97 results about "Impedance network" patented technology

The invention discloses a stability analysis method of a network tracking / constructing hybrid station based on an impedance model, and relates to a modeling and stability evaluation technology of a wind power plant grid-connected system. The method comprises the following steps: firstly, respectively establishing sequence impedance models of a following network type direct-driven fan and a construction network type direct-driven fan based on a harmonic linearization method, and verifying the accuracy of the established models in different frequency bands by combining an impedance sweep frequency method; secondly, on the basis of considering the influence of line impedance, deducing to form an impedance network structure of a hybrid wind power plant grid-connected system, and constructing a stability judgment condition suitable for system analysis; and finally, based on the established impedance stability criterion, identifying possible oscillation risks of the system in subsynchronous and supersynchronous frequency bands. The method is suitable for wind power system stability analysis in various hybrid access scenes, and provides theoretical basis and technical support for subsequent system parameter setting, control strategy optimization and oscillation suppression measures.

The invention discloses an electrical safety test data analysis method and system for an electrical cabinet, and relates to the technical field of electrical measurement and test. The method is used for solving the problems of single test dimension, poor anti-interference capability and inaccurate fault positioning in the safety test of the electrical cabinet. Firstly, multi-channel electrical parameter synchronous acquisition is triggered based on a working condition event, real discharge and interference signals are distinguished through time-frequency analysis, and a time sequence incidence matrix of discharge pulses and load currents is established; then, analyzing phase distribution characteristics of partial discharge, calculating a correlation coefficient between a discharge repetition rate and a load current, and dynamically adjusting a weight to generate an insulation state comprehensive test index; further, insulation degradation characteristics are extracted through signal decomposition, and an insulation degradation trend and a fault probability are predicted in combination with energy entropy analysis and discharge mode recognition; and finally, the position of a fault component is analyzed and positioned based on the impedance network, and a maintenance priority sequence is generated according to the fault probability and the degradation rate.

The invention discloses an energy storage power station oscillation risk monitoring method and device based on impedance network aggregation, and belongs to the field of power systems, and the method comprises the steps: obtaining impedance information and a first network topology structure of each device in an energy storage power station; obtaining a first impedance network framework by adopting a hierarchical calculation method; based on the framework and the impedance information, an impedance network aggregation method is adopted to calculate impedance characteristics of all frequency points to form full-frequency-domain impedance characteristics, and the oscillation risk of the energy storage power station is monitored according to the full-frequency-domain impedance characteristics and actual impedance data. The problem that it is difficult to accurately monitor the oscillation risk of the energy storage power station while guaranteeing the calculation efficiency in the prior art can be solved.

The invention relates to the technical field of power systems, and discloses a multi-level direct current sending end small disturbance stability assessment method, device and equipment and a medium. Carrying out frequency domain impedance modeling on the following network type new energy converter, the constructed network type energy storage converter, the following network type load converter and the modularized multi-level high-voltage direct current converter station, and constructing a frequency domain impedance network of the all-electric system based on an equivalent impedance model of each device; and performing small disturbance stability analysis on the frequency domain impedance network by using a generalized Nyquist stability criterion, and determining the small disturbance stability of the all-electric system in an alternating current and direct current hybrid scene through a Nyquist diagram of impedance ratios of two sides of a voltage source and a current source in the frequency domain impedance network. Therefore, an effective evaluation means is provided for stable operation of the alternating-current and direct-current series-parallel all-electric system.

The invention relates to an incremental learning CNN-Attention-based broadband impedance on-line identification method for a network construction type wind power plant, and belongs to the technical field of new energy grid connection, and the method comprises the following steps: S1, building a parallel collection type offshore wind power plant multi-machine dynamic equivalent model; s2, collecting and preprocessing parameters based on a multi-machine equivalent model of the network-building type wind power plant; s3, a CNN-Attention model is constructed and trained; s4, constructing an equivalent impedance model of the current collection submarine cable line between the wind turbine generators; s5, on the basis of the actual topology of the network construction type wind power plant station, connecting the broadband impedance models of the wind turbine generator and the current collection circuit into a frequency domain impedance network, and calculating the impedance characteristics of the current collection port of the multi-machine equivalent wind power plant; s6, a CNN-Attention model containing an incremental learning updating mechanism is constructed; and S7, performing broadband impedance on-line identification on the network construction type wind power plant.

