45 results about "Instantaneous energy" patented technology

The invention discloses a data processing method and system for a precise automatic multi-axis numerical control electric spark forming machine, and the method comprises the steps: mapping preprocessed data into a digital twin model for fusion analysis, and extracting fusion features including instantaneous energy density, an effective machining angle, a thermal error compensation amount and a chip removal efficiency evaluation value; based on the fused feature data, performing real-time state evaluation and future discharge trend prediction by using a LightGBM neural network model, and outputting a processing prediction result; and a multi-target optimization function is established, an improved NSGA-II algorithm is utilized to carry out rapid optimization search by taking the current processing parameters as an initial population, a multi-axis cooperative motion instruction is generated, and the multi-axis cooperative motion instruction is transmitted to a multi-axis motion control module and a pulse power supply module to be executed. And the processing stability and reliability are improved.

The invention relates to the field of electric power systems, in particular to an energy storage dynamic optimization scheduling method and system of an electric power system and a storage medium, and the method comprises the steps: S1, building an energy storage dynamic calculation model; s3, energy consumption models of a water chilling unit, an air source heat pump, a water pump and a cooling tower are established respectively, and instantaneous energy consumption under different working conditions is calculated by considering operation working conditions and environmental parameter correction; and S4, outputting the utilization rate, the maximum adjusting power, the average adjusting power, the maximum adjusting capacity proportion and the accumulative adjusting electric quantity proportion of the energy storage device, and carrying out quantitative evaluation. According to the method, supply and demand state changes such as valley load, flat load, peak load, peak load and the like of the power system can be identified in real time / quasi-real time, the time periods and power of energy storage and energy release are adjusted, dynamic power distribution of a host in each load time period is realized, and the overall energy efficiency level and operation stability of the system are improved.

The invention relates to the technical field of electronic data processing, and discloses a diesel engine operation state real-time monitoring method and system, and the method comprises the steps: obtaining a vibration signal of a measurement point on the surface of an engine body as an original signal; modal decomposition is carried out to obtain a final intrinsic mode function, and the decomposition process comprises the steps that multiple times of lumped operation are executed, in each time of lumped operation, an auxiliary noise signal is added into a to-be-decomposed original signal, then the screening iteration process is executed repeatedly, and a set of temporary intrinsic mode functions are obtained through separation in sequence; performing weighted average on the temporary intrinsic mode functions of the same order obtained in all the lumped operations to obtain a final intrinsic mode function of the order; hilbert transform is carried out on the intrinsic mode function, joint distribution of instantaneous energy and instantaneous frequency of the intrinsic mode function is constructed, and statistical and geometric morphological features are extracted to form feature vectors; according to the method, modal aliasing can be inhibited, noise residues are eliminated, and the accuracy of a running state monitoring result is improved.

The invention relates to the technical field of charging switching control, in particular to a dynamic switching system for cooperative work of wireless charging and wired charging, which performs node modeling and edge weight propagation on multiple parameters such as magnetic field intensity, current fluctuation ratio, contact resistance and temperature threshold through a graph neural network. Structured expression and dynamic updating of a nonlinear coupling relation among parameters are achieved, abnormal feature aggregation and channel state characterization are more refined, fuzzy reasoning and weight adjustment are conducted on multiple variables such as power output, the heat growth rate, the voltage drop rate and the energy efficiency ratio through fuzzy logic control, the stability of a channel priority sequence is enhanced, and the stability of the channel priority sequence is improved. Through dynamic detection of power curve intersection points and transition section time sequence calculation, continuous power distribution is converted into a smooth function interval, instantaneous energy abrupt change during switching is reduced, closed-loop correction of multi-period signals is achieved, and the system keeps stable operation and energy efficiency output consistency under high-dimensional parameter disturbance.

