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2550 results about "Three-phase electric power" patented technology

Three-phase electric power is a common method of alternating current electric power generation, transmission, and distribution. It is a type of polyphase system and is the most common method used by electrical grids worldwide to transfer power. It is also used to power large motors and other heavy loads.

Pole-mounted circuit breaker fault diagnosis method based on multi-information fusion

The invention relates to the technical field of fault diagnosis, in particular to a pole-mounted circuit breaker fault diagnosis method based on multi-information fusion, and the method comprises the steps: firstly obtaining electric quantity modal data such as three-phase current and coil current and mechanical quantity modal data such as mechanism vibration and voiceprint, and constructing a time-frequency domain alignment feature tensor; then, through a graph space-time attention fusion model, deeply mining physical structure association and time sequence evolution laws among heterogeneous data, and generating a dynamic space-time feature matrix; then, respectively constructing a mechanical evidence body for representing the state of the transmission chain of the operating mechanism and an electrical evidence body for representing the working condition of the vacuum arc-extinguishing chamber by adopting a feature level-decision level mixed framework; an improved D-S evidence theory is applied for fusion, when high-conflict evidences are detected, a self-adaptive arbitration mechanism is automatically triggered, conflict weights are dynamically attenuated or distributed to uncertain items, misjudgment is effectively avoided, and high-robustness collaborative diagnosis of the electromechanical state is achieved.
Owner:NANJING GREEN POWER INTELLIGENT TECH CO LTD

High-precision current closed-loop control system and method for servo driver

The invention relates to the technical field of servo control, in particular to a high-precision current closed-loop control system and method for a servo driver, and the method comprises the steps: collecting three-phase current, rotor position, winding temperature and bus voltage, and constructing a state data set; constructing a parameter identification model fusing physical prior and an attention mechanism, deducing inductance and flux linkage parameters influenced by temperature, saturation and cross coupling, and correcting a motor model in real time; the correction parameters are injected into an FOC decoupling and feedforward link, and a self-adaptive PI regulator is linked to set the gain of a current loop on line; calculating a d-q axis voltage command according to the update model to respectively control excitation and torque components; an extended state observer is introduced to estimate load abrupt change and parameter disturbance, feed-forward compensation is carried out, and three-phase PWM is generated through anti-Parker and SVPWM; and an inverter nonlinear compensation model of a dead zone and switch delay is constructed, PWM is pre-distorted and output to a power device, and robust and low-ripple current closed-loop control of the servo motor is realized.
Owner:ZHUHAI RUIHE ELECTRIC CO LTD

Three-phase four-wire inverter control method, controller and inversion control system

The invention belongs to the technical field of power electronics of power supply or power distribution, and provides a control method of a three-phase four-wire inverter, a controller and an inversion control system. A first control component is generated by using a phase angle, an inversion side three-phase current sampling value and a proportional integral compensator; a second control component and a third control component are generated by using a power grid voltage angular frequency, a neutral line current sampling value, a repetitive controller and a proportional resonance controller, the three control components are combined to control an inverter power switch tube, a proportional integral compensator is still adopted, the algorithm is simple, parameters are easy to design, and the reliability is high. And meanwhile, a repetitive-proportional resonance (RC-PR) composite controller is utilized to realize suppression of neutral line fundamental wave and harmonic current, and the method has faster dynamic response to load abrupt change, so that optimization of dynamic performance and steady-state performance is realized.
Owner:SHANGHAI ZHUOYANG ENERGY STORAGE TECH CO LTD

Three-phase imbalance compensation method and system based on negative sequence current, and medium

