Abstract: A capacitor capacitance diagnosis device includes a power supply which is for charging a capacitor, a discharge circuit which is connected to the capacitor in parallel to discharge energy of the capacitor, a resistance dividing circuit which is for measuring voltage drop value during discharging, a measurement circuit which measures divided voltage, and a diagnosis circuit which determines adequacy of capacitor capacitance from a time change in voltage due to the discharge. This makes it possible to diagnose adequacy of capacitor capacitance of an electric power apparatus during operation.

Abstract: The present document discloses several techniques of evaluating parameters relating to noise and excess current on a power line. The techniques are particularly well-suited for characterizing partial discharge, and for identifying a location of a source of the noise or excess current.

Abstract: The invention is related to an insulation deterioration diagnostic apparatus for an electric path connected between an inverter device and an inverter-driven load device, including: a zero-phase current transformer having an annular magnetic core, a magnetizing coil wound around the magnetic core, and a detecting coil wound around the magnetic core, the transformer being for detecting a zero-phase current of an electric path; a magnetization control circuit for supplying an alternating current having a frequency at least twice as high as a drive frequency of the load device to the magnetizing coil to magnetize the magnetic core; and a frequency extracting circuit for extracting a frequency component identical to the drive frequency fd, from the output signal of the detecting coil, whereby precisely measuring a current leaking from an inverter-driven load device over a wide range of frequencies.

Abstract: A method for assessing insulation deterioration in a live underground power cable may include, in one embodiment, attaching a coupling device to a live underground power cable and using the coupling device to couple a test signal onto the power cable. The power cable may carry a normal AC power signal at a first frequency, while the test signal may have a second frequency different from the first frequency. The test signal may be detected after it has traveled a distance along the power cable. It may then be analyzed to determine a change in velocity and/or attenuation of the test signal as a function of the normal AC power signal. The severity of water trees in the power cable may be inferred based on the magnitude of the change.

Abstract: A monitoring system adapted to assess insulation losses of an underground power cable includes a cable circuit having first and second, spaced-apart terminals. The cable circuit is disposed along a section of the underground power cable. The system further includes a communications device adapted to transmit data gathered at the first and second terminals, and a processor adapted to receive and process the data measured at the same time with the synchronization device and transmitted from the communications device.

Abstract: A continuity testing apparatus includes open/short detection circuits provided for to-be-tested terminals, respectively and configured to determine the presence or absence of at least any one of an open-circuit failure and a short-circuit failure in to-be-tested terminals. Then, the continuity testing apparatus generates detected results of the open/short detection circuits based on the condition of continuity of the to-be-tested terminals having connections to the open/short detection circuits and the detected results from the open/short detection circuits in the preceding stages, and outputs the generated detected results to the open/short detection circuits in the succeeding stages. Further, the continuity testing apparatus determines the condition of continuity based on the output from the open/short detection circuit in the last stage.

Abstract: An oil immersed electrical apparatus such as an oil immersed transformer that can detect copper sulfide precipitated on coil insulating paper is provided. In the oil immersed transformer in which a coil with its surface covered by insulating paper is arranged in a container filled with insulating oil, a detection member is prepared by providing two electrodes on a surface of a plate-like pressboard formed of cellulose, which is a same material as that of the insulating paper, this detection member is arranged in contact with the insulating oil, and generation of copper sulfide is detected from reduction in a surface resistance between the electrodes. The temperature of the detection member is set higher than the temperature of the coil so that copper sulfide is generated thereon prior to generation of copper sulfide on a coil unit.

Abstract: A nondestructive inspection method of testing insulators using frequency resonance function that can inspect an anomaly of an insulator by vibrating the insulator with a force having the characteristic of white noise, measuring the change in motion of the insulator according to the vibration and calculating the frequency resonance function of the insulator is disclosed.

Abstract: An insulation tester for measuring the surface resistivity of a coated electrical steel sheet using a cylindrical electrode that tests the entire surface area of the sheet. A specific voltage is applied across the insulative coating of the electrical steel sheet using the rotatable cylindrical electrode. The cylindrical electrode is roved over the entire surface of the coated electrical steel sheet to detect insulation defects. This roving tester can be used to locate insulation defects in the coating that can cause core failures, or measure the surface resistivity or dielectric strength of the insulative coating. This tester improves over a conventional Franklin tester which uses discrete button electrodes to test only a small portion of the sheet.

