70 results about "Electrical capacitance meter" patented technology

A system is disclosed for measuring and recording a quantity of liquid in an absorbing material (16), such as the quantity of urine in a nappy, which system comprises a sensor (1) comprising a first pair of electrodes (4, 7) for measuring the quantity of liquid, which first pair of electrodes is arranged to be placed around the absorbing material in, for example, a nappy, and a data logger (10), which is arranged to apply an alternating voltage across the first pair of electrodes and, concurrently herewith, to measure the capacitance between the two electrodes of the first pair of electrodes and to calculate, based on the measured capacitance, an estimate of the quantity of liquid in the absorbing material. In an embodiment, the system further comprises a second pair of electrodes (6, 8) for estimating the presence of a substance, such as faeces, there between using a similar method.

Computing the gradients of capacitances in an integrated circuit chip layout with respect to design and process parameters is described. Included is a shape processing engine in the form of a variational mapping engine and a capacitance calculation engine that includes a gradient calculation engine. The variational mapping engine translates physical parameter variations into variations on the edges of the elementary patterns to which the layout of the integrated circuit is decomposed. The gradient calculation engine computes capacitance gradients by combining information from two sources. The first source consists of pre-existing gradients in a capacitance lookup table. The second source consists of analytical expressions of capacitance correction factors.

A method for detecting presence of an interference source is to be performed by a touch sensing system that stores a threshold capacitance difference. The method includes the steps of sampling capacitances periodically within a time period for obtaining a base capacitance value; sensing a comparison capacitance after the time period; computing an absolute difference between the comparison capacitance and the base capacitance value; and determining that the interference source is present when the comparison capacitance is smaller than the base capacitance value and the absolute difference is greater than the threshold capacitance difference.

The invention relates to a detection device and method for rebar in concrete, and provides a static field capacitance principle-based low-cost, high-accuracy and nondestructive detection device and method. Various types of targeted detection are implemented on the rebar in the concrete, and an accurate and convenient detection result comprising rebar position, size and corrosion quantity is expected to be acquired, and operation efficiency of detection, building engineering acceptance and detection, reinforcement and identification of an existing rebar concrete structure are improved. The detection device comprises an electrode plate, a DC power supply and a data acquisition processing device, wherein the data acquisition processing device comprises a capacitance meter, a display module, an operation module, a processing module and a data connection line socket, wherein an angular frequency of the capacitance meter is set as 10KHz, the display module is used for displaying a numericalvalue obtained after detection of a capacitance sensor, the operation module is used for performing artificial actual operation and inputting special engineering information to set a parameter, the processing module is used for performing data analysis statistics on the numerical value measured by the capacitance meter and other relevant numerical values, and the data connection line socket is used for connecting the electrode plate.

Controller circuitry controls power supply circuitry to produce an output voltage. During operation of the power supply circuitry to produce the output voltage, the controller circuitry calculates a magnitude of capacitance of output capacitor circuitry in the power supply. According to one configuration, the controller circuitry utilizes a calculated magnitude of capacitance as a basis to adjust settings of the power supply circuitry.

The invention discloses a voltage measurement self-decoupling method based on multi-dimensional equivalent capacitance calculation. The method comprises the following steps: 1) determining the type of a power transmission line to be measured; 2) performing non-contact measurement on the voltage of the to-be-measured power transmission line by using a non-contact electric field sensor, and establishing a self-decoupling matrix of the to-be-measured power transmission line; 3) judging whether the sensor is symmetrically distributed based on x and z axial directions, and resolving a self-decoupling matrix; 4) performing singularity verification on the self-decoupling matrix, if the self-decoupling matrix has singularity, determining that the position of the non-contact electric field sensor is a singular measurement point, replacing the position of the non-contact electric field sensor, and returning to the step 2), and if the self-decoupling matrix has non-singularity, entering the step 5); and 5) calculating a three-phase voltage signal of the power transmission line to be measured. According to the invention, the size of the signal is actually measured through the sensor, the multi-terminal voltage signal characteristics of the power transmission line are accurate, the accuracy of the decoupling algorithm is improved, and the design difficulty caused by repeated correction is effectively reduced.