The invention discloses a three-phase imbalance compensation method and system based on negative sequence current and a medium, and relates to the technical field related to power imbalance compensation, and the method comprises the steps: executing the three-phase current, voltage and reactive power data collection of a power distribution network, and carrying out the three-phase imbalance recognition through negative sequence current analysis; carrying out additional acquisition of a load mode and environment data on the power distribution network; taking the data acquisition result and the additional data set as input data to execute negative-sequence current change trend prediction; a double-layer compensation device is configured for cooperative control optimization; power distribution network balance compensation is executed through a time sequence compensation strategy, and time sequence window feedback is established; and carrying out adaptive strategy correction. The technical problems that in the prior art, a three-phase imbalance compensation strategy lacks perspectiveness and self-adaptive capacity and cannot cope with a dynamically-changing power grid scene, and consequently compensation precision and stability are poor are solved, and the technical effects that perspectiveness and predictive compensation is achieved, and three-phase imbalance compensation precision and stability are improved are achieved.
Owner:TIANJIN YAOYUAN SMART ENERGY TECH CO LTD

Phase-loss self-fault-tolerant control method for phase-shift-free dual three-phase permanent magnet synchronous motor

The invention discloses an open-phase self-fault-tolerant control method for a phase-shift-free dual three-phase permanent magnet synchronous motor. The method can automatically adjust a current distribution relation in the case of an open-phase fault and suppress torque pulsation in combination with neutral point voltage compensation. Comprising the following steps: driving two pairs of three-phase winding modules of the phase-shift-free DTP-PMSM in parallel by adopting two two-level three-phase voltage source inverters, and providing a mathematical model of the motor; current distribution is automatically adjusted; compensating the voltage of the neutral point, and calculating the offset of the fault module; the current is redistributed to suppress the torque ripple after the fault, and the secondary oblique wave component generated by the phase failure fault is eliminated; a current loop controller is improved through dead-beat predictive control; the speed ring controller is optimally designed into an improved sliding mode controller; an improved double-loop controller system is formed by combining improved sliding mode control and dead-beat prediction control, high-gain parameters are set to improve the dynamic response performance of the system, and a new self-fault-tolerant control system is formed.
Owner:ZHEJIANG UNIV OF TECH

Dry-type air-core reactor turn-to-turn short circuit monitoring method based on magnetic field difference method

The invention relates to the technical field of fault testing, in particular to a dry-type air-core reactor turn-to-turn short circuit monitoring method based on a magnetic field difference method. According to the method, regularization constraint is introduced in an initial baseline stage to construct a reference electromagnetic coupling matrix, a heat accumulation index is recursively analyzed based on three-phase current energy, a thermally-induced magnetic field drift model is fitted in combination with magnetic field residual errors, and combined with combined constraint of the reference electromagnetic coupling matrix and the thermal drift model, a three-phase electromagnetic coupling model is established. The normal thermally induced magnetic field drift component is dynamically stripped in real-time monitoring; and under the constraint of a reference electromagnetic coupling matrix, fitting and optimizing a current vector through weighted least square state estimation, and integrating magnetic field and current two-dimensional deviation to obtain a structure consistency deviation index for fault monitoring. According to the invention, monitoring is carried out in consideration of a linear electromagnetic transfer rule and nonlinear thermal drift compensation, a complex magnetic field environment and a variable load operation condition of the dry-type air-core reactor are adapted, and continuous and reliable monitoring guarantee is provided for long-term stable operation of equipment.
Owner:UHV CO OF STATE GRID HEILONGJIANG ELECTRIC POWER CO LTD

Electrical variable monitoring method for operation of ring main unit

The invention relates to the technical field of power distribution network automation, and discloses an electrical variable monitoring method for ring main unit operation, which comprises the following steps: acquiring three-phase electrical variable data in response to a condition that a load current change rate exceeds a preset micro-motion excitation threshold value; calculating a reference voltage based on the circuit state equation containing the inter-phase mutual inductance coupling term; the method comprises the following steps: constructing a rotating coordinate system taking a current vector as a reference axis, performing vector decomposition on a voltage deviation vector, separating a resistive temperature drift voltage component parallel to the reference axis, and taking a nonlinear impedance voltage component perpendicular to the reference axis as a monitoring parameter to judge a contact state. According to the method, linear resistance drift caused by conductor temperature rise is effectively decoupled, baseline interference is eliminated, weak nonlinear impedance distortion characteristics caused by mechanical contact degradation can be captured, and the recognition sensitivity and accuracy of early latent faults of the ring main unit are improved.
Owner:DIKAI (FUJIAN) POWER COMPLETE EQUIP CO LTD

