Abstract: The present invention relates to a method for detecting a line-to-line fault location in power network, and more particularly, detecting the line-to-line fault location by direct 3-phase circuit analysis without using a symmetrical component transformation, so even in an unbalanced 3-phase circuit, the line-to-line fault location can be accurately detected. In the method using direct 3-phase circuit analysis of this invention, inverse lemma is used to simplify matrix inversion calculations, thus the line-to-line fault location can be easily and accurately determined even in the case of an unbalanced network without symmetrical component transformation.

Abstract: All feedback cycles in a circuit network which cross only non-scannable memory elements are detected in linear run time. The method models a circuit network as a directed graph, then attributes network elements so that a single feedback cycle may be found in constant time. In the breadth first version, feedback is detected by traversing at most a constant distance back to the last scannable memory element. In the depth first version, graph nodes are not FINISHED until all predecessors are FINISHED. Feedback is found immediately if a node runs into another node that is NOT—FINISHED. This feedback is illegal if both nodes are in a zone defined by the same scannable memory element. The resulting identification and removal of feedback loops crossing only non-scannable memory elements significantly reduces the subsequent complexity of test pattern generation. This ensures a faster, more reliable, and more accurate test process after circuit fabrication.

Abstract: One embodiment of a method comprises retrieving test data corresponding to test results from a plurality of fuses, each one of the plurality of fuses residing on a different one of a plurality of semiconductor devices and each one of the plurality of fuses having a common location on the semiconductor devices, determining from the test data which of the plurality of fuses are defective fuses, and specifying on an output report the common location of the determined defective fuses when a number of the defective fuses are at least equal to a predefined portion of the plurality of fuses.

Abstract: A method of predicting whether a failure of an electrical device may occur if a receiver within the electrical device is subjected to an electrical noise pulse. The method may include locating an integrated circuit that drives the receiver and locating an integrated circuit that is driven by the receiver, the integrated circuit that is driven by the receiver having a circuit type and a capacitance. The method may also include selecting a plurality of noise-tolerance curves and then selecting one of the plurality of noise-tolerance curves. The method may also include selecting a set of noise-propagation constants and then selecting a noise-propagation constant from the set of noise-propagation constants. The method may further include generating an offset noise-tolerance curve by offsetting the selected one of the plurality of noise-tolerance curves by the noise-propagation constant, determining a noise-tolerance for the receiver; and then comparing the noise-tolerance to the amplitude of the noise pulse.

Abstract: Embodiments are provided for testing termination circuits in SCSI bus controllers. In one embodiment, the termination circuits are tested by sending test data between respective SCSI controllers of the termination circuits for varying enabled/disabled statuses of the termination circuits.

Abstract: A method and apparatus permits use of a tester memory (31) as storage for an inversion mask. The inversion mask indicates to the tester which cells in a DUT memory (14) are logically inverted during testing. Data information and the inverse of the data information is input into a first data multiplexer (802). The stored inversion mask (902–908) is used to independently select a data information bit or its inverse for presentation as a masked output (814) at the output of the first data multiplexer (802).

Abstract: Disclosed is a method for detecting a fault by using harmonics and a state transition diagram. When the fault occurs on transmission lines, the fault is detected by using harmonics and the state transition diagram. Two logic signals are outputted by using apparent impedance of a steady state characteristic and a sum of harmonics components of a transient state characteristic. Such two logic signals are used as input parameters of the state transition diagram so that the state of an electric power system is presumed based on a state transition of the electric power system. It is possible to prevent a distance relay from being malfunctioned under an increase of load and unstable voltage. The state of the electric power system is presumed by using harmonics and the state transition diagram, and the fault on the transmission line is reliably detected.

Abstract: A method and system for performing sequence time domain reflectometry to determine the location of line anomalies in a communication channel is disclosed. In one embodiment, the system generates a sequence signal and transmits the sequence signal over a channel that is the subject of the sequence time domain reflectometry analysis. The system monitors for and receives one or more reflections, collectively a reflection signal, and presents the reflection signal to a reflection processing module. In one embodiment, the reflection signal is correlated with the original sequence signal to generate a correlated signal. The system may perform signal analysis on the correlated signal to determine a time value between the start of the reflection signal and the subsequent points of correlation. Based on the time value and the rate of propagation of the signals through the channel, the reflection processing module determines a distance to a line anomaly.