The invention relates to the technical field of electric energy metering, in particular to a high-precision voltage and current synchronous metering system of an alternating current and direct current integrated standard electric energy meter, which is characterized in that a hysteresis analysis module and an eddy current analysis module are used for respectively analyzing current signals to obtain a hysteresis intensity factor and an eddy current loss factor of the electric energy meter; a time scale weight and an instantaneous energy loss proportion are introduced through a hysteresis and eddy current coupling module, a comprehensive loss factor of an eddy current effect and a hysteresis effect is analyzed, self-adaptive distribution of weights of the eddy current effect and the hysteresis effect is realized, and primary compensation is performed on a current signal; the temperature compensation module analyzes the influence of the temperature on the electric energy meter, and performs temperature compensation on the voltage signal and the current signal. The system can effectively cope with complex dynamic working conditions, guarantees the temperature stability of measurement, cuts off the transmission and accumulation paths of errors from the source, improves the metering precision under AC / DC mixed signals, and guarantees the interpretability and reliability of the system.

A pumped storage unit main transformer winding inter-turn short circuit fault diagnosis positioning method and system, comprising: pulse injection is carried out on the main transformer of the pumped storage unit in the shutdown state, and the voltage response waveform is obtained; the characteristic waveform is calculated, the different connection modes of the pumped storage unit main transformer winding are combined, whether the pumped storage unit main transformer winding exists fault and the fault phase are judged; the VMD decomposition optimization model and the NTEO wave head extraction optimization model with optimal parameters are constructed, and the instantaneous energy spectrum is obtained based on the model and any characteristic phase containing characteristic phase; the fault positioning formula is constructed based on the instantaneous energy spectrum, the fault positioning formula corresponding to the relationship between the characteristic phase and the fault phase in the voltage response waveform is selected according to the relationship between the characteristic phase and the fault phase, and the positioning of the fault coil is obtained. The method has high reliability, high fault diagnosis accuracy and small positioning result error, and can meet the needs of pumped storage unit main transformer winding inter-turn short circuit fault diagnosis and positioning in engineering.

The invention relates to the technical field of industrial cleaning, in particular to an annular pulse plasma cleaning device and method for a precise instrument. According to the technical scheme, the plasma cleaning device comprises a high-voltage pulse power supply, a host device, a supporting bracket and an object carrying platform, the high-voltage pulse power supply, the host device, the supporting bracket and the carrying platform are sequentially arranged from top to bottom; the host device comprises an air valve, an outer electrode, a diagnosis port, a cylindrical inner electrode, a conical inner electrode, a solenoid, a top flange, an insulating part, a sealing part and a control computer. High-density compact ring plasma clusters are adopted for pulse type directional cleaning, cleaning uniformity is improved, heat input is greatly reduced due to the instantaneous energy deposition characteristic, damage to heat-sensitive materials is avoided, the modular generator is compact in structure and convenient and fast to maintain, accurate positioning is achieved through cooperation with X-axis and Y-axis guide rails, and the service life of the modular generator is prolonged. The device is suitable for efficient cleaning of complex structures and stubborn pollutants.

The invention discloses a fault positioning method and device for a power supply line of a coal mining machine, a medium and equipment, and relates to the technical field of coal mine intelligent power grid information. The method comprises the following steps: carrying out adaptive decomposition on an actual current traveling wave through a variational mode decomposition algorithm after parameters are optimized through a pigeon inspired algorithm; selecting a head end IMF component and a tail end IMF component from the plurality of IMF components at the head end of the actual current traveling wave and the plurality of IMF components at the tail end of the actual current traveling wave; respectively extracting instantaneous energy distribution diagrams of the head end IMF component and the tail end IMF component; capturing moments corresponding to energy abrupt change points from the instantaneous energy distribution diagrams of the head end IMF component and the tail end IMF component; according to the moment when the actual current traveling wave reaches the head end and the moment when the actual current traveling wave reaches the tail end, the distance between the single-phase earth fault point and the head end of the coal cutter power supply line is determined. The method can improve the accuracy of coal mine circuit fault positioning.