Cooperative optimization method and device for electric energy quality of high-permeability transformer area

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.
Owner:STATE GRID JIANGXI ELECTRIC POWER CO LTD

10kV distribution transformer on-load voltage regulation control method and system

The invention discloses a 10kV distribution transformer on-load voltage regulation control method and system, and relates to the technical field of transformer on-load voltage regulation, and the method comprises the steps: collecting the three-phase voltage and current of a low-voltage side of a distribution transformer and a tap switch gear signal, and loading a preset voltage regulation control mode and an oscillation region parameter; based on the acquired three-phase voltage and current of the low-voltage side of the distribution transformer and the tap switch gear signal, calculating a feeder comprehensive impedance parameter and a load reactive power parameter, and outputting a transformer operation state index; according to the transformer operation state index, the voltage regulation control mode and the oscillation area rule, current voltage out-of-limit and reactive power deviation are judged, and a voltage regulation strategy triggering instruction is generated according to the judgment result; and calculating upper and lower limit values of feed line correction voltage based on the voltage regulation strategy trigger instruction, and controlling the tap switch to execute voltage regulation action. According to the method, a combined calculation scheme of feeder comprehensive impedance and load reactive power is fused, and dynamic optimization of the triggering condition of the voltage regulation strategy is achieved.
Owner:JIANGSU NARI POWER ELECTRIC

Power distribution network fault section positioning method based on Beidou satellite time service

The invention belongs to the technical field of fault positioning, and discloses a Beidou satellite time service-based power distribution network fault section positioning method, which comprises the following steps of: acquiring three-phase current, and performing phase synchronization alignment on the three-phase current by using a Beidou satellite to obtain a three-phase current synchronization data sequence; performing modulus transformation on the three-phase current synchronous data sequence to obtain a zero-mode current component and a line-mode current component; performing adaptive waveform decomposition on the zero mode current component and the line mode current component to obtain an intrinsic mode component, and performing signal reconstruction on a target component to obtain an enhanced fault traveling wave signal; performing waveform curvature sudden change detection on the enhanced fault traveling wave signal to obtain a wave head arrival time and a time difference observation sequence; performing geometric analysis on the topological structure based on the time difference observation sequence and the traveling wave propagation speed to obtain a suspected fault section; and comprehensively studying and judging the suspected fault section to obtain an actual fault section. The power distribution network fault positioning efficiency can be improved.
Owner:SHANDONG UNIV OF TECH

Fault voltage ride-through optimization method and system for network construction type energy storage converter

The invention belongs to the technical field of new energy, and particularly relates to a fault voltage ride-through optimization method and system for a network construction type energy storage converter. Carrying out positive and negative sequence separation and Clark-Park coordinate transformation on the three-phase power grid voltage and the inversion current, calculating active power and reactive power of the network-forming type energy storage converter, and carrying out power loop control to obtain three-phase reference voltage and angular velocity; performing voltage loop control, and dynamically adjusting a positive sequence active current and a positive sequence reactive current according to whether a low-voltage-crossing indication signal exists or not; performing positive-sequence current loop control and negative-sequence current loop control, and then performing inverse Clark-park conversion to obtain positive-sequence three-phase reference voltage and negative-sequence three-phase reference voltage; and superposing the positive-sequence three-phase reference voltage and the negative-sequence three-phase reference voltage for PWM (Pulse Width Modulation). According to the invention, when the power grid voltage is unbalanced due to a fault, the oscillation of the direct current side voltage and power caused by the negative sequence component is eliminated, and the power angle stability is improved and the fault current is suppressed by dynamically adjusting the related reference value during the fault voltage ride-through period.
Owner:HKUST DIGITAL (SHANGHAI) ENERGY TECH CO LTD

