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844results about "Testing circuits" patented technology

GIS (Geographic Information System) tiny defect detection method and system based on X-ray multi-effect fusion

The invention discloses a GIS (Gas Insulated Switchgear) tiny defect detection method and system based on X-ray multi-effect fusion, and the method comprises the following steps: firstly, exciting a latent defect in a GIS to generate partial discharge by using an X-ray photoionization effect, detecting a discharge signal by using an ultrahigh frequency method and an ultrasonic method, and after the discharge signal is processed by a noise reduction model, carrying out noise reduction on the discharge signal; and respectively obtaining an ultrahigh-frequency discharge phase spectrogram and an ultrasonic discharge phase spectrogram. Then, the imaging plate is placed on the back face of the GIS, digital DR imaging is carried out through X rays, and an X-ray image is obtained; the ultrahigh frequency discharge phase spectrogram and the ultrasonic discharge phase spectrogram are fused after being denoised, an X-ray image is combined to establish a GIS health state diagnosis model, and reliable defect detection is carried out on the GIS according to the evaluation score of the diagnosis model. According to the method, multiple effects of X-rays are fused, so that smaller GIS latent defects can be found, the detection sensitivity is remarkably improved, and the problem that the traditional method is difficult to identify the tiny latent defects is solved.
Owner:NANCHANG POWER SUPPLY BRANCH OF STATE GRID JIANGXI ELECTRIC POWER CO LTD +2

Joint test system and test method for partial discharge and breakdown under wide temperature range and variable air pressure

The invention discloses a partial discharge and breakdown combined test system and test method under wide temperature range and variable air pressure, which are suitable for evaluating the insulating properties of insulating materials, cables and power equipment under high and low temperature and different air pressure conditions. The system comprises a vacuum oven, a partial discharge and withstand voltage breakdown joint test module, an explosion-proof cable joint, a control module and a detection module, the vacuum oven can realize temperature regulation and control from-70 DEG C to + 200 DEG C and an air pressure environment of 10 <-3 > Pa, and the test module integrates a high voltage generator, a coaxial electrode and a partial discharge sensor. Partial discharge detection and breakdown voltage measurement can be completed in the same test environment. According to the test method, the electrical response characteristics of the insulating material under different working conditions are obtained through regulation and control of environment temperature and pressure, execution of a test process and data acquisition and analysis. The device is compact in structure and high in safety, and has the capabilities of joint testing, high-precision regulation and control and adaptability to complex environments.
Owner:HARBIN UNIV OF SCI & TECH

Insulator pollution flashover monitoring device and method

The invention discloses an insulator pollution flashover monitoring device and method, and relates to the technical field of online monitoring and fault diagnosis of high-voltage power equipment. The monitoring unit comprises a fixing piece, a hanging piece arranged on the fixing piece, a swing arm rotationally arranged on the fixing piece and detection assemblies arranged on the swing arm at intervals in the length direction of the swing arm; the visual acquisition module is arranged on the unmanned aerial vehicle; the hanging piece is detachably connected with the unmanned aerial vehicle, the fixing piece is used for being detachably and fixedly connected with an insulator, the swing arm is in driving connection with a driving piece, the driving piece can drive the swing arm to swing around a first axis, and the first axis is perpendicular to a second axis of the insulator to be detected. The detection environment of the electric field probe is less affected by the surrounding insulator chain, so that the obtained monitoring data is more representative, and the monitoring result is more accurate.
Owner:ZHANGJIAKOU POWER SUPPLY COMPANY OF STATE GRID JINBEI ELECTRIC POWER COMPANY

Insulation inspection system with voltage and current balancing circuit

An insulation inspection system includes: a set of input terminals; a brush; a circuit connected to the set of input terminals, the brush, and a part being inspected, where the circuit includes at least one pair of resistors and a capacitor; and a control module configured to detect when a short circuit exists between a conductive element of the part and one or more conductive bristles due to insulative material missing on the part and as a result the one or more conductive bristles of the brush contacting the conductive element of the part.
Owner:GM GLOBAL TECHNOLOGY OPERATIONS LLC

