181 results about "Equivalent capacitance" patented technology

The invention provides an excitation amplitude automatic closed-loop control system and method for a DLCP test. The system comprises a multi-frequency alternating current excitation and direct current bias voltage applying module which is used for automatically applying alternating current excitation signals and direct current bias voltage signals according to a preset excitation amplitude sequence under a plurality of test frequencies; the PID closed-loop control module is used for performing closed-loop correction on the applied voltage according to the response of the test port of the tested semiconductor device, so that the condition of the applied voltage at the test port meets a preset requirement; the capacitance measurement module is used for acquiring an equivalent capacitance response signal of the tested semiconductor device; the capacitance test data caching module is used for performing associated marking and classified caching on the capacitance test data according to the test frequency, the excitation level and the bias voltage set point; and the main control module is used for coordinating automatic test processes under the conditions of a plurality of test frequencies and different excitation amplitudes and outputting corresponding capacitance test data so as to improve the consistency, stability and automation degree of the DLCP test.

The invention provides a method and device for determining the health state of a supercapacitor, and relates to the technical field of supercapacitors, and the method comprises the steps: obtaining the voltage variation and the current variation of the supercapacitor in the operation process; determining a target equivalent resistance value according to the voltage variation and the current variation; determining a target equivalent capacitance value according to the voltage variation and the current value in the corresponding time period; determining a resistance growth rate and a capacitance attenuation rate according to the target equivalent resistance value and the target equivalent capacitance value; and determining the health state of the supercapacitor according to the resistance growth rate and the capacitance attenuation rate. Therefore, the capacitance attenuation rate and the ESR growth rate can be extracted online based on the voltage data and the current data acquired in real time without interrupting the system or adding the test current in the equipment operation process, the process is simplified, and the accuracy and the reliability of determining the health state of the supercapacitor are also improved through the real-time data.

The invention relates to the technical field of circuit board detection, in particular to a printed circuit board drilling quality detection method and device, and the method comprises the steps: injecting sinusoidal current signals with preset frequencies into a plurality of test points of a to-be-detected drilling region of a printed circuit board, extracting impedance values under each frequency component, and calculating the drilling quality of the printed circuit board; constructing an equivalent impedance spectrum containing a real part and an imaginary part according to the impedance value; according to the interlayer structure and the equivalent impedance spectrum of the printed circuit board, calculating equivalent resistance and equivalent capacitance of the drilling area to be measured to form a characteristic parameter set; comparing the data of each grid point in the characteristic parameter set with a preset threshold value, and integrating the grid points exceeding the preset threshold value to generate a defect state mark; and performing electrical topology constraint on the defect state mark to generate a defect positioning result. According to the invention, hidden defects in the drill hole and interlayer structures can be deeply detected, the electrical performance of the drill hole can be comprehensively evaluated, and accurate defect positioning and state marking can be provided.

A three-phase wireless electric energy transmission device disclosed by the present invention comprises a three-phase inverter, a three-phase switch capacitor, a coil magnetic field coupling structure and a rectifier, the coil magnetic field coupling structure comprises a primary coil and a secondary coil which are arranged in mirror symmetry, the primary coil is provided with two layers, each layer comprises a three-phase coil, each phase coil occupies a 120-degree angle range of the circumference, and the rectifier is connected with the primary coil and the secondary coil. The two layers of coils form a staggered angle, each phase of switched capacitor of the three-phase switched capacitor comprises a first capacitor branch and a second capacitor branch which are arranged in parallel, the first capacitor branch is provided with a first capacitor, and the second capacitor branch comprises a second capacitor and a switch module which are arranged in series; the switch module adjusts the equivalent capacitance value of the second capacitor branch through the duty ratio and adjusts the transmission power of the three-phase wireless power transmission device. The invention further discloses a load power adjusting method of the three-phase wireless power transmission device, the transmission efficiency can be kept unchanged within the adjusting range, and soft switching can be achieved within the adjusting range.