The invention provides a capacitance calculation device, method and system. The method comprises the following steps: providing current flowing through a first flying capacitor in the switched capacitor power converter; measuring a first voltage at a first terminal of the first flying capacitor at a first voltage measurement time; measuring a second voltage at the first terminal of the first flying capacitor at a second voltage measurement time; and calculating a capacitance value of the first flying capacitor based on the first voltage, the second voltage, the first voltage measurement time, and the second voltage measurement time.

The invention discloses a power distribution network grounding fault recognition method, a device and equipment. The method comprises the following steps: firstly, injecting same-amplitude variable-frequency small-current signals from a neutral point of a power distribution network; measuring a feedback voltage signal by a voltage transformer, and calculating the ground conductance and the groundcapacitance of the power distribution network; calculating the incremental damping rate under each frequency by using the ground conductance and the ground capacitance, calculating and superposing theincremental damping rate generated by the fault transition resistance to perform the fault according to the preset criterion so as to realize the effective amplification of the fault characteristic quantity and greatly reduce the influence of the interference, thereby effectively identifying the high-resistance grounding fault. According to the method, the problem that the high-resistance grounding fault of the resonant grounding power distribution network is difficult to identify is solved, the grounding fault characteristics can be highlighted, the method has high anti-noise capability, andthe recognition capability of the high-resistance grounding fault is greatly improved.

A capacitance meter including an AC source providing a measurement voltage with a measurement frequency to a capacitor. A current sensor is arranged to measure a current going to or from the capacitance meter. A voltage sensor is arranged to measure a voltage over the capacitor. A capacitance calculation unit is arranged to calculate, using a controller, a capacitance of the capacitor using a measured current from the current sensor, a measured voltage from the voltage sensor and the measurement frequency. The capacitance meter is arranged to obtain measurements using the current sensor and the voltage sensor during a measurement duration. The measurement frequency and the measurement duration are selected such that the measurement duration equals a multiple of the period of the measurement frequency, and the measurement duration equals a multiple of the period of a mains electricity.

A method of calculating electrical interactions of circuit elements in an integrated circuit layout without flattening the entire database that describes the layout. In one embodiment, a hierarchical database is analyzed and resistance and capacitance calculations made for a repeating pattern of elements are re-used at each instance of the repeated pattern and adjusted for local conditions. In another embodiment, a circuit layout is converted into a number of tiles, wherein the resistance and capacitance calculations made for the circuit elements in the center and a boundary region of the tiles are computed separately and combined. Environmental information that affects electrical interaction between circuit elements in different levels of hierarchy is calculated at a lower level of hierarchy so that such calculations do not need to be made for each placement of a repeated cell and so that not all interacting elements need to be promoted to the same hierarchy level to compute the electrical interactions.

The present invention discloses a transformer oil clearance complex capacitance test method under a low frequency sine excitation. The method provided by the invention comprises: obtaining a direct current conductivity [Sigma]0, an ion mobility [Mu] and the thickness l of the oil clearance in the temperature T through a test, obtaining an amplitude U, a phase [Psi] and a frequency f applied by sine excitation through the test, and obtaining an instant expression u(t); then putting the obtained data (expression) in an oil clearance complex capacitance calculation model under the low frequency sine excitation; finally obtaining the complex capacitance of the oil clearance under the low frequency sine excitation. According to the method provided by the invention, obtained data (expression) through the test is putted into a calculation model to obtain the complex capacitance of the oil clearance through a numerical calculation method. On the basis of effectively obtaining the complex capacitance of the oil clearance, the method provided by the invention may solve the problem that the measurement time of the complex capacitance of the oil clearance under the low frequency sine excitation through adoption of an apparatus is long through the numerical calculation method, and the application efficiency of the frequency domain dielectric response method in the practical engineering may be improved.

