6483 results about "Low voltage" patented technology

Systems and apparatus are provided for a high-power microwave sensor using an unmanned aerial vehicle. The unmanned aerial vehicle may include a central body, at least one electric motor, and a barometric pressure feedthrough. The central body may include a first enclosure housing a plurality of low voltage components, a voltage feedthrough connector, and a second enclosure housing a plurality of high voltage components. The low voltage components may include a first signal processing system, a first radio transceiver, a flight controller, a second signal processing system, a second radio transceiver, and a navigation system. The high voltage components may include a plurality of electronic speed controllers, a power distribution module, an input power interface, and a plurality of high power filters. The components of each enclosure may be segregated such that the high voltage components do not create electromagnetic interference with the low voltage components.

The invention provides a test method and device for a motor active short-circuit relay, and a storage medium. The method includes the steps: performing the zero speed detection of a motor after a motor controller completes a low-voltage power-on operation, wherein when the motor controller is powered down, a first relay and a second relay are both switched on; controlling the second relay to be turned on if the motor passes the zero speed detection, and injecting a first excitation signal at the control ends of a first phase winding and a third phase winding through the motor controller; performing injection detection of the first excitation signal to determine whether the first excitation signal is successfully injected or not; controlling the first relay to be turned on if the first excitation signal is successfully injected, and obtaining a voltage across two ends of the first relay; and judging whether the power-on test of the first relay is successful or not according to the voltage across two ends of the first relay. The method can realize the turn-on test of the short-circuit relay, and ensures the reliability of the active short-circuit function of the vehicle motor duringdriving.

The present disclosure provides a method and device for calculating fault measurement impedance of a hybrid-connected grid-following and grid-forming wind power system. The method includes: obtaining characteristics of the grid-following and grid-forming converters and a corresponding low voltage ride-through control strategy; establishing an equivalent circuit under a corresponding fault state; conducting a simplified analysis on the wind power system to obtain an equivalent network diagram; obtaining a sub-circuit diagram of each power source excitation acting alone; obtaining short-circuit currents on both sides of the corresponding system and a grid connection point voltage; superimposing to obtain total short-circuit current on both sides of the wind power system and total grid connection point voltage; and obtaining a measurement impedance at a protection installation location on the new energy source side. The method can accurately calculate the measurement impedance value at the protection installation location after the wind power system has fault.

The invention discloses a high-low voltage switch cabinet feeder fault positioning method and system based on transient traveling waves, and belongs to the technical field of power system fault detection and positioning, and the method comprises the steps: synchronously collecting electric and acoustic multi-mode signals, and generating a weighted transient synchronization feature matrix; performing time-frequency transformation and feedback optimization on the matrix, and outputting a multi-scale time-frequency feature set; analyzing the feature set by using an integrated learning network, and outputting a layered preliminary positioning result; convergence to an accurate fault section is carried out through iteration calibration; and finally, fusing multi-model calculation and outputting a comprehensive fault positioning report. According to the method, a technical path of combining multi-modal signal fusion and a physical model is adopted, convergence from fuzzy region division to an accurate position can be realized in stages, and the accuracy, the speed and the anti-interference capability of switch cabinet feeder line fault positioning are remarkably improved.

The invention relates to the technical field of intelligent power distribution system state monitoring, in particular to a cable connection state online monitoring method for a low-voltage cable branch box, which comprises the following steps of: applying a disturbance excitation signal to a connection node of the cable branch box, and acquiring transient voltage, current and phase response parameters of the node in different excitation periods; establishing a mapping relation between the node electrical characteristics and the connection state; performing dynamic reference calibration on the acquired signals based on a multi-node space-time coupling matrix to form an adaptive judgment reference of electrical coupling between nodes; a connection degradation sensitive index is extracted through feature sequence differential calculation, a connection state quantitative evaluation result is generated, and real-time updating and anomaly recognition are carried out according to the state change trend; according to the method, the problems of misjudgment and delay caused by a monitoring mode depending on indirect parameters such as temperature and current are solved, high environmental adaptability and degradation identification precision are achieved, and the operation safety and monitoring reliability of the low-voltage power distribution system are greatly improved.