Abstract: A method and system for estimating the location of an injection point of foreign signals in a network comprises the steps of measuring signal samples at two points along the cable network distribution system, correlating the two signal samples to estimate propagation delay differences between the measurement locations and the source, and calculating the location and magnitude of the ingress. The propagation delay, or time correlation, is proportional to the offset of the injection point from the midpoint between the measurement sites, where the two parameters are related by the velocity of propagation in the cable. The amplitude of the correlation peaks represent the magnitude of the ingress at that location. Sensitivity may be increased by time-averaging the output of the correlation step. Multiple sources and/or ingress and egress sites may be measured simultaneously.

Abstract: The present invention relates to a method for calculating the distance to fault in a section of a power transmission network, which section is arranged with line terminals at both ends, each terminal including impedance relays (AA, BB), including the steps of, at the occurence of a fault; measuring the apparent impedances by each relay, measuring the relaying currents, determining the type of fault, checking whether the fault involves a fault resistance or not, and, if so, solving a quadratic equation for complex numbers, resolving the quadratic equation for the real and imaginary components, obtaining two quadratic equations for a fault distance in which the coefficients are real numbers, combining the two equations and obtaining a distance to fault, or, if not so, solving a quadratic equation for real numbers, obtaining two solutions for the distance to fault d1, d2 and comparing the solutions as 0<(d1 or d2)<1 pu, where pu is the length of transmission lines between the line terminals.

Abstract: A scan test viewing and analysis tool for an integrated circuit tester provides inter-related views of scan tests on an integrated circuit device. The tool processes a test program specification, execution results and device definition to produce cross-referencing data, which the tool then uses to provide navigation links between correlated locations in a cyclized test view, procedural test program view, and views of signal vectors, scan state and scan vectors. The tool also provides a capability to edit the test program in the views.

Abstract: The present invention includes a method and system of identifying parts prone to problems. The method includes the steps of establishing a problem threshold, establishing a part type with a problem, determining a problem level with the part type in response to the part type problem level, comparing the problem level with said problem threshold, establishing a production life of the part type, determining if the part type is within a threshold of the production life, identifying the part type as the problem prone part in response to the comparison and the production life determination.

Abstract: Method and apparatus for monitoring and controlling electrical current delivered to a computer subsystem are provided. One embodiment provides a method for detecting a short circuit in a computer subsystem, comprising: obtaining a measured current which is supplied to the computer subsystem during one or more time periods; determining an expected current utilized by the computer subsystem for the one or more time periods; and determining whether a short circuit condition exists based on a comparison between the measured current and the expected current. The method may further comprise terminating electrical power supplied to the computer subsystem.

Abstract: Fault detection and power network quality monitoring are performed for a power line network using power line communications (“PLC”) signal transceiving and data processing capabilities. Power line signals are continuously received and processed to obtain signal data representative of power line network operating conditions that are expressed in the received power line signals. The harmonic content and noise signature of the signal data are evaluated with reference to known fault signature data and power line network topology properties for detecting and identifying the location of an existing or anticipated fault in the power line network and assessing power transmission quality of the network.

Abstract: The present invention relates to a control system for automatically reconnecting power to customers in a distribution automation multi-feed power network on a fault disconnecting customers in the network. This invention provides the simple switching architecture with local control means that are implemented in the event of a fault. Each switch in the system has an intelligent switch controller which results in a faster restoration time which reduces customer down time in the event of a fault in the network. The system operates without the need for complex communication systems or central controllers. Each intelligent switch controller has the ability to cause its respective switch to open or close in the event of a fault. The network may be restored in a sequential manner subsequent to the detection of a fault in the network thereby allowing for the simple detection of the location of a fault.

Abstract: An apparatus and method for automatic measurement of insulation resistances of a multi-conductor cable. In one embodiment of the invention, the apparatus comprises a power supply source, an input measuring means, an output measuring means, a plurality of input relay controlled contacts, a plurality of output relay controlled contacts, a relay controller and a computer. In another embodiment of the invention the apparatus comprises a power supply source, an input measuring means, an output measuring means, an input switching unit, an output switching unit and a control unit/data logger. Embodiments of the apparatus of the invention may also incorporate cable fire testing means. The apparatus and methods of the present invention use either voltage or current for input and output measured variables.

