1022results about "Capacitance measurements" patented technology

The invention relates to the field of motor health management and predictive maintenance, in particular to a motor stator winding insulation state evaluation method and system based on a digital model. Comprising the following steps: S1, collecting high frequency of a motor stator winding, and generating multi-physical-quantity real-time data; s2, calculating a dynamic capacitance reference value according to real-time data of multiple physical quantities; s3, performing subtraction operation on the high-frequency equivalent capacitance measurement value and the dynamic capacitance reference value, and extracting an insulation degradation residual signal; s4, constructing a self-adaptive dynamic detection threshold according to multi-physical-quantity real-time data; s5, judging whether the absolute value of the insulation degradation residual signal is greater than a self-adaptive dynamic detection threshold or not: if so, judging that an insulation degradation event occurs; if not, judging that the operation state is a normal operation state; and S6, in response to the insulation degradation event, updating the insulation degradation index, and generating insulation state evaluation based on the updated insulation degradation index. According to the invention, false alarm under severe load fluctuation is avoided, and the accuracy and reliability of evaluation are significantly improved.

The invention discloses an insulation resistance and capacitance measuring circuit and method based on monopulse double-edge analysis, and relates to the related field of the electrical insulation online monitoring technology, and the circuit comprises a detected object and an insulation detection circuit. The insulation detection circuit comprises a controlled pulse voltage source, a coupling resistance network, a current sensor, a switch control module, a signal modulation circuit and a processor. The measurement method implemented based on the circuit comprises the following steps: injecting a common-mode voltage pulse into a transmission line of the power transmission system by adopting a pulse transmitter; pulse current response is collected in real time, a current oscillogram is drawn, and a three-point sampling method is introduced to record a current value for insulation impedance parameter calculation; according to a load condition, a double-edge verification method is applied based on a pulse current attenuation characteristic, and insulation impedance parameters including a resistive component and a capacitive component are independently calculated by analyzing a pulse current rising edge and a pulse current falling edge. According to the invention, non-intrusive synchronous monitoring of resistive and capacitive components of line-to-ground impedance is realized, and the detection precision is improved.

The invention provides a capacitance compensation method and device for a withstand voltage and partial discharge test of an extra-high voltage shunt reactor, and belongs to the field of reactor capacitance compensation, and the method comprises the steps: obtaining a winding inherent capacitance parameter, separating a high-frequency component from a low-frequency component, analyzing a space coupling path, and calculating a temperature and humidity induced variable capacitive reactance offset. A collaborative capacitance parameter matrix is generated after weighted fusion, a nonlinear polarization attenuation factor is introduced and dynamically calibrated, a capacitance compensation reference model is established, and compensation is executed through a multi-stage compensation device. According to the invention, through dynamic modeling, accurate capacitance compensation, voltage distortion suppression and improvement of partial discharge detection sensitivity, the problems of insufficient compensation precision and poor adaptability in the prior art are solved.

A system may include a resistive-inductive-capacitive sensor, a driver configured to drive the resistive-inductive-capacitive sensor at a driving frequency, a measurement circuit communicatively coupled to the resistive-inductive-capacitive sensor and configured to measure phase information and amplitude associated with the resistive-inductive-capacitive sensor, and a noise detection circuit communicatively coupled to the measurement circuit and configured to determine a presence of external interference in the system based on at least one of the phase information and the amplitude information.

A system may include an array of sensor elements, the array of sensor elements each comprising a first type of passive reactive element, a second type of passive reactive element electrically coupled to the array of sensor elements, a driver configured to drive the array of sensor elements and the second type of passive reactive element, and control circuitry configured to control enabling and disabling of individual sensor elements of the array of sensor elements to ensure no more than one of the array of sensor elements is enabled at a time such that when one of the array of sensor elements is enabled, the one of the array of sensor elements and the second type of passive reactive element together operate as a resonant sensor.

