593 results about "Induced voltage" patented technology

The invention discloses a pulsed eddy current detection method and system for a thermal power pipeline with a coating layer, and relates to the technical field of pulsed eddy current nondestructive detection.The pulsed eddy current detection method comprises the steps that pulsed eddy current detection simulation and experiment are conducted under the condition of a three-dimensional simulation model and a test piece, and excitation current waveform, amplitude and frequency parameters are determined; an induced voltage signal is collected, peak values, time points and attenuation characteristics are extracted, the corresponding relation between the wall thickness, the coating layer thickness and the welding seam structure and detection signals is constructed, a parameterized database is constructed, and temperature correction is completed; and optimizing a sensor structure and a signal acquisition scheme according to a parameterized database, obtaining detection data in a pipeline operation state, completing two-dimensional imaging of wall thickness distribution and welding seam positioning, and forming detection information covering a straight pipe, an elbow and a welding seam area. According to the method, wall thickness detection and welding seam positioning of the thermal power pipeline under the conditions of a thick wall and a thick coating layer are achieved through the full-process design of test piece modeling, simulation experiment and imaging collection.

A method for testing sheath impedance in a high-voltage cable cross-bonding system. Three-phase current data and three-phase grounding circulating current data from a first cable body segment and a last cable body segment in cross-bonding units, and three-phase current data, three-phase grounding circulating current data, and three-phase induced voltage data from a cable body at a cross-bonding box are detected and collected, thereby directly calculating three-phase sheath impedance of the three cable segments and determining whether the three-phase sheath impedance is abnormal (step 5), thus determining whether the tested cross-bonding units have a defect. The present invention involves a simple operation, achieves an accurate testing result, and can achieve energized testing without an external excitation source. By performing real-time testing on the cross-bonding units and calculating the sheath impedance of the three cable segments in the cross-bonding units in real time, the states of the cross-bonding units can be determined in real time, which makes it possible to detect a cable fault immediately, thereby preventing a loss caused due to the cable fault.

The invention provides a method and a system for measuring plasma current in a quasi-ring symmetrical star simulator, and relates to the technical field of star simulators, and the method comprises the steps: determining a sensor design index according to a bootstrap current simulation calculation result, and converting the design index into an actual arrangement scheme according to an installation environment constraint; all the magnet coils are independently excited in a plasma-free state, wall eddy current interference signals generated by the magnet coils are calibrated, and thus wall eddy current calibration voltage signals are output; a sensor in an actual arrangement scheme is used for synchronously collecting a total original induced voltage signal including plasma current and wall eddy current; an integral voltage signal representing the total current is output; and compensating the integral voltage signal by using the wall eddy current calibration voltage signal, and inverting the final measurement value of the plasma current in the quasi-ring symmetric star simulator. The device and the method have the beneficial effects that the interference of a stray field on a measurement result is weakened, and a high-precision diagnostic tool is provided for the plasma physical research of the star simulator.

The invention is suitable for the technical field of grounding grid defect evaluation, and provides a transient electromagnetism-based grounding grid corrosion defect evaluation method and system, and the method comprises the steps: placing a sensor of a transient electromagnetic detection device above a to-be-detected region of a grounding grid, injecting a pulse current excitation signal into a conical focusing excitation coil, and carrying out the detection of the to-be-detected region of the grounding grid; acquiring an induced voltage time sequence signal through a receiving coil; extracting at least one characteristic parameter from the induced voltage time sequence signal, wherein the characteristic parameter comprises a signal peak value, peak value time, an attenuation rate or a signal integral quantity; inputting the characteristic parameters into a preset corrosion evaluation model, and performing inversion to obtain a residual thickness value or a corrosion depth value of the grounding grid in the to-be-detected area; generating and outputting a quantitative evaluation result containing the residual thickness value or the corrosion depth value; the method can be implemented in a non-stop state of the grounding grid, and an efficient and reliable decision basis is provided for safe operation and state maintenance of a power system.

