1802 results about "Harmonics" patented technology

The invention discloses a data anomaly detection system and method based on power equipment, and belongs to the technical field of power system data processing and fault monitoring, and the method comprises the steps: obtaining a multi-dimensional operation parameter sequence of voltage, current, temperature, harmonic waves, switching states, topological energy transfer vectors and the like; constructing a local disturbance response map, extracting a micro-disturbance driving factor, and generating a high-dimensional feature embedding matrix; constructing a multi-scale state density map on the basis of the embedded matrix, and mapping an equipment behavior evolution track; introducing a coupling evolution path tracking algorithm based on the density map, identifying an abnormal state set, and constructing a cross-time-period risk channel; matching the current monitoring data with the risk channel, and calculating a risk evolution value; when the value exceeds a set threshold value, abnormal early warning is triggered, and an evolution path model is output; the method has the advantages of high accuracy, strong trend identification capability and early warning, and is suitable for intelligent operation and maintenance of power equipment under complex working conditions.

The invention relates to the technical field of power system monitoring and fault diagnosis, and particularly discloses a fault diagnosis system of an electrical variable measurement insulator detection device. The system comprises a synchronous acquisition module, a multi-physical field feature extraction module, a self-adaptive fault diagnosis engine and a feedback module. By synchronously acquiring voltage harmonic waves, leakage current and temperature data, extracting feature vectors of coupling electric-thermal influence and performing two-stage collaborative diagnosis by using a dynamic threshold value and a mahalanobis distance, high-sensitivity and self-adaptive accurate identification and early warning of an early latent fault of the insulator are realized. According to the system, by constructing a synchronous data acquisition module and a multi-physical field feature extraction module, two key influence factors, namely an operation voltage harmonic component and an environment temperature, are brought into a diagnosis system in a quantifiable feature form for the first time.

The invention belongs to the technical field of fault early warning, and discloses a heater fault early warning method and system based on current analysis. Comprising the steps that transient current signals of all heating wire loops in the copper bush heater are collected in real time, harmonic characteristic parameters are extracted, and a dynamic current fingerprint database and a multi-dimensional harmonic characteristic spectrum are generated respectively; dynamically calculating the contact impedance between each heating wire and the copper sleeve groove according to the dynamic current fingerprint database and the multi-dimensional harmonic characteristic spectrum; the current distribution path of each heating wire in the copper sleeve groove is restored in real time, the abnormal contact form of each heating wire is identified, the falling risk probability and falling risk strength of each heating wire are dynamically predicted by fusing the falling precursor signals of each heating wire detected in real time, and a grading early warning strategy report is generated in real time; according to the invention, fault early warning can be converted into preventive maintenance from post-maintenance, the intelligent level of operation and maintenance of the heater is improved, and the continuity and safety of production are guaranteed.

The invention relates to the technical field of power electronics and power supply and distribution, and discloses a data center AC / DC power distribution system input and output voltage and current monitoring method, which comprises the following steps: deploying an intelligent sensing unit with edge computing capability at each monitoring node, sampling according to a basic frequency, and extracting effective values, harmonic distortion rates, differential change rates and other characteristics of voltage and current in real time; judging that the system is in a steady state, a quasi transient state or a strong transient state according to the multi-stage dynamic threshold value, and respectively executing feature abstract uploading, local high-frequency backtracking or collaborative full-waveform synchronous acquisition; and the central server classifies and stores the data, constructs a state evolution model, and dynamically optimizes threshold parameters. The system comprises an intelligent sensing unit, a central monitoring server and an industrial Ethernet link. According to the method, the steady-state data transmission quantity is remarkably reduced, transient details are completely captured, and adaptive adjustment of the monitoring sensitivity is realized.

