749results about "Instrument screening arrangements" patented technology

The invention provides a power management chip pin state intelligent detection method and system. The method comprises the steps that temperature difference quantity is input into a gradient heat conduction compensation structure, and compensation current opposite to a temperature gradient vector is generated based on temperature field distribution in the copper-based composite material; superposing and coupling the voltage fluctuation signal and the compensation current to generate a reference voltage signal; performing frequency component separation processing on the reference voltage signal, and extracting electromagnetic interference characteristic data in a frequency component; performing time sequence correlation on the electromagnetic interference characteristic data and the temperature distribution data, dynamically adjusting an interference suppression parameter through closed-loop control, and acting the adjusted interference suppression parameter on an interference suppression process of a reference voltage signal to generate a pin state detection signal; and detecting the pin state of the power management chip according to the pin state detection signal. According to the invention, the pin voltage stability and the state detection precision of the power management chip are improved.

The invention discloses a non-contact magnetoelectric composite current sensor with magnetism gathering and magnetic shielding. A sensor core is composed of a magnetoelectric sensing element, a magnetofluid layer, a magnetism gathering structure and a magnetic shielding layer. The magnetoelectric sensing element is made of manganese-doped lead magnesium niobate and amorphous alloy film composite materials, the outer side of the sensing element is coated with a magnetofluid layer made of soft magnetic composite materials, the magnetism gathering structure is made of permalloy materials with high magnetic conductivity and is divided into an upper part and a lower part, the upper part accommodates the sensing element and the magnetofluid layer, and the lower part accommodates the magnetic gathering structure. And the lower part is provided with a standardized groove for placing a conductor to be tested. The outermost layer is a magnetic shielding layer composed of multiple layers of nanocrystalline alloy strips, the vertical split type design is also adopted, and it is ensured that the magnetic shielding layer is tightly matched with the magnetic gathering structure through precision machining. The upper magnetic shielding layer and the lower magnetic shielding layer are detachably connected, and field installation is facilitated. The overall structure is compact, a circuit does not need to be disconnected during installation, and the device is especially suitable for on-line current monitoring requirements in the fields of smart grids, industrial automation and the like.

The invention discloses an MEMS and TMR fused overhead line lightweight monitoring device, and the device comprises an annular shielding cover which sleeves a to-be-detected overhead conductor and is coaxial with the to-be-detected overhead conductor, and the side wall of the annular shielding cover is provided with a through hole; the sensing unit comprises at least two MEMS electric field sensors and at least two TMR magnetic field sensors and is used for detecting an electric field and a magnetic field generated by the overhead conductor to be detected; the analysis processing unit is used for receiving, processing and transmitting the signal generated by the sensing unit; and the power supply unit is arranged in the annular shielding cover and is electrically connected with the sensing unit and the analysis processing unit. The beneficial effect of the invention is that the coupling crosstalk phenomenon generated by an external electromagnetic field can be effectively suppressed. Moreover, the monitoring device is small in size, is convenient to install and deploy in a complex line environment, provides a stable hardware basis for precise inversion of voltage and current through structural cooperation, and provides reliable support for intelligent monitoring of an overhead line.

The invention discloses a phase-adjustable large-current generator, and the generator comprises a main circuit module, and a topological structure of the main circuit module employs a multi-stage IGBT inverter; the phase control module inputs a power grid voltage signal through a voltage transformer, adopts an SOGI-PLL structure to improve signal tracking precision, and combines a virtual synchronous machine technology to enhance system balance and a self-adaptive control strategy to dynamically adjust an output signal so as to realize phase control and synchronization; the electromagnetic compatibility optimization module adopts a layered shielding design and is combined with an optical fiber to transmit a control signal, so that the electromagnetic compatibility of equipment is improved; a relay protection test integration module, wherein the relay protection test integration module comprises a differential protection test mode and a distance protection test mode; according to the invention, the problems of low phase adjustment precision, poor synchronization stability and insufficient electromagnetic compatibility of a large current generator in a new energy grid-connected environment are solved.