The invention belongs to the technical field of geophysical exploration, and particularly discloses a differential transient electromagnetic method device and an unexploded ordnance detection method thereof.The differential transient electromagnetic method device is characterized in that a transmitter injects emission current into an emission loop, and the emission loop generates a primary field excitation signal; the underground anomalous body target generates a secondary field excitation signal under the action of the primary field excitation signal; the receiving coil assembly is based on the structure of a differential coil, synchronously counteracts a primary field excitation signal and a uniform background signal in an induced voltage, and expands a local asymmetric differential signal generated by an underground anomalous body target; and the receiver carries out time sequence analysis on the local asymmetric differential signals and extracts differential signal features so as to realize positioning and identification of an underground anomalous body target. The device is suitable for detection of shallow-buried small bodies such as UXO, the overall arrangement range of the device is small, and rapid arrangement and mobile observation in the field are facilitated.

The present invention discloses a wireless ultrasonic measurement system and a construction method thereof, wherein the measurement system includes a sensing module and a detection module; the sensing module includes a piezoelectric layer on the surface of the detection object, a first lead-out electrode structure, a first grounding electrode structure, a first insulating plate, and a sensing coil; the first insulating plate is provided with a first opening; the first lead-out electrode structure includes a first lead-out electrode on the top of the piezoelectric layer and a second lead-out electrode in the first opening; the first grounding electrode structure includes a first grounding electrode and a second grounding electrode; the second lead-out electrode and the second grounding electrode are respectively connected to the first lead-out electrode and the first grounding electrode; the sensing coil is provided at the top of the first insulating plate. The detection system of the present invention uses an insulating plate to isolate the sensing coil away from the surface of the detection object, which is conducive to the sensing coil generating a non-zero induced voltage U ind , thereby enhancing the signal of the receiving coil, and realizing contactless ultrasonic signal reception with a receiving distance of up to 20mm.

The invention belongs to the field of sensors and signal processing, and particularly relates to a wavelet kernel scale sensitivity oriented abrasive particle induced voltage signal noise reduction method, which comprises the following steps: acquiring an abrasive particle induced voltage signal, and carrying out harmonic elimination on the abrasive particle induced voltage signal to obtain a preprocessed signal; constructing a wavelet kernel function, and calculating the wavelet kernel function and the preprocessed signal to obtain a kernel scale guiding spectrum; constructing a sparse joint noise reduction model based on the kernel scale guiding spectrum; processing the sparse joint noise reduction model to obtain a convex optimization objective function; solving the convex optimization objective function by combining a self-adaptive step gradient descent method and a self-adaptive iterative shrinkage threshold method to obtain a weight vector representing the distribution of the abrasive particle characteristic signals; carrying out binarization processing on the weight vector representing the distribution of the abrasive particle characteristic signals to obtain a characteristic indication vector; carrying out Hadamard product on the feature indication vector and the preprocessed signal, and then carrying out low-pass filtering to obtain a noise reduction signal; according to the method, the abrasive particle characteristic signals can be self-adaptively subjected to non-destructive enhancement and noise reduction processing in a strong interference environment.

A power transmission tower grounding resistance non-contact measurement method based on the electromagnetic coupling principle comprises the following steps that transmitting and receiving electromagnetic coupling coils are arranged around an iron tower grounding body, and geometric calibration and spatial positioning of a measurement area are completed by combining grounding grid structure parameters and soil conduction characteristics; injecting a high-frequency alternating-current excitation signal into the transmitting coil, and synchronously acquiring the amplitude and phase response of the induced voltage at a receiving coil end; carrying out filtering processing on the induction signal by adopting a time-frequency analysis and phase decoupling algorithm, and solving a function relationship between electromagnetic response and grounding impedance by combining a coupling equivalent model; based on experimental calibration data and scene parameters, a nonlinear mapping model of induction response and grounding resistance is constructed, and real-time inversion calculation is carried out by combining a solving result obtained in the third step. According to the invention, the real-time accurate measurement of the grounding resistance under the conditions of no power failure and no wire breakage is realized, and the safety, the operation convenience and the anti-interference capability in a complex environment in the measurement process are obviously improved.