Abstract: An arc fault circuit interrupter test circuit is disclosed. The test circuit incorporates a controller along with at least one power transistor, a current sense circuit and a voltage sense circuit. When the power transistor is operated, the current flowing through the transistor is sensed, and if the current is not at least equal to a threshold value, the voltage at which the power transistor is operated is increased.

Abstract: A device for determining partial discharge in an insulation system of a rotating electrical machine with low capacitance decoupling has a coupler as a high pass and an adapter device connected or connectable to the coupler. The adapter device has a frequency separating filter for dividing a decoupled signal provided by the coupler into a high frequency signal and a low frequency signal. A mixer is provided for the high frequency signal and the low frequency signal for converting the high frequency signal. An output is provided where the converted high frequency signal is tapped for evaluation by an evaluation device connectable to the adapter device.

Abstract: A method and system is provided for determining leakage resistances in a bus system. The bus system has a floating DC bus connected to bus voltage source. The system also includes a pair of known resistors, each connected to the bus by a switch. The method includes with the first switch closed and the second switch open, measuring a voltage Vprtp between the bus and the ground and measuring a voltage Vnrtp between the ground and the second terminal. The method also includes, with the first switch open and the second switch closed, measuring a voltage Vprtn between the bus and the ground and measuring a voltage Vnrtn between the ground and the second terminal. The first and second leakage resistances are then calculated as a function of the known resistors and the measured voltages.

Abstract: An electrical power transmission system includes electrical insulators arranged to electrically isolate live power lines. Measurement devices are physically incorporated or integrated in the insulator structures. The measurement devices measure and report insulator properties during live wire conditions. A method includes deploying a measurement device in physical contact with an insulator in use to electrically isolate a power transmission line. This method also includes measuring properties of the insulator in use with the measurement device at substantially within time intervals corresponding to voltage zero crossings in the power transmission line.

Abstract: The disclosure relates to a method for partial discharge testing of an insulation component, wherein at least one X-ray pulse is applied to the insulation component, an AC voltage is applied to the insulation component and the partial discharge induced by the at least one X-ray pulse is measured, wherein the dose rate of the at least one X-ray pulse is at least about 10?2 Gray/s. The disclosure relates further to a system for partial discharge testing of an insulation component which includes a flash X-ray source for generating at least one X-ray pulse, an AC voltage source, a voltage sensor, a partial discharge sensor and a partial discharge detection device for evaluating the measured partial discharge.

Abstract: A test structure for testing electrical properties of a material comprises a first loop and a second loop, which are connected to form a closed test loop. A signal generator, for generating a test signal, is coupled to the first loop and the second loop. A signal propagation switching logic is coupled to the first loop and to the second loop for alternatingly flipping the test signal between the first and second loops, such that the test signal moves uninterrupted through the closed test loop. A probe logic detects any degradation of the test signal as the test signal travels along the closed test loop.

Abstract: A test element group (TEG) pattern formed of two wiring patterns alternately disposed in a swirl configuration is used for testing an insulation property of a wafer-level chip scale package (WL-CSP) having a micro wiring such as an inductor element. The insulation property of the WL-CSP can be monitored with enhanced accuracy by measuring a resistance value between solder terminals electrically connected to the swirl-shaped TEG pattern.

Abstract: Disclosed is a method for manufacturing an electrochemical cell, wherein an insulation failure product can be accurately rejected, and an electrochemical cell can be used again after the insulation failure inspection. In the method for manufacturing the electrochemical cell (1), which is configured by hermetically housing an electrochemical cell main body (20) such that the leading end of a metal terminal (21) protrudes to the outside of the outer housing (10), an impulse voltage is applied between the metal terminal (21) and a metal foil layer (12), the waveform of the voltage applied to the capacitance between the metal terminal (21) and the metal foil layer (12) is measured, and the insulation failure inspection step is performed.

Abstract: An insulation state detector includes a capacitor, a measurement section measuring a charging voltage of the capacitor, a measuring circuit that connects the capacitor, which is insulated from a DC power source after being charged by the DC power source, between the measurement section and a ground potential portion, a detector detecting an insulation state of a voltage boosting circuit, and a reversed-polarity measuring circuit that connects the capacitor to the measurement section and the ground potential portion with reversed polarity when a potential corresponding to a division ratio of a positive-side ground fault resistor and a negative-side ground fault resistor on a secondary side of the voltage boosting circuit exceeds a positive potential of the DC power source and the capacitor is charged with reversed polarity by a secondary-side positive potential at the time of charging of the capacitor using the positive potential of the DC power source.

