectively prevent major voltage and current spikes from impacting the grid. In addition, the surge suppressor units include various integration features which provide diagnostic and remote reporting capabilities required by most utility operations. As such, the surge suppressor units protect grid level components from major events such as natural geomagnetic disturbances (solar flares), extreme electrical events (lightning) and human-generated events (EMPs) and cascading failures on the power grid.

A system of surge suppressor units is connected at multiple locations on a power transmission and distribution grid to provide grid level protection against various disturbances before such disturbances can reach or affect facility level equipment. The surge suppressor units effectively prevent major voltage and current spikes from impacting the grid. In addition, the surge suppressor units include various integration features which provide diagnostic and remote reporting capabilities required by most utility operations. As such, the surge suppressor units protect grid level components from major events such as natural geomagnetic disturbances (solar flares), extreme electrical events (lightning) and human-generated events (EMPs) and cascading failures on the power grid.

Embodiments concern a plant for melting and/or heating metal material and a corresponding method to supply electrical energy. The plant comprises at least one induction furnace (11) and means (12) for supplying electrical energy to the induction furnace 11), wherein the electric power supply means (12) comprise at least one transformer (13) connected to an alternating current mains power network (14), at least one rectifier (15) located downstream of the transformer (13), at least one converter (16) located downstream of the rectifier device (15), and at least one coil (17) for melting and/or heating metal material.

Embodiments concern a plant for melting and/or heating metal material and a corresponding method to supply electrical energy. The plant comprises at least one induction furnace (11) and means (12) for supplying electrical energy to the induction furnace 11), wherein the electric power supply means (12) comprise at least one transformer (13) connected to an alternating current mains power network (14), at least one rectifier (15) located downstream of the transformer (13), at least one converter (16) located downstream of the rectifier device (15), and at least one coil (17) for melting and/or heating metal material.

A transformer assembly for electric grids including: an electric transformer including a magnetic core, a first side including one or more first windings enchained with said magnetic core and adapted to be electrically connected to a first grid section and a second side including one or more second windings enchained with said magnetic core and adapted to be electrically connected to a second grid section; a tap changer operatively associated with said electric transformer to vary the number of turns enchained with said magnetic core for said first windings; a control unit to: acquire input data indicative of an electrical connectivity condition of said second grid section with said second windings; determine whether said transformer is in a load condition or in a no-load condition; and, in a no-load condition, command said tap changer to set a maximum available number of turns for said first windings.

The present application provides a method and a system for controlling continuous low voltage ride-through and high 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 low voltage ride-through state to a high 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 low voltage ride-through state.