The invention relates to a multi-level wide-modulation-ratio energy balance cycle control method and device for a high-speed flywheel, and the method is applied to the recycling of regenerative braking energy of a metro traction power supply system, and the capacitor voltage balance of a sub-module is maintained by selectively adopting a bubble sorting-carrier phase-shifting modulation method. When the difference value of the capacitor voltage of the sub-module is large, the capacitor voltage balance of the sub-module can be maintained, a PWM signal is generated to control the on and off of a switching device of the sub-module, and the problem of voltage balance control of the sub-module of the modular multilevel converter under high-frequency fundamental waves is solved. The device can be mounted on a direct-current traction network side of a subway traction power supply system, is used for recycling regenerative braking energy of a subway, and can perfectly meet the instantaneous energy requirement of frequent start and stop of the subway. Compared with the prior art, the wide-modulation-ratio energy balance cycle control method is utilized, the electric energy and kinetic energy conversion efficiency can reach 90%-95%, and the electric energy and kinetic energy conversion efficiency is far higher than that of a traditional energy storage system.

This invention relates to a method and apparatus for high-speed flywheel multi-level wide-modulation specific energy balance cyclic control. The method is applied to the recycling of regenerative braking energy in subway traction power supply systems. By selectively employing a bubble sorting-carrier phase-shift modulation method to maintain the voltage balance of sub-module capacitors, it can maintain voltage balance even when the voltage difference between sub-module capacitors is large, and generate PWM signals to control the switching on and off of sub-module switching devices, thus solving the problem of voltage balance control for modular multi-level converter sub-modules under high-frequency fundamental frequencies. This apparatus can be installed on the DC traction network side of the subway traction power supply system to recycle the subway's regenerative braking energy, perfectly matching the instantaneous energy demands of frequent subway starts and stops. Compared with existing technologies, this invention, utilizing a wide-modulation specific energy balance cyclic control method, achieves an energy-to-kinetic energy conversion efficiency of 90%-95%, far exceeding traditional energy storage systems.

The invention relates to the technical field of power fault discrimination, in particular to a power supply network ground fault discrimination method and system based on zero-sequence electrical parameter signals, and the method comprises the steps: obtaining various zero-sequence electrical parameter signals; decomposing the various zero-sequence electrical parameter signals, analyzing similarity measurement of amplitude distribution between the various zero-sequence electrical parameter signals and each IMF component, and determining a noise influence characteristic value of each IMF component of the various zero-sequence electrical parameter signals in combination with the confusion degree of each IMF component; determining a peak distribution characteristic value of each IMF component based on the overall fluctuation characteristic of the instantaneous energy intensity, and obtaining a noise influence coefficient of each IMF component; determining a wavelet denoising threshold value for each layer of each IMF component; and reconstructing all the de-noised IMF components to obtain various filtered zero-sequence electrical parameter signals, and carrying out ground fault judgment. The invention aims to improve the accuracy of ground fault judgment.

The invention relates to the technical field of micro-grid instantaneous energy hierarchical regulation and control, and discloses a micro-grid instantaneous energy hierarchical regulation and control method, which comprises the steps of setting a hierarchical limit value of a micro-grid instantaneous energy balance index; dC side voltage values and current values of all converters in the microgrid are detected in real time, and an instantaneous energy balance index value of the microgrid is calculated; judging the instantaneous energy balance index value of the micro-grid, and judging whether the instantaneous energy per unit value of the micro-grid exceeds the limit or not; and if it is judged that large disturbance or fault occurs in the micro-grid, the micro-grid stops running. The method not only helps to guarantee safe and stable operation of the microgrid, but also helps to improve the absorption capability of the microgrid to the distributed power supply.

The invention discloses a method for tracing a dissipated energy flow of a power system. The method comprises the following steps: firstly, setting a sensitive subsynchronous oscillation online detection link with relatively low calculation complexity, and positioning subsynchronous oscillation in time at the initial stage of oscillation; secondly, retaining a subsynchronous frequency band component in the signal based on synchronous compression generalized S-transform; taking a 60 Hz system as an example, the subsynchronous oscillation (SSO) frequency is between 5 Hz and 55 Hz. Therefore, the band-pass filter in the frequency range can be used for variables such as voltage and active / reactive power; then, for the preprocessed and filtered signals, calculating instantaneous energy dissipation of each branch or each bus; and finally, comparing the instantaneous energy dissipation of the branches and the bus, and judging the oscillation source. The method is simple in calculation, can accurately calculate the frequency, the amplitude and the phase angle of each harmonic wave of the power system, and has a very high practical value.