The invention discloses a zero-voltage turn-on circuit and a zero-voltage turn-on method of a switching tube in a switching power supply, and belongs to the technical field of circuits. In a critical conduction mode, when a low-side power tube is turned off, the rising edge zero-voltage starting circuit compares a switch node voltage with an input voltage or compares the switch node voltage with an output voltage under the control of a low-side gate driving voltage, outputs a high level to a high-side gate driving end when the switch node voltage is equal to the input voltage or the output voltage, and outputs a low level to a low-side gate driving end when the high level is equal to the output voltage. A high-side power tube is controlled through a high level to realize zero-voltage starting; in a critical conduction mode, when the high-side power tube is turned off, the falling-edge zero-voltage starting circuit compares an induced voltage with a pull-up resistor voltage under the control of a high-side gate driving voltage, outputs a high level to a low-side gate driving end when the induced voltage is equal to the pull-up resistor voltage, and controls the low-side power tube to realize zero-voltage starting through the high level. The induced voltage is equal to the sum of the pull-up resistor voltage and the switch node voltage. According to the invention, the transmission delay can be reduced.

The present invention discloses a superconducting motor quench detection method and apparatus based on rotational symmetry of a motor, belonging to the technical field of superconducting motor quench detection. The method includes: acquiring terminal voltages of each group of superconducting magnets in a superconducting motor, where the superconducting motor is pre-divided into at least two unit motors by using the rotational symmetry of the motor, and superconducting magnets located at corresponding positions are selected from the at least two unit motors as a group of superconducting magnets; calculating an absolute value of a terminal voltage difference of each group of superconducting magnets; and judging whether the absolute value exceeds a preset threshold, and if the absolute value exceeds the preset threshold, determining that the superconducting magnets are in a quench state. According to the present invention, induced voltages coupled by the terminal voltages of superconducting magnets are eliminated.

The invention relates to a shaft grounding device for deriving an inductively generated voltage, current or charge from a first machine element (5), preferably a shaft, into a second machine element (1), having a shaft grounding element (4, 50) for discharging, according to the invention, the shaft grounding element (4, 50) is a component separated from a starting material, preferably a continuous article, said component being penetrated by channels (16) in the longitudinal direction thereof or being provided with perforations and / or surface structures and / or surface textures at least on the contact surface thereof with the first machine element. The invention also relates to a method for manufacturing the shaft grounding device.

The invention discloses a tunnel cable grounding ring current intelligent detection and analysis system and method, and relates to the technical field of intelligent detection, and the method comprises the following steps: collecting the current of cable metal sheath grounding ring current, sheath induction voltage, equipment temperature and tunnel humidity through a sensor; analyzing and processing the collected data to obtain comprehensive detection parameters; setting a threshold value, comparing and analyzing the obtained detection data, and judging whether an abnormal condition occurs or not; according to the generated instruction, carrying out early warning and abnormity prompting on the detected abnormal condition; according to analysis and detection of different parameters, the specific types of abnormalities can be judged, the safety detection mode is triggered when it is detected that only the safety evaluation index is abnormal, whether the numerical calculation process is abnormal or not is analyzed, the numerical abnormality situation caused by calculation abnormality can be eliminated, and the safety of the numerical calculation process is improved. Detection errors of abnormal conditions of the equipment are reduced, and the problem that the false alarm rate is high in the detection process is solved.