The invention relates to the technical field of cable preparation, in particular to an extruded insulation low-voltage power cable and a preparation method thereof.The preparation method comprises the steps that metal wires are twisted into a conductor according to preset twisting parameters, and the conductor is preprocessed; extruding an insulating layer on the surface of the pretreated conductor by using a screw extruder to obtain an insulated wire core; monitoring the diameter of the insulated wire core in real time by using a laser diameter measuring instrument, and determining the fluctuation characteristic type of the diameter of the wire core under a first preset condition; obtaining the eccentricity of the insulating layer and the void ratio between the insulating layer and the conductor; judging the qualification of the extrusion process according to the extrusion comprehensive quality index; under the condition that the extrusion process is unqualified, the qualification of the extrusion process is secondarily judged according to the insulation performance evaluation value; under the condition that the extrusion process is judged to be unqualified for the second time, an adjustment strategy of the extrusion process is determined; and after the insulated wire cores qualified in the extrusion process are twisted into a cable, an outer protective sleeve is extruded. The production efficiency and the product stability of the cable are improved.

The invention relates to a low-voltage motor insulation resistance online monitoring and early warning method, system and device and a medium. The method comprises the following steps: firstly, acquiring multi-dimensional operation data through a data acquisition link to form an original monitoring data set; preprocessing the original monitoring data set, and focusing core information through dimension reduction processing to obtain a key parameter set; and then inputting the key parameter set into a dynamic correlation model constructed based on a long short-term memory network, and outputting a prediction result of the variation trend of the insulation resistance value along with time and the deterioration degree quantification. And finally, carrying out early warning analysis based on a prediction result, and generating early warning fault features in combination with a real degradation judgment process. According to the method, the insulation resistance trend and the degradation degree are accurately predicted, the defect of insufficient real-time performance of off-line detection is overcome, the accuracy and the pertinence of fault early warning are improved, and equipment shutdown and safety risks caused by insulation faults are effectively reduced.

The invention discloses a fault ride-through test method for an offshore wind power flexible direct output system, and the method comprises the steps: building a fault equivalent circuit of the offshore wind power flexible direct output system, analyzing the operation characteristics of an AC power grid side under a low-voltage fault, and determining the incidence relation between the DC side excess energy and the power grid voltage drop; establishing a model representing each component in the fault equivalent circuit, wherein the components at least comprise a machine-side converter, a grid-side converter, a direct-current capacitor and an unloading resistor; when a low-voltage fault of an alternating-current power grid side is detected, executing the following cooperative control based on the model: synchronously starting unloading resistance control and reactive power support control, wherein an unloading resistor dissipates excess energy of a direct-current side through a direct-current chopper; the grid-side converter injects a capacitive reactive current which is deeply matched with the voltage drop of the power grid so as to improve the voltage of a grid-connected point; and if the direct-current voltage continuously exceeds the preset threshold value, starting power prompt drop control, and reducing the output power of the unit according to a gradient until the system recovers to be stable.

The invention relates to the technical field of electrical parameter testing, in particular to a high-low voltage frequency converter testing system which comprises a sampling point calibration module, a frequency cross-grade identification module, a current response re-sequencing module, a dynamic interference blocking module and an operation parameter output module. According to the method, the amplitude of the voltage sampling point is mapped into the trigonometric function curve, the waveform trend is deduced in combination with the amplitude change angle, a time delay calibration mechanism based on periodic trend identification is established, and the sampling point time sequence precision in different gear switching scenes can be effectively adapted. According to a combined judgment mode of the current rise rate direction and the frequency jump amplitude, a cross-cycle dynamic judgment path is constructed, a frequency jump index can be identified from a non-stable operation state, and the perception capability of a non-linear operation behavior is improved. A current response sorting reconstruction process is introduced, and the sorting matching capability of inconsistent response sequences is enhanced through cross analysis of frequency gears, current response directions and load states.