Grid-connected inverter control method, system, equipment and medium

The invention discloses a grid-connected inverter control method, system and device and a medium. The method comprises the steps of obtaining a power grid operation parameter, a system power instruction and a direct current bus voltage provided by a photovoltaic side hybrid energy storage system; a virtual inertia parameter is dynamically adjusted through an active-frequency control loop of the virtual synchronous machine in combination with an adaptive inertia algorithm, and a virtual rotor angular speed and an active power reference value are obtained through calculation according to a second-order motion equation of the synchronous generator; in combination with a reactive power instruction, a virtual internal potential amplitude is calculated according to a reactive-voltage droop relation through a reactive-voltage control loop of the virtual synchronous machine; and generating a three-phase voltage reference signal of the grid-connected inverter through synchronous rotation coordinate transformation. According to the invention, the dynamic performance, the operation efficiency and the grid-connected stability of the system under complex working conditions are obviously improved.
Owner:GUIZHOU POWER GRID CO LTD

Electric energy quality on-line monitoring device and cloud platform cooperation system

The invention provides an electric energy quality on-line monitoring device and a cloud platform cooperation system, and relates to the technical field of electric energy quality management, and the device comprises a signal collection unit which obtains three-phase voltage and current signals in parallel through a Rogowski coil and a capacitive voltage divider; the event detection unit is used for synchronously executing harmonic spectrum analysis and transient event capture by adopting a parallel processing architecture realized by an FPGA (Field Programmable Gate Array); the edge processing unit is connected with the event detection unit, and is configured to encode the transient event features into a Gramer angle field image and compress steady state data into feature vectors; the multimode communication unit comprises a 4G / 5G wireless module and an optical fiber Ethernet interface; and the strategy execution interface outputs a treatment instruction to the compensation device through the D / A converter and the current loop. Through collaborative innovation of the device and the cloud platform, the power quality monitoring and treatment efficiency is remarkably improved.
Owner:SHANGHAI YING KUANG ELECTRIC CO LTD

Direct current brushless motor control method and system based on current prediction

The invention relates to the technical field of motor control, discloses a direct current brushless motor control method and system based on current prediction, and aims to solve the problems of large torque ripple, low efficiency and poor stability caused by current loop lag in the prior art. The method comprises the following steps: acquiring a motor operation state signal in real time; determining a sector and an electrical angular velocity based on the rotor position and the rotational speed; inputting related parameters into the mixed current prediction model to obtain a three-phase current prediction value of the next period; a prediction error is calculated in combination with a current instruction, and an optimal voltage vector enabling a cost function to be minimum is solved through a model prediction control algorithm; and finally, a space vector pulse width modulation signal is generated to drive an inverter. According to the method, advanced control is realized by fusing a physical model and a data-driven prediction mechanism, the torque ripple is remarkably reduced, and the energy efficiency and robustness are improved.
Owner:LOUDI CHUANGWEIDA ELECTRICAL APPLIANCE CO LTD

Online evaluation method for voltage and frequency coupling cooperative control performance of new energy station

The invention is suitable for the technical field of data processing, and provides a new energy station voltage and frequency coupling cooperative control performance online evaluation method, which comprises the following steps: acquiring a three-phase voltage signal, a frequency signal, a unit output power signal and a power grid dispatching instruction signal of a new energy station grid-connected point, and calculating a voltage and frequency coupling characteristic matrix; performing collaborative quantitative analysis to generate a collaborative parameter matrix; performing control performance evaluation on the collaborative parameter matrix based on the collaborative evaluation network structure to generate collaborative evaluation parameters; constructing a dynamic coupling constraint function, and calculating to obtain a collaborative stability boundary representing the operation state of the station; and dynamically correcting the collaborative evaluation parameters to generate a station control performance optimization sequence. And the safety, the stability and the electric energy quality of the operation of the new energy station are effectively improved.
Owner:ELECTRIC POWER RES INST OF GUANGXI POWER GRID CO LTD