The invention belongs to the field of stability analysis of a grid-connected system of a grid-building converter, and particularly relates to a grid-building converter grid-connected resonance risk analysis method considering virtual impedance, which comprises the following steps: S1, establishing a three-phase time domain differential equation and simplifying the equation into a single-phase equivalent time domain model; converting into a harmonic state space model of the main circuit; s2, constructing a harmonic state space model of a control system comprising an active power control loop and a reactive power control loop; s3, introducing a virtual impedance control link, and correcting the voltage amplitude reference phasor output by the reactive power control loop; deriving an expression of a modulation signal disturbance phasor; s4, obtaining a complete frequency domain admittance model YGSC of the network construction converter considering the influence of the virtual impedance; an open loop gain TGFM of the grid converter grid-connected system is constructed; and S5, drawing a Nyquist curve based on TGFM, and carrying out resonance risk determination. According to the method, the interaction dynamic characteristics of the network building converter and the power grid under the influence of the virtual impedance can be accurately represented, and the resonance risk of the grid-connected system is evaluated.

The embodiment of the invention discloses a collaborative optimization method and device for the power quality of a high-permeability transformer area. The method comprises the following steps: acquiring three-phase voltage, three-phase current and environment temperature data; the voltage deviation, the three-phase unbalance degree, the total harmonic distortion rate and the reactive vacancy of the high-permeability transformer area are calculated based on the three-phase voltage and the three-phase current; taking voltage deviation as a primary optimization target, considering optimization of three-phase unbalance degree, total harmonic distortion rate and reactive vacancy, constructing a multi-target optimization function, and carrying out dynamic constraint on an optimization process based on environment temperature data; solving the multi-objective optimization function by adopting an optimization algorithm to obtain a group of optimal decision variables, and converting the decision variables into corresponding control instruction sets; and the control instruction set is issued to the on-load voltage regulating transformer, the reactive compensation equipment and the power electronic compensation module for execution. Therefore, the problems of voltage out-of-limit, harmonic pollution and imbalance are effectively solved through a multi-target cooperation and temperature self-adaption mechanism.

The invention relates to the technical field of intelligent power distribution control, and discloses an intelligent power distribution box control system based on the Internet of Things. The system comprises a power distribution parameter acquisition unit, a multi-dimensional electrical characteristic space construction unit, an overload risk simulation unit, a parameter dynamic optimization unit and a control instruction generation unit. The power distribution parameter acquisition unit acquires voltage waveform, current harmonic distribution, temperature distribution and the like in real time; the multi-dimensional electrical feature space construction unit classifies the parameters after preprocessing the parameters, extracts time-frequency domain features and fuses the time-frequency domain features into a multi-dimensional electrical feature space; the overload risk simulation unit marks an abnormal load interval, and matches historical and current features to generate a device degradation feature subset; the parameter dynamic optimization unit corrects the subset, simulates an overload risk diffusion path and outputs a feedback instruction; the control instruction generation unit generates an adjustment strategy and sends the adjustment strategy to the execution mechanism. According to the system, comprehensive perception and intelligent regulation and control of the power distribution operation state are realized, and the operation stability and adaptability of the power distribution box are improved.

The invention relates to the technical field of maglev motor dynamics and control, and discloses a bearingless asynchronous motor multi-frequency harmonic vibration cooperative suppression method, which comprises the following steps: acquiring radial displacement signals and mechanical angular velocity of a rotor in an x axis and a y axis under a stator fixed coordinate system, and stacking double-axis displacement signals into an observation vector; calculating a weighting coefficient of the normalized residual error through a Huber robust cost function, and outputting the amplitude, the phase and the confidence of each order of harmonic wave; estimating the total disturbance of the system by using a linear extended state observer with harmonic energy injection, wherein the total disturbance is obtained by weighted summation according to the confidence, order and mechanical angular velocity of each order of harmonic; calculating a feedback control force according to the total disturbance estimated value, and superposing the feedforward compensation force and the feedback control force to generate a total suspension force instruction; and according to the total suspension force instruction, inversely calculating a suspension winding current reference value and outputting a control instruction. According to the invention, a mutually complementary cooperative suppression mechanism is formed, and the suppression precision of multi-frequency vibration is improved.

The invention relates to the technical field of motor fault diagnosis, and discloses a multi-degree-of-freedom resonant excitation motor dynamic vibration test system and a test method, the system injects a specific harmonic current into a motor through closed-loop control and calculation and a high-bandwidth harmonic injection driver, so that the actual vibration of the tested motor tracks a preset target vibration profile in real time. In the testing process, the cross-spectral density of multi-point vibration signals is analyzed, and a transmission path and a collection area of vibration energy in a motor structure are calculated; and meanwhile, the electromagnetic impedance and the mechanical impedance of the motor are identified and decoupled on line by superposing a broadband disturbance signal in the driving current. In combination with energy flow analysis and an impedance decoupling result, the method can accurately position a vibration abnormal position, clearly causes whether a fault source is from mechanical structure characteristic change or electromagnetic part performance change from a physical level, and realizes deep and accurate diagnosis of the dynamic characteristics of the motor.

