摘要:
An arc fault circuit interrupter includes separable contacts, an operating mechanism and an arc fault detector structured to detect an arc fault condition operatively associated with the contacts. The arc fault detector includes a tuned current sensor structured to sense broadband noise of a current flowing through the contacts, a compression circuit including an input of the sensed broadband noise and an output. The compression circuit compresses the dynamic range of the sensed broadband noise. A minimum detector includes an input of the compression circuit output and an output of the minimum value of the minimum detector input. A processor includes a number of inputs and an output. One of the inputs is the output of the minimum value of the minimum detector. A trip mechanism cooperates with the output of the processor and the operating mechanism to trip open the contacts responsive to the detected arc fault condition.
摘要:
An electrical fault detection device for use in a branch of a power circuit that utilizes signals from an AC line current sensor coupled to an electrical distribution line having a primary and neutral lines, a line high-frequency sensor coupled to the electrical distribution line, a differential current sensor coupled to the primary and neutral lines, and a ground fault current sensor coupled to the primary and neutral lines. A signal conditioner receives the signals outputted by AC current line current sensor, the line high frequency sensor, the differential current sensor and the ground fault current sensor and generates a signal indicative of the load current associated with a branch of the power circuit. Output of the signal conditioner is sampled and processed by a processing resource. The processing resource has stored therein data representing a plurality of time-versus-current curves that define a plurality of regions in which tripping may or may not occur. One region has time data and current data that define a time-duration for a particular current magnitude for which no tripping will occur. Another region has time data and current data that define a time-duration of a particular current magnitude for which tripping will occur. Processing resource processes sampled signal to determine the region to which the processed time data and current data correspond, and generates a signal to initiate tripping if the sampled signal yields a time duration for a particular current magnitude that corresponds to a region for which tripping must occur.
摘要:
A system and a method are provided for specifying arbitrary nodes and identifying a section between them on a system diagram of a distribution system. It comprises a system diagram information management portion for managing information on each of nodes and spans constituting the system diagram and ID information given to each of the nodes, an input portion for receiving an input specifying the nodes, a search portion for creating a search condition using the ID information based on the node specification and searching the span between the specified nodes so as to identify the section constituted by the searched span, and an output portion for display-outputting the system diagram visually indicating the section identified by the search portion.
摘要:
A method for detecting stator ground faults in a generator is described. The method includes receiving a neutral voltage signal from a neutral point of a stator, receiving a plurality of terminal voltage and current signals from the stator, deriving a magnitude of a harmonic component from the neutral voltage signal, deriving a total complex power from the terminal voltage and current signals, calculating an expected value of a harmonic based on the complex power at a first time and a plurality of values of the complex power, where the values of the complex power are measured at times before the first time, and comparing the expected value and a measured value of the harmonic.
摘要:
A method for monitoring the adjustment movement of a component, in particular a window pane or a sunroof in motor vehicles, which is driven by a drive device and can be adjusted in a translatory or rotary fashion. A plurality of input signals which can be derived from the drive device and which represent a deceleration of the adjustment movement of the drive device are input at input neurons of an input layer of a neural network with at least one hidden layer having hidden neurons. Said network outputting, at least one output neuron of an output layer, an output value which corresponds to the adjusting force or to a trapped state or nontrapped state.
摘要:
A digital signal processor implementation of three algorithms used to detect high impedance faults. The algorithms can be wavelet based, higher order statistics based and neural network based. The algorithms are modified to process one second of data instead of ten seconds of data and a double buffered acquisition is connected to the output of the algorithms.
摘要:
An apparatus and method for detecting arc faults that have reduced susceptibility to nuisance tripping. The apparatus includes a current sensor, an input sense circuit, an arcing sense circuit, a power supply, a tripping (firing) circuit, a processor, and an electromechanical interface. The current sensor monitors a power input comprising an AC current, and provides high frequency components of the. AC current to the input sense circuit. The input sense circuit filters and rectifies the AC signal, and provides the rectified signal to the arcing sense circuit. The arcing sense circuit provides a voltage level accumulated over a predetermined time period, and digital signals indicative of possible electrical arcing occurring during the sampling period, to the processor. The processor measures the voltage level, stores information relating to measured voltages and the digital signals, and processes the stored information using one or more algorithms, thereby determining whether the signals resulted from an arc fault or a nuisance load. In the event the signals resulted from an arc fault, the processor activates the firing circuit to trip the electromechanical interface, thereby interrupting the power output to the load.
摘要:
An apparatus and method for detecting electrical arc faults that has reduced susceptibility to nuisance tripping. The apparatus includes a current sensor, an input sense circuit, an arcing sense circuit, a power supply, a tripping circuit, a processing unit, and an electromechanical interface. The processing unit measures multiple voltage levels provided by the arcing sense circuit during a specified number of consecutive time periods. Next, the processing unit determines the number of consecutive time periods during which the voltage levels exceeded a specified minimum value, take on successively lower or higher values, or fall outside a predetermined normal range of values. Based upon the results of this determination, the processing unit either trips the electromechanical interface to interrupt power to a load, or inhibits tripping of the electromechanical interface, thereby reducing the occurrence of nuisance tripping.
摘要:
An apparatus, system, and method for detecting high impedance faults in electrical power lines using a composite high impedance fault detection system having a voter logic that samples the logical outputs from a plurality of independent high impedance detection systems and determines a high impedance fault if any two of the plurality of independent high impedance detection systems indicates a high impedance fault. Preferably, the plurality of high impedance detection systems include a wavelet based high impedance fault detection system having a first logical output, a higher order statistics based high impedance fault detection system having a second logical output, and a neural net based high impedance fault detection system having a third logical output. Preferably, each of the plurality of high impedance fault detection systems includes an independent high impedance fault detection application that independently detects a high impedance fault on the electrical power line.
摘要:
The mobile element is a vehicle window pane, panel, movable seat or similar, conveniently guided, and driven by a DC electric motor with a permanent magnet, and the method comprises a step of detecting an entrapment or collision situation of the mobile element by means of a first fuzzy logic algorithm, which inputs are the mobile element's position and the increments that may occur in the intensity of the current demanded by said motor, which is evaluated from the relative increase of the current intensity at one turn of the motor and after one next, subsequent turn of the motor. A second fuzzy logic algorithm is used to control the mobile element's velocity, in close loop.