This invention provides an active power regulation method and system that considers instantaneous energy distribution efficiency, relating to the field of wind power grid-connected control technology. The invention establishes a synchronized operation system model based on the system parameters of the wind turbine and synchronous machine, determines the total inherent active power regulation coefficient and synchronous torque coefficient of the system to obtain the conservative instantaneous power of the synchronized system; introduces an active power regulation proportional coefficient into the model and constructs an instantaneous energy function during synchronized system oscillation, analyzing the instantaneous energy distribution law between synchronized units; after a disturbance, the instantaneous energy distribution efficiency is determined based on the instantaneous energy of the synchronous machine, a target efficiency is given, and the active power regulation proportional coefficient is solved based on the total instantaneous energy conservation, thereby calculating the design value of the active power regulation coefficient and setting it in the active power controller of the wind turbine unit, so that when the system detects frequency or power disturbances, the wind turbine participates in regulation according to the design value, thereby improving the power oscillation suppression capability.

This invention relates to the technical field of hydrogen production through water electrolysis, and discloses a collaborative support method and energy management platform for hydrogen production through water electrolysis energy storage devices. The platform includes a data acquisition layer, a collaborative control layer, and an execution layer. Instantaneous charge and discharge compensation is performed by the energy storage device to cover the response vacuum period during the initial stage of hydrogen production power ramp-up. Simultaneously, a stepped hydrogen production power adjustment mechanism is adopted to adjust the single power change amplitude to be lower than the rated power and adjacent adjustment intervals, forming a multi-timescale collaborative chain of "instantaneous energy storage compensation + stable hydrogen production follow-up." Through the hydrogen production start-up threshold and the energy storage device start-up threshold, combined with the energy storage power dynamic calculation model, the discharge power is linearly adjusted in real time following the frequency deviation amplitude, achieving intelligent division of labor of "high-frequency fluctuation energy storage main control and continuous fluctuation hydrogen production relay."

The invention relates to the technical field of coal-fired power plant boilers, and provides a boiler instantaneous energy quality accurate regulation and control rapid load changing system and a control method.The system comprises a main steam system and a reheat steam system and further comprises a first bypass steam system, a second bypass steam system and a control unit; an inlet of the first bypass steam system is connected to a water-cooled wall outlet of the main steam system, and an outlet of the first bypass steam system is connected to a platen superheater inlet of the main steam system; an inlet of the second bypass steam system is connected to a low-temperature reheater outlet of the reheat steam system, and an outlet of the second bypass steam system is connected to a high-temperature reheater inlet of the reheat steam system; the control unit is configured to adjust the steam working medium flow of the first bypass steam system and the second bypass steam system according to a load instruction during the unit load increasing period. According to the scheme, the transformation cost is low, the implementation difficulty is small, and a feasible technical path is provided for an active-service unit to achieve rapid load change and energy quality accurate regulation and control standard reaching.

This invention discloses a high-precision ranging method and system for time-refined DC back-traveling waves, belonging to the field of power system fault location technology. The method includes: acquiring signals and performing mode transformation to extract first-mode voltage and current signals; establishing a time-domain expression for the back-traveling wave; performing wavelet denoising on the signals to extract the first-mode DC voltage signal; reconstructing the time scale in the time-refined model; performing variational mode decomposition and Hilbert transform to obtain instantaneous amplitude and instantaneous energy sequences, constructing an energy kurtosis index, detecting sudden increases in energy kurtosis, and identifying the arrival time of the first DC back-traveling wavefront generated by the fault; calculating the wavefront arrival time difference based on the arrival times of the first DC back-traveling wavefront measured at both ends of the DC line, and determining the location of the fault point by combining the DC line length and traveling wave propagation characteristics. This invention has low dependence on traveling wave propagation parameters, provides reliable ranging results, and is applicable to deep-sea offshore wind power flexible DC systems.