The invention discloses a silicon carbide MOSFET parallel current sharing system and method for a pulse power supply, and belongs to the technical field of SiC MOSFET parallel current sharing, the system comprises a main power circuit connected with a plurality of SiC MOSFETs in parallel and an active driving circuit, when the SiC MOSFETs are turned on, a source inductor generates an induced voltage in direct proportion to the current rising rate, and when the SiC MOSFETs are turned on, the active driving circuit drives the main power circuit to rotate; current sharing when a plurality of SiC MOSFETs are connected in parallel is realized through an in-phase amplification circuit used for detecting and amplifying an induced voltage, a differential amplification circuit used for detecting and comparing an induced voltage value, and a proportional current source circuit is controlled to extract a SiC MOSFET gate drive current. By adopting the method, the unbalanced current can be suppressed, the balance of the current flowing through each branch of the parallel SiC MOSFETs is ensured, the SiC MOSFET device in the high-voltage pulse power supply is effectively protected, and the working reliability of the circuit is improved.

The invention relates to a metal component defect depth detection system and method based on sweep frequency pulsed eddy current. The system comprises a pulse eddy current probe module, a pulse signal excitation module, a current amplification module, a voltage amplification module, a band-pass filtering module and a signal acquisition module. The pulsed eddy current probe module comprises an excitation probe and a receiving probe which are respectively used for transmitting excitation signal pulsed eddy current and receiving sampling data; the pulse signal excitation module is connected with the upper computer module and the current amplification module, and is used for receiving the control command and exciting pulse signal current to control probe detection; the current amplification module is used for amplifying the pulse current; the voltage amplification module is connected with the receiving probe and the band-pass filtering module and is used for amplifying the induced voltage; the band-pass filtering module is used for frequency screening; and the signal acquisition module is responsible for performing format conversion on the sampling data and uploading the sampling data to an upper computer. The system can realize excitation and signal acquisition for different depth areas, and accurately determine the characteristic frequency of defect depth.

The invention relates to the technical field of high-precision positioning, in particular to a high-precision six-degree-of-freedom magnetic positioning system and method, and the method comprises the steps: generating a three-dimensional low-frequency magnetic induction field with a preset frequency in a space through a three-axis orthogonal transmitting coil; detecting the three-dimensional low-frequency magnetic induction field through a three-axis orthogonal receiving coil to obtain an induced voltage signal; transmitting the digitized induced voltage signal to a control layer; in the control layer, the position and attitude of the receiver are estimated in real time by using a joint estimation algorithm fusing error state extended Kalman filtering and particle swarm optimization; the error state extended Kalman filtering comprises the steps of constructing a state transition matrix F of a target carrying a receiver, and constructing a process noise covariance matrix Qk and a parameterized measurement noise covariance matrix R of the system through translation acceleration noise sigma a and rotation noise sigma omega. According to the invention, the PSO module is utilized to dynamically and adaptively adjust the key parameters of the ESKF, and high-precision positioning and low-delay response are realized.

The invention provides a non-isolated LED power supply minuteness-removing turn-off circuit, which comprises a second power supply processing module, a minuteness-removing turn-off module and an LED lamp module, and is characterized in that the second power supply processing module is used for converting a high-voltage direct-current power supply into an LED lamp module working power supply; the micro-brightness removal turn-off module is arranged between the output end of the second power supply processing module and the LED lamp module and comprises a direct-current impedance conversion unit, an alternating-current impedance conversion unit and a switching tube, and the switching tube is arranged on a direct-current loop; and the control unit of the second power supply processing module reduces the DC voltage and the non-isolated AC induced voltage to be below the set voltage through the switching signal and the DC impedance conversion unit and the combined action of the switching signal and the AC impedance conversion unit, thereby realizing the minuteness-removing turn-off of the LED lamp module. According to the invention, contactless switch control can be realized, circuit loss is reduced, and working noise is reduced.