An assembly of electronic components for reception of data using an optical fibre wherein said assembly comprises: a photodiode; a first amplifier coupled to said photodiode; a second amplifier, whose electrical behaviour is substantially identical to an electrical behaviour of said first amplifier; an impedance network comprising at least two electronic components coupled between an input of said second amplifier and a reference terminal, wherein those at least two electronic components comprise at least two impedance elements, one impedance element being capacitive and another being resistive or inductive, and wherein said at least two electronic components are adjustable under electronic control to adjust the impedance presented by said impedance network; and circuitry for creating a signal formed from a subtraction of outputs of the first and second amplifiers.

The invention discloses a power station arc discharge data acquisition control method, which comprises the following steps of: after equipment is electrified, carrying out equipment self-inspection to ensure that each piece of equipment in a system can operate normally and the equipment is accurately positioned when the equipment is abnormal, and ensuring that the abnormal equipment is quickly positioned and repaired; by automatically matching an actual data acquisition scene according to the current environment, the data acquisition efficiency and accuracy are improved, meanwhile, in order to protect equipment, a time interval is increased when an impedance network is set, and due to the increase of the time, secondary scene information checking is added for the accuracy of an arc discharge data scene label, so that the accuracy of the arc discharge data scene label is improved. Data is matched with scene information as much as possible; scene configuration information is obtained in real time before execution each time, and the scene configuration information is synchronously updated to a scene configuration file after data acquisition is completed; it is ensured that data cannot be collected repeatedly when execution is started next time if the data collection is abnormal midway or manually interrupted, errors possibly caused by manual intervention are reduced, and the use threshold of a control system is lowered.

To provide a flicker value calculation and power supply harmonic analysis device capable of estimating flicker values and power supply harmonic analysis results compliant with required standards while being connected to a commercial power supply.SOLUTION: A processor is configured to store a measured voltage and measured waveform thereof in a memory, extract voltage and current waveforms within a predetermined time range from the measured voltage and measured waveform thereof stored in the memory, perform a standard-compliant power supply harmonic calculation current conversion for converting the extracted voltage and current waveforms into voltage and current waveforms when connected to a power supply compliant with predetermined standards, analyze the power supply harmonic current from the converted current waveform, perform a standard-compliant flicker value calculation voltage conversion for converting the extracted voltage and current waveforms into voltage and current waveforms when connected to a power supply compliant with predetermined standards and a reference impedance network, calculate a flicker value from the converted voltage waveform, and output results of the power supply harmonic analysis and the calculated flicker value to an output interface.SELECTED DRAWING: Figure 1

The application discloses a charged water body equivalent impedance model construction and parameter acquisition method and related devices, and innovatively establishes a calculation system containing resistance and inductance correction factors, and realizes high-precision characterization of water body impedance characteristics by introducing an electrode spacing function. Specifically, a scalable grid technology is used to construct an adaptive calculation framework, and the calculation accuracy of resistance and inductance parameters is significantly improved through a power function correction algorithm. A reliable numerical calculation is provided for water body impedance network model analysis in complex hydrological environments. The application solves the problems of the prior art, such as complex modeling process, difficulty in accurately describing nonlinear behavior, insufficient precision, and inability to accurately capture the real behavior of water body.

The application discloses a power converter, a power supply system, a control method and related devices. The power converter comprises an impedance network and a three-phase power conversion circuit, each phase of the three-phase power conversion circuit comprising a four-switch Buck-Boost circuit; the DC side of the three-phase power conversion circuit is used for connecting a DC source, and the AC side of the three-phase power conversion circuit is used for connecting a load or a power grid; wherein the load adopts star connection, and the power grid adopts star connection; the first end of the impedance network is connected to the positive pole of the DC side of the three-phase power conversion circuit, and the second end of the impedance network is used for connecting the neutral point of the load or the neutral point of the power grid. In the embodiment of the application, in the case that the power converter is switched from three-phase three-wire system to three-phase four-wire system, the impedance network is connected between the N line (the DC side of the three-phase power conversion circuit and the neutral point of the load or the neutral point of the power grid), the inrush current on the N line is reduced, and the risk of damage of the switching device in the power converter is reduced.