The invention relates to the technical field of electrical equipment insulation tests, and discloses a medium-voltage cable variable-frequency resonance voltage-withstanding test system and a medium-voltage cable variable-frequency resonance voltage-withstanding test method. The method comprises the steps of configuring a test loop and setting related parameters, and presetting a target test voltage, test time, a system quality factor range, a local discharge capacity threshold and a current change rate threshold based on a cable model, a cable length, a laying environment temperature and an equivalent capacitance. And executing frequency scanning in a preset frequency range through an adaptive step length strategy, adjusting the step length according to the current response, identifying the resonant frequency and verifying the quality factor of the system. In the test process, the loop current change rate, the partial discharge capacity and the equipment temperature are monitored in real time, a protection mechanism is triggered according to abnormal characteristics, and insulation state diagnosis is completed. When the test is ended, voltage is reduced at a controllable rate, residual charges are dissipated, and a test report is automatically generated. The method improves the accuracy and safety of the test, and is suitable for various field conditions.

This invention discloses a live-line detection device and method for partial discharge in GIS (Gas Insulation System), relating to the field of live-line detection of power equipment. The equivalent capacitance between the primary and secondary windings of a current transformer coil is used as a pulse signal coupling channel. Two sets of pulse current signals within the high-voltage conductor of the GIS are acquired through these two pulse signal coupling channels. Then, the partial discharge voltage signal of a specified frequency is extracted through a pulse partial discharge detection circuit. The two extracted pulse signals are output to a differential mode comparison and acquisition module. This module compares the pulse signals input from the two channels, effectively eliminating interference signals. This invention simultaneously solves two problems in GIS live-line partial discharge pulse detection: pulse coupling and high-voltage side partial discharge interference during live operation. It achieves accurate detection of partial discharge during GIS operation, ensuring the safe and stable operation of GIS electrical equipment.

Embodiments of the present disclosure relate to reverse wireless charging. A method and system for operating a power circuit capable of transmitting wireless power and receiving wireless power are provided. The method includes determining that the power circuit is operating in a receive mode and, based thereon, having a first equivalent capacitance. The method further includes determining that the power circuit is operating in a transmit mode and, based thereon, having a second equivalent capacitance. The first equivalent capacitance is different from the second equivalent capacitance.

The application provides a non-continuous three-phase rectifier adjustable power decoupling method, and relates to the field of power electronics. The method is characterized in that a capacitor equivalent circuit is connected in parallel to the DC side of a three-phase PWM rectifier, the capacitor equivalent circuit is composed of a first capacitor connected in series with an active negative capacitor circuit, and a digital signal controller is used to sample the relevant voltage and current signals of the AC side and the DC side, and the active negative capacitor capacitance is adjusted by controlling the switching tube, so that the equivalent capacitor circuit can be flexibly adjusted. The application does not require an additional DC power supply, the capacitance and inductance of the passive device used are small, and the volume advantage is significant. The closed-loop control has high precision and equivalent inhibition effect as the traditional large capacitor. The equivalent capacitance is adjusted only by software, the external physical structure does not need to be changed, and the adjustment range is wide. The preset DC side voltage fluctuation amplitude can be calculated and adjusted automatically, different unbalanced working conditions can be adapted, the fluctuation suppression demand can be met, different working modes can be switched according to the AC side working condition, and the application is not continuously operated, so that the switching loss is lower.

A method comprises discharging electrical energy from an intermediate circuit comprised in the apparatus, measuring a direct current voltage, and inputting measured values to a parameter estimator for the intermediate circuit. The parameter estimator comprises at least a first parameter and a second parameter whose values are determined based on an equivalent capacitance value of the intermediate circuit, an equivalent resistance value of the intermediate circuit and an electrical load power value of the intermediate circuit, the parameter estimator outputting values for time constant and values for power-to-capacitance ratio of the intermediate circuit. The method further comprises storing values at least temporarily for condition monitoring.

The invention relates to a method and system for detecting the vacuum degree of a vacuum arc-extinguishing chamber based on high-frequency discharge and spectral analysis, and the method comprises the steps: exciting the interior of the vacuum arc-extinguishing chamber to generate field emission current through a high-frequency electric field, and obtaining a high-frequency current peak value through the spectral analysis of the field emission current; the vacuum degree is determined according to a pre-constructed vacuum degree-high-frequency current peak value standard relation curve, a high-frequency power source is connected to a vacuum arc extinguish chamber, the output voltage of the high-frequency power source is gradually increased until a vacuum gap breaks down, the voltage waveform in the process is recorded, and the total current of a loop is calculated; calculating a capacitive current component by combining the equivalent capacitance of the loop; and selecting a stable current section between two dielectric breakdown events in the total current, intercepting a current peak signal in the section, and subtracting the capacitive current component from the total current corresponding to the peak signal to obtain the field emission current. Compared with the prior art, the method has the advantages of high sensitivity, simplicity and convenience in operation, accurate result and the like.