Dual-channel parallel processing architecture for ultrahigh frequency partial discharge signals

In order to solve the problem that quick response and distortionless recording of ultrahigh-frequency partial discharge signals are difficult to realize when accidental pulses are generated in the prior art, the invention relates to a dual-channel parallel processing architecture for ultrahigh-frequency partial discharge signals, which comprises a signal cloning circuit and a signal processing circuit, the ultrahigh-frequency partial discharge module is used for receiving ultrahigh-frequency partial discharge signals and synchronously outputting the ultrahigh-frequency partial discharge signals as first target signals and second target signals after lossless copying; the low-gain channel circuit is used for performing buffer transmission for maintaining an original bandwidth and a dynamic range on the first target signal to generate a first gain signal; the high-gain channel circuit is used for performing gain amplification on the second target signal to generate a second gain signal; the digital signal processing unit is used for performing synchronous clock control on the low-gain channel circuit and the high-gain channel circuit; and the FPGA chip is integrated in the digital signal processing unit and is used for performing fusion splicing processing on the first gain signal and the second gain signal based on a waveform fusion splicing algorithm and generating a fusion signal.
Owner:HANGZHOU KELIN ELECTRIC CO LTD

High-voltage direct-current cable state online monitoring method and system based on MMC low-frequency injection

The invention discloses a high-voltage direct-current cable state online monitoring method and system based on MMC low-frequency injection. The method comprises the steps that an MMC controller injects a low-frequency three-phase alternating-current signal into a direct-current cable based on an MMC low-frequency injection control strategy; the MMC low-frequency injection control strategy comprises the steps that an MMC controller adopts a double-closed-loop control mode composed of an outer voltage loop and an inner current loop; a voltage error is calculated through an outer voltage loop, and a differential-mode voltage Udiffdq * and a common-mode voltage Ucomdq * are calculated through an inner current loop, so that the MMC outputs a target voltage Ugoal signal to a direct-current cable; according to the method, active injection of the low-frequency alternating-current signal with the specific frequency and amplitude is achieved by setting the specific MMC control strategy, a hardware structure of a main loop of an MMC system does not need to be modified, and implementation is safe, easy, convenient and flexible; and meanwhile, online quantitative evaluation of the insulation state of the direct-current cable is realized, and the monitoring process is high in precision, simple, convenient and efficient.
Owner:STATE GRID SHANGHAI MUNICIPAL ELECTRIC POWER CO

Method for detecting night insulation resistance of photovoltaic system

The invention discloses a photovoltaic system night insulation impedance detection method, which comprises the following steps: before a photovoltaic system works at night, power is taken from a power grid through a power taking framework to supply power to a bus cathode of the system, so that ground insulation impedances of positive and negative electrodes of all photovoltaic group strings and the power taking framework form a grounding loop; the ground insulation resistance of the direct current side of the system is calculated by measuring the voltage of the power taking framework; when the photovoltaic system works at night, ground insulation fault positioning is carried out by controlling the power taking framework and the switching tubes of the DC / DC units. The beneficial effects of the invention are that the system can achieve the online detection of the night insulation resistance of a photovoltaic system, and the whole detection architecture is simple in structure, and even does not need to modify an existing hardware circuit, thereby effectively reducing the cost.
Owner:NINGBO GINLONG TECH

Temperature rise test system

The invention provides a temperature rise test system, and relates to the field of heating characteristic testing of power equipment. The system comprises a power supply control system, an electric field regulation and control system, an environment simulation system, a discharge detection system, a three-dimensional temperature field monitoring system and a processing system. The power supply control system simulates equipment operation voltage; the electric field regulation and control system simulates a non-uniform electric field in the equipment; the environment simulation system simulates external environment conditions; the discharge detection system detects the partial discharge condition of the equipment under the simulation condition, obtains discharge parameters and transmits the discharge parameters to the processing system; the three-dimensional temperature field monitoring system monitors temperature distribution on the surface and in the equipment and transmits the temperature distribution to the processing system; and the processing system determines an association relationship between the partial discharge condition and the temperature rise based on the temperature distribution and the discharge parameters. Through cooperation of multiple systems, the influence of the external environment and internal electrical parameters on heating of the equipment is comprehensively simulated, and the heating behavior of the equipment under the actual working condition is reflected more truly, so that the accuracy of temperature rise simulation is improved.
Owner:MEIZHOU POWER SUPPLY BUREAU OF GUANGDONG POWER GRID CORP +1