The invention provides a capacitance value detection method and device for a capacitor in an inverter, and belongs to the field of inverters. The method comprises the following steps: based on pre-stored voltage change rate information of a to-be-measured capacitor, determining voltage recording moments when the current of the to-be-measured capacitor is zero, the voltage recording moments at least comprising a first moment and a second moment; obtaining a first voltage value of the to-be-measured capacitor at the first moment and a second voltage value of the to-be-measured capacitor at the second moment, and obtaining an accumulated charge quantity of the direct current bus for charging and discharging the to-be-measured capacitor in a time period corresponding to the first moment and the second moment; and finally, determining the capacitance value of the capacitor to be measured according to the first voltage value, the second voltage value and the accumulated charge quantity. According to the method, the inverter does not need to be shut down, the capacitor does not need to be detached and measured, the capacitance value of the capacitor is calculated according to the voltage value when the current of the capacitor is zero, the influence of ESR can be eliminated, and accurate detection of the capacitance value can be achieved in real time.

Devices and methods for measuring capacitance of a load. A device may include a ground connector configured to couple to ground and an output connector configured to couple to the load. The device may include a direct current (DC) supply arranged in a conduction path between the ground connector and the output connector wherein the DC supply is configured to apply a DC voltage and noise voltage onto the conduction path. The device may include a voltage monitor configured to monitor the noise voltage applied by the DC supply and the device may include a current monitor configured to measure current in the conduction path that results from the noise voltage. The device may include a capacitance module coupled to the current monitor and voltage monitor, the capacitance module configured to determine the capacitance based upon the monitored current and noise voltage.

The invention discloses a film capacitor enabling control method and system, a medium and a program product, and the method comprises the steps: determining current sampling data and voltage sampling data of a film capacitor in a first time period; calculating an equivalent impedance sequence within a first time length, and determining distribution characteristics of impedance components under different frequencies; dividing a plurality of frequency band intervals, and calculating an impedance change rate matrix in each frequency band interval; determining energy transmission efficiency, and determining a target frequency band interval; generating a compensation coefficient, and adjusting the amplitude and the frequency by using the compensation coefficient to obtain a target sine-wave voltage; performing energizing processing on the thin-film capacitor by adopting the target sine-wave voltage within the remaining time of the energizing duration, and calculating an instantaneous power factor in real time; and when the stability of the instantaneous power factor reaches a preset condition and the leakage current is reduced below a preset threshold value, generating an enabling completion signal. According to the invention, the adaptability between the energizing effect and the actual demand of the thin film capacitor is improved, and the energizing effect is further improved.

The invention discloses a CVT internal capacitance state comprehensive evaluation method and system based on temperature compensation, and belongs to the field of capacitor voltage transformer optimization compensation, and the method comprises the following steps: S1, detecting the primary voltage amplitude and phase angle of a capacitor transformer, and obtaining the performance parameters of the capacitor transformer; s2, acquiring environment temperature information; s3, determining a mathematical relationship between the environment temperature and the performance parameters of the capacitance transformer, and calculating a temperature compensation coefficient according to the mathematical relationship and the environment temperature value; s4, compensating a primary voltage amplitude and a phase angle by using a temperature compensation coefficient; and S5, analyzing the compensated voltage amplitude and phase angle data to obtain an analysis result, and evaluating whether the internal capacitance state of the capacitance transformer is normal or not according to the analysis result. By accurately detecting the primary voltage amplitude and the phase angle of the capacitance transformer and combining environment temperature information, the method can calculate an accurate temperature compensation coefficient, so that the influence of temperature change on the performance of the CVT is effectively corrected.

The invention relates to the technical field of electrical mechanical parameter measurement, in particular to a slip ratio measurement method of a three-phase asynchronous motor. The method comprises the following steps: carrying out temperature gradient analysis and copper loss temperature rise ratio calculation on the three-phase asynchronous motor to obtain a thermal feature vector; carrying out air gap area capacitance measurement on the motor stator to obtain a fusion capacitance signal; performing rotor period feature extraction on the fused capacitance signal to obtain a rotor slot frequency feature spectrum; performing thermal field-capacitance field characteristic correlation on the thermal characteristic vector and the rotor slot frequency characteristic spectrum to obtain a characteristic correlation matrix; performing double-field reliability weight dynamic allocation under different working conditions according to the feature correlation matrix to obtain a fusion credibility index; and calculating an initial slip rate estimated value based on the thermal feature vector and the rotor slot frequency feature spectrum to obtain a dual-source slip rate value. According to the invention, the precision and accuracy of slip ratio measurement in a variable-temperature environment are significantly improved through an electrical mechanical parameter measurement technology.

