Westinghouse Electric Corporation

Ian A Whyte

Leonard C Vercellotti

James P McGivern

Paul H Haley

Tamas I Pattantyus-Abraham

Louis G Ottobre

Stephen R Swanson

Richard F Cook

A static VAR generator for providing reactive power compensation to an n-phase AC network subject to transient surge currents utilizing mechanically switched shunt circuits in parallel with the thyristor arrays.

Static VAR generator

A distribution network power line communication system divided into addressable communication zones defined by signal repeaters located at spaced intervals along the distribution network. The signal repeaters are switchably disposed in signal communication between the primary and grounded neutral conductors of the primary distribution network. Each repeater, when uniquely addressed by an interrogation signal from a central communication terminal, transfers the interrogation signal from the primary conductor to the primary grounded neutral conductor whereon it is transmitted to a uniquely addressed remote communication terminal coupled to a secondary neutral conductor within the communication zone of the signal repeater. A timely response signal from the remote communication terminal on the grounded neutral conductor is transferred by the repeater to the primary conductor and then to the central communication terminal. Coupling circuitry, responsive to repeater logic section control signals, connects the receiver and transmitter sections of each signal repeater to either the primary or grounded neutral conductors of the distribution network for signal amplification and bidirectional signal transmission.

Signal repeater for a distribution network communication system

An automated electric power distribution network includes a radio communication system for transmitting multipurpose, multitone signals in one or more signaling channels over the auxiliary channel or channels of one or more commercial broadcast stations. Energy management terminals receive the signals at remote locations served by the distribution network. Radio receivers at the terminals have frequency selective detectors responsive to different multitone signals. The selective allocation of the multitone signals at different remote locations provides different communication links for effecting common or different electric energy usage related responses at grouped or separate locations. Complex address and/or function encoded signal information is reduced by providing the frequency selective reception of the several multitone signaling channels available in a radio or television station auxiliary channel.

Multichannel radio communication system for automated power line

A high voltage signal coupler couples carrier communication signals between a distribution network primary conductor and communication elements located at spaced intervals on the distribution network. A single bushing, high frequency, coupling capacitor communicates the carrier communication signals between one of the distribution network primary conductors and a conductor which is at ground or real earth potential with respect to power current frequencies. A parallel resonant circuit, formed by a tuning capacitor and a hollow core of magnetic material inductively surrounding the power frequency ground conductor, couples the carrier communication signals to the communication elements connected thereto at a predetermined frequency without interfering with the operation of the ground conductor at the frequency of the power current.

High voltage signal coupler for a distribution network power line

A distribution network power line communication system which includes coupling means for applying a carrier current communication signal to the polyphase primary distribution conductors with a proportional relationship between the signal voltages applied to the various conductors selected to provide a predetermined propagation mode. Impedance elements are connected between the conductors at selected points remote from the coupling point, such as at the location of unbalanced loads, line taps, branches, capacitor banks, distribution transformers, and other line discontinuities which may cause mode conversion. The impedance elements are selected and connected to re-establish the predetermined propagation mode.

Distribution network power line communication system

Carrier current signals are impressed to and detected from grounding conductors connected to the power system and to real earth ground. The communication links provided by the grounded neutral conductors of the power system and by the real earth ground return path transmit the carrier communication signals between a substation communication terminal and remote communication terminals at the premises of utility company customers. The communication signals are coupled to the ground conductors by transformer-type couplers in which the grounding conductor constitutes one winding of the transformer.

Power line carrier communication system for signaling customer locations

A distribution power line communication system wherein communication signals are transferred between a communication terminal at a substation and communication terminals at customer locations. The communication signals are transferred between the terminals by using a two-conductor line, with one of the conductors effectively grounded and with the other of the conductors effectively isolated from ground. The conductor which is isolated from ground provides a conduction path which travels along the primary distribution line to a distribution transformer location. At this location, the conduction path is transferred to a messenger wire which supports other transmission lines between various distribution transformer locations. The messenger wire is suitably isolated from ground and the conduction path is transferred to separate secondary distribution lines adjacent to the messenger wire. The final portion of the ground-isolated conduction path which directs signals to the communication terminals at the customer locations is provided by the secondary distribution lines and by the service lines extending to the customer locations.