The invention relates to the technical field of electrical engineering and intelligent fault diagnosis, and discloses a water pump motor fault diagnosis method and system based on current harmonic characteristics, and the method comprises the steps: collecting stator current, rotating speed and load signals; generating an alpha-beta current component through Clark transformation, constructing an analytic signal, extracting an instantaneous phase, and calculating an instantaneous frequency; a mapping relation is established in combination with the rotating speed, and the current signals are resampled to eliminate frequency dispersion; obtaining a high-resolution harmonic energy distribution diagram by adopting multi-scale synchronous compression wavelet transform; and extracting an energy concentration ratio, a peak offset and a bandwidth expansion coefficient in the characteristic frequency band, inputting the energy concentration ratio, the peak offset and the bandwidth expansion coefficient into the pre-trained multi-layer perceptron classifier, and outputting a fault type. According to the method, through high-precision time-frequency focusing and multi-dimensional feature fusion, the fault recognition accuracy and robustness are remarkably improved, and online diagnosis of multiple typical faults can be achieved only through current signals.

A self-excitation motor disclosed by the present invention comprises a rotor, a first end of the rotor is equipped with a rectification circuit, the rotor comprises a rotor iron core and a plurality of harmonic windings and excitation windings, the rotor iron core is provided with rotor teeth, and each harmonic winding and each excitation winding are respectively wound on the corresponding rotor teeth. Each harmonic winding comprises a first harmonic winding and a second harmonic winding, the winding directions of the first harmonic winding and the second harmonic winding are the same, star connection is adopted, one ends of the first harmonic winding and the second harmonic winding are connected in series in a one-to-one mode, and the other ends of the first harmonic winding and the second harmonic winding are jointly connected to form a star neutral point; the other end of each second harmonic winding is connected with the midpoint of each bridge arm in the rectifying circuit in a one-to-one manner; the winding directions of the excitation windings on every two adjacent rotor teeth are opposite, and the two ends of each excitation winding are electrically connected with the direct current output end of the rectification circuit. This induces and rectifies the current for excitation more efficiently. The invention further provides a motor control strategy based on high-frequency harmonic current phase optimization.

The invention provides a hysteresis loop analysis method for a transformer no-load loss test, and belongs to the technical field of transformers. Exciting voltage and current signals are collected in a transformer no-load state, and an active filter is used for carrying out digital filtering processing to eliminate harmonic interference; a data corresponding relation between magnetic flux density and magnetic field intensity is established through a digital integration algorithm and a magnetic field intensity calculation formula to form original hysteresis data, the original hysteresis data is processed by using a hysteresis loop optimization model, a complete hysteresis loop curve is generated, and the hysteresis loop area is calculated. According to the hysteresis loop area, the hysteresis loss power density is calculated through the iron loss calculation function, the total value of the transformer no-load loss is obtained by combining the eddy current loss calculation result, and the technical problems that the hysteresis loop reconstruction precision is not high and the complex hysteresis phenomenon cannot be adapted in the transformer no-load loss test are solved.

The invention relates to the technical field of supervision control, in particular to a new energy storage optimization control method and system, and the method comprises the following steps: collecting a grid-connected point voltage amplitude deviation, a frequency deviation and a voltage total harmonic distortion rate, and generating a power grid stress index; according to the method, the multi-dimensional state vector is constructed by collecting the grid-connected point voltage amplitude deviation, the frequency deviation and the total harmonic distortion rate to generate the stress index reflecting the power grid operation pressure, accurate quantitative sensing of the power grid state is achieved, the power grid supporting gain coefficient is dynamically generated according to comparison of the index and the preset threshold value, and the power grid supporting effect is improved. And the total required power to be responded by the energy storage system is adjusted and determined, so that the power support strength is matched with the actual demand of the power grid, and insufficient response or excessive response is avoided.

