The present invention provides a system for operating a power line communications system that is comprised of a plurality of network elements, which may take the form of repeaters, bypass devices, backhaul devices, wireless backhaul devices, enhanced bypass device, communication interface devices and others. In one embodiment, two groups of network elements in the same electrical distribution system are isolated except selected communication link.

Power line communication system and method of operating the same

A device for providing communications through power lines that are communicatively coupled to an electrical distribution network infrastructure and to the internal wiring of at least one customer premises having one or more communication devices therein is provided. One embodiment comprises a coupler configured to be coupled to the electrical distribution network infrastructure, a modem in communication with the coupler to communicate data through the power lines; and a wireless transceiver in communication with said modem. In some embodiments, the electrical distribution network infrastructure may be a structure that uses electricity, such as a street light.

Device and method for coupling with electrical distribution network infrastructure to provide communications

Communications apparatus is disclosed which is adapted for use with a mains electricity transmission and/or distribution network, and includes signal transmission and/or reception means (232), and frequency conversion means (200-208) for converting the frequency of a signal transmitted or received by signal transmission and/or reception means to a frequency which facilitates improved propagation of the signal on the network. Preferably the signal transmission and/or reception means is adapted to operate according to a telephony standard which uses a relatively high carrier frequency (e.g. CT2), and the frequency conversion means is usable to convert a signal having a relatively high carrier frequency to a signal having a lower carrier frequency.

Powerline communications network employing tdma, fdma and/or cdma

Data signals are communicated between a power line and a computer, wherein the power line provides power to the computer via a distribution transformer and the computer is in communication with a wireless communication path. A first data signal is communicated with the power line. A conversion is made between the first data signal and a second data signal capable of being communicated wirelessly. The second data signal is wirelessly communicated with the wireless communication path.

Data communication over a power line

The last portion of the electrical distribution system is used to provide high-speed communications to residential homes. An aggregation point interfaces a medium voltage power line with a point-of-presence, and a power line bridge enables flow of communications signals between the medium voltage power line and a low voltage power line across a distribution transformer.

Power line communication system and method of using the same

A system for monitoring the capacitor batteries of a three-phase filter circuit. Each capacitor battery is formed of a plurality of parallel legs each having a plurality of sectional capacitors which are connected in series with fuses. Adjacent ones of the sectional capacitors are coupled to one another. In a three-phase system, three capacitor batteries are coupled to one another in a Y-circuit configuration, the Y-circuit node being coupled to a reference potential, illustratively ground. The magnitude and phase of the fundamental frequency component of the current flowing from the Y-circuit node to the reference potential is monitored, variations therein being evaluated to identify defective sectional capacitors. Only variations in the Y-circuit node current which occur rapidly will trigger fault signals, thereby preventing false indications resulting from variations in temperature.

Monitoring system for the capacitor batteries of a three-phase filter circuit

A monitoring system for measuring the phase currents of a filter circuit, the monitoring system having current measuring transformers coupled to respective filter sections for suppressing the harmonic content. Voltage measuring transformers are provided for measuring the network phase voltages, each such voltage measuring transformer being coupled to an electronic filter simulator and a filtering section for suppressing harmonic content. The fundamental frequency component of the measured phase currents and the simulated phase currents are conducted to transient comparator circuitry which is coupled to indicating and triggering circuitry having individual counter stages. Only rapid variations between the measured and simulated phase currents will result in fault indications, thereby preventing false indications resulting from variations in temperature.

Monitoring system for an LC filter circuit in an AC power network

A monitoring system for detecting earth contact of at least one phase of a polyphase network. Each of the phases in the network is connected by a capacitive-inductive filter to a neutral node which is connected to earth. In one embodiment of the invention, the current flowing from the neutral node to earth is detected by an induction current transformer which provides a signal responsive to said earth current. The output signal of the induction current transformer is conducted through at least one low pass filter for suppressing harmonics, and rectified to produce a direct current voltage signal, the amplitude of which is proportional to the amplitude of the fundamental frequency component of said signal. A fault indicating signal is produced when the direct voltage signal exceeds a predetermined value.

Earth contact monitoring device for a polyphase three-phase filter circuit

The outputs of a system to be protected are connected to current transformers. A summing circuit is connected to the secondary winding of the current transformers and produces the algebraic sum of the currents flowing in the system to be protected and provides an electrical magnitude derived from such sum to an indicator. The indicator produces an output signal which controls circuit breakers or the like in order to disconnect the system to be protected.

Differential protective circuit

Die Kondensatorbatterien (C R , C S , C T ) von Drehstrom-Filterkreisen bestehen jeweils aus einer Anzahl von parallelen Strangen mit jeweils einer Anzahl von in Reihe geschalteten Teilkondensatoren (C l ) mit Sicherungen (X,). The capacitor bank (C R, C S, C T) of three-phase filter circuits consist of a number of parallel strings each having a number of series-connected partial capacitors (C l) with fuses (X,) respectively. Zur Ermittlung von Kondensatordefekten werden Anderungen von Betrag und Phasentage der Grundschwingung des vom Sternpunkt des Drehstrom-Filterkreises nach Erde (M) abfliessenden Nullstrom ermittelt und zur Bestimmung von defekten Teilkondensatoren ausgewertet. To detect defects capacitor changes of magnitude and phase of the fundamental of the day from the neutral point of the three-phase filter circuit to ground (M) are determined effluent zero current and analyzed to determine broken part capacitors. Es wird vorzugsweise eine transiente Auswertung des Nullstroms vorgenommen, bei der nur rasche Anderungen ausgewertet werden. It is preferably a transient analysis of the residual current carried out, aiming to evaluate the only rapid changes.

Alfons Dipl Ing Fendt

Papers

Monitoring system for the capacitor batteries of a three-phase filter circuit

Monitoring system for an LC filter circuit in an AC power network

Earth contact monitoring device for a polyphase three-phase filter circuit

Differential protective circuit

Monitoring device for capacitor banks of a three-phase filter circuit