This invention discloses a low-voltage pre-calibrated single-current sampling DBD equivalent parameter measurement method and system. Addressing the core shortcomings of existing DBD parameter measurement technologies, such as complex hardware, significant safety hazards from high-voltage sampling, inherent errors introduced by measurement capacitors, and imprecise derivations of single-current sampling schemes, this invention employs a two-step method to achieve full parameter measurement using only single-channel current sampling: First, pre-calibration is performed under low-voltage, undischarged conditions to obtain the DBD series equivalent capacitance and the initial phase of the excitation voltage; then, the circuit current is sampled under normal discharge conditions, and the discharge / undischarge interval is accurately divided using the sliding window variance method. Based on the data from the undischarged interval, a complete excitation voltage waveform is fitted, and finally, all equivalent parameters, including dielectric capacitance, air gap capacitance, discharge sustaining voltage, and discharge power, are calculated. This invention eliminates the need for additional hardware such as high-voltage probes and measurement capacitors, enabling online measurement of equivalent parameters.

The invention relates to the field of synchronous phase modifiers, and discloses a static synchronous phase modifier and a method and device for determining the capacitance value of a super capacitor of the static synchronous phase modifier. According to the technical scheme, the balance between the reactive compensation capability and the frequency supporting capability of the static synchronous phase modifier is ignored, and the capacitance value is calculated from multiple angles according to the relation between the kinetic energy value and the active power released by the static synchronous phase modifier and the capacitance voltage change rate in unit time. The reactive compensation capacity is improved while the frequency supporting capacity is guaranteed, capacitance values are calculated through inertia time constants, more accurate state analysis is achieved from the angle of instantaneous values, and finally the capacitance value of each super capacitor is calculated through the maximum value in the calculated equivalent capacitance values. And the balance between the reactive compensation capability and the frequency supporting capability of the static synchronous phase modifier is realized.

The application provides a touch driving circuit and a touch driving method. The touch driving circuit comprises a first power supply voltage generating circuit and a switch circuit. The first power supply voltage generating circuit is configured to generate a first power supply voltage. The switch circuit is configured to control the touch electrode to be connected to the first power supply voltage generating circuit in a first time period, to charge the equivalent capacitance of the touch electrode in the first time period, so that the voltage of the touch electrode is equal to a first intermediate voltage; control the touch electrode to be disconnected from the first power supply voltage generating circuit in a second time period, so that the voltage of the touch electrode remains the first intermediate voltage; and control the touch electrode to be connected to the first power supply voltage generating circuit in a third time period, to charge the equivalent capacitance of the touch electrode in the third time period, so that the voltage of the touch electrode is equal to the first power supply voltage; wherein the first intermediate voltage is between a ground voltage and the first power supply voltage. The technical solution can reduce the interference of touch detection on display.

A display panel and a display device, the display panel comprising a virtual gate line (G2) and a virtual conductive part (31) in a non-display area (BB), the virtual conductive part (31) is in the orthographic projection of the substrate within the orthographic projection of the virtual gate line (G2) in the substrate, the virtual conductive part (31) and the virtual gate line (G2) form an equivalent capacitance, by setting the RC load of the virtual gate line (G2) to match the RC load of the gate line (Gl) of the display area (AA), and taking the virtual gate line (G2) as the scan load of the second GOA unit (200) in the display panel which only provides a reset signal, so that the second GOA unit (200) and the first GOA unit (100) have a matched total load, thereby improving the display brightness unevenness.