A method and system for measuring distribution network system parameters based on harmonic injection, for use in a low-current grounding system containing an arc suppression coil. The system injects currents of multiple frequencies into the neutral point of the low-current grounding system through an injection source and measures the neutral point voltage. The system uses formulas to calculate and obtain the line capacitance, arc suppression coil inductance, and damping resistance parameter values ​​in the distribution network system. This application can accurately measure line capacitance, arc suppression coil damping resistance, and reactance by injecting only two frequencies of current. This method has little impact on grid operation, high measurement accuracy, and broad application prospects.

The invention provides a rapid detection and diagnosis method and system for a short-circuit fault of a transformer winding, and relates to the technical field of transformers, and the method comprises the steps: collecting the electrical parameters of the transformer winding, calculating equivalent impedance, building a transfer function model and an equivalent impedance model, and extracting a frequency domain fault characteristic quantity and a short-circuit force characteristic; and constructing a characteristic quantity judgment matrix to obtain a weight coefficient, carrying out multi-source information fusion by utilizing a D-S evidence theory, and realizing fault diagnosis by combining fuzzy comprehensive evaluation. The method can accurately identify the short-circuit fault type of the transformer winding, and improves the reliability and accuracy of fault diagnosis.

The invention discloses a systematic monitoring method for the electrical safety performance of a cable, and relates to the field of electrical safety, and the method comprises the steps: collecting sensor data to an edge calculation node, preprocessing the data, and outputting the data as real-time calculation temperature data, local discharge point data, resistance and capacitance data and vibration data; the data are sent to a hidden danger classification model and a fault positioning model in the cloud, and the models output early warning information to an operation and maintenance project for processing; the sensor data sending process is judged according to the data frequency, when it is judged that the frequency is larger than 1 kHz, a 1D-CNN electric arc detection model is loaded, when it is judged that the frequency is smaller than 1 kHz, a Light GBM feature classification model is loaded, and 24-hour sensor data smaller than 1 kHz are periodically loaded into an LSTM-Attention gradient analysis model; and related data of partial discharge generated by judgment of the 1D-CNN arc detection model is sent to an LSTM-Attention gradient analysis model for evaluating the partial discharge trend of the global cable. Classification model output is used as prior knowledge of a positioning model, and the positioning accuracy can be improved.

The technology described herein is directed towards a capacitor with a modified design (relative to standard capacitors), in which a first conductor is coupled to a second conductor via a distributed array of conducting interconnects through a dielectric that separates the conductors. The array of interconnects facilitates electrical surface current flow between the first conductor and the second conductor, and determines the self-resonant frequency of the capacitor. The array (or enlarged area) of conducting interconnects, not present in standard capacitors, results in capacitors with larger self-resonant frequency, e.g., having a substantially stable capacitance over a range of high radio frequencies, including millimeter wave frequencies. This further provides an improved quality factor. The improvements resulting from the technology described herein facilitate more optimal surface current density. The modified capacitor provides benefits in various circuits, e.g., in an impedance or a millimeter wave frequency phase shifter for antenna elements.

A capacitance measurement circuit includes an analog front-end (AFE) circuit with current mirror circuits, a parasitic capacitor, an AD converter, an output shift register, and a controller. The controller disconnects a capacitor to be measured and connects one current mirror circuit to record an AFE output voltage VN collected at an inverting input terminal of the AD converter, then connects the capacitor to be measured to collect an AFE output voltage VP at a non-inverting input terminal of the AD converter, and converts a value of (VP−VN) into a first digital signal; determines, based on the value of the first digital signal, a connection number m of the current mirror circuits, controls the analog front-end circuit to connect m current mirror circuits, and repeat the steps to obtain a second digital signal; and shift the second digital signal based on the connection number m to obtain a capacitance measurement value.

