Abstract: A circuit (C1-C4) is employed in a TWACS transponder (T) installed in an electric meter (M). The transponder generates inbound signals (IB) transmitted from the location of the electric meter to a central location (R). Firmware (F) within the transponder controls the flow of current for each pulse through the circuit by triggering a semi-conductor device such as a SCR (X1) or TRIAC (X2). The resulting current flow through the inductor for a subsequent pulse, regardless of the pulse's polarity, will be in the opposite direction to that of the previous pulse. The result is to maintain a constant level of magnetization of the inductor core which does not have to be overcome by energy in the subsequent pulse resulting in amplitude of all the pulses imposed on an AC waveform being substantially the same.

Abstract: Improvements in the detection of TWACS outbound message signals. A first improvement involves matching some (or all) of the intermediate points in an outbound preamble occurring between bits of the preamble currently being detected. This reduces the possibility of a false synchronization and therefore decreases the probability of missing outbound message signals. A second improvement is to require some or all of the known preamble bits to exceed a predetermined threshold where both the thresh-old and which bits are adjustable. An additional approach is using 4-8 additional buffers in a transponder to detect preamble patterns in the outbound message. Each half cycle of the outbound message waveform requires entering a bit only into the buffers active for the particular frame of reference in which the message is being transmitted, since only buffers for that frame of reference are employed. The process continues until all bits specified to be sent, based on the length of the outbound message, are extracted.

Abstract: A method for use in a power line communication systems for an electrical distribution system (1) to quickly and accurately poll electrical meters (6) installed at user facilities to determine if an outage has occurred at a facility. An outbound communications message is transmitted to the meter at the facility requesting a short response consisting of a bit pattern that is either partially or completely known to the receiver. Any perceived response from the meter is then processed to ascertain whether or not the meter actually transmitted a message. Receipt of a message indicates that an outage has not occurred at that site, while an indication the message was not received indicates an outage has likely occurred. In processing the received message, two types of errors can potentially occur; i.e., a false positive or a false negative.

Abstract: A communications network (12) for use by a utility (10) for communication, command, and control of the utility's distribution area for gas, water and electrical services including the utility's distribution system, security, workforce, and asset management. The network includes apparatus for obtaining information and data concerning usage of the electricity, gas, or water by each of the utility's customers, the operation of installations throughout the system, and how electricity, gas, or water is being distributed throughout the system. The information and data from each source (16) is processed to provide an up-to-date overview of the system and its operation to the utility's management and operating personnel. This includes identification of any current problems, including distribution or security, within the system, and asset monitoring and management to identify possible future problems which may occur within a predetermined period of time.

Abstract: A method for load control in an electrical distribution system using energy usage profiles based on temporal measurements. A load control unit (10) installed at a customer site profiles equipment (E1-En) directly connected to the load control unit and remotely located equipment (RE1-REn) wirelessly connected to the load control unit using measurements of time rather than energy usage. This reduces the cost and complexity of the load control unit. Profiling is done for individual pieces of load controlled equipment rather than for the site as a whole. This improves data resolution. The load control unit controls the load only when the equipment is powered, and adaptively synchronizes load shedding during this time, so to improve local load control performance. Termination of a load control event results in gradual reduction in load shedding so to control the inrush of demand seen by the distribution system.

Abstract: A point-to-point communications system (20) for transmitting messages from any location (A) within a power distribution system or network (10) to any other location (B) within the network. A transceiver (12) at the one location includes a transmitter (X) that impresses a waveform (WR) on a waveform (WG) propagated by the network to supply power throughout the network. The transmitter is a resonant transmitter that includes a reactive load (13) which is selectively connected to and disconnected from the power distribution network. A controller (16) controls operation of the transmitter to connect and disconnect the reactive load from the network so to impress on the propagated waveform a dampened sinusoidal waveform whose characteristics represent information conveyed over the power distribution system. A receiver (Yn) at the other location receives and demodulates the dampened sinusoidal waveform to extract therefrom the information being conveyed by it.

Abstract: A method for producing a set of inbound pulse patterns and detection vectors for lengths longer than 4 cycles in an AC waveform. These are used for generating inbound messages in a two-way automatic communication system (TWACS). The method uses Hadamard matrices adapted to generate a set of detection vectors by permuting rows of a matrix and removing certain columns of the matrix to meet system design requirements. The method can be extended to any length and modified to accommodate multiple pulses per half-cycle to support higher data rates.

Abstract: Detection of fault occurrences within a power distribution system. A transient detector and fault classification system (10) implements an algorithm that detects transients which may result from the occurrence of a fault in the power distribution system. The system includes a detection module (18) which processes a set samples obtained from electrical waveforms propagated of through the power distribution system and appear to be statistically anomalous compared to other sample data. This is done using an adaptive detection algorithm that is applied when large changes occur in a waveform over a relatively short period of time. The identified samples are then provided to a signal classifier module (20) which processes sets of samples to classify a transient they represent as a likely fault occurrence or some other type of anomaly which is likely not a fault occurrence.

Abstract: A method for use in a power line communication systems for an electrical distribution system (1) to quickly and accurately poll electrical meters (6) installed at user facilities to determine if an outage has occurred at a facility. An outbound communications message is transmitted to the meter at the facility requesting a short response consisting of a bit pattern that is either partially or completely known to the receiver. Any perceived response from the meter is then processed to ascertain whether or not the meter actually transmitted a message. Receipt of a message indicates that an outage has not occurred at that site, while an indication the message was not received indicates an outage has likely occurred. In processing the received message, two types of errors can potentially occur; i.e., a false positive or a false negative. A false positive occurs when a detection algorithm used to process the response indicates that the meter sent a response when actually it did not.

Abstract: A method of correcting errors in a message transmitted over a digital communication channel, where the message was encoded using a CRC for purposes of error detection. A parity-check matrix representation of the CRC is computed for any fixed-length message, and that parity-check matrix is combined with the parity-check matrix for any error correcting code that used in conjunction with the CRC. The combined parity-check matrix is extended using sparsification algorithms to allow it to work well under a message passing decoder (MPD). Received messages are decoded using the message passing decoder, making it possible to correct more errors than if the CRC were decoded in a conventional manner.

Abstract: A method of data compression for use in a data communication's system for an electrical utility or the like to affect the most efficient transfer of data. The data is first formed into a forming a block (B). A parameter (M) is selected from among a group of parameters. Each data value in the block is divided by the selected parameter to produce, for each data value, a quotient (q=?n/M?) and a remainder (r=n?qM). The quotient of each data value is encoded using unary coding in which the value for the quotient is encoded by transmitting an appropriate number of zeroes followed by a one. The remainder of each data value is encoded using binary encoding, and the resultant encoded block of data is then transmitted. The data values comprising the block of data are positive integer values and the encoding employs a Golomb-Rice code defined by a positive integer parameter.

Abstract: A method for load control in an electrical distribution system using energy usage profiles based on temporal measurements. A load control unit (10) installed at a customer site profiles equipment (E1-En) directly connected to the load control unit and remotely located equipment (RE1-REn) wirelessly connected to the load control unit using measurements of time rather than energy usage. This reduces the cost and complexity of the load control unit. Profiling is done for individual pieces of load controlled equipment rather than for the site as a whole. This improves data resolution. The load control unit controls the load only when the equipment is powered, and adaptively synchronizes load shedding during this time, so to improve local load control performance. Termination of a load control event results in gradual reduction in load shedding so to control the inrush of demand seen by the distribution system.