The invention relates to the technical field of remote monitoring, and discloses an intelligent AI-based fault detection method and system for a high-low voltage power distribution cabinet, and the method comprises the steps: constructing an LSTM-Attention hybrid network of a multi-modal data flow, extracting the time sequence characteristics of the multi-modal data flow, extracting the non-stationary signal frequency domain characteristics of the multi-modal data flow, and carrying out the fault detection of the multi-modal data flow. The method comprises the following steps: constructing a fault knowledge graph of a high-low voltage power distribution cabinet, analyzing a topological correlation feature vector of the high-low voltage power distribution cabinet, training a pre-constructed power distribution cabinet fault global model to obtain a trained power distribution cabinet fault global model, and analyzing a fault probability matrix of the high-low voltage power distribution cabinet by using the trained power distribution cabinet fault global model. And establishing a digital twinborn body of the high-low voltage power distribution cabinet, analyzing a fault evolution path of the high-low voltage power distribution cabinet by using the digital twinborn body, and analyzing a fault detection report of the high-low voltage power distribution cabinet. The maintenance efficiency of the high-low voltage power distribution cabinet can be improved.

The invention discloses a response control method for a charging station participating in a low-voltage treatment scene, and the method comprises the following steps: S1, collecting the voltage data of a charging pile, calculating a deviation, and judging a low-voltage grade; s2, when the deviation is in a light interval, outputting reactive power support voltage in proportion; s3, when the deviation exceeds a heavy threshold value, reducing active power and starting V2G feedback; s4, constructing a graph structure model, and extracting inter-node power coupling and user behavior factors; s5, inputting the model into an improved prediction controller, predicting a future voltage state, and optimizing and outputting a current period power control value; s6, power adjustment is executed, and feedback power is slowly output in the V2G stage; and S7, comparing the control deviation with the behavior factor change, updating the node control priority, and feeding back for rolling optimization of the next period. According to the invention, while the charging regulation and control precision is improved, the user experience and the voltage stability are effectively considered, and the method is suitable for various low-voltage treatment scenes.

The invention discloses a low-voltage cabinet fault prediction method and system based on artificial intelligence, and relates to the technical field of low-voltage electrical equipment state monitoring, and the method comprises the steps: obtaining operation data, such as current and voltage, collected by a sensor in a low-voltage cabinet; a multi-dimensional tensor structure containing spatial topological codes is constructed through preprocessing such as normalization; inputting a fault prediction model to obtain fault type probability and trend evaluation parameters, and generating a dominant abnormal factor index set through an interpretable module; analyzing a root cause path by using a fault causal knowledge graph in combination with the data, and determining a fault evolution chain; and finally generating interpretable early warning prediction information. The technical problems that a traditional low-voltage cabinet fault detection mode is difficult to process multi-dimensional complex data, cannot efficiently mine key fault information and is difficult to accurately predict are solved, the prediction model is constructed by using the deep learning technology, and then efficient processing of the multi-dimensional complex data of the low-voltage cabinet and deep mining of the key fault information are achieved. The technical effect of accurate fault prediction is achieved.

The invention relates to the technical field of electric power engineering automation, in particular to a low-voltage equipment power factor automatic adjusting system and method based on end compensation, and the system comprises a load monitoring module, a compensation strategy generation module, an end compensation execution module, a dynamic balance correction module and an effect evaluation module. According to the invention, the sequential relationship between the load fluctuation and the compensation demand can be accurately identified by continuously monitoring the current waveform, the voltage waveform and the phase difference change trend of the low-voltage equipment, and the compensation strategy is dynamically formulated in combination with the response duration and the compensation demand matching rule, so that the compensation response agility and the matching property of the fluctuating load are improved; dynamic scheduling is carried out according to the capacitor switching capacity and the combination relation in compensation execution, switching weight configuration is analyzed and optimized through the power factor change rate before and after compensation and the load synchronization characteristic, the dynamic balance of the compensation process is enhanced, the power factor stability and the load fluctuation matching capacity after compensation are effectively improved, and the compensation efficiency is improved. And the adaptability and continuity of the adjusting effect are enhanced.