According to the multi-ring sensor for transformer substation partial discharge detection and positioning and the positioning method, a multi-ring sensor structure is formed by arranging a first magnetic ring and a second magnetic ring which are embedded with each other, are vertically placed and form an included angle of 90 degrees, and whether a discharge source exists or not is judged by measuring the induced voltage of the sensor; a measurement azimuth angle and a calculation result azimuth angle are obtained according to a positioning formula calculation result of a plurality of multi-ring sensors, the specific position of the area where the discharge source is located is obtained, re-confirmation is conducted by checking whether discharge equipment exists or not, and finally a positioning result is output. According to the invention, the acquisition of partial discharge signals can be realized, the positioning of the discharge signals can be realized, the reliability of the detection signals is improved by calculating the detection signal-to-noise ratio in real time, the loss of weak discharge signals is avoided, and the positioning accuracy is improved by analyzing and judging the positioning result. According to the invention, effective detection of partial discharge weak signals in a complex environment of industrial and mining enterprises can be met, and sudden insulation faults of equipment are avoided.

The present disclosure provides a method for optimizing a broadband noise of an inductive magnetic field sensor as well as a magnetic field sensor, including: determining a functional relationship between an induced voltage of a coil and an effective permeability of a magnetic core of the inductive magnetic field sensor; determining an equivalent voltage noise expression of a temperature variation-induced permeability noise of the magnetic core according to the functional relationship; determining a key influencing factor of the magnetic core according to the equivalent voltage noise expression of the temperature variation-induced permeability noise of the magnetic core; modifying the magnetic core according to the key influencing factor of the magnetic core to optimize the temperature variation-induced permeability noise of the magnetic core; and constructing a dual-channel composite multi-stage modulation signal-noise separation circuit to optimize a low-frequency band noise and a high-frequency band noise of the inductive magnetic field sensor.

The invention relates to the technical field of power electronics, in particular to a portable load adaptive bidirectional charging and discharging circuit module. The module comprises a battery and a load port. The first half-bridge is composed of a gallium nitride switch, and the second half-bridge is composed of a silicon-based field effect transistor; a main winding of the coupling inductor is connected with two half-bridge switch nodes, and a secondary winding outputs induced voltage to provide bias power supply through rectification and filtering; an auxiliary resonant branch comprising an auxiliary switch and a resonant capacitor is connected in parallel to two ends of the switch, and the starting time sequence of the auxiliary switch is ahead of the first gallium nitride switch; the control unit determines a direct current and a high-frequency ripple component according to the shunt resistor and the secondary winding signal, and generates a PWM signal in combination with the port voltage to control the on and off of all the switches. According to the scheme of the invention, self-bias power supply and high-precision composite current detection are realized, the switching loss is reduced, and the energy conversion efficiency is improved.

The invention discloses an oil abrasive particle detection device based on pseudo-random signal excitation and an inversion method, a pseudo-random excitation module outputs pseudo-random alternating current excitation formed by combining a plurality of waveforms, and the pseudo-random waveforms are not less than three frequency waveforms; the sensing module is a three-coil balance type, double-coil mutual inductance type or single-coil self-inductance type inductance sensing unit, coils in the sensing module construct a detection area with an alternating magnetic field under the excitation of alternating current, and the alternating magnetic field has pseudo-random characteristics; the signal acquisition and fitting module detects an induced voltage signal of the coil, and signal pulses generated by the metal abrasive particles under different excitation waveforms are obtained through fitting according to pseudo-random alternating current excitation characteristics; and the abrasive particle feature inversion module performs inversion according to the abrasive particle pulse signals generated by fitting under each excitation, and calculates the equivalent radius, the conductivity and the magnetic conductivity corresponding to the abrasive particles, so as to determine the material and the size of the abrasive particles. According to the invention, the material, size and concentration information of the abrasive particles can be accurately obtained.

The invention discloses a low-power-consumption electromagnetic water meter system with dynamic excitation and self-calibration functions, which comprises a sensor layer, a metering board, a main control board and a communication board, and is characterized in that the sensor layer comprises an excitation coil, an electrode pair, a temperature sensor and a pressure sensor; the metering board comprises an excitation driving circuit, a signal conditioning circuit, a high-precision ADC and a register block, the main control board comprises an embedded processor, an RTC clock, a data storage module and a display screen, and the embedded processor is used for receiving signals and processing and executing tasks according to a pre-written program; the RTC clock is used for providing an accurate and continuous time reference for the embedded processor; the communication board comprises an NB-IoT / 485 / PWM multimode communication interface, when water flow passes through the measuring pipe, the electrode pair generates an induced voltage signal, after the induced voltage signal is converted by the signal conditioning circuit and the high-precision ADC, the main control board optimizes excitation parameters in real time by combining environmental parameters and a cloud platform strategy, and meanwhile, triple calibration is periodically executed to ensure the precision of a signal chain.