Abstract: A method is disclosed for the identification of weak and/or strong nodes of an electric power transmission system. Electric parameters characterizing nodes and branches of an electric power transmission system are subject to computational treatment to obtain equations of power flow in all nodes of the system at assumed 100 percent system load value. Using earth as the reference point, nodal impedance values are computed for all nodes, and used to construct a P-Q curve which presents the functional relation between the system's reactive and active load. The nodal coefficient of voltage stability is determined as the relative distance between the base load point of that node and the critical point on the P-Q curve situated most closely to the base point. The coefficient is compared with a threshold value considered to be a safe margin to maintain voltage stability for a given node.

Abstract: A reference output characteristic of a photovoltaic power system at the time of normal operation is obtained in accordance with an installation condition (topography of installation site, meteorological condition, configuration of the system itself, or the like) of the photovoltaic power system, an output characteristic in the photovoltaic power system during operation is actually measured, the obtained reference output characteristic and the measured output characteristic are compared and, based on the comparison result, the normality/abnormality of the output is diagnosed and, at the same time, the cause is diagnosed in the case of abnormality. The reference output characteristic at the time of normal operation can also be obtained based on the measured value of the past output characteristic.

Abstract: An improved intrinsically safe field maintenance tool is provided. The tool is operable with process communication loops in accordance with a plurality of process industry standard protocols. Aspects of the invention include hardware features such as an infrared port; removable memory module; and an expansion memory module. Additional aspects of the invention include protocol-specific diagnostic methods executable with the improved intrinsically safe field maintenance tool.

Abstract: Building and testing complex electronic products especially large scale computer systems are handled with control remaining with the owner of the design while a contract manufacturer does the basic manufacturing processes and testing. Nearly all levels of testing are accomplished without sharing high level descriptions of the end product or its features by providing only low level files for test functions. Testing is accomplished without sharing the high level code descriptive of the system design so confidential information is retained. Testing using the low level data is made sufficient to identify what parts need repair despite the lack of high-level information transfer.

Abstract: When a disturbance (for example, lightning strike) occurs on a high-voltage overhead transmission line, the line must be checked for any possible damage. If the distance-to-fault is known, line crews can be quickly dispatched for any necessary repair. The present invention is a fault location method and system that uses filtered, time-synchronized positive- or negative-sequence voltage and current measurements from both ends of the overhead transmission line to determine the exact distance to the fault with respect to either end.

Abstract: A data sample and transmission module for a power distribution system having a microprocessor, a locator device, and a network interface is provided. The microprocessor samples one or more first signals indicative of a condition of power in the power distribution system. The locator device is changeable between a first state and a second state. The network interface can place the microprocessor in communication with a network so that the microprocessor samples the first signals based in part upon a synchronization signal receivable from the network and so that the locator device changes from the first state to the second state in response to a command receivable from the data network.

Abstract: A system and method for examining or verifying distances such as insulation distances within electrical systems and their respective components without producing actual electrical system prototypes. In such an insulation verification method, a bounding box tree of each component is produced, and root node pairs are put in a queue. Each root node pair in the queue is subjected to the following process. The distance between boxes corresponding to two nodes of the root node pair is calculated. If the calculated distance is greater than a predetermined value, no further process is performed for this root node pair. However, if the distance is less than the predetermined value, triangular patches contained in the respective nodes are extracted, and the exact distance between the two triangular patches is calculated. If the resultant distance is less than the predetermined value, the patches are determined to be adjacent to each other.

Abstract: A line current differential protective relay and method for protecting transmission lines with power transformers tapped between the substations without any measurements taken at the tap point. The protection method uses distance supervision by an overcharging instantaneous impedance zone to prevent malfunction of the relay during external faults at the distribution busbar of the tapped transformer. The protection method uses modified current differential principle that compares the zero sequence compensated differential and restraining signals to provide relay stability on external ground faults. The protection method combines both the traditional and modified current differential principles to provide phase-selective operation.

Abstract: A method of precisely determining velocity of propagation and the location of a fault on an electric transmission line, using a system of high frequency transmitter and receiver combinations to monitor and detect high frequency bursts produced by the transmitters and by faults, including memory and analysis capability to store and analyze high frequency data before and after a detected fault.

