1130results about "Testing circuits" patented technology

The invention provides a high-voltage cable partial discharge identification and positioning method, and relates to the technical field of high-voltage cable diagnosis, and the method comprises the steps: collecting partial discharge pulse signals through high-frequency current transformers disposed at two ends of a high-voltage cable; carrying out noise reduction processing on the acquired partial discharge pulse signal by using an adaptive multi-scale wavelet decomposition and reconstruction method to obtain a partial discharge characteristic signal after noise reduction; inputting the partial discharge characteristic signal into a pre-trained lightweight residual attention network for identification and classification, and outputting a discharge type discrimination result, discharge intensity and characteristic parameters; and based on the discharge type discrimination result, the discharge intensity and the characteristic parameters, a self-correction double-end positioning algorithm is adopted to position the discharge source, and the position of the discharge source is calculated. According to the invention, the technical problems of unsatisfactory signal noise reduction effect, low discharge type identification accuracy, unstable positioning precision and the like in the prior art can be solved, so that high-precision identification and positioning of partial discharge of the high-voltage cable are realized.

The invention discloses a + / -800kV converter station lightning arrester insulation cooperation checking method considering multiple lightning strokes, and the method comprises the steps: S1, building a high-frequency electromagnetic transient simulation model according to the engineering practice and the high-frequency demands of lightning overvoltage simulation calculation; s2, multiple lightning stroke lightning current waveform parameters and lightning stroke time intervals are selected, and parameters capable of representing different frequencies of ground-to-ground lightning in the region where the research object is located are obtained; s3, simulating and analyzing residual voltage, current and absorbed energy of the lightning arrester at different positions of multiple lightning / multiple lightning shielding failure; s4, comparing and analyzing amplitude values of residual voltage, current and absorbed energy of the lightning arrester under single lightning stroke / multiple lightning stroke, and selecting a maximum value; and S5, proposing a lightning arrester configuration scheme, adjusting the type of the lightning arrester in the simulation model, and repeating the steps S3 and S4 to carry out secondary checking and adjustment. According to the method, a lightning arrester type selection scheme capable of effectively inhibiting single lightning overvoltage and multiple lightning overvoltage is provided, and the lightning accident rate of the lightning arresters in the converter station is reduced.

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.

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.

The invention provides an insulation detection method and an insulation detection system, and the method comprises the steps: controlling a bridge measurement circuit to carry out two times of balance calibration when a complete insulation detection mode starting signal of a vehicle is detected, and obtaining measurement data; obtaining a first resistance value of a standard adjustable resistor in the bridge measurement circuit based on the initial balance state of the bridge measurement circuit, and calculating a first insulation resistance ratio; acquiring a second resistance value of the standard adjustable resistor based on a secondary balance state of the bridge measurement circuit, and calculating a second insulation resistance ratio; calculating an insulation resistance value corresponding to each insulation resistor by combining the first insulation resistance ratio and the second insulation resistance ratio; and judging whether the insulation resistance value accords with a preset safety threshold, and if not, generating alarm information. In the mode, through a two-time bridge balance calibration method and in combination with a vehicle state self-adaptive detection mode, the insulation detection mode can be dynamically adjusted under different working conditions, and the power consumption is reduced while the measurement precision is ensured.

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.

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.

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.

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.

The present disclosure relates to a partial discharge monitoring system and a partial discharge monitoring method that are capable of monitoring and determining a defect generated in a high-voltage power device in real time by classifying signals generated from the high-voltage power device with a machine learning algorithm being applied, and capable of easily forming feature dot data clusters in both a high-density area and a low-density area of two-dimensional feature dot data by performing a process of clustering feature dot points generated from the signals of the power device on the basis of density and distance in parallel, respectively, thereby generating PRPD data for each cluster without missing a signal to improve partial discharge determination accuracy.

The invention relates to the technical field of variable-frequency series resonance voltage withstanding tests, and particularly discloses a variable-frequency series resonance voltage withstanding test system and a variable-frequency series resonance voltage withstanding test device. Comprising a theoretical resonant frequency calculation module, an output frequency information acquisition module, a test resonant frequency evaluation module, a voltage withstanding test information acquisition module, a voltage withstanding performance stability analysis module and a power cable insulation performance evaluation module. According to the method, the resonant frequency accuracy of a series resonant circuit in a complete resonant state is deeply analyzed, and the voltage-withstanding stability and the insulation performance of the power cable are analyzed by combining the voltage condition, the leakage current condition, the temperature condition and the partial discharge condition of the power cable in a voltage-withstanding test; and meanwhile, the coverage of voltage-withstanding stability evaluation of the power cable is improved, so that the persuasion of the insulation performance of the power cable to unqualified evaluation is improved, and a more targeted basis is provided for maintenance and repair of the power cable.

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.

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.

A first insulation resistance monitoring circuit includes a first resistor connected between a positive terminal of a battery pack and a node, and connected between the positive terminal of the battery pack and a ground terminal of an external device, and has a first monitoring terminal. A second insulation resistance monitoring circuit is connected between the ground terminal and the negative terminal of the battery pack, and has a second monitoring terminal. A voltage monitoring circuit is connected between the node and the negative terminal of the battery pack, and has a third monitoring terminal. A processor measures the voltage of the battery pack.

A variety of methods, apparatuses, and systems are disclosed, involving, in one example, a method including traversing the length of a conductive substrate with a holiday detector, inducing an arc voltage at a defect of a coating disposed on the conductive substrate, detecting the arc voltage with sensors, and recording an electrode voltage with electronics disposed at the holiday detector.