The invention discloses a continuous force value standard device based on Planck quantum flattening traceability. The device comprises an unequal-arm balance, a permanent magnet system, an induced voltage synchronous measurement system and a laser interference displacement speed measurement system, the permanent magnet system is used for generating kN-order standard electromagnetic force, and continuously changing electromagnetic force is obtained by changing the magnitude and direction of coil current; the induced voltage synchronous measurement system is used for measuring the induced voltage generated when the coil cuts the magnetic induction line; the laser interference displacement and speed measurement system is used for measuring the displacement and speed of the coil; and the unequal-arm balance is used for amplifying the standard electromagnetic force generated by the coil and acting on the force sensor to be calibrated. According to the invention, the generated electromagnetic force can be traced to the Planck constant, the calibration precision is improved, and flattening of mechanical value metering traceability is promoted.

The invention belongs to the field of aviation electromagnetic detection, and particularly relates to a time domain aviation electromagnetic induction type B field signal acquisition system and method, and the system comprises a signal input stage unit which converts an amplified acquisition signal into a single-end induction voltage signal; the reference compensation unit outputs a bipolar reference compensation voltage signal; the signal integration unit receives the single-end induction voltage signal and the reference compensation voltage signal, converts the signals into current signals through an integration resistance network, and outputs an integration reconstruction B field signal; the analog-to-digital conversion unit is used for converting the single-ended induced voltage signal into 24-bit dB / dt acquisition data and converting the integral reconstruction B-field signal into 24-bit integral reconstruction B-field acquisition data; and the digital control logic unit generates compensation data and adds the compensation data with the 24-bit integral reconstruction B-field acquisition data to obtain large-dynamic-range compensation reconstruction B-field acquisition data. According to the invention, the measurement dynamic range of the induction type B field signal is obviously improved, and the deep target detection capability is improved.

This invention discloses a frequency-hopping method and apparatus for magnetic field quality assessment based on radio electromagnetic positioning, relating to the field of radio electromagnetic positioning. The method includes: constructing and calibrating a radio electromagnetic positioning system to obtain a calibration coefficient matrix; traversing each group of excitation signals in the signal combination, inputting the excitation current corresponding to the three different frequencies of excitation signals in each group of excitation signals to the transmitting module; acquiring the induced voltage generated by the receiving module and performing a Fourier transform to obtain a voltage amplitude matrix; calculating the corresponding magnetic flux density matrix based on the voltage amplitude matrix and the calibration coefficient matrix; constructing and solving an objective equation based on the vector formed by the magnetic flux density matrix and its singular values ​​to obtain three singular values; calculating the magnetic field quality coefficient corresponding to each group of excitation signals based on the three singular values, and determining the operating frequency of the radio electromagnetic positioning system for electromagnetic positioning. This invention solves the problem of increased positioning errors caused by magnetic field distortion.

The invention provides heat pump comprising a chamber for accommodating electrically charged or chargeable particles, having a thermal conductive wall, and an electrically insulating sink wall. A resistive layer made of electrical resistive material, is positioned outside the chamber with one of its faces proximal to the sink wall. The chargeable particles hit the internal surface of the sink wall, and the thermal conductive wall is in thermal communication with the particles. Thermal fluctuations of the charged particle in the chamber induce variable electric field on the resistive layer, which is harvested into electric current.