Automatic voltage regulating device for power distribution area and control method of automatic voltage regulating device

The invention discloses an automatic voltage regulating device for a power distribution area and a control method of the automatic voltage regulating device, and belongs to the technical field of power distribution network voltage treatment. The device comprises a three-phase power supply, a power supply side input circuit, a load side output circuit, a current transformer, a single-P air switch, a power supply conversion module, a three-phase independent voltage regulation module, a main path control system, an automatic bypass control system, a gear driving module, a man-machine interaction module, a display module, a monitoring module, a mode switching module, a parameter storage module and an alarm module. The system comprises a manual adjustment execution module, a counting module, a voltage detection module, a current detection module, a 4G communication module and an over-temperature protection module. A main circuit control system depends on input and output voltage data fed back by a voltage detection module, compensation voltage U can be independently calculated for differential voltage fluctuation of L1, L2 and L3 phases, intelligent adjusting switches of all phases are driven to act accurately, and finally three-phase output voltage U2 is stabilized within an allowable range.
Owner:QUJING POWER SUPPLY BUREAU YUNNAN POWER GRID CO LTD

Combined iron core type three-phase reactor and winding device thereof

The invention discloses a combined iron core type three-phase reactor and a winding device thereof, and belongs to the technical field of reactor processing, the combined iron core type three-phase reactor comprises a winding assembly, one side of the winding assembly is sequentially provided with a height limiting assembly, a core loading assembly and a switching assembly, and the same sides of the winding assembly, the height limiting assembly, the core loading assembly and the switching assembly are jointly provided with a pay-off assembly; the winding assembly comprises a first sliding table, a first mounting plate is mounted at the sliding end of the first sliding table, a winding motor is mounted on the side, close to the height limiting assembly, of the upper end of the first mounting plate, a positioning circular plate is mounted at the end of a driving shaft of the winding motor, and a plurality of winding positioning rods used for being matched with different core sections are arranged on the positioning circular plate. According to the bobbin assembly device, the switching assembly is used for installing the end of an enameled wire on the winding assembly before a new coil square barrel is wound, automatic winding and installation of bobbin components are achieved, bobbin assembly can be conducted on similar special-shaped core bodies, and the overall working efficiency is improved.
Owner:HEFEI ECRIEE TAMURA ELECTRIC

Method and device for suppressing specific grid-connected current harmonic waves of energy storage converter

The invention discloses a specific grid-connected current harmonic suppression method and device for an energy storage converter, and belongs to the technical field of power systems, and the method comprises the steps: obtaining a given current value of a fundamental current loop, and carrying out the dq / abc conversion to obtain a three-phase current reference value; acquiring a three-phase current value of a power grid side, and subtracting the three-phase current value from the three-phase current reference value to obtain a harmonic current value; converting the harmonic current value to a target subharmonic synchronous rotating coordinate system to obtain a target subharmonic current value; extracting the target sub-harmonic current value in a direct current form through a low-pass filter, and sending the target sub-harmonic current value to a PI regulator for regulation to obtain a harmonic voltage compensation amount; and injecting the harmonic voltage compensation amount into a modulation wave to realize suppression of the target subharmonic current. According to the invention, the grid-connected side current harmonic of the energy storage converter can be effectively suppressed, and the grid-side current quality is improved.
Owner:STATE GRID JIANGSU ELECTRIC POWER CO LTD RESEARCH INSTITUTE +1

Deceleration control method for high-speed motor-driven hydraulic 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.
Owner:ZHEJIANG POTENTIAL DRIVE INTELLIGENT CONTROL EQUIPMENT CO LTD