The invention discloses a super capacitor SOC calculation method. The method comprises the steps of 1, establishing a first-order RC model of a super capacitor; step 2, selecting open-circuit voltageOCV of the super capacitor as a characteristic parameter, and establishing a dynamic balance voltage model to obtain DEV = OCV + eta ps; establishing a DEV-SOC relation function model: fDEV (SOC) = x1, i (SOC-SOCmin, i ) + x2, i + x3, iln (SOC-SOCmin, i ) + x4, iln (SOCmax, i-SOC); 3, describing a dynamic equivalent circuit model by using a discretized nonlinear state space equation and a measurement equation; taking the working current Ibat of the super capacitor monomer as an input quantity; taking the terminal voltage Ubat as an observed quantity, taking the nonlinear state-space equation in the step 3 as a state equation of extended Kalman filtering, taking the measurement equation in the step 3 as a measurement equation of extended Kalman filtering, and calculating the SOC of the super capacitor by using an extended Kalman filtering algorithm. According to the method, a good closed-loop SOC optimal estimation effect can be formed, the SOC calculation precision is high, and the stability is good.

A relative-dielectric-constant measuring apparatus according to the present invention includes an ellipsometer and a capacitance measuring part. The ellipsometer allows non-contact measurements of the film thickness and optical constants of an insulation film formed on the upper surface of a wafer. The capacitance measuring part, on the other hand, allows non-contact measurements of the gap between the insulation film and an electrode and accumulation capacitance. The relative-dielectric-constant measuring apparatus can calculate the relative dielectric constant of the insulation film based on the measured film thickness, gap, and accumulation capacitance. Thus, the relative dielectric constant of the insulation film can be determined without contact and with high precision.

The invention discloses an online frequency domain dielectric spectrum detection method for an insulating bush, and relates to the technical field of high-voltage insulating sleeve detection. The method comprises the following steps: S1, obtaining voltage and current signals at a high-voltage bush; S2, calculating a harmonic voltage and a harmonic current at the high-voltage bush; S3, calculatingthe complex capacitance of the main insulation of the bush within a certain frequency band range through the amplitude and phase relation; S4, calculating the frequency spectrum of the complex dielectric constant; S5, completing online monitoring of the frequency domain dielectric spectrum. According to the invention, the complex capacitance and the complex dielectric constant of a bushing main insulation system are calculated by using fundamental frequency and high-frequency components contained in steady-state harmonic waves; the passive online monitoring of the frequency domain dielectric spectrum of the bush can be realized without offline testing of equipment or active injection of broadband voltage signals, the problem that power frequency dielectric loss is not sensitive enough to insulation performance change is solved, and the problem that online monitoring is difficult to realize in traditional frequency domain dielectric spectrum testing is also solved.

The invention discloses a CDSM-MMC electromagnetic transient overall modeling method and device based on a weight method. The method comprises the steps that initialization processing is conducted onsystem data; equivalently replacing a switching device in the sub-module with a double-value variable resistor, and discretizing a capacitor in the sub-module by adopting a weight numerical integration method; thevenin equivalent resistance and Thevenin equivalent voltage of each sub-module are calculated. Solving an equivalent model of the CDSM-MMC, so as to enable the equivalent model to carry out simulation operation; sorting the capacitor voltages of all the sub-modules of the MMC by adopting a classification sorting voltage-sharing algorithm to obtain a sorting result; judging whether thecurrent simulation moment is greater than the total simulation duration or not; if so, ending the simulation; If not, entering the next simulation moment, and determining the trigger state of the switching device of each bridge arm at the next simulation moment according to the sorting result and the number of capacitors and the bridge arm current which need to be input by each bridge arm at present. According to the invention, the weight coefficient can be flexibly adjusted according to the simulation requirement so as to obtain different stability and calculation precision.

The invention provides a capacitive current online test method for a neutral point ungrounded system, a storage medium and a device. The method comprises the steps: obtaining the ground capacitance ofa non-fault line; according to the ground capacitance of the non-fault line, obtaining the ground capacitance current of the non-fault line; calculating the ground capacitance of a faulty line according to the ground capacitance of the non-faulty line, the length of the non-faulty line and the length of the faulty line; calculating ground capacitance current of the fault line according to the ground capacitance of the fault line; and calculating bus capacitance current according to the ground capacitance current of the non-fault line and the ground capacitance current of the fault line. The invention further provides a low-current grounding line selection storage medium and an online test device. According to the method, the capacitance current of each bus and the capacitance current of each section of the bus are calculated on line, the calculation result can provide an effective basis for compensating the single-phase grounding current of the power distribution network, inhibiting intermittent arc light overvoltage, selecting the capacity and the installation position of the arc suppression coil and selecting PT equipment in time, and extra hardware devices do not need to be designed.