The present application relates to the technical field of motors, and discloses a motor control method and apparatus based on harmonic injection, and a device and a storage medium. The method comprises: on the basis of a motor and noise of the motor, determining a specified-order harmonic wave needing to be injected; acquiring a rotational speed and torque of the motor, and determining a voltage magnitude and a phase angle of the specified-order harmonic wave corresponding to the rotational speed and the torque from a preset specified-order harmonic wave table; performing transformation processing on the voltage magnitude and the phase angle to obtain a target voltage value in a three-phase coordinate system; and superimposing the target voltage value onto a fundamental voltage to obtain a control voltage, wherein the control voltage is used for controlling the operating state of the motor. In the present application, torque harmonic waves generated by the driving of a motor are eliminated, thus significantly reducing the noise during the operation of the motor and a load system.

The invention relates to the technical field of logistics warehouse storage equipment, in particular to a speed reduction control method for a high-speed motor driven hydraulic system, which comprises the following steps: S1, the output torque of a high-speed motor is transmitted to a gear pump through a motor shaft, a planetary reducer and a planet carrier in sequence to drive the gear pump to work; s2, acquiring a three-phase current instantaneous signal and a direct current bus voltage signal, and performing preprocessing and frequency spectrum conversion to determine a current frequency spectrum; s3, in the current frequency spectrum, extracting an energy value in a preset frequency band with the meshing frequency and harmonic waves of the planetary gear as the center, and calculating to obtain a disturbance characterization value of the planetary gear; s4, determining a torque smooth adjustment coefficient according to the planet wheel disturbance characterization value; and S5, dynamically adjusting a dynamic response parameter of a torque control ring of the high-speed motor according to the torque smooth adjustment coefficient. The problems that in the prior art, a high-rotating-speed motor and a hydraulic pump are not matched in rotating speed, and mechanical disturbance is difficult to restrain are solved.

The invention discloses a low-harmonic high-voltage speed regulation system based on a multi-pulse phase-shifting transformer, and particularly relates to the field of power electronic technology and motor speed regulation, which is characterized in that the primary side of the multi-pulse phase-shifting transformer is in star connection, and N groups of windings on the secondary side are in extended delta connection, so that phase difference is realized; the multi-path low-voltage alternating current is converted into multi-path low-voltage alternating current and low-order harmonics are High voltage is output through cascade H-bridge topology series connection, and reliable conversion is guaranteed through rectification filtering inversion and device redundancy design; the motor control module collects signals through multiple sensors, and PWM drive signals are generated through a vector control algorithm and coordinate transformation. The harmonic detection and compensation module detects harmonic waves based on an FFT algorithm, and injects a reverse compensation component through a modulation strategy to offset the harmonic waves; and the auxiliary protection module integrally realizes low-harmonic and high-precision high-voltage motor speed regulation through multi-dimensional monitoring and hardware protection.

The invention relates to the technical field of wireless communication, and provides a power amplifier, a power amplification module and a multi-mode multi-frequency power amplifier, the power amplifier comprises a first-stage low-frequency power amplifier, a second-stage low-frequency power amplifier, a harmonic suppression circuit, a first output matching circuit, a first filter circuit and a second filter circuit; the first-stage low-frequency power amplifier and the second-stage low-frequency power amplifier are used for amplifying low-frequency-band signals, the harmonic suppression circuit is used for suppressing harmonic waves output by the first-stage low-frequency power amplifier and the second-stage low-frequency power amplifier, and the output end of the first output matching circuit is used for outputting signals; and the first output end of the first filter circuit and the output end of the second filter circuit respectively provide filtered power supply voltage for the first-stage low-frequency power amplifier and the second-stage low-frequency power amplifier. According to the invention, the harmonic leakage of the multi-mode multi-frequency power amplifier can be optimized.