Power distribution network fault location method and system based on fault point voltage transient waveform comparison

The invention is suitable for the technical field of fault distance measurement, and provides a power distribution network fault distance measurement method and system based on fault point voltage transient waveform comparison, and the method comprises the steps: collecting three-phase voltage and current signals at two ends of a line when a power distribution network fault occurs, and extracting a transient component signal in a preset frequency range; performing phase-mode transformation decoupling processing on the transient component signal; constructing a transient voltage differential equation from the two ends of the line to a hypothetical fault point, dynamically adjusting the fault position hypothetical point in a preset distance measurement interval by adopting a dichotomy, and calculating a transient voltage calculation waveform from the two ends of the line to the fault position hypothetical point; performing time domain similarity analysis on the transient voltage calculation waveform, and calculating a waveform consistency index; judging whether a preset convergence condition is met or not; if yes, determining that the current fault position hypothesis point is a target fault point; otherwise, adjusting the dichotomy interval according to the waveform comparison difference direction, and carrying out the next round of iterative calculation until the convergence condition is met, thereby effectively improving the fault distance measurement accuracy.
Owner:ELECTRIC POWER RES INST OF GUANGXI POWER GRID CO LTD

Motor winding fault monitoring method and system

The invention discloses a motor winding fault monitoring method and system, and relates to the technical field of winding fault monitoring. According to the motor winding fault monitoring method, three-phase current waveform signal data and running state data of a set motor are obtained; based on a pre-trained current waveform identification model, in combination with three-phase current waveform signal data of the set motor, a winding fault induction characteristic value of the set motor is analyzed; based on the running state data of the set motor, the winding comprehensive disturbance risk characteristic value of the set motor is analyzed, and the winding fault risk assessment characteristic value of the set motor is analyzed in combination with the winding fault induction characteristic value. Therefore, the dynamic change rule of the current waveform in the time sequence is effectively described, the identification depth and the time response speed of fault causes are improved, and the accuracy of fault risk assessment is enhanced.
Owner:JIANGMEN HUACHUANG MOTOR CO LTD

Single-stage ac-to-DC resonant converter

A single-stage AC-to-DC resonant converter is used to convert a three-phase AC power source into a DC power source. The single-stage AC-to-DC resonant converter includes a primary-side circuit, a resonant circuit, and a secondary-side circuit. The primary-side circuit includes three primary-side switch circuits, and each primary-side switch circuit is coupled to one phase of the three-phase AC power source. The resonant circuit includes three transformers, and primary-side windings of the transformers are respectively coupled to the primary-side switch circuits, and secondary-side windings of the transformers are coupled to the secondary-side circuit.
Owner:DELTA ELECTRONICS INC(CN)

Method, device and equipment for realizing equivalent apparent power of three-phase electric energy meter

The invention relates to the technical field of three-phase electric energy meters, and discloses an equivalent apparent power implementation method, device and equipment of a three-phase electric energy meter and a medium. Comprising the following steps: acquiring cyclic wave voltage sampling data and cyclic wave current sampling data of each phase of the three-phase electric energy meter in at least one cyclic wave; calculating the equivalent voltage of the three-phase electric energy meter according to the cyclic wave voltage sampling data; calculating the equivalent current of the three-phase electric energy meter according to the cyclic current sampling data; and calculating the equivalent apparent power of the three-phase electric energy meter based on the equivalent voltage and the equivalent current. According to the invention, the accuracy of apparent electric energy charging and line loss calculation can be improved.
Owner:ZHEJIANG CHINT INSTR & METER

Power quality disturbance positioning identification method based on phase perception and multi-modal fusion