The invention discloses a multi-frequency antenna radiation unit device with a decoupling function, and belongs to the field of mobile communication antennas. The high-frequency radiation unit comprises a balun electrically connected with the reflecting plate and a radiation arm connected to the balun; the low-frequency radiation unit is positioned on the periphery of the high-frequency radiation unit and is arranged on the reflecting plate; the capacitor loading assembly comprises a coupling patch connected with the radiation arm and a capacitor branch connected to the balun, the capacitor branch is located on the side, close to the reflecting plate, of the balun, the coupling patch and the capacitor branch form an additional capacitor connected with the high-frequency radiation unit in parallel, and the total equivalent capacitance of the high-frequency radiation unit is changed through the additional capacitor; therefore, the resonant frequency of the high-frequency radiation unit is shifted out of the low-frequency working frequency band, common-mode resonance generated when the high-frequency radiation unit and the low-frequency radiation unit are adjacently arranged is eliminated, the standing-wave ratio of a low-frequency port is improved, the working bandwidth is widened, distortion of a low-frequency radiation pattern is eliminated, and the coverage quality of a base station is guaranteed.

This application discloses a delay prediction method, apparatus, device, and storage medium. The delay prediction method includes: acquiring the unit characteristic information of each unit in a circuit and the characteristic sequence of each unit's interconnection; calculating the equivalent capacitance value of the interconnection path between units based on the capacitance and resistance values ​​of each unit's interconnection, and determining the target interconnection delay characteristics between units based on the equivalent capacitance values; determining the unit delay characteristics of each unit based on the equivalent capacitance values ​​and unit characteristic information; inputting the interconnection delay characteristics and unit delay characteristics into a preset delay prediction model; and performing prediction processing on the interconnection delay characteristics and unit delay characteristics based on the delay prediction model to obtain the delay result of the circuit. This application equates the capacitance and resistance values ​​of each unit's interconnection to equivalent capacitance values, overcoming the deficiency in related technologies where the load capacitance ignores the resistance shielding effect, thereby reducing the error of the load capacitance and improving the accuracy of timing prediction.

The utility model discloses a motor and electrical equipment, and the motor includes: stator subassembly, stator subassembly includes stator core, rotor subassembly, rotor subassembly includes rotor main body and is worn in rotor main body's rotor shaft, two bearing seats, two bearing seats are arranged respectively in rotor main body's axial both sides, and rotor shaft passes through two bearings and is supported and is installed in two bearing seats, and bearing includes inner ring and outer ring, and inner ring is connected with rotor shaft electricity, and outer ring is connected with bearing seat electricity, capacitor, capacitor, stator core and one of bearing seat series connection, and two bearing seats pass through first conducting part electricity and are connected, so that capacitor, stator core and two bearing seats form equivalent capacitance. According to the utility model embodiment's motor balances the inner ring and outer ring of bearing, effectively reduces the voltage difference of bearing inner ring and outer ring, improves the problem of bearing electric corrosion, is favorable for reducing bearing noise.

A compensation circuit of realizing equivalent capacitance amplification is provided. The compensation circuit includes an error amplifier, a resistor and a capacitor. A first terminal of the resistor is connected to a first output terminal of the error amplifier. A second terminal of the resistor is connected to a second output terminal of the error amplifier and the capacitor. An amplified error current signal outputted from the first output terminal of the error amplifier flows through the resistor, and is then divided into a capacitor charging signal and an error amplified reverse current signal. The capacitor charging signal flows to the capacitor. The error amplified reverse current signal flows through the second output terminal of the error amplifier into the error amplifier. The error amplified reverse current signal is larger than the capacitor charging signal.

The application discloses a tobacco cut tobacco variable frequency motor state monitoring method based on a common mode loop and belongs to the motor state monitoring field. In view of the problem that early-stage faults of insulation deterioration of a variable frequency motor are difficult to detect in a high-dust, high-humidity and strong electromagnetic interference environment of a tobacco cut tobacco workshop, the application utilizes the correlation characteristics between a common mode loop signal and a motor insulation state, firstly establishes a common mode loop impedance model considering a common mode inductance of a stator winding, an inter-turn equivalent capacitance and a stray capacitance to ground, and calculates a common mode loop resonance frequency; then high-frequency oscillation loop models and medium-frequency oscillation loop models are respectively constructed to obtain an analytical relationship between a common mode current oscillation frequency and an insulation capacitance; a variational mode decomposition algorithm is adopted to separate multi-frequency oscillation characteristics in the common mode current, and high-frequency and medium-frequency common mode oscillation frequencies are extracted; and through online monitoring of an oscillation frequency drift amount, the deterioration degree of phase terminal insulation and internal insulation to ground of the motor winding is evaluated in real time. The application realizes non-invasive online precise monitoring of early-stage insulation faults of the tobacco cut tobacco variable frequency motor, and effectively reduces the risk of unplanned shutdown of a cut tobacco production line.