GIS ultrahigh frequency sensor ultrasonic cooperative detection system based on piezoelectric energization

The invention discloses a GIS ultrahigh frequency sensor ultrasonic cooperative detection system based on piezoelectric energization, and relates to the field of electric power detection, and the system comprises an excitation module which is used for transmitting a piezoelectric excitation signal with a specific frequency to a preset detection region in GIS equipment, so as to trigger the potential partial discharge acoustoelectric signal radiation of the region; the sensing module is used for receiving ultrahigh-frequency electromagnetic signals and ultrasonic vibration signals radiated by partial discharge in the GIS equipment; the excitation frequency, the filtering bandwidth and the sampling rate are dynamically optimized according to the detection result, the detection accuracy and efficiency are continuously improved, and reliable and effective guarantee is provided for safe operation and defect early warning of GIS equipment.
Owner:国网湖北省电力有限公司直流公司

Omnibearing intelligent monitoring device for locomotive roof

The invention relates to the technical field of locomotive roof monitoring, in particular to a locomotive roof omnibearing intelligent monitoring device which comprises a roof high-tension porcelain insulator monitoring module, a pantograph monitoring module, a display module and a data analysis module. By monitoring the state of the high-tension porcelain insulator on the roof in real time, the situation that the current cannot be blocked after the high-tension porcelain insulator is damaged in the running process of the locomotive is avoided, and accidents are avoided. The high-definition monitoring camera and the infrared monitoring camera are used for respectively collecting a view and a thermal imaging diagram, so that the judgment result is more accurate. The detection result is analyzed and judged through data, the vehicle roof high-tension porcelain insulator monitoring unit judges the breakage state of a porcelain insulator to ensure the driving safety of a locomotive and the efficiency of traffic transportation, and the pantograph monitoring unit ensures the accuracy of the detection result through two times of verification in a layered and emphasized manner. And the arc discharge monitoring unit judges the arc discharge duration and the arc discharge times, so that the safety and the service life of the line are further guaranteed.
Owner:BEIJING QICHEN ZHIDA TECH CO LTD

Partial discharge pulse signal extraction method

The invention discloses a partial discharge pulse signal extraction method comprising the following steps: step 1, collecting a first signal which is an original pulse signal; step 2, performing combined balance noise reduction and filtering processing on the first signal to obtain a second signal which is a complete pulse signal; 3, a signal threshold value is set, a third signal is extracted from the second signal, and the third signal is an effective pulse signal; and step 4, SVD noise reduction is carried out on the third signal, and a fourth signal is output. According to the method, the signal threshold value is set, the effective partial discharge waveform is extracted, and the partial discharge signal data volume for training is remarkably reduced; the calculation speed of the device is accelerated, and the response rate of the device is improved; and the memory occupation of the collected data is reduced, so that the device can store more waveform data and effective information.
Owner:GLOBAL SCI & TECH (SHANGHAI) CO LTD

Power conversion apparatus and insulation impedance detection method

This application provides a power conversion apparatus and an insulation impedance detection method. The insulation impedance detection circuit is connected to the direct current bus and the ground, and the isolation switch is connected to the insulation impedance detection circuit and the alternating current voltage detection circuit. The controller is configured to control the isolation switch to be turned on, and control the insulation impedance detection circuit to detect a voltage between the direct current bus and the ground, to obtain an insulation impedance based on the voltage. The controller is further configured to control the isolation switch to be turned off before controlling the insulation impedance detection circuit to detect the voltage, to protect a person from suffering an electric shock and hand numbness due to touching the output end of the inverter circuit.
Owner:HUAWEI DIGITAL POWER TECH CO LTD