Distribution power line communication system including a messenger wire

An arrangement of components for a distribution line communication system. Two or more independent secondary distribution lines are connected, through distribution transformers, to a primary distribution line. Carrier communication signals are transferred between the primary distribution line and one of the secondary distribution lines by a repeater located near one of the transformers. The carrier communication signals are propagated directly along this secondary distribution line and through associated service lines to communications terminals located near the electrical loads. Coupling apparatus is connected between the two independent secondary distribution lines to provide a path for the communication signals between the repeater and the communications terminals associated with the other secondary distribution line. The coupling apparatus provides a low-impedance path for the communication signals and a high-impedance path for signals at conventional electrical power frequencies.

Power line carrier communication system having efficient carrier signal

Apparatus for powering a signal amplifier or repeater connected to the primary or high-voltage portion of a power distribution system. Oscillator and amplifier circuits are energized by power from the secondary or low-voltage portion of the power distribution system. The oscillator and amplifier circuits are connected to the primary winding of an air-core transformer. A capacitor is also connected to the primary winding to make the primary circuit of the air-core transformer resonant at the frequency of the oscillator. The secondary winding of the air-core transformer is connected to a resonating capacitor and to transformer and rectifier circuits which convert the AC voltage into DC voltage for powering the signal amplifier. Electrical isolation between the high-voltage and low-voltage portions of the distribution system is provided by the separation distance between the primary and secondary windings of the air-core transformer. Sufficient electrical energy is transferred between the primary and secondary windings of the air-core transformer by energizing the primary winding with a high-frequency voltage from the oscillator and amplifier circuits. The mutual inductance between the primary and secondary windings of the air-core transformer is low enough to permit reasonably efficient power transfer when the oscillator and amplifier circuits operate at high frequencies.

Power supply for power line carrier communication systems

An arrangement of communication components to provide communications between a central control center and various customer load locations in an electrical power distribution system. Control or interrogation signals are originated at the control center and transmitted over a suitable facility, such as a telephone line, to an FM broadcast station. The control signals frequency modulate an ultrasonic subcarrier which modulates the FM broadcast transmitter simultaneously with the normal broadcast program material. Radio receivers at the customer load locations receive, filter, and decode the broadcast signals which are used to activate the control or logic circuits associated with the customer location. A reply signal is generated at the customer location and applied to the power lines by carrier techniques. The power line carrier reply signal is remotely detected by a suitable receiver and transferred over a suitable wire line facility which terminates at the control center.

Bidirectional communication system for electrical power networks

A distribution network power line communication system which is divided into addressable communication zones defined by repeaters located at the distribution transformers of the distribution network. Each repeater, when uniquely addressed by an interrogation signal from an interrogating source, strips its address from the interrogation signal and sends the resulting modified interrogation signal to its associated remote communication terminals, by-passing the associated distribution transformer. A timely, error-free response signal from a remote communication terminal is modified by a repeater to include the repeater address, and the modified response signal is sent back to the interrogating source. The binary base band interrogation and response signal information is preferably pulse width modulated to provide a self clocking format, and this self clocking signal is passed through two stages of frequency modulation to provide a signal which makes the receivers thereof substantially immune from drift.

Distribution network power line communication system including

A distribution network power line communication system including a central communication terminal at a distribution substation in signal communication with a plurality of remote communication terminals via the electrical distribution power lines. The central communication terminal uniquely addresses a selected remote communication terminal with an interrogation signal which requests the performance of a selected distribution automation function. The selected remote communication terminal performs the requested function and sends a response signal back to the central communication terminal. Signal amplifying repeaters are disposed in signal communication with the electrical distribution power lines, which ensure that the interrogation and response signals are at usable signal levels when they reach their intended destinations. The signal amplifying repeaters include delay devices which provide a signal delay time interval selected such that a repeater will not apply a signal to the electrical distribution power lines at the same time a signal is to be received by the repeater. In one embodiment, the message elements or bits of a signal word are spaced such that each bit of the word is delayed and transmitted by a repeater before the repeater receives the next bit of the word; and, in another embodiment the complete signal word is received by a repeater before the transmitter portion of the repeater is operated.

A distribution powerline carrier communication system for providing distribution automation functions. The communication system includes a distribution powerline, with inductive couplers and frequency translating repeaters cooperating to circumvent signal obstructions, such as distribution transformers, and to increase the signal strength. The inductive couplers pick up the communication signals without metallic contact to the primary distribution lines, and the repeaters change the frequency band of the communication signals, enabling the amplifier gain of the repeaters to be selected without limitation due to undesirable feedback and oscillation.

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Pittsburgh, PA, United States of America

Ian A Whyte