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.

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.

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.

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.

An electrostatic discharge and electrical overstress detection circuit includes protection circuit, sensing circuit, clamp circuit, several stages of sampling logic circuits connected in sequence and storage circuit. Protection circuit is coupled between input / output pin and internal chip and discharges to a power supply terminal when the electrostatic discharge or electrical overstress events happen. Sensing circuit and clamp circuit are coupled between power supply terminal and ground terminal. Each stage of sampling logic circuit is coupled to power supply terminal and memory cell of storage circuit, and the first stage of sampling logic is coupled to the clamp circuit, and when the electrostatic discharge or electrical overstress events happen, the several stages of sampling logic circuits sample voltage of the power supply terminal one by one and change state of corresponding memory cell, so that the electrostatic discharge or electrical overstress events are successively recorded by the memory cell.

A method detects an electrical insulation fault between an electric power source and an electrical ground, via a circuit that includes a controllable voltage generator and an electrical measuring resistor connected in series between a terminal of the electric power source and the electrical ground. The method includes controlling the voltage generator to establish, between its terminals, a non-zero voltage value, and measuring the voltage at the terminals of the electrical measuring resistor to detect an electrical insulation fault between the electric power source and the electrical ground. The method further includes a computer determining, depending at least on the voltage measured at the terminals of the electrical measuring resistor, at least two parameters characteristic of a disturbance affecting the detection of the electrical insulation fault, and calculating a reliability level of the detection of the electrical insulation fault depending on at least one of the two parameters.

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.

The invention belongs to the technical field of cable insulation evaluation, and provides an on-service cable insulation evaluation method and system fused with multivariate target optimization in order to solve the problem that it is difficult to comprehensively and accurately evaluate the cable insulation state in the prior art. The active service cable insulation evaluation method fused with multivariate target optimization comprises the following steps: determining a time domain incident signal and a frequency domain incident signal; variational mode decomposition is carried out on the measured time domain reflection signal to obtain a time domain actual reflection signal; designing a cable propagation filter by using an initial propagation constant, and estimating a time domain reflection signal by combining a frequency domain incident signal; determining a target function according to energy and position differences between the estimated time domain reflection signal and the actual time domain reflection signal, and optimizing a propagation constant in a set range to minimize a target function value under each frequency; and calculating a dielectric loss factor according to the optimized relationship between the propagation constant and the dielectric constant, and evaluating the cable insulativity.

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.

The invention provides an insulation detection and abnormal position judgment method suitable for an energy storage converter, and the method comprises the following steps: 1, completing the auxiliary power supply of an internal control system after an AC / DC molded case circuit breaker of the energy storage converter is closed; 2, detecting the working state of the current energy storage converter, and if the current energy storage converter is in a non-shutdown state or the battery voltage detection value is not greater than a set threshold value, not carrying out insulation detection related operation; if the battery is in the shutdown state at present and the voltage value of the battery is greater than a set threshold value, entering the next step, and calculating an insulation resistance value; according to the invention, the optimized insulation impedance detection circuit is matched with a multi-software filtering method to detect whether insulation abnormity exists, and whether an abnormal point is located in the converter is judged according to the direct current difference between the positive electrode inlet and the negative electrode outlet of the direct current side.

The invention discloses an insulation detection circuit, method and device which can be used in the field of electronic circuits, the insulation detection circuit comprises a first switch, a second switch and a sampling branch, and the sampling branch comprises a divider resistor, a sampling resistor and a third switch; the sampling branch is connected with a positive power line through a first switch and connected with a negative power line through a second switch. The sampling branch is provided with a first part connected with the first earth impedance in parallel and a second part connected with the second earth impedance in parallel, the first part comprises at least one divider resistor and a sampling resistor, and the second part comprises at least one divider resistor; the third switch is connected in parallel with at least one divider resistor. Therefore, the sampling branch is connected only under the condition of insulation detection, the number of electronic components is small, the circuit structure is simpler, the size of insulation detection equipment can be effectively reduced, and the circuit cost is reduced.

The invention discloses a defect detection circuit and method, and the method comprises the steps: switching the connection state of a circuit through controlling the connection state and the closing state of each switching element in the circuit, thereby detecting the output voltage of a resistor network module and a bridge arm module; whether the switch element and each loop in the circuit break down or not is detected based on the output voltage collected in different connection states, so that the insulation detection circuit is comprehensively detected, and the situation that the accuracy of insulation detection is affected by circuit component faults is avoided.

The invention provides an insulation detection method and an insulation detection circuit, and the method comprises the steps: obtaining a first unsteady-state voltage array and a second unsteady-state voltage array collected in a sampling period, the first unsteady-state voltage array comprises a plurality of first voltages at the two ends of a first insulation resistor, the second unsteady-state voltage array comprises a plurality of detection voltages, and the first voltage is greater than the detection voltages; the detection voltage refers to voltage obtained by detecting partial impedance of the first insulation impedance; processing the first unsteady-state voltage array and the second unsteady-state voltage array by using a steady-state voltage algorithm to obtain a first steady-state voltage and a second steady-state voltage; according to the first steady-state voltage, the second steady-state voltage and a second voltage determined according to the first steady-state voltage, the first insulation impedance and the second insulation impedance are determined, and the second voltage refers to the voltage at the two ends of the second insulation impedance. According to the insulation detection circuit, the circuit is simple, and the detection efficiency is improved while the detection cost is reduced.

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.

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