The invention discloses an electric energy quality disturbance positioning identification method based on phase perception and multi-mode fusion, and relates to the technical field of electric power system monitoring and fault diagnosis. The electric energy quality disturbance positioning identification method based on phase perception and multi-modal fusion comprises the following steps: acquiring an original voltage signal of a three-phase electric power system; extracting a sample embedding vector of each phase based on the original voltage signal, comparing the sample embedding vector with a normal sample vector, and determining a disturbance phase with power quality disturbance in combination with an adaptive threshold value; performing time sequence feature vector extraction and bispectrum image feature extraction on the disturbance phase, and performing alignment and collaborative fusion to obtain fusion features; the electric energy quality disturbance type is identified based on fusion features, phase-level positioning of the three-phase PQD is achieved, through an innovative phase perception embedding and prototype comparison mechanism, accurate and rapid positioning of abnormal phases in a three-phase system is achieved for the first time under the condition of not depending on disturbance phase labels, and the core pain point of a traditional method is solved.
Owner:ANHUI UNIV

Generator set fault diagnosis and detection method based on deep learning

The invention relates to the technical field of motor detection, in particular to a generator set fault diagnosis and detection method based on deep learning, and the method comprises the steps: firstly, synchronously collecting three-phase voltage, current and rotating speed signals, and constructing a multi-dimensional time sequence matrix through data cleaning and sliding window segmentation; then, carrying out multi-scale decomposition on the matrix by adopting adaptive wavelet packet transformation, combining each frequency band reconstruction coefficient with an original signal channel, and constructing an enhanced feature tensor; then, a CNN-BiLSTM parallel network is constructed; and finally, dynamically fusing the features of the two branches through a self-adaptive weighted fusion strategy, and inputting a multi-layer full-connection classifier to output a fault type. According to the method, early weak fault features are effectively enhanced, bearing faults, rotor eccentricity, electrical imbalance and composite faults thereof can be accurately recognized, the intelligent level and accuracy of fault diagnosis of the generator set are remarkably improved, and the method can be widely applied to online monitoring and health management of power generation equipment of a power system.
Owner:CHONGQING XINYANDA ELECTRICAL & MECHANICAL EQUIP CO LTD

Power distribution network electric energy quality multi-disturbance source positioning and traceability analysis method, system and device and medium

The invention relates to the technical field of power system power quality analysis and control, and discloses a power distribution network power quality multi-disturbance-source positioning and traceability analysis method, system and device and a medium, and the method comprises the steps: optimally configuring a monitoring point network according to a power distribution network topological structure; collecting three-phase voltage and current data of each monitoring point, and extracting multi-dimensional features after preprocessing; identifying disturbance types by adopting a hierarchical classification strategy, and separating composite disturbance; the disturbance information and the time sequence of each monitoring point are fused, and accurate space positioning of harmonic waves and transient disturbance sources is realized by combining parameters of the power distribution network; establishing a disturbance propagation model, and analyzing a propagation path and an influence range; and finally, generating a comprehensive traceability report containing a positioning result, disturbance characteristics, influence evaluation and governance suggestions, and calculating the overall traceability confidence. According to the method, the problems of accurate positioning and tracing in a multi-disturbance-source coexistence scene are effectively solved, and the positioning accuracy and the recognition reliability are improved.
Owner:GUIZHOU POWER GRID CO LTD

Position-free sensing method for joint module based on rotating speed estimation and virtual Z correction

The invention discloses a position-free sensing method for a joint module based on rotating speed estimation and virtual Z correction. The method comprises the following steps: firstly, acquiring three-phase current of a permanent magnet motor for a joint module, and acquiring d-axis estimated current of a current period based on a d-axis current model in combination with a state quantity of the permanent magnet motor in a previous control period; based on the d-axis estimated current, constructing a rotating speed estimator taking the d-axis estimated current error as a sliding mode surface to obtain the estimated rotating speed of the motor rotor; integrating the estimated rotating speed, and combining with the initial position of the rotor to obtain the estimated position of the motor rotor in the current period; at the same time, at the zero crossing point of the stator phase current, the estimation position is forcibly corrected to a predetermined electrical angle corresponding to the zero crossing point so as to eliminate the integral error. The invention aims to directly estimate the rotating speed without depending on any intermediate signal, and simulate the correction mechanism of a mechanical sensor to eliminate the estimation error, thereby realizing high-performance noise-free full-speed-domain position-free sensing control.
Owner:NORTHWESTERN POLYTECHNICAL UNIV