Intelligent control system for insulation test of marine dry-type transformer

The invention relates to the technical field of control systems, and particularly discloses an intelligent control system for an insulation test of a marine dry-type transformer. The system comprises a high-voltage test power supply module, a multi-mode sensing acquisition module, an insulation state evaluation module, a self-adaptive boost decision module and a test process control module, and evaluates an insulation state and dynamically decides a boost rate and a holding strategy by acquiring voltage, leakage current, partial discharge and temperature data in real time. Intelligent control and safety protection in the insulation test process are achieved, potential insulation damage is effectively avoided, and diagnosis precision is improved.
Owner:BENXI TAIFENG POWER EQUIP

Method for researching external short-circuit current impact damage mechanism of lithium ion battery

The invention discloses a method for researching an external short-circuit current impact damage mechanism of a lithium ion battery, and the method comprises the steps: testing the limit short-circuit current of the battery through a fitting mode, and determining the time upper limit of short-circuit current impact through an uncontrolled time short-circuit experiment; millisecond-level short-circuit current impact tests of different time scales are carried out on the battery, and performance tests are carried out on the battery every N times of impact so as to monitor recession characteristics of parameters such as capacity and internal resistance of the battery; performing prediction and quantitative calculation on damage mechanisms such as positive and negative electrode active material loss and lithium ion loss by combining a capacity increment curve and an open-circuit voltage curve; and disassembling the battery in an inert gas atmosphere, carrying out microstructure, morphology and element distribution characterization on the electrode and the diaphragm, and verifying a damage mechanism. According to the method, electrochemical testing and material characterization are combined, the corresponding relation and evolution law of battery performance degradation and internal material damage under external short-circuit current impact are disclosed, and a basis is provided for safety design and reliability evaluation of a battery system.
Owner:BEIJING JIAOTONG UNIV +2

Arc fault detection circuit, photovoltaic inverter and photovoltaic system

The utility model relates to the field of photovoltaic systems, in particular to an arc fault detection circuit, a photovoltaic inverter and a photovoltaic system. The arc detection circuit comprises at least one current detection unit which is used for being coupled with lines connected with a plurality of corresponding input ends so as to detect current signals of the lines connected with the input ends; the signal conversion unit is connected with the at least one current detection unit and is used for converting the current signal into a voltage signal; the signal processing unit is connected with the signal conversion unit and is used for processing the voltage signal to obtain a digital sampling signal; and the first control unit is connected with the signal processing unit and is used for determining whether an arc fault exists in a line connected with the plurality of input ends according to the digital sampling signal. The circuit is simple in structure, the size of the photovoltaic inverter is reduced, and the cost is saved.
Owner:HANGZHOU HELI NEW ENERGY CO LTD

Signal processing device and signal processing method

To provide a signal processing device and a signal processing method, capable of discovering unlearned noise.SOLUTION: According to an embodiment, a signal processing device includes an arithmetic unit and a determination unit. The arithmetic unit outputs feature data indicating a feature of a target signal when a signal measured from a target apparatus is input to a machine learning model. The machine learning model is learned to output the feature data by using as input a superposition signal obtained by superposing noise of an environment provided with the target apparatus on the known target signal generated by the target apparatus. The determination unit determines whether or not the input signal includes unlearned noise on the basis of the feature data.SELECTED DRAWING: Figure 5
Owner:KK TOSHIBA +1

Vehicle charging system for an electric vehicle having arc detection

A vehicle charging system for an electric vehicle includes a housing having a mating end for mating with a charging component and a charging terminal held by the housing connected to a power conductor to form a power transmission line. The vehicle charging system includes a charging controller for controlling vehicle charging along the power transmission line. The vehicle charging system includes a charging sensor assembly coupled to the charging controller monitoring charging status of the vehicle charging system and generating a charging output signal. The charging sensor assembly detects an arc signature from an arc event and generates an arc output signal. Based on the arc output signal, the charging controller generates a primary control output to perform a primary protective action including shutting down the charging operation and generates a secondary control output to perform a secondary protective action.
Owner:TE CONNECTIVITY SOLUTIONS GMBH