The invention relates to the field of three-level inverters, and particularly discloses a model-free strong-robustness predictive control method and system for a three-level SNPC inverter, and the method comprises the steps: carrying out the real-time sampling and coordinate transformation of the inverter, and obtaining the current and voltage components under a two-phase static coordinate system; establishing a hyper-local model, enabling the system parameter deviation and the external disturbance to be uniformly equivalent to lumped disturbance, and designing a full-order sliding-mode observer for real-time estimation; calculating a reference voltage vector based on the disturbance estimation value and the extrapolated reference current; and an optimal double-vector combination is selected through space vector optimization, action time is solved, redundant small vectors are selected according to midpoint voltage deviation, and PWM driving signals are generated. According to the method, excellent current tracking performance and low harmonic distortion can still be kept under the conditions of parameter mismatch and working condition change, meanwhile, neutral-point potential balance on the direct-current side is achieved, and the method has the advantages of being small in calculation amount, high in robustness, easy to achieve in engineering and the like.

The invention relates to a DSTATCOM harmonic current detection and tracking control method, which comprises the steps of collecting instantaneous current and instantaneous voltage of a load side of a power distribution network, processing a power distribution network instruction current signal detected in real time through an improved dq0 compensation amount detection algorithm, obtaining a to-be-compensated negative-sequence frequency doubling component and a to-be-compensated specific subharmonic component, and carrying out harmonic current tracking on the to-be-compensated negative-sequence frequency doubling component and the to-be-compensated specific subharmonic component. The obtained negative sequence frequency doubling component and the specific sub-harmonic component to be compensated are sent into a current inner loop, three-phase reference voltage is obtained through a PIR controller, generation of PWM pulses is controlled, then on-off of a DSTATCOM bridge arm switching tube is controlled, and a closed-loop control system is formed. A path for extracting an orthogonal component in instruction current is reconstructed, the positive sequence fundamental current detection error under the three-phase imbalance working condition is remarkably reduced, a compensation current control strategy based on a PIR controller is adopted in a current inner loop, and zero-static-error tracking of a frequency doubling component and a low-frequency harmonic component in compensation current is achieved.

The invention relates to the technical field of precision transmission, and discloses an impact resistance design method for a harmonic gear transmission mechanism, which is used for constructing an impact performance evaluation model by analyzing an impact force change rule in an engaging impact process. The method comprises the following steps: firstly, establishing a harmonic gear transmission impact model based on an improved kinematics method, calculating a contact force when a flexible gear is engaged with a rigid gear based on a Hertz contact theory and an elastic thin plate theory, solving a hysteresis damping coefficient in a collision process by combining a Hunt-Crossley hysteresis model with a damping coefficient and an energy conservation law, and calculating a harmonic gear transmission impact model according to the hysteresis damping coefficient. According to the method, a harmonic gear transmission collision process impact force model is established, an engaging-in impact force and impact duration conforming to a Hunt-Crossley hysteresis loop are obtained, an impact slow release index (IRI) is constructed, and the impact resistance of a harmonic gear transmission mechanism is evaluated. Through a transient dynamics analysis method, the accuracy of a theoretical impact model calculation method is verified. The method can effectively predict the shock resistance of the harmonic reducer, and provides a theoretical basis for the flexible gear profile design of the harmonic reducer.

The invention provides a motor vibration noise control method and system based on modal resonance frequency prediction, and belongs to the field of motor control. The method comprises the following steps: acquiring each order of intrinsic mode frequency of the permanent magnet motor; a cost function parameter, a current constraint condition and a control target are set, and a model prediction control method is adopted to drive an inverter to operate, specifically, the current operation state quantity of the permanent magnet motor is collected; predicting a state response in a future finite time domain based on the operation state quantity; constructing a value function, and evaluating and optimizing a state change result; and selecting an optimal voltage vector, generating a pulse signal to drive an inverter to execute, obtaining a motor high-frequency electromagnetic force wave distribution condition, comparing the motor high-frequency electromagnetic force wave distribution condition with the intrinsic mode frequency of the permanent magnet motor, and optimizing an optimal voltage vector selection logic. The problems that harmonic waves are concentrated and resonance is easily caused by a fixed switching frequency modulation method in the prior art, and a passive suppression method is high in cost and poor in flexibility are solved.