This invention relates to the field of electricity metering technology, specifically to a high-precision voltage and current synchronous metering system for AC / DC integrated standard electricity meters. The system uses a hysteresis analysis module and an eddy current analysis module to analyze the current signal, obtaining the hysteresis intensity factor and eddy current loss factor of the electricity meter. Then, through a hysteresis and eddy current coupling module, time scale weights and instantaneous energy loss ratios are introduced to analyze the combined loss factor of eddy current and hysteresis effects, achieving adaptive allocation of their weights and performing primary compensation on the current signal. A temperature compensation module analyzes the temperature effect on the electricity meter and performs temperature compensation on both the voltage and current signals. This system can effectively handle complex dynamic operating conditions, ensure temperature stability of measurements, and cut off the transmission and accumulation path of errors at their source, improving metering accuracy under AC / DC mixed signals and ensuring the interpretability and reliability of the system.

The invention discloses a subsynchronous traceability method for a power system, and the method comprises the steps: firstly expanding a phase angle of a voltage signal, eliminating error data in the signal, and interpolating missing data; secondly, retaining subsynchronous frequency band components in the signal based on improved multiple synchronous compression transformation; taking a 60 Hz system as an example, the subsynchronous oscillation (SSO) frequency is between 5 Hz and 55 Hz. Therefore, the band-pass filter in the frequency range can be used for variables such as voltage and active / reactive power; then, for the preprocessed and filtered signals, calculating instantaneous energy dissipation of each branch or each bus; and finally, comparing the instantaneous energy dissipation of the branches and the bus, and judging the oscillation source. The method is simple in calculation, can accurately calculate the frequency, the amplitude and the phase angle of each harmonic wave of the power system, and has a very high practical value.

The application provides a flexible direct current power transmission system fault detection method, comprising the following steps: obtaining an original current signal; setting a search range for a parameter of a variational mode decomposition, thereby obtaining an original setting parameter; decomposing the original current signal into mode functions with different center frequencies; selecting a value corresponding to a minimum relative entropy as an optimal parameter; performing a final variational mode decomposition on the original current signal by using the optimal parameter, thereby obtaining final mode functions in an ordered arrangement; selecting a second final mode function from the final mode functions; performing a Hilbert-Huang transform on the second final mode function, thereby obtaining a Hilbert spectrum of the second final mode function; performing a synchronous compression transform on the Hilbert spectrum, thereby obtaining an instantaneous energy density of the Hilbert spectrum; and comparing an amplitude of the instantaneous energy density with a steady-state threshold, thereby realizing fault detection. The application can realize accurate and rapid fault detection on a flexible direct current power transmission system.

This invention discloses an automatic detection and alarm system for electrical faults in generator sets, relating to the field of fault detection technology. By constructing a multi-module collaborative system consisting of signal acquisition, energy calculation, dynamic threshold generation, spectral feature extraction, waveform morphology recognition, comprehensive judgment, and alarm response, it integrates instantaneous energy, spectral disturbance characteristics, and non-periodic waveform morphology characteristics. Employing multi-dimensional feature fusion and intelligent discrimination algorithms, it effectively solves the problems in existing technologies where high-impedance faults are easily misjudged by low-frequency interference, leading to system passivation and missed fault detection. It achieves intelligent identification and real-time alarm for high-impedance electrical faults with high sensitivity, low false alarm rate, and graded response, significantly improving the operational safety and maintenance efficiency of generator sets in complex industrial environments.