Open-circuit fault detection method, device, domain controller, system and vehicle

The invention relates to an open-circuit fault detection method and device, a domain controller, a system and a vehicle, and relates to the technical field of open-circuit fault detection. According to the method, the three-phase current data of the cooling water pump can be firstly obtained, and under the condition that at least one phase of current data in the three-phase current data meets the pre-judged open circuit condition, at least one of the following motor parameters including the three-phase current unbalance degree, rotor data and water pump vibration data is monitored. If it is monitored that any motor parameter in the three-phase current unbalance degree, the rotor data and the water pump vibration data is abnormal, it is determined that the current data meeting the pre-judgment open-circuit condition occurs, and an open-circuit fault occurs to the target phase corresponding to the current data meeting the pre-judgment open-circuit condition. Therefore, under the condition that the suspected open circuit of the corresponding phase is predicted according to the single-phase current, prediction can be performed by fusing at least one motor parameter of the cooling water pump, so that the misjudgment rate of the open-circuit fault of the cooling water pump can be reduced and the open-circuit phase positioning precision can be improved through multi-data cooperative detection.
Owner:CHONGQING CHANGAN AUTOMOBILE CO LTD

RCBO-oriented fault positioning distribution box control method and system

The invention relates to an RCBO-oriented fault positioning distribution box control method and system, and belongs to the technical field of intelligent power distribution and fault diagnosis in the field of electrical engineering, and the method comprises the following steps: S1, collecting a three-phase current signal and a residual current signal of a power distribution system; s2, calculating a harmonic distortion rate and a load unbalance degree based on the three-phase current signal; s3, based on the residual current signal, calculating a residual current waveform complexity index; s4, combining the harmonic distortion rate, the load unbalance degree, the residual current waveform complexity index and a preset basic threshold to generate an adaptive threshold; s5, selecting one of a plurality of preset fault judgment modes according to the numerical value of the residual current waveform complexity index; and S6, the selected fault judgment modes are adopted, the residual current signals are processed to generate fault judgment results, at least one fault judgment mode uses a self-adaptive threshold value, and a solid data basis is provided for subsequent self-adaptive adjustment.
Owner:TAMM ELECTRIC (HANGZHOU) CO LTD

Hidden danger pre-diagnosis method for elevator traction system

The invention discloses a hidden danger pre-diagnosis method of an elevator traction system, relates to the technical field of elevator safety monitoring, and is used for solving the technical problems of poor real-time performance, low accuracy and difficulty in defect positioning of hidden danger diagnosis of the elevator traction system in the prior art. The hidden danger pre-diagnosis method for the elevator traction system comprises the steps that multi-source data are synchronously collected, specifically, a current transformer is deployed in a power supply loop at the input end of an elevator traction motor to collect a three-phase current instantaneous value, a speed measurement encoder is used for measuring the speed, the elevator running state, the speed, the floor position and the time-variable load weight are synchronously obtained, and a time-space correlation data set is constructed; signal self-adaptive preprocessing: performing layered noise reduction, working condition alignment and dynamic normalization processing on the acquired current signals; multi-scale feature fusion extraction: current signal features are extracted from a basic feature layer, a time domain feature layer, a frequency domain and a time-frequency domain feature layer; and feature optimization and decision making: after feature screening and dimension reduction fusion, inputting a pre-training classification model to output hidden danger types, positions and risk levels.
Owner:GUANGDONG INSPECTION & RES INST OF SPECIAL EQUIP ZHUHAI INSPECTION INST +1