The invention relates to a vertical magnetic field interference resistant inductor, an electric power meter and a manufacturing method thereof, the vertical magnetic field interference resistant inductor comprises a Rogowski coil and an annular vertical magnetic field counteracting coil located in the Rogowski coil, the Rogowski coil comprises an even number of self-adhesion hollow coils which are connected in series end to end, the wire diameter, the number of turns, the number of layers, the inner diameter and the outer diameter of each hollow coil are consistent, and the vertical magnetic field counteracting coil is located in the Rogowski coil. The Rogowski coils are arranged in the same horizontal plane and are symmetrically distributed on the same horizontal plane with a circle as the center, hole parts of the hollow coils jointly form an annular channel, the inning area of the vertical magnetic field offset coil is equal to the inning area defined by the Rogowski coils, and a pre-positioning support is arranged in the annular channel in a penetrating and matched mode. The vertical magnetic field counteracting coil is located at the center of the annular channel, and the Rogowski coil and the vertical magnetic field counteracting coil are provided with output ends. Therefore, the technical problem that small current detection is easily interfered by an external power frequency electromagnetic field is solved.

The invention discloses gap detection equipment and a capacitance detection device thereof, which are applied to the technical field of signal detection, and comprise a bipolar capacitive sensor which is provided with a first detection electrode and a second detection electrode and is used for outputting a first capacitance signal and a second capacitance signal which reflect the capacitance of a detected position; the excitation generation circuit is used for applying excitation to the first capacitance signal and the second capacitance signal based on the first excitation carrier and the second excitation carrier which are symmetrical and opposite in phase to obtain a modulated first detection signal and a modulated second detection signal; the capacitance-voltage conversion circuit is used for receiving the first detection signal and the second detection signal and carrying out conversion from a capacitance signal to a voltage signal and signal amplification in a differential amplification mode to obtain a first conversion signal and a second conversion signal; and the detection processing circuit performs phase-sensitive demodulation to obtain a phase-sensitive demodulation result and extracts a detection result of the capacitance corresponding to the detected position from the phase-sensitive demodulation result. According to the scheme of the invention, the common-mode interference suppression capability is high, and the precision of capacitance detection is effectively improved.

The utility model relates to a control device for a microwave anechoic chamber test system. Comprising a shielding box which is a sealed cavity provided with a cover plate, and the shielding box is provided with a power supply socket, a data socket and an optical fiber coupler; a control circuit board, an AC-DC power supply module, a data optical fiber transceiver and other modules are installed in the shielding box. A plurality of motor control units, a power supply interface and a communication interface are integrated on the control circuit board, and a first output end of the AC-DC power supply module is connected with the control board and is used for supplying power to the control board; one end of the data optical fiber transceiver is electrically connected with the optical fiber coupler, and the other end is electrically connected with the communication interface for converting the signal into an optical signal and outputting the optical signal. The control circuit board is placed in the shielding box, so that the size of the rotary table or antenna tower equipment is reduced, and the electromagnetic interference risk of a motor and a darkroom environment is reduced; the control circuit board integrates the servo motor control unit and the stepping motor control unit for modular design, serves as an independent unit of the darkroom test system, and is high in universality.

A current sensor includes busbars through which a current to be measured flows, magnetic detectors capable of detecting a magnetic field generated when the current to be measured flows through the busbars, a storage space storing the magnetic detectors, and a housing with which part of the busbars is integrated. Ends of the busbars are connected to an external first unit including a cooling device, and other ends of the busbars are connected to an external second unit whose temperature becomes higher than that of the first unit when the current to be measured flows. In the current sensor, which is capable of measuring a current value of the current to be measured from a result of the detection performed by the magnetic detectors, the housing has first vents penetrating from the inside of the storage space to the outside on a side facing the first unit.

The invention belongs to the technical field of gap measurement, and particularly relates to a high-temperature-resistant transparent shell type eddy current tip gap measuring device and method, and the device comprises a sensor probe module, a signal conditioning module, a data collection module and a data processing module. The sensor probe module is mounted on the outer wall of the casing; the sensor probe module comprises a permanent magnet excitation source, a soft magnet magnetic core and a receiving coil; the signal conditioning module is electrically connected with the receiving coil and is used for amplifying, filtering and integrating the weak induction signal; the data acquisition module is electrically connected with the signal conditioning module and converts an analog signal into a digital signal; the data processing module is used for processing the acquired digital signals and extracting blade tip clearance information.

Systems and Methods for capacitance testing of a unit under test with parasitic capacitance directed to a guard rail. The system includes test points, wherein the plurality of test points are divided into at least two groups; a stimulus source; a first group guard relay electrically connected to each of the test points in a first; a second group guard relay electrically connected to each of the test points in a second; a guard rail coupled to the first group guard relay and the second group guard relay; a first group return relay electrically connected to each of the test points in a first group; a second group return relay electrically connected to each of the test points in a second group; a current measurement rail coupled to the first group return relay and the second group return relay; a current meter coupled to the measurement rail; and a controller.