The invention belongs to the technical field of integrated circuit design, and particularly discloses a low-delay sampler structure and method for high-speed data processing, and in a pseudo reset stage, an unlocking network module and a pre-latching network module are connected in parallel to form an equivalent low-impedance network unit; the transconductance module is used for inputting a sampling signal and a reference level signal and driving the equivalent low-impedance network unit; the pre-latch network module is used for enabling an output node of the pre-latch network module to start charging and discharging according to a sampling signal and a reference level signal and pre-sampling the sampling signal; meanwhile, in the latching stage, the transconductance module is used for driving the pre-latching network module to preliminarily amplify the sampling signal, and the strong latching network module is used for stably latching the sampling signal under the driving of the pre-latching network module. According to the invention, the sampling delay of the signal is obviously shortened, and meanwhile, the requirement of high-speed data processing on the time sequence progress is met.

The invention provides a high-stability control method for a power grid simulator, and the method comprises the steps: embedding a virtual impedance feature Zvirref (s) in an integral controller of a voltage controller module, and forming a controller structure of Ki * Zvirref (s) / s; and dynamically adjusting the integral gain Ki according to the virtual impedance generated by the power grid simulator and the physical impedance provided by the impedance network B so as to meet the condition that the amplitude of the virtual impedance is not higher than the amplitude of the physical impedance in the frequency range in which the virtual impedance is presented to be non-passive. Decoupling between internal control dynamic and virtual impedance characteristics of the power grid simulator is realized, and the self-stability of the power grid simulator under different impedance simulation conditions is ensured; the self-adaptive adjustment of the closed-loop transfer function of the power grid simulator is realized, the virtual impedance and the physical impedance are ensured to meet the Nyquist stability criterion, and the interaction stability between the power grid simulator and the tested object is improved.

An oscillator includes first and second comparators, a first impedance network having a first trim element therein, and a second impedance network having a second trim element therein. The first impedance network is electrically connected to a first input terminal of the first comparator, and the second impedance network is electrically connected to a first input terminal of the second comparator. The first and second impedance networks are configured to cause an improvement in common mode variation within the first and second comparators, in response to trimming of at least one of the first and second trim elements.

The present application relates to the technical field of probe card signal optimization, in particular to a high-frequency probe card signal optimization method based on dynamic impedance matching and related devices. The method steps include: obtaining real-time high-frequency signal reflection parameters of the probe card test channel to provide real-time detection basis for dynamic impedance matching. The present application relies on the real-time acquisition of the high-frequency signal reflection parameters of the probe card test channel to complete the quantitative tracing of the dynamic impedance deviation, and through the closed-loop feedback adjustment, the integrated adjustable impedance network of the driving probe is used to complete the real-time correction of the output impedance. From the root level of transmission line impedance matching, the present application breaks through the inherent limitation of the traditional static matching scheme which can only adapt to the nominal working condition, and can effectively offset the dynamic impedance mismatch introduced by the contact state difference, the probe structure micro-deformation, the device individual parasitic parameter dispersion and the nonlinear evolution of the parasitic parameters under high frequency in the actual test process, and solves the reflection residual problem that cannot be eliminated by static matching.

The application belongs to the technical field of wireless communication, and discloses a backscattering communication method, device and system based on multi-carrier differential modulation t The transmission vector at t-1 time is expanded into a symmetric and full-rank subcarrier block transmission matrix, the transmission vector u t is subjected to rectangular differential modulation to obtain the transmission vector at t time, and then is converted into a time-domain data frame and mapped into a reflection coefficient; and the excitation source signal is modulated by means of an impedance network to generate a backscattering signal. Since differential modulation transmits information based on the difference between adjacent symbols, the channel state information is cancelled in the process of data detection at the receiving end, and the original sending data can be recovered by non-coherent detection of the receiving signal at the receiving end, without a complex cascaded channel estimation process, so that the complexity of the multi-carrier backscattering communication system is effectively reduced.