Abstract: A method for determining the amplitude and phase angle of a measuring signal corresponding to a current or a voltage on an electrical power supply network by using sampled values of the measuring signal, a model of the measuring signal containing at least a sinusoidal component being used to calculate the amplitude and phase of the measuring signal with the sampled values by applying a recursive least-squares estimation method. In order to be able to determine the frequency of the measuring signal together with the amplitude and the phase angle, use is made of a model of the measuring signal in accordance with the relationship y=A·sin(2&pgr;ft+&phgr;), and by using this model and the sampled values (ym), the determination of the frequency of the measuring signal (um) as well is carried out via a recursive nonlinear least-squares estimation method. By expanding the signal model, measuring signals with a DC component and with frequencies that change over time also can be investigated.

Abstract: A method for eliminating false failures saved by redundant paths during critical area analysis of an integrated circuit layout is described. Monte Carlo simulation generates simulated defects for an integrated circuit layout. Vertices significantly encroached by the simulated defects are identified. Information of predefined sets of vertices associated with individual nets including at least one of the identified vertices is retrieved. Failures resulting from the simulated defects are indicated only if all elements of at least one of the predefined sets of vertices are one of the identified vertices. The predefined sets of vertices are determined prior to circuit area analysis by extracting nets from an integrated circuit layout, and determining the predefined sets of vertices for individual nets such that the net fails only if all elements of individual of the predefined sets of vertices are significantly encroached by simulated defects.

Abstract: Provided is a Doppler based automated direction finding system that detects radio frequency (RF) leaks in a cable television plant. During a ride-out, the system detects leaks and stores leak data, such as amplitude, location, and bearing. The stored data is uploaded to a computer that performs a leak analysis. The leak analysis isolates the leaks using Doppler-based bearing information and separates cable leaks from other RF sources, such as power sources and noise. Erroneous information that results from RF reflections (multi path) may be eliminated while processing the data using triangulation. After the leak analysis, the computer generates work orders and maps, makes the data available to users, and may also compile information and file reports based on the data.

Abstract: The invention relates to a method, a computer program product, a computer program and a device (20) for the plausibility checking of voltage transformers (8) in an electrical switchgear (1) as well as a switchgear (1) with such a device (20). According to the invention, a topological sub-area (1a; 1b) with several galvanically connected voltage transformers (8) is recorded for an instantaneous topology of the switchgear (1), groups of voltage transformers (8) with the same measured signals are identified and, if more than one group is present, an indication or alarm signal is generated by the substation control system (2). Amongst other things, exemplary embodiments relate to: Criteria for the production of warning or alarm messages for problematic voltage transformers (8) and/or sub-areas (1a; 1b); presentation of the results of the plausibility test; coordination of the plausibility test with switching operations.

Abstract: A zone arc fault detection system for detecting arcing faults in a defined zone of an electrical circuit, such as an aircraft circuit, includes a pair of substantially identical parallel insulated conductors for each zone in which arcing is to be detected. A detection zone is defined by the parallel conductors between end points where the two conductors are coupled together. A current sensor is operatively associated with each pair of parallel conductors. The current sensor and conductors are respectively configured and arranged such that the current sensor produces a signal representative of a difference in current between the two conductors.

Abstract: A manufacturing method of an electronic device is to improve test efficiency using test structure and improve yield. The manufacturing method performs test using a first lead wire disposed on an insulating layer formed on a substrate and a second lead wire electrically connected to the substrate and disposed on the insulating layer and manages the electronic device on the basis of results of the test to manufacture the electronic device. The manufacturing method includes a step of testing whether the first lead wire is disconnected or not by measuring an electric resistance between both ends of the first lead wire and a step of testing whether the first and second lead wires are short-circuited or not by measuring an electric resistance between the first lead wire and the substrate.

Abstract: The invention relates to a method for producing at least one signal (oscillation signal), which indicates an oscillation in an electrical power supply system. In order to allow the oscillation behavior of an electrical power system to be detected safely and reliably at all times, an oscillation model is used which is formed from previous impedance values associated with the oscillation, or from variables dependent on these impedance values. A check is carried out to determine whether a further impedance value formed at that time or a variable which is dependent on this further impedance value differs from the oscillation model, and any occurrence of a further impedance value or of a variable dependent on this impedance value which differs from the oscillation model is assessed as the oscillation having stopped.