According to the self-shielding type anti-interference current transformer and the dynamic magnetic field compensation method thereof, external interference magnetic field data are detected in real time through the magnetic field sensing layer, a basis is provided for interference shielding of a magnetic field, reverse magnetic field data are set based on the external interference magnetic field data, a main shielding winding generates a reverse magnetic field, the reverse magnetic field and an interference magnetic field are superposed and offset, and the self-shielding type anti-interference current transformer is obtained. Auxiliary magnetic field data are set for further magnetic field shielding through the residual suppression layer based on the offset condition of reverse magnetic field data on external interference magnetic field data, the auxiliary shielding winding further eliminates high-frequency residual interference, finally 0-20 kHz broadband interference suppression is achieved, performance stability can be kept within the temperature range of-40 DEG C to 120 DEG C, three dynamic shielding layers are adopted, and the performance stability is improved. The problem of dynamic interference in a complex electromagnetic environment is solved, and the measurement precision is improved to 0.1%.

The utility model relates to the field of electromagnetic field detection, in particular to an electromagnetic field detection device of an internet of things sensor, which comprises a shell, a circuit board, a shielding cover, a detection probe, a signal processing module and a signal transmission module. The detection probe can collect electromagnetic field signals in the environment where the detection probe is located and send the collected signals to the signal processing module, and the signal processing module sends the processed signals to the signal transmission module and sends the processed signals to the cloud server. According to the utility model, the internal circuit board is isolated from the external electromagnetic field environment through the shielding cover, so that the influence of the electromagnetic field in the external environment on the internal circuit is reduced.

The invention relates to the technical field of charge and discharge detection, and discloses a multichannel EIS charge and discharge in-situ test system and method, and the system comprises a DC charge and discharge module which is used for carrying out the constant-current, constant-voltage or cyclic charge and discharge test of a battery; the alternating current impedance test module is connected in parallel with the direct current charging and discharging module and is used for applying an alternating current disturbance signal to the battery and collecting impedance response in the charging and discharging process; and the unified clock module is used for providing a synchronous triggering reference signal for the direct current charging and discharging module and the alternating current impedance test module. The direct current charging and discharging module and the alternating current impedance test module are designed to be of a parallel connection normally-connected structure, no relay switching is needed, continuous and uninterrupted online EIS test in the charging and discharging process is achieved, contact resistance drift and transient errors caused by physical circuit switching in a traditional scheme are effectively avoided, and the reliability of the EIS test is improved. And the stability and repeatability of the test are obviously improved.

Provided is a test module for testing the performance of an image sensor, the test module including a test board having an area greater than an area of the image sensor and configured to be coupled to the image sensor, and a connector electrically connected to the image sensor and configured to transmit an electrical signal received from the image sensor to a test socket, wherein the test board includes a dummy region of which an outer perimeter corresponds to a perimeter of the test board and configured to be electrically cut off from the image sensor, and a cut-off region formed corresponding to an inner perimeter of the dummy region, located between the dummy region and the image sensor, and configured to electrically cut off the dummy region from the image sensor.

The invention discloses a partial discharge detection method and device based on discharge spectrum chromaticity, and belongs to the technical field of power systems, and the method comprises the steps: collecting a plurality of discharge optical signals of switch cabinet equipment; for each discharge optical signal, carrying out chromaticity analysis on the RGB monochromatic light signal, and respectively calculating color chaos degree, spectrum color gamut deviation degree, spectrum chromaticity dynamic coupling parameters and hue purity ratio; calculating a chromaticity difference weight based on the full-band optical signal and the RGB monochromatic light signal; performing weighted integration on the color chaos degree, the spectrum color gamut deviation degree, the spectrum chromaticity dynamic coupling parameter and the hue purity ratio based on the chromaticity difference weight to obtain a chromaticity comprehensive magnitude; calculating the mean value of the comprehensive chromaticity values of the plurality of discharge optical signals; and comparing the chromaticity comprehensive magnitude mean value with the plurality of judgment chromaticity ranges, and determining a discharge type detection result of the switch cabinet equipment. According to the invention, the problem of low accuracy of partial discharge detection in the prior art can be solved.