Circuit and method for monitoring insulation performance of fuel cell stack

There is provided a circuit for monitoring an insulating property of a fuel cell stack, comprising: a low-frequency voltage source for negatively injecting a low-frequency signal only to a high-voltage bus of the fuel cell stack; a first resistor; and a second resistor; wherein the low-frequency voltage source, the first resistor and the second resistor are connected in series, and the low-frequency voltage source, the first resistor and the second resistor which are connected in series are connected with a high-voltage bus negative ground insulation resistor of the fuel cell stack in parallel; and the voltage on the first resistor can be measured so as to be used for determining the insulating property of the fuel cell stack. Therefore, the low-frequency voltage source only injects the low-frequency signal at the negative single side of the high-voltage bus, so that only the insulating property of the negative single side of the high-voltage bus is reduced, and the insulating property of the positive side of the high-voltage bus is not influenced.
Owner:ROBERT BOSCH GMBH

Insulation detection apparatus and method, and energy storage apparatus

The present disclosure provides an insulation detection apparatus and method, and an energy storage apparatus, and relates to the technical field of energy storage safety. The insulation detection apparatus includes: a coupling conductor and a signal acquisition unit, where the coupling conductor and the signal acquisition unit are electrically connected, the coupling conductor and the signal acquisition unit are used to form an insulation detection loop with a device under test, and the signal acquisition unit is further used to detect an electrical signal in the insulation detection loop. The coupling plate and signal acquisition unit used in the present disclosure have a simple structure and low cost. Compared with the existing insulation impedance detection, the present disclosure has a high detection sensitivity and more reliable detection result.
Owner:DELTA ELECTRONICS (SHANGHAI) CO LTD

Device for locating partial discharges based on a high-speed scanning arrangement

A device for locating partial discharges based on a high-speed scanning arrangement, characterized in that it comprises an equipment box and a detection device arranged in the equipment box, wherein the equipment box is provided with a tensile structure and is designed to be slidable; wherein the detection device comprises a partial discharge detection arrangement, a power supply arrangement, a synchronization arrangement, a sensor connection arrangement, a network arrangement, and a signal transmission arrangement, wherein the power supply arrangement, the synchronization arrangement, the sensor connection arrangement, the network arrangement, and the signal transmission arrangement are arranged sequentially from top to bottom and positioned adjacent to a partial discharge detection arrangement; wherein the partial discharge detection arrangement comprises a high-speed scanning arrangement and a keyboard arranged one above the other in the equipment box;wherein a temperature and humidity monitoring arrangement is provided on the other side of the partial discharge detection arrangement opposite the power supply arrangement;
Owner:CHINA YANGTZE POWER +1

Unknown working condition running rail insulation fault positioning method and device and storage medium

The invention discloses an unknown working condition running rail insulation fault positioning method and device and a storage medium, and relates to the technical field of urban rail transit, and the method comprises the steps: obtaining potential signals at a plurality of preset nodes of a steel rail of which the fault position is to be determined; and inputting the potential signals at the plurality of preset nodes of the steel rail into a pre-obtained fault positioning model, obtaining a fault label of the potential signal of each node, and determining a fault position according to the fault labels. According to the invention, the technical problem that fault positioning cannot be accurately and timely carried out on an insulation fault position under an unknown working condition can be solved.
Owner:SUZHOU UNIV

LED light bar discharge test method

The invention discloses an LED light bar discharge test method. The method comprises the following steps: setting test parameters and inputting the test parameters to a multi-channel synchronous data acquisition module; applying a preset voltage to the driving circuit, then triggering power failure and synchronously starting timing; collecting dynamic discharge waveform data of each node in real time; intercepting data in a segmented manner based on a preset time window, and extracting characteristic parameters of a voltage attenuation rate, a current abrupt change amplitude and a waveform distortion coefficient; dynamically comparing the characteristic parameters with a safety threshold range to mark an abnormal interval; and generating a test report according to the abnormal distribution. Through a multi-channel synchronous acquisition and time window segmentation analysis technology, discharge full-period transient response is accurately captured, abnormity caused by non-uniform capacitance distribution or local insulation defects is identified in combination with a dynamic comparison rule, the problem of missing detection in transient abnormity detection of a traditional test method is solved, the test precision and reliability are remarkably improved, and the test efficiency is improved. And efficient data support is provided for safety assessment of the LED light bar.
Owner:SUZHOU HONGJIA ELECTRONICS CO LTD