The invention provides a hydro-generator shaft insulation multi-parameter monitoring method and system, and the method comprises the steps: employing a common excitation proportion method, introducing a high-frequency excitation current source through a grounding brush, loading a high-frequency voltage on the basis of a shaft voltage, respectively detecting an oil film voltage and an insulation pad voltage, and calculating a voltage amplitude ratio, analyzing oil film capacitance and insulation capacitance based on the high-frequency signal; a co-excitation polling method is adopted, high-frequency excitation current paths are sequentially switched through a polling device, high-frequency current flows through different impedance branches, high-frequency and low-frequency voltage signals are separated through a frequency-selecting filter, and oil film impedance and insulation impedance are analyzed; an independent excitation method is adopted, a high-frequency excitation source is independently introduced from a bearing bush, a frequency-selecting filter or an impedance converter is combined, independent measurement of oil film impedance and insulation impedance is achieved, and oil film thickness and insulation parameters are calculated. According to the invention, multi-parameter monitoring of bearing insulation can be realized.

The invention discloses a cable high-frequency impedance characteristic analysis method based on bipolar trapezoidal wave excitation, and belongs to the technical field of power equipment state monitoring and fault diagnosis. In order to solve the problems of low test efficiency, insufficient high-frequency parameter modeling precision and weak anti-interference capability in cable high-frequency impedance characteristic analysis of a traditional sine wave excitation method, the method comprises the following steps: generating an odd-symmetry bipolar trapezoidal wave excitation signal with specific frequency and amplitude, and injecting the signal into the head end of a cable to be tested through a coupling device after power amplification; synchronously acquiring a high-frequency response signal of the key position of the cable under the excitation of the bipolar trapezoidal wave by using a data acquisition system; preprocessing the high-frequency response signal, converting the high-frequency response signal into a frequency domain through Fourier transform, calculating input impedance of the cable under different harmonic frequencies, and synthesizing a broadband impedance spectrum; based on the broadband impedance spectrum, the amplitude-frequency characteristic and the phase-frequency characteristic of impedance are analyzed, and cable state evaluation, partial discharge detection, insulation defect diagnosis or fault point positioning are realized. The method is used for an electric power system.

Systems and Methods for capacitance testing of a unit under test with parasitic capacitance directed to a guard rail. The system includes test points, wherein the plurality of test points are divided into at least two groups; a stimulus source; a first group guard relay electrically connected to each of the test points in a first; a second group guard relay electrically connected to each of the test points in a second; a guard rail coupled to the first group guard relay and the second group guard relay; a first group return relay electrically connected to each of the test points in a first group; a second group return relay electrically connected to each of the test points in a second group; a current measurement rail coupled to the first group return relay and the second group return relay; a current meter coupled to the measurement rail; and a controller.

The invention relates to the technical field of explosion-proof lamp detection, and discloses an anti-disassembly detection method and system for a portable explosion-proof lamp and a storage medium. The method comprises the following steps: arranging a detection contact and a sensor at the detachable structure, and forming a detection loop through a detection module; and collecting total detection data in real time and comparing the total detection data with the initial data to obtain detection change data so as to identify the state of the lamp and the specific disassembled structure. If the disassembly is illegal, light warning is given out, the warning brightness or the flicker frequency is related to the change data, and the disassembled structure is indicated. Initial data can be updated through a reset instruction to adapt to gauge operation. According to the method, accurate detection and positioning of illegal disassembly are achieved, warning is visual, and the use safety and detection flexibility of the explosion-proof lamp are improved.

The multi-point pressing intelligent watch touch sensitivity detection device comprises a detection table, a height-adjustable sleeve is installed over the detection table, a first motor is fixedly connected to a top port of the sleeve, and the output end of the bottom of the first motor is in shaft connection with a transmission shaft vertically and movably penetrating through the sleeve; the outer wall of the sleeve is rotationally sleeved with a first hexagonal block, the bottom of the transmission shaft is fixedly connected with a second hexagonal block, downward pressing mechanisms are fixedly installed on the six edges of the first hexagonal block, detection mechanisms are fixedly installed on the six edges of the second hexagonal block, and a driving mechanism used for driving the first hexagonal block to rotate is fixedly installed on the sleeve. The invention relates to the technical field of detection. According to the invention, the problem that the detection result is inaccurate and unreliable due to the fact that the traditional smart watch touch sensitivity detection technology cannot accurately simulate diversified touch operations in actual use is solved.