The invention discloses a distributed photovoltaic system DC arc fault identification method and system, a medium, equipment and a product, and belongs to the technical field of DC arc fault identification. The method comprises the following steps: carrying out data preprocessing on collected current data, and carrying out feature extraction on the preprocessed current data by utilizing a Teager energy operator to obtain an instantaneous energy change feature sequence; performing sliding window processing on the instantaneous energy change characteristic sequence, and calculating a mean value, a standard deviation and a dynamic threshold th1 of numerical values in each time window; if th2 numerical values in continuous n numerical values are greater than a dynamic threshold value th1 in the instantaneous energy change characteristic sequence, it is judged that direct current arc is generated, and otherwise, it is judged that the state is normal. According to the method, local nonlinear energy analysis is carried out on the current time domain signal, arc detection is realized in combination with the adaptive threshold, and the method has the advantages of high operation efficiency, low false alarm rate, high real-time performance and the like, and is suitable for a distributed photovoltaic system.

The application relates to a high-transmission-ratio electric grab and a control method thereof, and effectively solves the problems of increased friction loss, low energy conversion efficiency, poor transmission, fixed transmission ratio and wasted energy consumption of a traditional electric grab; the technical solution comprises the following steps: the high-transmission-ratio electric grab and the control method thereof are provided with a magnetic transmission module, a hydraulic impact module and a self-adaptive control system, the magnetic non-contact transmission can greatly reduce the friction loss and reduce the maintenance cost, the magnetic transmission module can drive the hydraulic impact module to realize instantaneous energy release, thereby effectively improving the transmission of the electric grab and reducing energy loss; the self-adaptive control system can detect the magnetic field intensity and the hydraulic pressure, thereby fusing and calculating the load torque, and the linear driving mechanism can be used for real-time dynamic adjustment of the magnetic gap, so that the impact frequency of the electric grab can be dynamically adjusted according to the load condition, different working conditions can be adapted to, and the energy consumption can be effectively reduced.

The invention belongs to the field of data processing of industrial process supervision, and discloses a carbon emission evaluation method for waste incineration power generation, which comprises the following steps: synchronizing business management data and operation parameters of a process control system, establishing a background thermal power baseline model in a new material-free period, and establishing a background thermal power baseline model; the deviation integral of the actual thermal power relative to the baseline model after each time of feeding is calculated, an instantaneous energy response value is obtained, when signal superposition is caused by high-frequency feeding, unaliasing processing based on a self-learning response template is started to separate each time of response, and standard fuel is periodically injected to calibrate the baseline model; according to the method, continuous industrial data are segmented and attributed by using the discreteness characteristics of commercial events, and the corresponding relation between the batch of materials with specific sources and the real combustion performance in the furnace is reconstructed under the condition that the physical forms of the garbage are mixed, so that the technical problem of management information failure caused by production homogenization operation is solved.

The invention discloses a real-time measurement system for the use process of a high-energy-efficiency distribution transformer. The real-time measurement system comprises a data acquisition module, a loss calculation module, an energy efficiency evaluation module and an optimization scheduling decision module, the invention relates to the technical field of power monitoring. According to the real-time measurement system for the use process of the high-energy-efficiency distribution transformer, an electromagnetic-mechanical-thermal multi-physics field coupling monitoring system is formed, abnormal vibration caused by looseness of an iron core is monitored and captured through vibration acceleration, insulation degradation caused by partial discharge is monitored through a discharge pulse signal of the distribution transformer, the loss calculation precision is improved, and the real-time measurement of the use process of the high-energy-efficiency distribution transformer is realized. An iron loss-copper loss-stray loss three-level decomposition framework is adopted, the loss estimation precision is further improved, an instantaneous energy efficiency and accumulated energy efficiency two-dimensional evaluation framework is constructed, data support is provided for dynamic scheduling of the distribution transformer, long-term energy consumption analysis can be achieved without power failure, and the real-time performance of detection is guaranteed.