Power device breakdown voltage parameter test system and method

The invention provides a power device breakdown voltage parameter test system and method.A control module is connected with a high-voltage power supply module, a current adjusting module, a digital-to-analog conversion module and an acquisition card, and the digital-to-analog conversion module is connected with the current adjusting module; the positive end of the high-voltage power supply module is connected with the first end of the current adjusting module, the negative end of the high-voltage power supply module is connected with the emitting electrode of the to-be-tested IGBT, and the second end of the current adjusting module is connected with the collecting electrode of the to-be-tested IGBT; the acquisition card is connected with the data acquisition module, the data acquisition module is further connected with the collector and the emitter of the IGBT to be tested, and the acquisition card is further used for being connected with an upper computer. By changing the current setting condition, the current on the power supply loop of the to-be-tested IGBT can be correspondingly adjusted, so that the breakdown voltage test is completed in a high-voltage and set current value environment, and the requirements of testing the breakdown voltage parameters of the IGBT in various test scenes are met.
Owner:CHENGDU FUSEMI TECH CO LTD

Transformer partial discharge positioning method and system

The invention discloses a transformer partial discharge positioning method and system, and the method comprises the steps: recording a first pulse signal through a high-frequency sensor, and recording a second pulse signal through at least three ultrasonic sensors; taking the time mark corresponding to the minimum energy accumulation value of the first pulse signal as a first arrival time, and correcting the first arrival time by using the time mark corresponding to the maximum amplitude value of the first pulse signal; taking the time mark corresponding to the minimum energy accumulation value of the second pulse signal as a second arrival time, and correcting the second arrival time by using the time mark corresponding to the maximum amplitude value of the second pulse signal; performing partial discharge positioning by using the coordinates of the at least three ultrasonic sensors, the corrected first arrival time and each corrected second arrival time to obtain a discharge point position; and correcting the position of the discharge point based on a clustering algorithm. According to the embodiment of the invention, the error of time delay can be reduced, the positioning position is corrected through the clustering algorithm, and the positioning accuracy is further improved.
Owner:STATE GRID ECONOMIC TECH RES INST CO LTD

Phototube high-voltage excitation type solar blind ultraviolet discharge detection method and system

The invention relates to the technical field of photoelectric tube detection, in particular to a photoelectric tube high-voltage excitation type solar blind ultraviolet discharge detection method and system, and the method comprises the steps: obtaining original voltage sequence data collected by a high-speed transimpedance sampling circuit in real time; positioning feature points of each suspected pulse according to the original voltage sequence data, and extracting pulse waveform features; obtaining a physical confidence factor of each suspected pulse according to the falling edge attenuation characteristics; calculating effective discharge energy flow in unit time based on the physical confidence factor; calculating a discharge stability coefficient according to a coupling relationship between the time correlation entropy and the effective discharge energy flow; according to the method, a scheme from microscopic physical judgment, waveform form deconstruction and time law analysis to multi-dimensional trend prediction is constructed, so that the contradiction between the detection sensitivity and the quantification precision is solved; and adaptive tracking monitoring of the partial discharge process is realized.
Owner:HANGZHOU ZHONGDIAN INTELLIGENT TECH CO LTD

Power device characterization on the wafer using automated parametric system

In some examples, the system may include a parametric system matrix coupled one or more test and measurement instruments. Also, the system may include an adapter circuit coupled to the parametric system matrix, the adapter circuit having a voltage clamping circuit coupled to the parametric system matrix. Furthermore, the system may include a probe circuit coupled to the adapter circuit and to the power device, where the power device is disposed on a wafer.
Owner:KEITHLEY INSTRUMENTS LLC

