An apparatus for deicing and compensating reactive power is a mobile apparatus eWatch that includes a primary coil generating electromagnetic force, wherein a circuit comprises a voltage source and a switcher, and reactive power compensator that comprises an AC/AC converter and a reactive power compensating coil. The apparatus comprises blades to remove snow and ice.

A high-voltage overhead electric transmission line extends from a first electrical substation to a second electrical substation and includes at least one T junction that forms a joint with three sections A first section and a second section allow connection between the first and the second electrical substations. A third section allows connection to the high-voltage overhead electric transmission line of a user or a third electrical substation or primary substation. The at least one T junction has a first switchgear unit configured to allow grid reconfigurations and installed on the first section, and a second switchgear unit configured to allow grid reconfigurations and installed on the second section. Each switchgear unit has a plurality of switchgear unit poles. Each switchgear unit pole is associated with a respective phase of the high-voltage overhead electric transmission line and has a line circuit breaker and at least one line disconnector.

A lossless coupling structure of power line communication signals between different phase lines includes two signal coupling and isolation modules, two signal receiving and transmitting modules, and a digital signal processing module. The signal coupling and isolation modules load a control signal into a power line or extract from the power line, and isolate alternating current. The signal receiving and transmitting modules digitalize an analog signal extracted from the power line by the signal coupling and isolation modules to be loaded into the power line. The digital signal processing module digitally processes and exchanges signals obtained from power lines for A and B phases.

In the presented solution reactive power is compensated for in connection with a power transmission line with an arrangement which comprises at least one transformer and at least one reactive power compensator. The at least one reactive power compensator comprises a voltage source converter and switched elements. The switched elements may be thyristor switched capacitors and/or thyristor switch reactors, for example. The voltage source converter may provide reactive power in a linear or step less manner. The transformer is a three winding transformer having a high voltage side connectable to the power transmission line, a first low voltage side connected to the voltage source converter and a second low voltage side connected to the switched elements.

In the presented solution reactive power is compensated for in connection with a power transmission line with an arrangement which comprises at least one transformer and at least one reactive power compensator. The at least one reactive power compensator comprises a voltage source converter and switched elements. The switched elements may be thyristor switched capacitors and/or thyristor switch reactors, for example. The voltage source converter may provide reactive power in a linear or step less manner. The transformer is a three winding transformer having a high voltage side connectable to the power transmission line, a first low voltage side connected to the voltage source converter and a second low voltage side connected to the switched elements.

This invention relates to a method and apparatus for power factor adjustment in a waveguide circuit or a transmission line circuit. In this invention, it is shown that, in a waveguide circuit or a transmission line circuit, the power supplied by the source and the impedance can be adjusted by controlling the amount of the phase change of the signal when it propagates through the (equivalent) transmission line once the medium, the structure, and the load of the waveguide circuit or the transmission line circuit are chosen. It is also shown that, by choosing an appropriate frequency, transmission line, and load, one can achieve the negative power factor of the (equivalent) transmission line circuit, and also make the power delivered from the source be lesser than that consumed at the load.

This invention relates to a method and apparatus for power factor adjustment in a waveguide circuit or a transmission line circuit. In this invention, it is shown that, in a waveguide circuit or a transmission line circuit, the power supplied by the source and the impedance can be adjusted by controlling the amount of the phase change of the signal when it propagates through the (equivalent) transmission line once the medium, the structure, and the load of the waveguide circuit or the transmission line circuit are chosen. It is also shown that, by choosing an appropriate frequency, transmission line, and load, one can achieve the negative power factor of the (equivalent) transmission line circuit, and also make the power delivered from the source be lesser than that consumed at the load.

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.

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.

A modular power flow control system is described for optimizing power flow control in a multi-phase power transmission system. Identical impedance injection modules are arranged in an m?n matrix, where m is the number of series-connected modules inserted into each phase (forming a leg of the installed bank of modules), and n is the number of parallel-connected legs per phase. Each impedance injection module in a phase is configurable to collectively insert a pre-determined (controllable) power control waveform into the phase to which it is attached. The modular flow control system is agile with respect to configurability, reconfigurability, maintenance, size, weight, and cost.