The invention relates to the technical field of power electronic driving control, in particular to a driving system and method for an ultrasonic air pump, and the system comprises a control signal generation module which is used for generating a control signal; the voltage superposition driving module is coupled to the control signal generation module and is used for superposing and lifting the driving voltage according to the control signal and executing reversing operation, and the reversing operation comprises forward driving and reverse driving; the driving frequency adjusting module is coupled to the control signal generating module and is used for adjusting the driving frequency and speed of the ultrasonic air pump based on the control signal; and the working circuit protection module is coupled to the voltage superposition driving module and is used for setting dead time between forward driving and reverse driving to prevent short circuit. According to the invention, the dependence of the ultrasonic air pump on an independent high-voltage power supply and how to realize high-voltage alternating driving through voltage superposition and avoid the risk of bridge arm direct connection and resonance mismatch under the constraint of a low-voltage power supply are effectively solved.

A described example includes: a leadframe having a high voltage section and a low voltage section spaced from and electrically isolated from the high voltage section, and a heat slug mounted to the high voltage section. The high voltage section includes an input portion connected to the heat slug at an interior end by a mount portion, and further includes an interior lead portion that is connected to the mount portion by a flexible connect portion. An insulating material mounted to the heat slug provides a die mount area for a semiconductor die having a Hall element that is positioned so that the Hall element is proximate to the heat slug. Mold compound covers the semiconductor die, portions of the leadframe, and portions of the heat slug while a board side surface of the heat slug is exposed forming a thermal pad for a semiconductor device package.

In one implementation, an apparatus, such as an ESD protection circuit, is disclosed. The apparatus can include a filter coupled between a local supply voltage rail to a supply voltage rail. A switch circuit can be connected in parallel with the filter. The apparatus can include a clamp configured to 1) provide a first ESD shunt path from an input line to the local supply voltage rail and 2) provide a second ESD shunt path from the input line to a lower voltage rail. A second clamp can be configured to provide a third ESD shunt path from the local supply voltage rail to the lower voltage rail. The switch circuit can be configured to close a switch to bypass the filter.

The invention provides an abnormal power failure diagnosis method and device, and relates to the technical field of power failure diagnosis, the device comprises an MCU, the MCU is connected with a selection switch through a line, and one end of the selection switch is provided with a capacitor. Hardware hidden dangers can be eliminated at the beginning of power-on through hardware self-inspection in the system pre-starting stage, and it is guaranteed that operation baselines of the whole delay power supply module and the MCU are correct; according to the following capacitor energy charging function, a super capacitor is connected in parallel to the 12V low-voltage power supply side, and the charging current and voltage slope are monitored in real time, so that even if the capacitor stably and safely stores enough energy, overcharge damage is prevented, and monitoring is interrupted by data heartbeat of an MCU and a BMS master controller and power-down cmd, it is ensured that the system can sense a power-off instruction in time at any time, and the power-off state of the system is ensured to be stable and reliable. And persistent storage of the key operation parameters is completed in an atomicity write-in mode, so that the data loss risk caused by communication timeout or software faults is greatly reduced.

The invention discloses an active island detection method and system based on harmonic impedance characteristic identification, and the method comprises the steps: analyzing the harmonic impedance difference of grid-connected points in a grid-connected state and an island state, and building a state criterion based on resonant frequency deviation and impedance amplitude through the comparison of the frequency response characteristics of island impedance and grid-connected impedance; fitting the grid impedance into an RLC parallel model in a selected frequency band, and mapping the topological difference of the power grid into a parameter difference; embedding a low-voltage ride-through strategy in the control of the voltage source converter, and adjusting reactive current in a grading manner according to the voltage drop degree of a grid-connected point; fundamental waves and harmonic waves are separated through a cascade notch filter, two synchronous harmonic waves are injected into the system through constant current control, and it is ensured that injection signals of a multi-voltage source converter are in the same phase in a phase locking link; and solving an overdetermined equation set based on the double-frequency response data to identify RLC parameters, setting an island criterion, and synchronously completing island judgment in a low-voltage ride-through time window. Detection precision is improved, dynamic response is optimized, and power generation efficiency is improved.

