A capacitive power transmission cable (1) having at least two sets of conductive strands (2) and the strands of the sets are distributed in a transverse cross-section of the cable, whereby the two sets are in capacitive relation to each other, wherein preferably, the capacitance is at least 10 nF/m.

Disclosed is a reactance-injecting module and its method of use to balance the currents among the phases of polyphase electric power transmission lines or to manage power flow among alternate paths, where the reactance-injecting module has high-speed, dedicated communication links to enable the immediate removal or reduction of injected reactance from all phases of a phase balancing cluster when a fault is detected on any one of the multiple phases. The reactance-injecting module may communicate information on a detected fault to the other reactance-injecting modules of the phase balancing cluster within 10 microseconds after the fault is detected to allow the phase balancing cluster to eliminate injected reactance from all phases within a time that is short compared to a cycle of the alternating current, such as 1 millisecond after the fault is detected. This provides extremely fast neutralization of injected reactance to minimize interference with fault localization analyses.

A capacitive power transmission cable (1) comprising at least two sets of conductive strands (2). The strands of the sets are distributed in a transverse cross-section of the cable, whereby the two sets are in capacitive relation to each other.

A capacitive power transmission cable (1) comprising at least two sets of conductive strands (2). The strands of the sets are distributed in a transverse cross-section of the cable, whereby the two sets are in capacitive relation to each other.

An arrangement for reactive power compensation at an electric energy transmission line includes at least one first reactive power compensation device including a first type of power electronic switches, at least one second reactive power compensation device including a second type of power electronic switches and a transformer having a first secondary coil connected to the first device, a second secondary coil connected to the second device and a primary coil connectable to the electric energy transmission line. The primary coil has more windings than any of the first and second secondary coils.

An arrangement for reactive power compensation at an electric energy transmission line includes at least one first reactive power compensation device including a first type of power electronic switches, at least one second reactive power compensation device including a second type of power electronic switches and a transformer having a first secondary coil connected to the first device, a second secondary coil connected to the second device and a primary coil connectable to the electric energy transmission line. The primary coil has more windings than any of the first and second secondary coils.

Disclosed is a reactance-injecting module used to balance the currents among the phases of polyphase electric power transmission lines or to manage power flow among alternate paths, where the reactance-injecting module has high-speed, dedicated communication links to enable the immediate removal of injected reactance from all phases of a phase balancing cluster when a fault is detected on any one of the multiple phases. The reactance-injecting module may communicate information on a detected fault to the other reactance-injecting modules of the phase balancing cluster within 10 microseconds after the fault is detected to allow the phase balancing cluster to eliminate injected reactance from all phases within 1 millisecond after the fault is detected. This provides extremely fast neutralization of injected reactance to minimize interference with fault localization analyses.

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.

Disclosed is a reactance-injecting module used to balance the currents among the phases of polyphase electric power transmission lines or to manage power flow among alternate paths, where the reactance-injecting module has high-speed, dedicated communication links to enable the immediate removal of injected reactance from all phases of a phase balancing cluster when a fault is detected on any one of the multiple phases. The reactance-injecting module may communicate information on a detected fault to the other reactance-injecting modules of the phase balancing cluster within 10 microseconds after the fault is detected to allow the phase balancing cluster to eliminate injected reactance from all phases within 1 millisecond after the fault is detected. This provides extremely fast neutralization of injected reactance to minimize interference with fault localization analyses.

A dynamic line rating determination apparatus configured to control the current applied to a power line conductor by determining a dynamic maximum current rating for said power line conductor, based on measured voltage and current phase vectors taken at two temporally spaced sample times, the phase vectors including a voltage and current phase vector for each phase of electrical power carried by the power line conductor at a first and second end of the power line conductor; and determining the dynamic maximum current rating by; applying the phase vectors to a power line model to estimate the conductor temperature, applying the estimate to a thermal model to predict a steady state temperature that the power line conductor will reach, and calculate the dynamic maximum current rating based on the prediction of the steady state temperature, a power line conductor current, and a maximum temperature limitation value.