The invention relates to the technical field of transformer substation monitoring, and discloses a power supply and distribution safety monitoring method and system for a transformer substation. The method comprises the following steps: acquiring various data in a transformer substation, and performing time synchronization calibration on the three types of data; dividing a power supply and distribution operation mode into a steady-state mode, a transient mode and an overload mode based on the calibrated data, extracting a harmonic distortion rate, a dielectric loss angle tangent value and a vibration spectrum entropy value of a current waveform in each mode, and generating an operation characteristic matrix; detecting an operation mode switching event, and calculating a characteristic offset between modes; decomposing a degradation characteristic component in the operation characteristic matrix according to a matching degree between an insulation aging stage and current dielectric loss data in a historical fault case library; coupling compensation correction is performed on the degradation characteristic component in combination with the cross influence relationship between the electrical parameters and the mechanical parameters of the equipment; and reversely tracing the abnormal signal source equipment node along the topological structure of the power supply and distribution network based on the corrected degradation characteristic component, and outputting an equipment maintenance sequence.

The invention belongs to the technical field of grid-connected inverter harmonic analysis, and particularly discloses a grid-connected inverter harmonic closed-loop transmission analysis method and system considering broadband coupling. The method comprises the following steps: respectively establishing a harmonic component transfer function of each module; based on the harmonic component transfer function of the sampling module, calculating to obtain harmonic active power and harmonic reactive power input to the power outer loop control module; based on a harmonic component transfer function of the power outer loop control module, calculating to obtain a harmonic current component in a reference current signal output by a power outer loop; based on a harmonic component transfer function of a current inner loop control module, obtaining a three-phase modulation voltage harmonic component and an inverter port voltage harmonic component through coordinate inverse transformation; on the basis of the inverter port voltage harmonic component, a main circuit harmonic transfer equation is combined, and a grid-connected point harmonic current component is obtained through calculation; the method overcomes the defects that a traditional analysis method cannot consider the control of a whole loop by a closed loop, and the broadband coupling is insufficiently considered.

The invention belongs to the technical field of power electronic conversion, and particularly discloses an MMC-STATCOM system direct optimization model prediction control method and system, and the method comprises the steps: respectively calculating a differential mode voltage and a common mode voltage between an upper bridge arm and a lower bridge arm of each phase; third harmonic voltage is injected into the upper bridge arm and the lower bridge arm of each phase to obtain upper bridge arm voltage and lower bridge arm voltage of a newly-added third voltage component of each phase; and based on the obtained voltage of the upper and lower bridge arms of the newly added three-time voltage component, determining the input number of the sub-modules of the upper and lower bridge arms of each phase by adopting a nearest level approximation modulation strategy, and determining the input sub-module of each bridge arm according to the capacitor voltage sequence of each sub-module of the bridge arms and the current direction. According to the method, on the basis of keeping a discrete control structure, direct injection of third harmonic voltage under an MPC framework is achieved, and higher real-time performance and expandability are achieved.

The invention provides a motor stator fault detection system and method, and relates to the technical field of data processing, and the method comprises the steps: synchronously collecting a three-phase current signal and a stator winding temperature signal during the operation of a motor in real time through a current sensor and a temperature sensor; performing time-frequency domain analysis and spectrum feature extraction on the three-phase current signal to obtain a current unbalance degree and a current harmonic distortion rate, and forming a current feature parameter set; performing filtering noise reduction and trend elimination processing on the stator winding temperature signal to obtain a processed signal; on the basis of the processed signals, temperature abnormal points are recognized through a k-nearest neighbor clustering algorithm of the three-dimensional Euclidean distance, the temperature instantaneous change rate is calculated according to the temperature abnormal points, and a temperature characteristic parameter set containing the abnormal point density and the temperature rise rate is obtained. According to the invention, stator fault detection and differential early warning are realized.

The single-phase bidirectional single-stage isolation matrix converter comprises a pre-stage circuit and a post-stage circuit, and the pre-stage circuit comprises an LC filter on the power grid side, a pre-stage single-phase matrix conversion circuit and an LLC resonance circuit with a high-frequency transformer; the post-stage circuit comprises a post-stage conversion circuit and an output filter capacitor; the front-stage single-phase matrix conversion circuit comprises four bidirectional switch assemblies of a full-bridge structure. Each bidirectional switch assembly comprises two unidirectional controllable MOS tubes which are reversely connected in series, one end of each bidirectional switch assembly is connected to an L line or an N line of a power grid, and the other end of each bidirectional switch assembly is connected to the LLC resonance circuit. The rear-stage conversion circuit comprises a bidirectional MOS (Metal Oxide Semiconductor) tube bridge circuit and three high-frequency transformer secondary windings which are in triangular connection or star connection; and two end points of each secondary winding are respectively connected to the upper MOS tube and the lower MOS tube of the corresponding bridge arm and then are connected to output positive and negative ends. The converter has the advantages of high power density, low current harmonic, high power factor and the like, and is small in size, strong in anti-interference capability, wide in buck-boost range, and safe and reliable in commutation.