The invention relates to a neutral electrode heat effect test system, a temperature rise characteristic test method and a cooling characteristic test method. The neutral electrode heat effect test system comprises an upper computer for generating a test configuration instruction; the central control module is connected with the upper computer and interacts data; each electronic skin module comprises a skin contact surface, a human body skin impedance network capable of simulating skin impedance of different crowds, a temperature measurement feedback device for collecting temperature and a heating device; the high-frequency variable-frequency constant-current source module outputs high-frequency constant current to enable the neutral electrode and the impedance network to generate heat; the central control module receives the temperature parameters and / or the constant current output parameters and uploads the temperature parameters and / or the constant current output parameters to the upper computer. According to the invention, the heat effect test of the neutral electrode can be effectively realized.

The invention relates to the technical field of bioelectrical impedance testers, in particular to a calibration device of a bioelectrical impedance tester and a calibration method thereof. According to the technical scheme, the calibration device of the bioelectrical impedance tester is connected with a host of the bioelectrical impedance tester through a communication interface and a calibration port, and comprises a main control unit used for communicating with the host of the tester and analyzing an instruction from the host; the control end of the high-speed multiplexer is connected with the main control unit, and the output end of the high-speed multiplexer is connected to the calibration port; the standard impedance network is composed of a plurality of high-precision passive elements and comprises resistors, capacitors, inductors and series-parallel combinations of the resistors, the capacitors and the inductors, and the impedance elements are connected to different input channels of the high-speed multiplexer respectively. Through a highly integrated standard impedance network and an automatic switching mechanism, full automation of a calibration process is realized, manual errors are thoroughly eliminated, and calibration efficiency and consistency are greatly improved.

The present disclosure relates to a digital-to-analog converter comprising an impedance network and a transfer function modification circuit. The transfer function modification circuit comprises a DAC and a demultiplexer. The demultiplexer may be used to selectively connect the output of the DAC to different respective nodes of the impedance network, allowing positive or negative currents to be injected into the node and modify the transfer function. By using a demultiplexer to selectively couple to different nodes, the node into which the current is injected may be modified post-manufacture, allowing transfer function modification.

The invention discloses a test platform for simulating photovoltaic direct-current fault arc waveforms. The test platform comprises a simulation optical direct-current fault arc waveform test platform cabinet, a simulation photovoltaic direct-current power supply cabinet, a decoupling device cabinet, an impedance network cabinet, a simulation arc cabinet, a product test cabinet and a photovoltaic power supply inverter cabinet. The test platform simulates a photovoltaic direct current power supply, a decoupling and impedance network and a fault arc; an industrial personal computer system is used for automatically capturing signals for testing, and fault arc waveform signals are restored in real time; multi-point automatic measurement acquisition, analysis and comparison are carried out on test signals; multiple key parameters related to the fault arc are displayed in real time based on a touch screen, and finally a test conclusion, a specific numerical value of response time, a judgment basis and all waveforms and analysis data are integrated into a final test report to be output. According to the invention, a traditional oscilloscope can be replaced to observe waveforms, and high-precision performance testing of photovoltaic protection products can be realized in all directions.

The application belongs to the technical field of audio power amplifier filtering, and particularly relates to a band-pass filter circuit for eliminating radio frequency interference of an audio power amplifier. The band-pass filter circuit comprises an operational amplifier AMP, a reference voltage BYP connected to a non-inverting input terminal of the operational amplifier AMP, an input impedance network connected between an audio input terminal IN grounded and an inverting input terminal of the operational amplifier AMP, and a feedback impedance network connected between an output terminal and the inverting input terminal of the operational amplifier AMP. The feedback impedance network is composed of two parallel feedback branches. A first feedback branch is composed of a resistor R2, and a second feedback branch is composed of a resistor R3 and a capacitor C2 connected in series. A zero point is introduced in a transfer function of the band-pass filter circuit, and a zero point frequency is determined by a resistance value of the resistor R3 and a capacitance value of the capacitor C2, so as to suppress a gain near the zero point frequency, thereby effectively suppressing interference of high-frequency noise.