Abstract: Methods and systems are presented for detecting partial electrical discharges in a printing machine and for determining the source of the discharge events by detecting radio frequency signals using an antenna located near high voltage components of the printing system and determining whether a partial electrical discharge has occurred based on the detected signals. One or more of the high voltage components are then selectively enabled alone or in groups to isolate the source of the partial electrical discharge to expedite identification of suspect components and facilitate repair and system maintenance.

Abstract: Exemplary methods are directed to insulation monitoring of non-grounded electrical DC power supply systems and AC power supply systems which have a resistive (Rf) and capacitive (Cf) insulation impedance between the power supply system and ground. The method includes applying a pulsed AC voltage (U0) having alternately different pulsed voltage values to the power supply system to be monitored via a resistive system interface (Ri) between the power supply system and ground. The insulation impedance (Rf) between the power supply system and ground is determined using time profiles of transient processes of the measurement voltage (Vm) prior to transient recovery of the power supply system to the respective pulsed voltage value (U0) of two polarity-inverted pulsed voltage value application processes.

Abstract: An object is to detect an insulation failure of a DC circuit with high sensitivity and in safety by means of a simple detection circuit. An insulation resistance measurement device of this invention is a device for measuring an insulation resistance to ground of a DC source circuit and is provided with connection terminals for connections to a positive electrode and a negative electrode of a series power supply, switch elements connected between the connection terminals and the ground potential and configured to switch connections between the connection terminals and the ground potential, resistive elements connected through the switch elements between the connection terminals, respectively, and the ground potential, and a voltage detection unit for detecting voltage drops in the resistive elements.

Abstract: A partial discharge detection sensor is used for detecting a partial discharge signal in a gas-insulated equipment using a PCB substrate, and a partial discharge detection device employs the partial discharge detection sensor. The partial discharge detection sensor includes a PCB substrate, a partial discharge signal detection pattern formed on the PCB substrate to detect a partial discharge signal in the gas-insulated equipment, and a connection terminal for receiving the partial discharge signal detected by the partial discharge signal detection pattern and transmitting the partial discharge signal to a connector that emits the partial discharge signal to the outside. The partial discharge detection sensor is attached to an inner wall of an enclosure of the gas-insulated equipment.

Abstract: A high voltage power transmission system includes an insulator arranged to electrically isolate a live power transmission line and a testing device in physical contact with the insulator, The teat device measures properties of the insulator by conducting electrical tests of and/or optical examination on the insulator while it is in-service to electrically isolate the live power transmission line.

Abstract: An insulation measurement method in an insulation measurement apparatus of a flying capacitor type, includes a first power supply charge voltage measurement process of applying a voltage of a power supply to a flying capacitor for a first charge time period a first grounding resistor measuring voltage measurement process of applying the voltage of the power supply to the flying capacitor via an insulation resistor on one electrode side of the power supply, a second power supply charge voltage measurement process of applying the voltage of the power supply to the flying capacitor for a second charge time period, a second grounding resistor measuring voltage measurement process of applying the voltage of the power supply to the flying capacitor via an insulation resistor on the other electrode side of the power supply, and an insulation resistor conversion process of obtaining a value of the insulation resistor based on measurement results of the first and second charge voltage measurement processes and the fir

Abstract: A multiplexed input/output (I/O) system detects leakage currents on a selected input channel. The system includes a leakage detection multiplexer connected to provide an output selected from one of a plurality of input channels. In addition, the leakage detection multiplexer provides as part of the output measured leakage currents associated with the selected input channel. Based on the detected leakage currents, a determination can made regarding whether the detected leakage currents have compromised the integrity of the multiplexer output. In addition, the detected leakage current can be used to compensate the output provided by the multiplexer to account for the presence of leakage currents on the selected channel.

Abstract: A method and a device for determining a humidity content of an insulation of a transformer, the insulation having a liquid. At least one dielectric property of the insulation is measured, an uncorrected humidity content of the insulation and a conductivity of a liquid which is included in the insulation is derived from a model of the insulation, said model being chosen depending on the measured dielectric property of the insulation, and the humidity content of the insulation is corrected by means of the conductivity.