The invention relates to a multi-mode control method and device for an energy storage converter. The method comprises the following steps: aiming at the operation of an energy storage converter in a network following mode, establishing a second-order infinite impulse response IIR filter, and establishing a low-voltage ride-through control strategy based on conforming to repetitive control; for the operation of the energy storage converter in an off-grid mode, a three-phase four-bridge-arm topology is adopted to provide a zero-sequence path, and a preset proportional multi-resonance control strategy is established; establishing a parallel pre-synchronization control strategy aiming at the operation of the energy storage converter in a network construction mode; and realizing multi-mode control of the energy storage converter based on a low-voltage ride-through control strategy conforming to repetitive control, a preset proportional multi-resonance control strategy and a parallel pre-synchronization control strategy. Any resonant frequency and filtering radius can be set to suppress the harmonic peak, the system stability is ensured, meanwhile, compared with a traditional pre-synchronization method, pre-synchronization can be completed without additional control links by only utilizing the self frequency modulation characteristic, and control resources are greatly saved.

An apparatus for safety testing a battery pack of an electric vehicle includes a low voltage data connector configured to couple to a battery management system controller of the electric vehicle battery pack for data communication with the battery management system controller. A test connector is configured to couple a battery module of the electric vehicle battery pack for use in testing the battery module. Measurement circuitry measures a parameter of the battery module through the test connector. A diagnostic controller couples to the low voltage data connector and the measurement circuitry and is configured to identify an error in data received from the battery management system controller based upon a comparison of the parameter measured by the measurement circuitry and the data received from the battery management system controller.

The invention relates to the technical field of power electronic devices, in particular to a low-voltage direct-current circuit breaker, a fault protection method and a related device.The low-voltage direct-current circuit breaker comprises a through-flow branch, a transfer branch and an energy consumption branch which are connected in sequence; the through-current branch comprises an isolating switch and an MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) commutation switch which are connected in series; the transfer branch comprises a first power electronic switch group and a buffer branch which are connected in parallel; the energy consumption branch comprises a first metal oxide MOV, a second metal oxide MOV and a second power electronic switch group; the first metal oxide MOV is connected in parallel with the second power electronic switch group; and the second metal oxide MOV is respectively connected with the first metal oxide MOV and the second power electronic switch group. The technical problems that an existing hybrid direct current circuit breaker is not suitable for a low-voltage direct current system and the loss is high in the turn-off process are solved.

The invention relates to the technical field of intelligent power grids, in particular to a low-voltage draw-out type switch cabinet which comprises a cabinet body, a power grid arranged on the inner side wall of the cabinet body, a heat dissipation plate arranged on the inner side wall of the cabinet body, a plurality of static contacts arranged on the inner side wall of the cabinet body and a cleaning mechanism arranged on the inner side wall of the cabinet body and used for cleaning the power grid. The cleaning mechanism comprises two first electric sliding rails arranged on the inner side wall of the cabinet body, according to the low-voltage draw-out type switch cabinet, the overturning plate is driven by the first motor to rotate at multiple angles, the spraying head can evenly cover the outer corners of the cabinet body after the insect repellent is atomized, reptiles are dispersed from the source, and the low-voltage draw-out type switch cabinet is convenient to use. The cleaning mechanism can be quickly started, heat dissipation blocking and equipment faults caused by accumulation of dead insects are prevented, and it is guaranteed that the low-voltage draw-out type switch cabinet is always kept in a safe and stable working state in long-term operation.

The invention discloses a voltage acquisition circuit, an alternating current power supply, a voltage acquisition method, a voltage acquisition device and a medium. A far-end sampling unit; the in-phase input end of the first comparison unit is connected with the near-end sampling unit, and the inverted input end is grounded; the in-phase input end of the second comparison unit is connected with the far-end sampling unit, and the inverted input end is grounded; the input end of the XOR unit is connected with the output ends of the first comparison unit and the second comparison unit; the in-phase input end of the third comparison unit is connected with the output end of the XOR unit, the inverted input end inputs reference voltage, and the reference voltage is smaller than half of the power supply voltage; the control unit is used for judging that far-end sensing sampling is abnormal when the difference effective value of the voltages output by the near-end sampling unit and the far-end sampling unit is smaller than the preset compensation voltage and the abnormal comparison voltage output by the third comparison unit is 1. According to the invention, when the AC power supply outputs low voltage, the conditions of disconnection and reverse connection of the far-end induction sampling can be identified.