The application discloses a resonator and a compact ultra-narrow-band high-temperature superconducting filter, which adopts SISO spiral structure and interdigital structure to form a dual composite left-right hand resonator in parallel, wherein the interdigital structure forms an open end of the resonator, the SISO spiral structure forms a closed end of the resonator, and the interdigital structure is composed of a plurality of mutually parallel interdigital branches; the interdigital structure is used for introducing a left-hand capacitor and increasing an equivalent capacitance of the resonator; a first end of the interdigital structure is directly connected with a microstrip line and spirals in a clockwise direction, spirals out in a counterclockwise direction along the microstrip line at a rotation center, bypasses the interdigital structure, is connected to a second end of the interdigital structure to form the SISO spiral structure; and the overall filter size can be greatly reduced, the insertion loss in a passband of the filter, the out-of-band suppression capability, the roll-off coefficient of a transition band are greatly improved, and the selectivity of the filter is enhanced.

The application discloses a common-mode electromagnetic interference modeling method, equipment, medium and product for a gallium nitride synchronous step-down converter, relates to the technical field of electromagnetic compatibility and power electronic modeling, and comprises the following steps: determining a common-mode conduction path, and then determining an EMI noise source; constructing an equivalent circuit of the gallium nitride synchronous step-down converter based on the EMI noise source; constructing a voltage-dependent nonlinear equivalent capacitance model of a switching device in the gallium nitride synchronous step-down converter, and further constructing an analytical model of the gallium nitride synchronous step-down converter; determining simulation data of the analytical model; constructing a unified composite excitation source based on the simulation data by using the superposition principle; replacing the EMI noise source in the equivalent circuit with the unified composite excitation source to obtain a unified CM-EMI model, and then obtaining a final common-mode electromagnetic interference model. The application can improve the prediction accuracy of high-frequency resonance.

This invention belongs to the technical field of electromagnetic emission systems based on electric sources, specifically an electromagnetic emission system based on an adaptive resonant matching structure. The system includes: an adaptive resonant matching structure connected in series with a current source, the adaptive resonant matching structure including an adaptive resonant matching unit, and the adaptive resonant matching unit including an inductor L. C and resistance r L After being connected in series, it is connected in parallel with capacitor C, and in the inductor L C and resistance r L The first switch is set on the branch in series, and in the inductor L C and resistance r L After being connected in series with capacitor C, a second switch is set up. By changing the frequency of the first switch, the overall equivalent capacitance of the adaptive resonant matching unit is reduced. The transmitting system of this invention, employing an adaptive resonant matching structure, can adjust the equivalent capacitance within a certain range to adapt to the corresponding current input frequency.

The invention discloses a power supply circuit fault diagnosis and analysis system based on frequency domain feature extraction, and relates to the field of power supply circuit fault diagnosis. The method comprises the following steps: acquiring output voltage and output current time domain signals in a power supply circuit operation state, and obtaining a switching frequency; short-time test disturbance is injected by superposing a test modulation signal in a switch driving signal, and a power supply circuit generates corresponding frequency domain response under the condition that steady-state power supply of a power supply is not changed; performing frequency domain transformation on the acquired signal, extracting a voltage amplitude, a current amplitude and a phase difference at a test disturbance frequency, and calculating an equivalent series resistance and an equivalent capacitance based on a preset capacitor series impedance model; and determining the capacitance degradation degree according to the variable quantity of the parameter relative to the reference parameter, and outputting a fault diagnosis result. According to the invention, online measurement of capacitance parameters can be realized in the normal operation process of the power supply, the reliability of parameter identification is improved, and support is provided for maintenance of a power supply system.