The invention discloses a plasma ignition circuit integration device adopting a dual-redundancy design, relates to the technical field of combustion chambers of gas turbines, and aims to solve the problems that an existing plasma ignition circuit adopting a multi-redundancy or dual-redundancy power supply is long in switching time and poor in current sharing precision. The device comprises a detection module, an intelligent selection module, a load balancing module and a super capacitor compensation module, the detection module is used for collecting state data of two power supplies, sending the state data to the load balancing module, generating a switching control signal according to the state data, and sending the switching control signal to the intelligent selection module; the intelligent selection module executes power supply switching based on the MOSFET switch according to the switching control signal; the load balancing module generates a trigger signal according to the state data and dynamically adjusts the output impedance of the double-path power supply to realize current balanced distribution; and the super capacitor compensation module provides instantaneous energy injection for the load under the action of the trigger signal.

The application discloses a kind of mobile power car and grid diesel generator protection method and system based on Teager energy operator.This method only utilizes power car machine end single-end measurement data, without relying on external communication or external CT.Through processing the collected voltage and current signals, the instantaneous energy value is calculated using Teager energy operator, and a multi-dimensional feature index is constructed to accurately distinguish and differentiate the faults inside and outside the vehicle.This method has small calculation amount and extremely fast response speed, can identify faults in the initial stage of short-circuit current rise, reduce the impact of faults on the generator, has strong anti-interference ability, can effectively shield the mis-trip caused by non-short-circuit disturbance of the power grid, and can also sensitively capture early minor faults inside the generator.

The invention relates to the technical field of data processing, and discloses a capacitor loss trend prediction method based on big data analysis, and the method comprises the steps: periodically collecting basic operation data in the operation process of a capacitor, dividing the operation stage of the capacitor in combination with the operation time of equipment, and constructing stage loss characteristics. On this basis, the instantaneous energy consumption is continuously accumulated to form an accumulated loss energy curve, and the loss growth rate and the acceleration are further introduced to identify whether the loss mechanism has structural change. Aiming at the difference between the abnormal mechanism interval and the stable interval, establishing a loss evolution trend model in the stable interval, predicting a future loss trend and a time point which may reach a design limit according to the loss evolution trend model, and calibrating abnormal data generated by interference. And classifying the operation risk of the capacitor by combining the residual loss capacity with the residual use time, and outputting an operation and maintenance processing instruction.

The invention provides a fault detection method for a flexible DC power transmission system. The method comprises the following steps: acquiring an original current signal; setting a search range for the parameters of the variational mode decomposition so as to obtain original set parameters; decomposing the original current signal into modal functions with different center frequencies; selecting a value corresponding to the minimum relative entropy as an optimal parameter; carrying out final variational mode decomposition on the original current signal by adopting the optimal parameter to obtain orderly arranged final mode functions, selecting a second final mode function, and carrying out Hilbert-Huang transform on the second final mode function to obtain a Hilbert spectrum of the second final mode function; and performing synchronous compression transformation processing on the Hilbert spectrum to obtain the instantaneous energy density of the Hilbert spectrum, and comparing the amplitude of the instantaneous energy density with a steady-state threshold to realize fault detection. According to the invention, accurate and rapid fault detection of the flexible DC power transmission system can be realized.

The present application provides a needle-free injection device, comprising a mechanical spring energy storage assembly, a seat force balance assembly, a closed-loop magneto-electric device adjustment assembly, an injector assembly and a circuit control assembly; the circuit control assembly is used to control the mechanical spring energy storage assembly to generate mechanical energy storage and instantaneous energy release; the seat force balance assembly is used to balance the seat force when the mechanical spring energy storage assembly releases the instantaneous energy; the closed-loop magneto-electric device adjustment assembly comprises a magnetic shaft and a coil on a magnetic shaft motor; the magnetic shaft is used to bear the impact force when the mechanical spring energy storage assembly releases the instantaneous energy and transmit the impact force to the injector assembly to inject liquid; the circuit control assembly adjusts the current of the coil according to the speed sensing signal of the magnetic shaft monitored by the coil to accelerate or decelerate the movement of the magnetic shaft. Through the design of the seat force balance assembly and the closed-loop magneto-electric device adjustment assembly, the present application can control the injection process, has low energy consumption, can solve the problem of the back seat force and has a small size.