Abstract: A system for the measurement of degradation of electrical wire insulation quality is described. The system includes a clamping device for engaging the electrical wire to be tested for insulation degradation, the clamping device comprising a channel formed therein for placement of the electrical wire, a plurality of plates placed proximate the channel, the plates electrically connected to generate a capacitance and placed proximate the channel such that the wire insulation provides a portion of a dielectric for the generated capacitance, and a measurement device operatively attached to the plurality of plates such that the measurement device is configured to indicate an amount of degradation associated with the wire insulation based on at least one of the measured capacitance and dissipation factor.

Abstract: An integrated circuit has an inhomogeneous protective layer or coating over a circuit to be protected, and a sensing circuit (80) arranged to sense a first impedance of a part of the protective coating compared to a reference impedance (CO) located on the integrated circuit. The sensing circuit is able to measure a change in the first impedance, e.g. caused by tampering. The sensing circuit has an amplifier (OTA) having a feedback loop, such that the impedance being sensed is in the feedback loop. The sensing circuit can be incorporated in an oscillator circuit (OTA, Comp) so that the frequency depends on the impedance. Where the impedance is a capacitance, sensing electrodes adjacent to the protective layer or coating, form the capacitance. The electrodes can be arranged as selectable interdigitated comb structures, so that the protective layer or coating extends in between the teeth of the comb structures.

Abstract: In an insulation coated conductor inspection method for inspecting an electrical insulation characteristic of an insulation coated conductor in a coil formed by winding the insulation coated conductor, the coil is disposed in a test container, an internal pressure of the test container is reduced, an electrodes are provided so as to face the coil with a gap therebetween, an alternating-current voltage is applied between the electrodes and the coil, a generation frequency of a discharge that is generated between the coil and the electrodes upon application of the alternating-current voltage is measured, and the coil is determined to be a non-defective product having a superior electrical insulation property when the generation frequency of the discharge is higher than a reference generation frequency and determined to be a defective product having a defective electrical insulation property when the generation frequency of the discharge is lower than the reference generation frequency.

Abstract: A short detection apparatus, system and method detect short circuits in an inkjet printhead using a comparison of measured current consumption and an estimate of current consumption based on print data. The apparatus includes a current sensor to measure current consumed by the printhead to eject a droplet of ink, a current estimator to estimate a current consumption of the printhead due to print data provided to the printhead, and a comparator to compare the measured consumed current to the estimated consumed current. A short circuit in the printhead is indicated when the comparison exceeds a predetermined threshold.

Abstract: An insulation measurement apparatus includes a path including a first resistor, a capacitor electrically floated from a ground, and a second resistor between a positive to a negative electrode side of a power supply, a first switching element between the power supply positive electrode side and the capacitor, a second switching element between the capacitor and the power supply negative electrode side, a detection section detecting a charge voltage on the capacitor and determining a power supply insulation state, and a voltage setting section executing a power supply voltage measurement mode controlling the first and second switching elements to charge the capacitor for a predetermined time period, and an insulation voltage measurement mode charging a terminal of a positive or negative electrode side of the capacitor via a resistor between the power supply positive or negative electrode and the ground for a predetermined time period.

Abstract: A partial discharge coupler for detecting partial discharges in a conductor includes a frequency dependent network, a differential amplifier and a frequency selective coupling component. The frequency dependent network includes a first filter component, a fuse component and a load component, typically coupled together in series with reference to a first ground. The first filter component filters the high voltage, low frequency alternating current signal carried by the conductor from the load component and passes high frequency partial discharge pulse signals to the load component. The frequency selective coupling component couples in series between the differential amplifier and the load component. The output of the differential amplifier is configured to provide an output that is isolated from the ground connection for communicating detected partial discharge signals to partial discharge test equipment.

Abstract: A power electronics system configured to determine a condition of a winding insulation is disclosed. The system may include at least one capacitor, and a first resistance coupled to the at least one capacitor. The system may further include a plurality of electronic switching devices coupled to at least the first resistance and the at least one capacitor, wherein the plurality of electronic switching devices are configured to selectively couple the at least one capacitor to a power source to charge the at least one capacitor during a first time interval and selectively couple the at least one capacitor to a second resistance during a second time interval. The system may further include a voltage measuring device configured to detect a change in voltage at a terminal of the at least one capacitor in response to the selective coupling of the at least one capacitor to the second resistance.

Abstract: The present invention relates to a method for determining partial discharges at an electrical component (10). In the case of the method, an electrical signal that comprises partial discharge pulses due to the partial discharges at the electrical component (10) is detected. Through filtering of the electrical signal by means of n filters (18-20) having n differing filter characteristics, n filtered partial discharge signals are generated. Respectively one of the filtered partial discharge signals is assigned, respectively, to one of the n filters (18-20), n being greater than or equal to two. Finally, the partial discharges are determined by linking the n filtered partial discharge signals.