The invention discloses a high-efficiency converter for adjusting the voltage of a power grid, and belongs to the technical field of power electronics. The converter comprises a first voltage regulation circuit, a second voltage regulation circuit, a filter circuit, a detection circuit and a control circuit. By detecting the amplitude difference between the power grid voltage and the load voltage, the control circuit automatically switches the Buck working mode or the Boost working mode, and stable alternating current output in a wide input voltage range is achieved. The invention has the advantages of compact structure, high efficiency, fast response, small harmonic wave and the like, and is suitable for industrial and civil occasions with large-range fluctuation and frequent power grid voltage.

The invention discloses an intelligent switching control method and system for a double-voltage automobile generator, and relates to the technical field of automobile electrical control, and the method comprises the following steps: S001, constructing a frequency response baseline of an automobile power distribution network, and calibrating an inductance parameter of a wiring harness and a capacitance parameter of a filter based on frequency response measurement data; and generating an inherent frequency distribution diagram for reflecting the dynamic electrical characteristics. According to the method, the frequency response base line and the harmonic characteristic spectrum are constructed, so that accurate identification and dynamic prediction of the resonance risk are realized; avoiding the inherent frequency by adopting a multi-level control frequency planning strategy; virtual impedance and an active damping mechanism are introduced to improve the switching stability; and closed-loop optimization control is constructed in combination with residual signal feedback, and continuous convergence of the control performance is realized. According to the overall scheme, the stability, robustness and electromagnetic compatibility of the voltage switching process are improved, and safe operation of the double-voltage architecture under complex working conditions is guaranteed.

The invention discloses an electric energy metering method and system for reducing multi-loop cross interference, and the method comprises the following steps: collecting the real-time voltage and real-time current of each loop in a multi-loop electric energy meter at a first frequency, and synchronously recording the load type and operation state of each loop; the method comprises the following steps: collecting real-time data, pre-identifying a high-risk interference scene according to the collected real-time data, dynamically adjusting a sampling frequency according to an identification result, enabling the adjusted sampling frequency to be a second frequency, analyzing harmonic characteristics, phase offset, amplitude fluctuation rules and the like with extracted sampling data, positioning a cross interference source between loops, identifying an interference transmission path, and carrying out high-risk interference scene identification. Voltage or current data of the interfered loop are corrected in real time, interference parameters are adjusted and compensated in a self-adaptive mode, and accurate metering data are output. According to the invention, the problem that the traditional metering mode is difficult to meet the current high-precision and high-reliability electric energy metering requirements in an actual complex electricity utilization scene can be solved, and the electric energy can be accurately metered.

The invention discloses a transformer substation AC power supply residual current detection method and device, and the method comprises the steps: carrying out the vector synthesis of three-phase current data and zero line current data, forming a current difference sequence, exporting a residual current reference curve, and carrying out the fluctuation analysis of the residual current reference curve, and judging the leakage characteristics. After effective leakage features are formed through harmonic elimination, dominant frequency components are locked through frequency spectrum decomposition; calibrating a leakage type identifier according to the dominant frequency component and forming segmented leakage distribution; a deviation degree is formed by means of segmented leakage distribution and residual current reference curve deviation analysis, a correction deviation value is formed through load fluctuation compensation, and a standard exceeding coefficient is formed according to threshold value comparison to detect abnormal nodes to form hidden danger data; establishing a judgment rule based on the hidden danger data and the leakage type identifier to form a detection evaluation index; and executing path tracking on the detection evaluation indexes to form leakage position information, forming a disposal priority through intensity analysis to generate a residual current detection report, and realizing leakage current classification identification and self-adaptive evaluation.