The invention discloses a wave-absorbing material dielectric parameter measurement and inversion method based on an open-circuit coaxial line. The method comprises the following steps: step 1, deducing a calculation formula for the power consumption capacity of a medium to be measured in an equivalent circuit; step 2, calibrating a measurement reference surface; and step 3, measuring and inverting the dielectric parameter of the wave-absorbing material. The wave-absorbing material dielectric parameter measurement and inversion method based on the open-circuit coaxial line can be used for replacing a traditional direct-current equivalent resistance testing method, electrical parameter measurement of the wave-absorbing material can be carried out more accurately, parameter calibration of various wave-absorbing materials can be carried out accurately, and more accurate electrical parameter guidance is provided for design and model selection of electromagnetic systems such as radar stealth, electromagnetic shielding and radio frequency matching. Meanwhile, the method is a relatively simple and low-cost method for measuring and inverting the dielectric parameters of the wave-absorbing material.

The present invention relates to a method for measuring the active area of an active material in an electrode, comprising: manufacturing three types of electrodes including a first electrode coated with an electrode mixture including both an electrode active material and a conductive material, a second electrode coated with an electrode mixture which includes the electrode active material as a main ingredient and does not include the conductive material, and a third electrode coated with an electrode mixture which does not include the active material and includes the conductive material as a main ingredient; a cell manufacturing step of manufacturing three types of monocells by using the same types of electrodes; a capacitance measuring step of measuring, from the monocells, capacitance of each electrode used in the monocells; and an active area calculating step of calculating the active area of the electrode active material from the capacitance.

The embodiment of the invention provides a transformer oil aging degree evaluation method, a transformer oil aging degree evaluation device and a sensing system. The transformer oil aging degree evaluation method comprises the following steps: recording a polarization curve and a non-polarization curve of transformer oil under direct-current voltage; collecting no less than one voltage effective value and no less than one current effective value of the transformer oil under the alternating current excitation signal; calculating the first conductivity of the transformer oil by combining the capacitance of the conductivity electrodes at the two ends of the transformer oil; calculating at least one second conductivity according to the voltage effective value and the current effective value; and obtaining the infrared light absorptivity of each aging product, and calculating the aging index of the transformer oil by combining the first conductivity and at least one second conductivity to obtain the aging degree evaluation result of the transformer oil. Compared with the prior art, online testing can be carried out, the influence of impurities on the conductivity of the transformer oil is considered by obtaining no less than one conductivity of the transformer oil under the direct-current voltage and the alternating-current voltage, and the accuracy and the real-time performance of testing are improved.

The present application discloses a parameter design method for an electric field coupled wireless power transfer system with constant current output. On the basis of analyzing the total input impedance of the electric field coupled wireless power transfer system, the conditions for constant output current and the current during constant current output are deduced. Gain expression, determine the operating frequency and compensation capacitance of the system according to the current gain expression and the area of ​​the coupler as a constraint; calculate the compensation inductance according to the constant output current condition and the determined operating frequency and compensation capacitance; if any of the compensation inductance If one is greater than the preset inductance threshold, modify at least one of the operating frequency and the compensation capacitor until the compensation inductance is not greater than the inductance threshold; simulation experiments are carried out on the system parameters designed based on this method, and it shows that the system output current has nothing to do with the load impedance; This design method solves the problem of unstable output current when the system load impedance changes, and makes the system have excellent constant output current characteristics.

A method for detecting presence of an interference source is to be performed by a touch sensing system that stores a threshold capacitance difference. The method includes the steps of sampling capacitances periodically within a time period for obtaining a base capacitance value; sensing a comparison capacitance after the time period; computing an absolute difference between the comparison capacitance and the base capacitance value; and determining that the interference source is present when the comparison capacitance is smaller than the base capacitance value and the absolute difference is greater than the threshold capacitance difference.