Abstract: The present invention relates to a method and a measuring arrangement for the non-destructive detection of coating errors in an electrically conductive substrate layer, which is coated with at least one electrically insulating cover layer. An input signal is inductively or capacitively input into the electrically conductive substrate layer by means of a signal input device. A measurement signal is output from the substrate layer via the cover layer by means of a signal output device. An evaluation unit is used to evaluate the output measurement signal. In this case, a coating error is detected when a signal parameter change of a signal parameter of the output measurement signal exceeds an adjustable threshold value.

Abstract: An instrument (1) and a method for measuring pulses of partial electrical discharges in an electrical system comprise data processing means (5) operatively associated both with an input stage (2), able to receive an analogue signal (3) representing said pulses and to provide a digital representation of the entire wave form of the pulses, to receive said digital representation, extract the value of predetermined parameters relating to the wave form of the pulses and transfer to and output stage (4) a processed digital signal comprising said values, the processing means (5) being able to operate substantially in real time, i.e. with no need for a memory for the intermediate storage of the data.

Abstract: A method of testing an insulation system is disclosed. The method comprises coupling a first test lead to a first conductor, the first conductor at least partly isolated by the insulation system and coupling a second test lead to a second conductor or a ground. The method further comprises applying a test signal to the first test lead, receiving a test response from the second test lead, and analyzing the test response from the second test lead to determine a harmonic content of the test response. The method further comprises, when the harmonic content is equal to or greater than a predetermined threshold, determining that the insulator system has non-linear properties.

Abstract: A method of detecting a ground fault condition between a direct current power system and the chassis ground of an electric or hybrid-electric vehicle is provided. The method includes sequentially opening and closing a first switch connected between a positive node of the direct current power system and the chassis ground of the vehicle and a second switch connected between a negative node of direct current power system and the chassis ground. The sequential opening and closing of the first and second switches charges and discharges an inherent capacitance present between the metal components of the direct current power system and the chassis. First and second currents are created as the inherent capacitance is charged and discharged. Measurements of the created first and second currents are then used to determine whether a ground fault condition exists between the direct current power system and the vehicle chassis ground.

Abstract: An insulation diagnosis method according to the present invention includes: measurement step through which a signal generated at a diagnosis target device is measured; detection step through which a frequency or a frequency band manifesting a maximum amplitude signal strength is detected from the signal having been measured through the measurement step; and identification step through which an insulation defect type pertaining to an insulation defect having occurred in the diagnosis target device is identified based upon the frequency or the frequency band manifesting the maximum amplitude signal strength having been detected through the detection step.

Abstract: Method for the simulation of defects in the case of spark testers, in which breakdowns are recognized and displayed by a detector and added by means of a defect counter, wherein the high voltage is applied to a stationary standard spark gap and pulsed test voltages of predetermined level, duration and frequency are generated by the high voltage generator of the spark tester in short regular intervals.

Abstract: A method for altering an impedance of a conductive pathway on a microelectronic package includes applying a magnetic field to the conductive pathway. The microelectronic package may be, for example, a printed circuit board. The method also includes controlling a magnitude of the magnetic field at the conductive pathway for altering the impedance of the conductive pathway. The magnetic field may be applied by, for example, an electromagnet or a permanent magnet. A magnetic field may also be applied for simulating crosstalk effects on a conductive pathway.

Abstract: In large-scale photovoltaic systems, it is not appropriate to use a conventional insulation monitor, since its test pulse is damped too much by the number and length of the feed lines. According to an embodiment of the invention, a remedy is provided here in that the photovoltaic system is subdivided through circuit design into multiple subsystems that are electrically insulated from one another, and the test pulse is transmitted to the connecting line associated with the applicable subsystem in sequential order. According to a second embodiment, the behavior of the current of the test pulse through the connecting lines is sensed by current sensors and evaluated in an analysis unit.

Abstract: A test method for a spark plug ceramic insulator includes placing a first electrode in an inner hole of the ceramic insulator and placing a second electrode on an outer peripheral side of the ceramic insulator, developing a defect in the ceramic insulator by the application of a first voltage onto the ceramic insulator between the first and second electrodes and detecting the defect in the ceramic insulator by the application of a second voltage, which is lower than a flashover voltage that causes a flashover of the ceramic insulator, onto the ceramic insulator between the first and second electrodes.