The application relates to a relay sticking detection method and device, a battery management system and a battery equipment. When a first relay and a second relay are triggered to be turned off, and the switching actions of a first insulation detection circuit and a second insulation detection circuit are controlled, if it is detected that a sampling voltage suddenly changes following the switching actions, it is considered that the second relay is actually turned off. If it is detected that the sampling voltage does not suddenly change following the switching actions, the detection result of whether the second relay sticks is determined by further combining the sampling voltage and a preset voltage range. According to the above scheme, the sampling voltage suddenly changes and jumps out of the preset voltage range when the second relay does not stick, by controlling the switching actions of the first insulation detection circuit and the second insulation detection circuit. The phenomenon that the second relay sticks is falsely reported due to the fact that the equivalent capacitance of a load connected to a load end of the relay is not completely discharged, and the discharge voltage is obtained by the second sampling circuit voltage division.

The application relates to the field of digital-to-analog converter design, in particular to a VCM type lower plate sampling CDAC circuit and a switching circuit thereof, a first capacitor array, a second capacitor array, a first switch group, a second switch group and a comparator; wherein the first switch group and the second switch group adopt time sequence controlled multi-selection switches, have natural advantages of reducing the risk of short circuit and glitch of a reference end; unified switch matrix and complementary control are easier to realize injection offset and equivalent capacitor balance, reduce voltage disturbance return to the VCM / VREF during switching of the lower plate, and improve the linearity of the circuit.

The invention relates to the technical field of fault discrimination, and discloses a cosine similarity-based single-phase earth fault line selection method, system and device and a medium, and the method comprises the steps: obtaining real-time signals of zero-sequence current and voltage of a bus; comparing the rated voltage of the bus with the real-time voltage, and judging whether fault line selection is started or not; if so, sampling to obtain zero-sequence current and bus zero-sequence voltage of each line in the first period after the fault; calculating a cosine similarity coefficient of each line; constructing a main criterion, and distinguishing a faulty line and a non-faulty line; and if the cosine similarity coefficient does not conform to the main criterion, constructing an auxiliary criterion, and determining a fault line. The difference between the polarity of the zero-sequence current and the derivative of the zero-sequence voltage is measured through a cosine similarity comparison method, and an equivalent capacitance value does not need to be determined; according to the method, the comprehensive detection criterion based on the synergistic effect of the main criterion and the auxiliary criterion is constructed, the simplification error of the line model is considered, the reliability is high when the high-resistance grounding fault occurs, and the zero-sequence current does not need to be filtered.

When a current flowing in a series circuit including an equivalent resistance, an equivalent inductor, and an equivalent capacitance in an electric equivalent circuit of a specific resonator in each filter is defined as an acoustic path current, under conditions that a phase of an acoustic path current of a first transmission filter at a side of a common terminal at a frequency within a first pass band is represented as θ1Tx1, a phase of an acoustic path current of the first transmission filter at the side of the common terminal at a frequency within a second pass band is represented as θ2Tx1, a phase of an acoustic path current of a second transmission filter at the side of the common terminal at a frequency within the first pass band is represented as θ1Tx2, and a phase of an acoustic path current of the second transmission filter at the side of the common terminal at a frequency within the second pass band is represented as θ2Tx2, a multiplexer satisfies a first condition: |(2·θ1Tx1−θ2Tx1)−(2·θ1Tx2−θ2Tx2)|=180°±90°, or a second condition: |(2·θ2Tx1−θ1Tx1)−(2·θ2Tx2−θ1Tx2)|=180°±90°.

The invention particularly relates to a semi-solid lithium battery safety test method, which relates to the technical field of lithium battery safety test, and comprises the following steps: acquiring sufficient baseline capacitance data in a standard environment and a battery state matched with the test, calculating a capacitance average value and a standard deviation, and storing qualified baseline parameters after validity verification is completed. According to the invention, an integrated high-frequency test circuit of a main loop, a signal injection branch and a signal acquisition branch is adopted, and orthogonal demodulation and real-time equivalent capacitance calculation are matched, so that the measurement precision and in-situ characterization capability of a lithium battery safety test are remarkably improved; dC components are isolated through AC coupling, wiring is shielded, electromagnetic interference is suppressed, the problem that high-frequency signals are interfered by charging and discharging DC and environmental noise in a traditional test is solved, microstructure changes such as the internal polar distance of a battery cell, the dielectric state of electrolyte and interface contact can be captured in real time by means of optimal frequency band injection and high-speed acquisition demodulation, and the test accuracy is improved. The defect that only macroparameters such as voltage, temperature and external force can be monitored in a traditional test is overcome.