The invention relates to a power distribution line grounding fault property identification and recovery method, which comprises the following steps of: after a power distribution line grounding fault occurs, overlapping a certain phase before power transmission of a power distribution line; collecting the voltage and current waveforms of the overlapped phase, and filtering; calculating derivatives of the voltage and the current; constructing a least square method identification capacitance model, and solving the capacitance under the least square meaning; calculating a model error EC (k) of the capacitance model; constructing a least square method identification resistance-inductance model, and solving resistance and inductance under the least square meaning; and calculating a model error EZ (k) of the resistance-inductance model, wherein when EZ (k) is less than krelEC (k), the fault is a permanent grounding fault, otherwise, the fault is an instantaneous grounding fault. According to the invention, no additional device is needed, and the fault property can be determined only by overlapping a certain phase and detecting the current and voltage values of the overlapped phase; and the ground fault property identification method is simple, efficient and low in cost.

The invention provides a control method of a door closing resistance self-adaptive elevator door motor. The control method of the door closing resistance self-adaptive elevator door motor comprises the following steps of: S1, judging whether no passenger or no foreign matter exists in an elevator door closing stroke or not in real time, and if so, performing S2; if not, performing S4; S2, obtaining capacitance between elevator doors on the two sides through a capacitance sensor, calculating the movement speed between the elevator doors on the two sides, judging whether the door closing resistance is larger than a threshold value or not according to the movement speed, if yes, executing a step S3, and if not, executing the step S4; S3, enabling a door motor controller to reduce the operation speed of a door motor to a first speed V1 and increase the door closing torque until the doors are closed; and S4, enabling the door machine controller to control the door machine to operate at the normal speed V0 and control the door closing moment to be the normal door closing moment until the doors are closed. According to the control method of the door closing resistance self-adaptive elevator door motor provided by the invention, the actual closing speed of the elevator doors is monitored in real time, the actual closing speed of the elevator doors is used as a condition for judging whether the closing resistance of the elevator doors is too large or not, and the reliability is high aiming at all factors except the air outlet force.

The invention belongs to the technical field of special vehicle comprehensive power system high-voltage safety protection, and particularly relates to an electrically-driven special vehicle distributed capacitance testing device which comprises a precise current source, a reference voltage source, an electronic switch, a voltage comparator, an electronic switch control unit and a single-chip microcomputer. The device enables the reference voltage source to charge the distributed capacitor through switching the electronic switch, discharges the distributed capacitor through the precision current source, records the discharge time of the distributed capacitor through the single-chip microcomputer, and obtains the capacitance value of the distributed capacitor according to a capacitance calculation formula. The circuit realizes the distributed capacitance detection function of the electrically-driven special vehicle, can measure the distributed capacitance value of the vehicle, and provides a basis for the duration of applying insulation detection excitation voltage to an on-vehicle insulation detection device. And meanwhile, an electric leakage subcircuit of the vehicle caused by distributed capacitance is effectively evaluated, the electric shock risk of personnel is reduced, and the safety of personnel and equipment on the vehicle is effectively ensured.

The invention discloses a diode junction capacitance calculation method. The method comprises the following steps: A1, measuring an apparent capacitance value, an apparent conductivity value, an S11 parameter real part, an S11 parameter imaginary part and voltage-current of a diode; A2, calculating a real part and an imaginary part of diode impedance by using the real part and the imaginary part of the parameter S11; A3, according to the impedance relation between the two equivalent circuits of the diode, obtaining calculation formulas of junction capacitance and series resistance; A4, setting an initial junction conductance value Ginit; A5, substituting the initial junction conductance value into the junction capacitance calculation formula to obtain a current junction capacitance value; A6, substituting the current junction capacitance value and the initial junction conductance value into the series resistance calculation formula to obtain a current series resistance value, obtaining a voltage applied to the junction conductance or the junction capacitor according to a voltage-current relationship, and obtaining a current junction conductance calculation value G' according to a conductance formula; and A7, judging whether the difference value between the Ginit and the G' is smaller than a preset threshold value or not; if so, taking the current junction capacitance value as the final value of the junction capacitance; and if not, making Ginit to be equal to G', and executing the step A5 again.