Abstract: A leak current breaker is provided which includes a detector (10) to detect a leakage current from electric lines, a first removing unit (12) to convert the detected leakage current into a voltage and a voltage detector (14) to detect a voltage developed in electric lines A under testing, a second removing unit (16) to remove a harmonic component included in the voltage, a phase contrast detector (20) to detect a phase contrast from a signal waveform having the harmonic component removed, a frequency calculator (21) to calculate a frequency occurring on electric lines A on the basis of the signal waveform of the voltage having the harmonic component removed by the second removing unit (16), a phase angle calculator (22) to calculate a phase angle of the leakage current flowing through the electric lines A on the basis of the phase contrast and frequency, a root-mean-square value calculator (24) to calculate a root-mean-square value of the voltage having the harmonic component removed by the first removing uni

Abstract: A marker pulse discriminator monitor that enables filtering of partial discharge pulses for monitoring the condition of a generator in a power plant system. The monitor detects partial discharge pulses emanating from the generator and includes a plurality of first modules connected to respective isophase buses adjacent to the generator. Each of the first modules generate a marker pulse in response to a partial discharge pulse. The monitor also includes an analyzer unit connected to the isophase buses adjacent to a step-up transformer. The analyzer unit receives each partial discharge pulse and each marker pulse and determines a differential value corresponding to a difference between a time of arrival of a partial discharge pulse and a time of arrival of a corresponding marker pulse to identify partial discharge pulses originating at the generator and to identify the isophase bus associated with the corresponding partial discharge pulse.

Abstract: Systems and methods for improved Variable Speed Drives are provided. One embodiment relates to apparatus for common mode and differential mode filtering for motor or compressor bearing protection when operating with Variable Speed Drives, including conducted EMI/RFI input power mains mitigation. Another embodiment relates to a method to extend the synchronous operation of an active converter to the AC mains voltage during complete line dropout. Another embodiment relates to an active converter-based Variable Speed Drive system with Improved Full Speed Efficiency. Another embodiment relates to a liquid- or refrigerant-cooled inductor. The liquid- or refrigerant-cooled inductor may be used in any application where liquid or refrigerant cooling is available and a reduction in size and weight of a magnetic component is desired.

Abstract: This invention relates to high voltage electrical or power systems and in particular to a method and device for monitoring partial discharges in high voltage electrical or power systems. The method comprises defining a low trigger level and a high trigger level electrical pulse amplitude levels, monitoring at least one phase of the electrical system for an occurrence of a pulse within a defined minor time frame; detecting a peak amplitude of a pulse occurring in the electrical system within the minor time frame; determining if the detected peak amplitude of the pulse exceeds the lower and higher trigger levels; assigning a pulse number to the pulse if the peak amplitude of the pulse exceeds the trigger levels; capturing the pulse if the pulse number associated with the pulse is less than a predetermined pulse number threshold in the minor time frame; and storing the captured pulses in a memory.

Abstract: An insulation resistance determining system (50) comprises an insulation resistance determining portion configured by connecting a coupling capacitor (52), a detection resistor (54), and a pulse oscillating circuit (56) in series with a common mode potential measuring point (30), and an insulation resistance determining portion having a filter (58) which processes an AC signal (vx) at a junction between the coupling capacitor (52) and the detection resistor (54), an amplifier (60), a wave-peak value detection circuit (62), and a controller (70).

Abstract: A method for measuring degradation of electrical power system device insulation utilizes a conductive composite sensor. A selected polymeric matrix of the conductive composite provides a sensor resistance response that correlates to degradation of the insulation. The sensor may be embedded in the windings, core or stator of the electrical power system device and wired to a connector on the electrical power system device for interrogation by an ohmmeter.

Abstract: There is here disclosed a method and apparatus for detecting the occurrence of arcing of a conductor by monitoring the current on an AC power line. The signal detected is split and directed along four separate paths to generate four signals having separate characteristics which represent the current in the line. A first path is for a signal representative of the current flowing in the line. A second path is for a signal having a pulse for each occurrence of a positive step change in current that is significant and has a di/dt value above a predetermined value. A third path is for a signal having a pulse for each occurrence of a negative step change in current that is significant and has a di/dt value above a predetermined value. A fourth path is for a signal having a voltage level representative of the broadband noise signal on the line. Using at least one of five different methods in combination with one of three input signals, a reference signal designated as “SINE” is generated.