This invention relates to the field of bioelectrical impedance analysis (BIA) technology, and more particularly to a calibration device and method for a BIA. The technical solution is as follows: A calibration device for a BIA, the device being connected to a BIA host via a communication interface and a calibration port. The device includes: a main control unit for communicating with the host and parsing instructions from the host; a high-speed multiplexer, the control terminal of which is connected to the main control unit, and the output terminal connected to the calibration port; and a standard impedance network composed of multiple high-precision passive components, including resistors, capacitors, inductors, and their series-parallel combinations, wherein each impedance component is connected to a different input channel of the high-speed multiplexer. Through a highly integrated standard impedance network and an automatic switching mechanism, the calibration process is fully automated, completely eliminating human error and greatly improving calibration efficiency and consistency.

The invention discloses a charged water body equivalent impedance model construction and parameter acquisition method and a related device, innovatively establishes a calculation system containing resistance and inductance correction factors, and realizes high-precision characterization of water body impedance characteristics by introducing an electrode spacing function. Specifically, a scalable grid technology is adopted to construct an adaptive calculation framework, and the calculation precision of resistance and inductance parameters is remarkably improved through a power function correction algorithm. And reliable numerical calculation is provided for water body impedance network model analysis in a complex hydrological environment. The method solves the problems that in the prior art, the modeling process is complex, nonlinear behaviors are difficult to describe accurately, the precision is not high enough, and the real behaviors of the water body cannot be captured accurately.

The present application relates to the technical field of power system, discloses a kind of multi-level DC sending end small signal stability evaluation method, device, equipment and medium, the present application considers the coupling influence between different heterogeneous devices, to network type new energy converter, network type energy storage converter, network type load converter and modular multi-level high voltage direct current converter station are carried out frequency domain impedance modeling, and based on the equivalent impedance model of each device, the frequency domain impedance network of all-electric system is constructed, the small signal stability of frequency domain impedance network is analyzed using generalized Nyquist stability criterion, the Nyquist diagram of impedance ratio on the two sides of voltage source and current source in frequency domain impedance network is determined The small signal stability of all-electric system under AC / DC hybrid scene, so as to provide an effective evaluation means for the stable operation of AC / DC hybrid all-electric system.

The invention provides a method for predicting viscoelastic particle flooding pore scale pressure conduction, and the method comprises the steps: S1, obtaining a target region rock core to construct a digital rock core, and constructing an impedance network; s2, performing grid division on the pore space of the digital core, and calculating the flowing process of fluid; s3, calculating throat impedance according to the relationship between the pore network and the pore throat and the speed of the fluid; s4, constructing a pressure transmission network mathematical model according to the impedance network; and S5, determining a pressure conduction characteristic and a flow distribution rule according to the pressure transmission network mathematical model. Rapid calculation of network pressure and channel flow is achieved, and efficient prediction of the viscoelastic particle flooding pore scale pressure conduction process and flow distribution is completed.

The invention discloses a Z-source inverter circuit, a circuit board, a controller and an air conditioner, and the Z-source inverter circuit comprises a first magnetic integrated inductor, a second magnetic integrated inductor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a first IPM module and a second IPM module. A first magnetic integrated inductor formed by winding a first inductor winding wire and a second inductor winding wire on a first magnetic core at the same time is connected with a first capacitor and a second capacitor respectively to form a first X-type impedance network; and a second magnetic integrated inductor formed by winding a third inductor winding wire and a fourth inductor winding wire on a second magnetic core at the same time is respectively connected with a third capacitor and a fourth capacitor to form a second X-type impedance network, so that two paths of positive and negative inductors can be integrated together under the condition of ensuring the power supply efficiency of two paths of parallel loads of the Z-source inverter; therefore, the number of circuit elements is reduced, the space is saved, the cost is reduced, the influence of electromagnetic coupling between inductors is reduced, and the EMI problem of an electric control system is solved.