Abstract: Quick recovery or recovery support of a faulty power generating facility by real time diagnosis such as facility failure diagnosis, supervision for failure symptoms, facility diagnosis by evaluation of performance using databases between said power generating facilities and an operation control system. The operation control system transfers information on operating status and secular characteristic changes of apparatus from power generating facilities or information from operators of selected power generating facilities. The level of a failure of a power generating facility which has a failure is evaluated and repairing information (e.g. recovery procedures, processes, required parts, inventory of the parts, possible failure causes, etc.) is automatically created from repairing information prepared in advance for each evaluation condition. The repairing information is then sent to the operation supporting section of the power generating facility.

Abstract: A technique for isolating and indicating faults or defects in a personal computer system. The personal computer includes a power supply system with an internal fault detector and an enabling input that, when active, instigates the power supply fault detection procedure. In normal operation, an enabling signal is applied to the enabling input when the computer ON/OFF control is activated and when other aspects of the personal computer system have been determined to be operational. A mechanism for simulating an enabling signal and an indicator driven by the power supply fault detector permit fault indications to be localized as existing either in the power supply or elsewhere in the PC system.

Abstract: A method for inspecting lithography masks includes generating integrated circuit design data and using context information from the integrated circuit design data to inspect a mask.

Abstract: The present invention relates to a method for detecting a line-to-ground fault location in power network, and more particularly, detecting the line-to-ground fault location by direct 3-phase circuit analysis without using a symmetrical component transformation, so even in an unbalanced 3-phase circuit, the line-to-ground fault location can be accurately detected. In the method using direct 3-phase circuit analysis of this invention, inverse lemma is used to simplify matrix inversion calculations, thus the line-to-ground fault location can be easily and accurately determined even in the case of an unbalanced network without symmetrical component transformation.

Abstract: An accident point locating system locates an accident point on a power transmission line. A digital protective control system has a plurality of digital protective controllers that receive state data representing a state of an electric power system and convert the same into corresponding digital state data. An absolute time acquiring means acquires an absolute time when the state data is sampled. A state data processing decides whether any malfunction occurred in the power transmission system on the basis of the digital state and executes a protective operation when it is decided that an accident occurred in the power transmission system. A recording device adds an absolute sampling time to the digital state data and records the digital state data with the absolute time. A digital data sending device provides the digital state data with the absolute time on a communication network.

Abstract: A monitoring system includes a sensor that detects operating conditions in a plurality of control loops of a heater system and generates signals corresponding to the detected operating conditions. The monitoring system also includes a controller that receives the signals from the senor and determines whether the signals indicate the presence of an alarm condition in one or more of the control loops. The controller is configured to temporarily disconnect power to the plurality of control loops when it is determined that an alarm condition is present, determine whether the alarm condition is present in an individual connector loop, and reconnect power to only those control loops in which the alarm condition is not present.

Abstract: The invention describes a method, system, device, and computer-readable medium having computer-executable instructions for classifying faults on an electrical power line. In particular, the invention permits the classification of crossover faults using a local measurement technique. The inventive method includes providing a first electrical power transmission line and a second electrical power transmission line, and monitoring the first electrical power transmission line to identify a crossover fault occurring between the first and the second electrical power transmission lines.

Abstract: An apparatus and method for the detection of and recovery from a plurality of electrical transients in a plasma generator system is disclosed. The plasma generator system comprises a plasma chamber and a power amplifier is provided, wherein the apparatus comprises a sensor, the sensor detects an electrical transient in the electrical transients and outputs a first signal when the electrical transient is detected. The system also includes a first circuitry for receiving the first signal, the circuitry controlling said power output from said power amplifier in response to the first signal and outputting a second signal communicating the controlled power output, and a second circuitry for receiving the second signal, the second circuitry outputting a reset signal to the first circuitry, wherein the first circuitry receives the reset signal and resets the power output in response to the reset signal.