The invention provides a transformer DC capacitor state monitoring device and method based on an FPGA, and relates to the technical field of capacitor state monitoring. The device comprises a voltage acquisition module used for synchronously acquiring voltage analog signals at two ends of a DC capacitor in a plurality of MMC modules and performing analog-to-digital conversion; the current acquisition module is used for synchronously acquiring bridge arm current analog signals of a plurality of MMC modules and performing analog-to-digital conversion; the master control FPGA module is respectively connected with the voltage acquisition module and the current acquisition module, and is used for receiving and caching the digitized voltage signal and current signal, respectively calculating a real-time capacitance value of a direct-current capacitor in each MMC module based on a parallel sliding window and a hardware acceleration real-time capacitance value tracking algorithm, and outputting the real-time capacitance value of the direct-current capacitor in each MMC module; the degradation state of each direct-current capacitor is evaluated according to the real-time capacitance value; and the communication module is connected with the master control FPGA module and is used for uploading the degradation state data to an upper computer. According to the method, the real-time performance of monitoring can be remarkably improved while the calculation precision is ensured.

The invention is suitable for the technical field of circuit monitoring, and provides a capacitance value online monitoring method and system based on thin film capacitor self-healing feature perception, and the method comprises the steps: synchronously collecting a voltage signal and a current signal of a to-be-detected thin film capacitor based on a preset sampling period, and constructing a voltage sequence and a current sequence with a unified time sequence; determining a candidate transient time window based on a preset sampling period and the voltage sequence; in the candidate transient time window, a time sequence of a self-healing event is determined based on the voltage sequence and the current sequence, and the self-healing event comprises an arcing stage, an arc quenching stage and a charging recovery stage; and based on the initial voltage, the final voltage and the effective charging current in the charging recovery stage, determining an effective capacitance estimation value of the to-be-tested thin-film capacitor. According to the technical scheme provided by the invention, the self-healing behavior of the thin-film capacitor is accurately identified, so that online monitoring of the capacitance value of the thin-film capacitor is realized, and the capacitance value monitoring error is effectively reduced.

A system including a plurality of first wires and a plurality of second wires is disclosed. Each second wire overlaps over one or more first wires at a respective overlapping area of one or more first wires. A dielectric material is disposed in a vertical gap at each respective overlapping area forming a capacitance sensor including a first electrode corresponding to a first wire and a second electrode corresponding to a second wire. The first and second electrodes are connected to a positive bias and a negative bias of at least one voltage source, respectively. The system includes at least one processor configured to periodically measure change in respective electric field of each capacitance sensor of a subset of capacitance sensors of a plurality of capacitance sensors, and store data corresponding to periodically measured change in the respective electric field of each capacitance sensor of the subset of capacitance sensors.

The invention relates to the technical field related to bio-electricity signals, in particular to a plant emotion visualization method and device, electronic equipment and a storage medium. The method comprises the following steps: acquiring bio-electricity signals of different parts of a plant in different scenes by adopting a signal amplification circuit; extracting feature vectors of the corresponding bio-electricity signals under different scenes; based on the feature vector, a reinforcement learning algorithm is adopted for classification so as to identify the emotion type of the plant electric signal, and the corresponding relation between the bio-electricity signal and the emotion type is constructed; wherein different emotion types correspond to different scenes; acquiring real-time bio-electricity signals of different parts of the plant; and determining the emotion type of the plant based on the real-time bio-electricity signal and the corresponding relationship, and further determining the actual scene of the plant.

The invention relates to the field of capacitor monitoring, and provides a capacitor quasi-online state monitoring method and system for a wind power converter, and the method comprises the steps: extracting a data slice comprising DC bus voltage, capacitor branch current, housing temperature and output power from a data buffer area; furthermore, output power data is utilized, intelligent screening is carried out through a quasi-steady-state slice trigger, and only effective data with the power average value large enough and the fluctuation small enough are reserved. And for the screened effective data slices, extracting the DC bus voltage and the capacitance branch current, and accurately identifying the voltage, current amplitude and phase information of the main harmonic through fast Fourier transform. Based on the key harmonic data, the complex impedance of the capacitor is calculated, and then the original ESR and capacitance estimation value are calculated. And finally, in combination with the capacitor shell temperature extracted from the same data slice, performing temperature compensation on the original parameters, and outputting a final result capable of truly reflecting the aging state of the capacitor.