The present disclosure provides a gate driving circuit and a display panel. by the control of one of the fourth node, the output end of the second output module, and the first node of the shift register of the next stage, the voltage regulating module may utilize a low voltage signal to stabilize or reduce the gate voltage of the second transistor, so that the second transistor is stable or preferably in the cut-off state to reduce the leakage current. In this way, voltage level of the second gate driving signal can be maintained at a high voltage level or a pulse amplitude.

The invention discloses a low-voltage equipment management method and system for a power distribution network, and the method comprises the steps: S1, collecting the operation parameters of all low-voltage equipment in real time through an Internet of Things terminal node disposed at the low-voltage side of the power distribution network; s2, on the basis of the real-time data in the S1, combining dynamic change characteristics of the power distribution network topology, constructing an adaptive topology network model through edge computing nodes, and dynamically updating a connection relation and a load path between equipment by the model by adopting a graph theory algorithm; s3, inputting the real-time data in the S1 into a preset fault diagnosis model, identifying abnormal equipment and positioning a fault type by the model through fusion of a deep belief network and a random forest algorithm, and predicting a health degree attenuation trend of the equipment at the same time; and S4, according to the topology model in the S2 and the fault diagnosis result in the S3, generating a resource optimization allocation strategy based on a dynamic programming algorithm, including adjusting the switching priority of standby equipment, reconstructing a load allocation path, and sending a control instruction to a specified terminal through a communication module.

A heterojunction device having at least three terminals, the at least three terminals comprising a high voltage terminal, a low voltage terminal and a control terminal. The heterojunction device further comprises at least one main power heterojunction transistor, an auxiliary gate circuit comprising at least one first low-voltage heterojunction transistor, a pull-down circuit comprising a capacitor and a charging path for the capacitor. The heterojunction device further comprises at least one monolithically integrated component, wherein the capacitor is configured to provide an internal rail voltage for the at least one monolithically integrated component.

A system comprises: a high voltage (HV) direct current (DC) to DC converter (HVDC) including: one or more transformers; a bridge driver connected to a primary side of the one or more transformers; and one or more bridge rectifiers connected to a secondary side of the one or more transformers, the one or more bridge rectifiers including one or more bridge rectifier switches; a low voltage (LV) DC to DC converter (LVDC) connected to the HVDC; and a boost converter including: an inductor connected to the one or more bridge rectifier switches; and one or more boost configuration switches operable, in combination with the one or more bridge rectifier switches, to configure the boost converter into each of a bypass configuration and a boost configuration, to regulate a voltage at the LVDC.

The invention relates to the technical field of partial discharge detection, in particular to a partial discharge detection method and system for a high-low voltage switch cabinet, and the method comprises the steps: obtaining electromagnetic wave signals and power system voltage data of each sensor position in real time; acquiring a partial discharge period in each detection window according to the electromagnetic wave maximum value of all the sensors in each power frequency period in each detection window, the distance between the electromagnetic wave maximum value and the voltage wave crest and the voltage wave trough of the power system, and the electromagnetic wave signal difference between the sensors; and according to the dispersion degree of the electromagnetic wave maximum values of all the sensors under each partial discharge period in each detection window, the electromagnetic wave signal frequency domain energy of each partial discharge period and the proportion of the partial discharge period in each detection window, obtaining the existence confidence of each detection window, and judging whether partial discharge exists under the current detection window or not. According to the invention, by analyzing the distinguishing characteristics of the partial discharge and the electromagnetic interference in the electromagnetic wave signals at multiple positions, the detection precision of the partial discharge is improved.

A pixel includes a light-emitting element including a first electrode and a second electrode connected to a low power line which transmits a low power voltage, a pulse width modulator which controls an emission time duration of the light-emitting element based on a data voltage and a sweep signal, and a constant current generator which supplies a driving current having a constant level to the light-emitting element based on a constant current generation voltage. The sweep signal has a first high voltage level in a non-emission period, and is boosted to a second high voltage level, which is higher than the first high voltage level, before decreasing to a low voltage level lower than the first high voltage level in an emission period.

Systems and methods for operating a vehicle power system are described. The vehicle power system includes an inverter and an electric machine. Switches and a diode are arranged in a way that allows a traction battery to be charged by either a lower voltage charger or a higher voltage charger. Additionally, the switches and diode allow the vehicle power system to heat the traction battery so that the traction battery may operate in a desired temperature range.