Live detection device for lightning arrester

The invention discloses a live detection device for a lightning arrester. The live detection device comprises an electric signal detection module and a data processing module, the electric signal detection module is used for detecting a voltage signal and a three-phase current signal of a lightning arrester to be detected; the data processing module is used for performing harmonic analysis on the voltage signal and the three-phase current signal detected at the same moment to obtain a fundamental wave resistive current component and a plurality of higher harmonic resistive current components; and determining the resistive current value of the lightning arrester to be detected according to the fundamental wave resistive current component and the plurality of higher harmonic resistive current components. By adopting the lightning arrester live detection device provided by the invention, automatic detection of the resistive current value of the three-phase lightning arrester can be realized without on-site long-distance wiring, and interference influences such as electric field interference, magnetic field interference and interphase interference in the measurement process are effectively reduced, so that the detection precision of the resistive current value can be improved, and the detection accuracy of the three-phase lightning arrester is improved. And the insulation performance of the lightning arrester can be timely and accurately determined.
Owner:INNOVATION & INNOVATION CENT OF STATE GRID ZHEJIANG ELECTRIC POWER CO LTD +2

Electric signal detector, diagnosis device, partial discharge detection system, partial discharge detection method, and program

To provide an electric signal detector, a diagnosis device, a partial discharge detection system, a partial discharge detection method, and a program, which can detect occurrence of partial discharges with high accuracy.SOLUTION: An electric signal detector comprises: a first reception unit 12 for receiving an electric signal generated in a cubicle 4; a wide-band filter F0 for extracting an electric signal of a first frequency band from the received electric signal; a plurality of narrow-band filers F1-F3 for extracting an electric signal of a frequency band which is a portion of the first frequency band; a selection switch 14 for selecting the wide-band filter F0 and one of the narrow-band filters F1-F3; a level determination unit 20 for determining whether or not the level of the electric signal extracted by the wide-band filter F0 is greater than or equal to a threshold level; and a control unit 22 for sequentially selecting the narrow-band filters F1-F3 by switching the selection switch 14 when the electric signal level is determined to be higher than or equal to the threshold level, and transmitting the electric signals extracted by the narrow-band filters F1-F3 to the diagnosis device 3 that diagnoses occurrence of a partial discharge.SELECTED DRAWING: Figure 2
Owner:TOHO ELECTRONICS INC

Insulation monitor and method for operating same

An insulation monitor for a high-voltage onboard electrical system of a motor vehicle is provided. A respective Y-capacitor is arranged between the positive potential and the vehicle earth and between the negative potential and the vehicle earth. The insulation monitor has a current or voltage source, a voltmeter for measuring at least one of the potentials, and is configured to apply a negative current by the current source when the potential measured by the voltmeter exceeds a predefined upper value and to apply a positive current by the current source when the potential measured by the voltmeter falls below a predefined lower value. The current thus being limited to a maximum permissible contact current in the case of an insulation fault and it is possible to infer the magnitude of the insulation resistances using the voltage measured by the voltmeter and the recharging current that has been fed in.
Owner:MERCEDES BENZ GROUP AG

Porcelain insulator zero value detection device and detection method thereof

The invention belongs to the technical field of porcelain insulator zero-value detection, and discloses a porcelain insulator zero-value detection device and a detection method thereof, and the device is used for portable rapid zero-value detection or zero-value detection for early defective insulators / partially degraded insulators. The portable rapid zero value detection device comprises an impulse voltage generator, an insulator unit and a measurement module, the output end of the impulse voltage generator is connected with the input end of the insulator unit, and the output end of the insulator unit is connected with the measurement module; the device for detecting the zero value of the early defective insulator / the partially degraded insulator comprises an impulse voltage generator, a Rogowski coil, an integrator and an oscilloscope, the Rogowski coil is arranged on a wire to be detected in a surrounding mode, the output end of the Rogowski coil is connected into the integrator, and the output end of the integrator is connected with the oscilloscope. The invention provides a porcelain insulator zero value detection method taking a high-frequency component as a criterion, and the method can achieve the quick and reliable detection of whether the value of the insulator is zero or not.
Owner:ELECTRIC POWER RESEARCH INSTITUTE OF STATE GRID SHANDONG ELECTRIC POWER COMPANY +1