The utility model discloses a non-contact eddy current sensor, which relates to the technical field of eddy current sensors, and comprises a main control circuit for outputting square wave signals; the waveform conversion circuit converts the received square wave signal into a sine wave signal and outputs the sine wave signal; the high-frequency excitation circuit is used for generating a high-frequency magnetic field according to the received sine wave signal, and generating an induced voltage under the combined action of a metal object when the metal object is close to the non-contact eddy current sensor; and the front-end acquisition circuit acquires the induced voltage and outputs a corresponding voltage signal to the main control circuit, so that the main control circuit outputs corresponding measurement information according to the voltage signal. Therefore, the eddy current sensor can carry out non-contact measurement, the reliability is higher, and the measurement range is wider.

The invention discloses a grid induced voltage suppression circuit and a driving system, and relates to the technical field of power electronics. The gate induced voltage suppression circuit comprises a gate driving module, the input end of which is electrically connected with a driving signal end, and the output end of which is electrically connected with the gate of a target power device; the first end of the positive voltage stabilization clamping module is electrically connected with a first target node in the gate driving module, and the second end of the positive voltage stabilization clamping module is electrically connected with a first power supply voltage end; the first end of the positive voltage absorption module is electrically connected with a second target node in the gate driving module, and the second end of the positive voltage absorption module is electrically connected with the reference grounding end; the first end of the negative pressure clamping absorption module is electrically connected with the grid electrode of the target power device, and the second end of the negative pressure clamping absorption module is electrically connected with the source electrode of the target power device and the reference grounding end. According to the embodiment of the invention, the grid induced voltage of the power device can be effectively suppressed.

The utility model discloses an isolation handcart for a high-voltage switch cabinet, which comprises a handcart body provided with a circuit breaker. The circuit breaker is provided with a moving contact and a fixing piece used for fixing the moving contact, a first fastening piece is arranged in the moving contact, and the first fastening piece penetrates through one end of the moving contact and then is connected with the fixing piece, so that one end of the moving contact is fixed on the circuit breaker; a grounding piece is further arranged on the bottom face of the vehicle body, and the grounding piece is rotationally installed on the bottom face of the vehicle body. Therefore, installation and replacement of the moving contact are simple and convenient, maintenance is convenient, and power failure time can be reduced. Besides, the grounding piece is arranged at the bottom of the vehicle body, so that the whole-course reliable grounding can be realized through frictional contact no matter the switch cabinet is in a running state or a quit state, the electric shock risk caused by static accumulation or fault current is avoided, the residual charge or induced voltage after the equipment is powered off can be quickly discharged, and the safety of maintenance personnel is guaranteed.

A device in a chamber is provided. The device comprises at least one die. The at least one die comprise a first voltage generator, a dielectric layer and a first voltage regulator circuit. The first voltage generator is charged to have a first induced voltage by induced charges generated in response to a first voltage of a first electrode of a chuck in the chamber. The dielectric layer surrounds the first voltage generator to isolate the first voltage generator from the first electrode. The first voltage regulator circuit is coupled to the first voltage generator to receive the first induced voltage and generates a first power supply voltage according to the first induced voltage for a first circuit in the device.

The invention provides a three-core submarine cable metal sheath induced voltage elimination method, which comprises the following steps: acquiring a first induced voltage threshold value of a submarine cable sea area section, and acquiring a second induced voltage threshold value of a submarine cable land section; according to a submarine cable metal sleeve distributed induced voltage calculation model, calculating a first segment length of the submarine cable generating a first induced voltage threshold under a wet condition; according to a submarine cable metal sleeve distributed induced voltage calculation model, calculating a second segment length of the submarine cable generating a second induced voltage threshold under a dry state condition; and performing mutual short-circuit processing on the three-phase metal sleeve of the submarine cable with the first segment length or the second segment length. The three-phase metal sleeves of the submarine cable are subjected to mutual short-circuit treatment, so that the problem that the PE semi-conductive layer is overheated and melted due to temperature rise caused by rise of induced voltage of the three-phase metal sleeves can be prevented.