The application discloses an inverter stability optimization control method based on PLL link parameter adjustment. Firstly, the inverter, grid impedance network and the like are introduced into a phase-locked loop in the form of coupled interference of port characteristics, and a synchronous dynamic mathematical expression of the phase-locked loop and the coupled interference is established; secondly, according to the coupling relationship of the PLL in the system, a dynamic control equation of the inverter is determined. Then, based on the PLL dominant loop, the system stability is determined through the phase margin of the equation at the crossing frequency; finally, by adding a transfer function H(s) in series in the PLL to change the loop characteristics of the PLL, parameter design is carried out for the control optimization method of the PLL in different control modes; the application can clearly reveal the dynamic coupling between different frequencies in the phase sequence, can more intuitively study the admittance characteristics of the grid-connected inverter based on the PLL structure, and further proposes an optimization control method of the phase-locked loop to improve the stability of the PLL synchronization control under the condition of a weak grid.

Hybrid lattice filters with acoustic baluns are disclosed. In one aspect, a hybrid lattice filter may be formed using acoustic elements. The hybrid lattice filter may operate with acoustic baluns such as coupled resonator filters (CRF) or stacked crystal filters (SCF). To achieve the desired common mode rejection, an additional rejection or low common mode intermediate impedance network may be supplied between the acoustic balun and the hybrid lattice filter. By combining the acoustic balun with the low common-mode intermediate impedance network and the hybrid lattice filter, a passband filter with a desired bandwidth may be created.

The present application relates to a kind of neutral electrode thermal effect test system, temperature rise characteristic test method and cooling characteristic test method.The neutral electrode thermal effect test system includes: host computer, generates test configuration instruction;Central control module, connect host computer and interact data;Multiple electronic skin modules, contain skin contact surface, the human body skin impedance network for simulating the skin impedance of different population, temperature measuring feedback device for temperature acquisition and heating device;High-frequency variable-frequency constant-current source module, output high-frequency constant current makes neutral electrode and impedance network heat production;Central control module receives temperature parameter and / or constant-current output parameter and uploads host computer.The present application can effectively realize the thermal effect test of neutral electrode.

The invention discloses a network construction type PCS test power supply, which comprises an impedance network superposition module and a main power distribution module, and is characterized in that the impedance network superposition module comprises a waveform injection unit, and the main power distribution module comprises a circuit breaker and a plurality of contactors; each phase of the power grid or the power grid simulator is connected with each phase of the grid-forming type energy storage converter through a circuit breaker and a plurality of contactors in sequence, and each phase of one contactor is connected with a waveform injection unit in parallel; by controlling the start and stop of the waveform injection units connected with each phase and outputting voltages with different frequencies and amplitudes, the harmonic wave, oscillation and impedance change conditions of each phase of a power grid are simulated, and the grid-forming type energy storage converter is tested. The method has the advantages that accurate simulation of power grid characteristics and flexible adaptation to different test scenes are realized.

The invention relates to the technical field of electromagnetic interference filtering, in particular to a transient impact influence power electronic device prediction model based on broadband modeling. The system comprises a parameter analysis module, a platform building module, an equivalent model module, a voltage derivation module and a prediction verification module. The high-frequency parasitic inductance of an input wire and the ground parasitic capacitance of the converter are accurately measured through the parameter analysis module, the platform building module builds a DC / DC converter test platform based on a linear impedance network, and the equivalent model module builds an equivalent transient impact behavior model based on the substitution theorem. The voltage derivation module determines a voltage relation between the voltage at the two ends of the MOSFET and the transient impact signal, the prediction verification module predicts the signal of the voltage at the two ends of the MOSFET, the harmonic amplitude of the transient impact signal is obtained, and the accuracy and reliability of the model in the broadband range are ensured.