Abstract: A hybrid model formed from a semi-physical device model along with an accurate data-fitting model in order to implement a relatively accurate physical device model as a large signal microwave circuit computer-aided design (CAD) tool. The semi-physical device model enables accurate representation of known physical device characteristics and measured bias-dependent characteristics. This model is used to accurately simulate the effect of process variation and environmental changes on bias-dependent characteristics. The data-fitting model is used to model these characteristics with relatively good fidelity. The expressions of the model are constructed to be charge conservative. As such, the model is computationally robust within the harmonic balance algorithms employed by known large signal microwave circuit CAD tools.

Abstract: The present invention discloses a method and an apparatus for improving measurement fault detection in a sequential measurement processing estimator, and is particularly applied to Global Positioning Receivers.

Abstract: A method of determining distance to fault of a transient event in a transmission system uses per frequency triggered I and Q data representing voltage and phase of a return signal in the frequency domain. Initially a result set of data entries, one for each discrete frequency in a specified frequency range, is filled with zeros and an initial acquisition set of per frequency I and Q data from the transmission system is used to fill a reference set of data entries. Subsequent acquisitions of per frequency data sets are used to fill a current set of data entries. Between each acquisition of data sets for the current set a comparison is made, entry by entry, between the current set and the reference set, and the data from the current set is used to update the corresponding entry in the result set when the difference exceeds a specified tolerance.

Abstract: Utility failures are automatically detected and potential causes for these failures are automatically located and identified without having to physically search a utility provider's network. Detection systems capable of monitoring utility status are located at each, or a subset, of the customer premises serviced by a utility provider. A monitoring system, capable of correlating the geographical location of the detection systems with the geographical location of the equipment that comprises the utility provider's network, is located at a utility provider and interconnects with the detection systems through a communications network. The monitoring system queries the detection systems to determine utility status and to subsequently locate an outage and deduce a possible cause for the outage. Detection systems can also be configured to automatically contact the monitoring system to report utility status.

Abstract: A method and apparatus for locating a short between two nets in an electrical wire network of a microelectronic structure (e.g., chip, chip carrier, circuit card, etc.). A first net and a second net of the electrical wire are electrically shorted at an unknown point PS on the first net. Points PA and PB on the first net such are selected such that PS is located on a path between PA and PB along the first net. A constant current pulse source is electrically connected between PA and PB and is activated. Voltage drops VAB (from PA to PB) and VAC (from PA to a point PC on the second net) are measured. A length LAS of the path from PA to PS is calculated as a function of VAC/VAB. Computer graphics may be used to graphically display the location of the short within the microelectronic structure.

Abstract: The invention is directed to a method for producing a fault signal indicating a short-circuit between a first phase conductor and a second phase conductor of two different, parallel-running, three-phase power transmission lines. The method produces a fault signal indicating a short-circuit which has occurred between a first phase conductor and a second phase conductor of a power transmission arrangement.

Abstract: Aspects of failure detection of an isolation device in a power supply of a redundant power supply system are described. The aspects include an isolation device coupled to a voltage input line of a power supply. A comparator coupled to the isolation device provides a predictive failure analysis (PFA) signal when the isolation device fails.

Abstract: Faults on power lines are detected by measuring the voltage and current at one end of a power line and using these measurements, together with values of series and shunt parameters of the line, to calculate values of voltage and current at an intermediate point on the line—the so-called “reach point”. At least the calculated voltage is used to determine whether a fault lies within a particular zone on the line. The calculation utilizes a value of a derivative of the measured current with respect to time and is able to take into account the sectioning of a line into discrete lengths corresponding to, for example, overhead and cable sections. To increase accuracy, the line or each discrete section of the line is conceptually divided into subsections each having its own parameter values.

Abstract: Power is provided from an energy storage device to a utility network based on a detected condition, such as a fault, in the network. Specifically, it is determined whether a fault on the utility network is a near fault or a far fault relative to the energy storage device. Whether a fault is classified as “near” or “far” is determined based on a voltage drop in the utility network. Power is then supplied to the utility network based on whether the fault is a near fault or a far fault.

Abstract: A method for predicting zero crossings of fault currents in a multi-phase power system includes sensing a fault current in each respective phase, estimating parameters of a model of each respective fault current, and independently using the estimated parameters for each respective fault current to predict a zero crossing of the respective fault current.