A wearable electronic device which can detect a wearing state, comprising: at least one first electrode, provided in a first region of the wearable electronic device; at least one second electrode, provided in a second region of the wearable electronic device; a capacitance calculating circuit, configured to calculate first capacitances generated by the first electrode and configured to calculate second capacitances generated by the second electrode, wherein the capacitance calculating circuit further calculates a capacitance difference between the first capacitance and the second capacitance; and a processing circuit, configured to determine the wearing state according to the capacitance difference. Via such structure, a wearing state, a wearing location, a wearing angle of the electronic device can be automatically detected, thus the problem caused by an improper wearing manner can be improved.

The invention discloses a capacitance counting module for insect pest detection, an insect pest detection device and an insect pest detection method. The module comprises a base, a porous fairing, a capacitance plate, a shell and a processing unit, wherein the base is provided with an inner interlayer and an outer interlayer which are concentric, the outer interlayer is located outside the inner interlayer, and the area between the inner interlayer and the outer interlayer is communicated with the outside. The porous fairing is arranged in a manner of gradually shrinking from bottom to top andis arranged on the inner interlayer; the inner capacitor plate is adjacent to the inner interlayer, and the outer capacitor plate is adjacent to the outer interlayer and faces the inner capacitor plate to form a capacitor plate pair; partition plates are arranged on the base to equally divide the area between the inner interlayer and the outer interlayer and separate the adjacent capacitor platepairs, and every two partition plates and the capacitor plate pair between the two partition plates jointly define a capacitor detection area. The processing unit is connected with each capacitor plate pair and is used for detecting the capacitance value of each capacitor plate pair in real time, judging whether pests exist in each detection area or not and obtaining a pest counting result. According to the invention, pest detection and counting can be reliably and accurately realized.

The present disclosure provides for a sensor system for determining a flow rate of a fluid flow within a fluid channel comprising an elastic segment arranged next to a rigid segment, wherein a first pair of electrodes is provided at the rigid segment and a second pair of electrodes is provided at the elastic segment of the fluid channel. The system further comprises a sensor unit for detecting a capacitance of the first and second electrode pairs, and a processing unit for calculating and monitoring a distance between the electrodes of the second electrode pair based on the detected capacitance of the first electrode pair and the second electrode pair, wherein the first electrode pair is in contact with the rigid segment and the second electrode pair is in contact with the elastic segment. Moreover, a respective method for determining a flow rate of a fluid flow within a fluid channel is provided by the present disclosure, as well as a use of the sensor system.

The invention provides a method, a device and a system for testing the capacitive current. The method comprises the following steps: respectively and electrically connecting the test terminals of thecurrent output module of a capacitive current testing device with the A-phase terminal, the B-phase terminal and the C-phase terminal of a switch cabinet electrified indication device; electrically connecting the grounding terminal o of the capacitive current testing device with the grounding terminal of the switch cabinet electrified indication device; electrically connecting a current transformer of each phase between the capacitor of a corresponding electrified indication sensor and the capacitor of a switch cabinet electrified display device; outputting an abnormal-frequency current signal; acquiring an abnormal-frequency voltage and an abnormal-frequency current corresponding to each phase of the an abnormal-frequency current signal; calculating the ground capacitance of each phase ofa neutral point ungrounded system; according to the ground capacitance of each phase, calculating to obtain the ground capacitance current. According to the invention, the test loop is simple. The ground capacitance of each phase of the power system, relative to the ground, can be calculated respectively. Meanwhile, the condition of power outage is not required and the safety is high. The methodcan be used for testing the capacitive currents of ungrounded systems.

The invention discloses a distribution network grounding fault identification method, device and equipment. The method first establishes that a small current signal with the same amplitude and frequency conversion is injected from the neutral point of the distribution network, and the voltage signal fed back is measured through a voltage transformer, thereby Calculate the conductance and capacitance to ground of the distribution network, and then use the conductance to ground and capacitance to ground to calculate the incremental damping rate at each frequency, and then calculate the incremental damping rate generated by the fault transition resistance and superimpose Faults are carried out according to preset criteria to achieve effective amplification of fault characteristic quantities, and at the same time greatly reduce the impact of interference, thereby effectively identifying high-resistance grounding faults. The invention solves the problem of difficult identification of high-resistance ground faults in a resonant ground distribution network, can highlight the characteristics of ground faults, has high anti-noise ability, and greatly improves the identification ability of high-resistance ground faults.