The invention discloses a capacitance parameter determination method and device of an iron core sensing device for transformer partial discharge detection, electronic equipment and a storage medium, and belongs to the technical field of sensor design, and the method comprises the steps: obtaining an iron core three-dimensional model of a transformer; performing electromagnetic simulation on the iron core three-dimensional model to generate antenna characteristic parameters of the transformer iron core under each frequency in a preset frequency band; determining a target detection frequency band of the transformer core according to the antenna characteristic parameters; repeatedly executing the parameter adjustment operation of the iron core sensing device until the current test frequency band covers the target detection frequency band, and determining the capacitance parameter of the iron core sensing device; therefore, by implementing the invention, the problem that the capacitance parameters of the iron core sensing device in the prior art are not accurately determined can be solved.

The invention provides a direct-current support capacitor capacitance online identification method based on multi-frequency-point collaborative analysis, and relates to the technical field of direct-current support capacitors, and the method comprises the steps: collecting a ripple voltage signal and a ripple current signal; determining a delay step length, and constructing a pulse weight sequence based on the delay step length; performing discrete convolution operation on the pulse weight sequence, the ripple voltage signal and the ripple current signal, and extracting a periodic signal; performing signal processing on the periodic signal, and extracting a signal amplitude; determining an optimal parameter combination; an optimized amplitude value is obtained; calculating a first capacitance value and a second capacitance value according to the amplitude relation; and performing multi-frequency-point collaborative analysis based on the first capacitance value and the second capacitance value, and determining an actual capacitance value of the DC support capacitor. According to the method, high-precision extraction is carried out on signals of different frequency points through adaptive time slot pulse weighting, synchronous demodulation and integral filtering processing, and rapid and accurate identification of capacitance parameters of the direct-current support capacitor is realized in combination with a multi-frequency-point collaborative analysis mechanism.

The invention discloses a capacitor on-line monitoring method based on a time-frequency domain joint model. The method is suitable for DC-Link capacitor state evaluation of power electronic equipment. Capacitive current is dynamically reconstructed through port current of an active inductor and a switching signal, and dependence on a special sensor is eliminated. An equivalent series resistance (RESR) is calculated based on a power loss model in a time domain, a 300Hz harmonic component is combined in a frequency domain to decouple a capacitance value, and synchronous high-precision monitoring of the RESR and the capacitance value is achieved. Simulation and experiments show that the RESR monitors error lt; 4%, capacitance error lt; and the monitoring period can be shortened to 30ms. According to the method, a main circuit does not need to be transformed, the method can be deployed in a DSP controller in an embedded mode, and a real-time non-intrusive state monitoring solution is provided for equipment such as an active inductor and a frequency converter.

The invention discloses a transformer fault detection method and device based on a dynamic threshold value, and belongs to the technical field of fault detection, and the method comprises the steps: collecting the current basic parameters, environmental parameters and current actual load of a transformer in real time; calculating a real-time load rate based on the current actual load; obtaining a transformer static threshold value corresponding to each current basic parameter; based on the environmental parameters, converting the static thresholds of the transformers into dynamic thresholds of the transformers; correcting each transformer dynamic threshold based on a preset equipment state correction parameter and a real-time load rate to obtain a corrected transformer dynamic threshold; and on the basis of each corrected transformer dynamic threshold value, performing anomaly detection on each current basic parameter to obtain a detection result of each parameter, and obtaining a transformer fault detection result on the basis of a preset hierarchical fault mechanism table and correlation analysis of each parameter detection result. Therefore, by implementing the method and the device, the problem of low transformer fault detection accuracy in the prior art can be solved.

Systems and methods are provided herein for determining the planarity of a semiconductor wafer. The systems and methods described herein utilize a capacitive measurement tool to detect and characterize the bow of a semiconductor wafer. The capacitive measurement tool disclosed herein utilizes a non-contact, capacitive sensor unit to measure wafer bow. Unlike conventional capacitive sensing techniques used to measure wafer bow, the capacitive sensor unit disclosed herein uses a plurality of electrodes for simultaneously obtaining a plurality of capacitance measurements from the wafer at various locations on the wafer surface. By including a plurality of electrodes within the capacitive sensor unit, the techniques described herein increase the amount of data collected across the wafer surface at any given time to improve the throughput and measurement accuracy of the capacitive measurement tool.