The invention discloses a radiation-inhibiting needle point structure, a two-dimensional probe and a microwave test system, belongs to a microwave radio frequency test technology, and aims to solve the problems that radiation crosstalk is aggravated and insertion loss is abnormal in a millimeter wave to terahertz frequency band on-chip test, and a traditional three-dimensional probe is limited by process precision and is difficult to meet high-frequency test requirements. The radiation-inhibiting needle point structure comprises a ground wire and a signal wire, the ground wire is located on two sides of the signal wire to form a GSG needle point structure, and a supporting structure is arranged between the ground wire and the signal wire; a cantilever type shielding layer is arranged above the ground wire, and a G needle root hollowed-out structure is arranged at the position, close to the root of the needle tip, of the cantilever type shielding layer; each of the ground wire and the signal wire comprises a GSG needle point structure lower nickel layer and a GSG needle point structure upper copper layer, the needle point part of the ground wire is provided with a transition structure, and the thickness of the transition structure is gradually reduced from the root of the needle point to the tip of the needle point; a signal line is constrained in a quasi-TEM mode for transmission, so that high-frequency radiation leakage is effectively inhibited; and the stress of the needle tip can be optimized by adjusting structural parameters.

The invention relates to the technical field of electromagnetic measurement, and discloses a measurement unit stabilization method and system, electronic equipment and a storage medium, and the method comprises the steps: obtaining three-dimensional displacement trajectory data in real time, and building a motion error compensation model containing a mechanical vibration direction vector and a phase offset; on the basis of asymmetric magnetic pole distribution, combined with phase difference calculation of a magnetic circuit gradient direction vector and a mechanical vibration direction vector, a closed loop current orthogonal to the mechanical vibration direction vector is generated on an interface to realize gradient isolation; based on a multi-branch common-mode suppression mechanism, an interference signal reaches a preset attenuation amplitude before a loop is closed through combination of a magnetic core impedance matching characteristic and an eddy current effect; and performing dynamic matching based on the displacement parameter and an electromagnetic interference attenuation result, adjusting a magnetic pole inclination angle in real time, and forming a closed-loop control path of magnetic field gradient compensation and mechanical vibration suppression. According to the invention, the stability and anti-interference capability of the measuring unit under severe working conditions can be improved.

The invention discloses a vehicle body domain control compatible load box which comprises a box body, the top surface of the box body is provided with an upper cover panel, the bottom surface of the box body is provided with a grounding panel, and the side surface of the box body is provided with a plugging adapter panel, a load indication panel, a communication interface panel and a shielding panel. The plug-in switching panel and the load indication panel are connected through a switching line, and the plug-in switching panel is provided with an IDH high-level analog input module, an IDL low-level analog input module, a sensor analog module, an LIN bus communication analog module and a CAN bus communication analog module. Wherein the LIN bus communication simulation module and the CAN bus communication simulation module are connected with the communication interface panel through patch cords, and the load indication panel is provided with an HSD high-side driving simulation module, an LSD low-side driving simulation module and an H-bridge driving simulation module. Complex EMI interference is greatly reduced, the redundant degree of the load is greatly reduced, the load box can be compatible with different items, and the universality of the load box is improved.

The invention discloses a capacitance parameter determination method and device of an iron core sensing device for transformer partial discharge detection, electronic equipment and a storage medium, and belongs to the technical field of sensor design, and the method comprises the steps: obtaining an iron core three-dimensional model of a transformer; performing electromagnetic simulation on the iron core three-dimensional model to generate antenna characteristic parameters of the transformer iron core under each frequency in a preset frequency band; determining a target detection frequency band of the transformer core according to the antenna characteristic parameters; repeatedly executing the parameter adjustment operation of the iron core sensing device until the current test frequency band covers the target detection frequency band, and determining the capacitance parameter of the iron core sensing device; therefore, by implementing the invention, the problem that the capacitance parameters of the iron core sensing device in the prior art are not accurately determined can be solved.

The utility model discloses an electromagnetic compatibility assessment device, and belongs to the technical field of wireless communication. The equipment comprises a data processing module, a signal generator module, a low-frequency / high-frequency amplifier, a combining unit, a shielding frame and a power supply module, and accurate evaluation of the electromagnetic compatibility of the weak current equipment is realized through modular design. The signal generator module adopts a multi-band vector signal generator to generate configurable interference signals; the low-frequency amplifier and the high-frequency amplifier respectively adopt independent high-precision amplification circuits; and the combining unit couples the two paths of signals into a composite interference signal and outputs the composite interference signal. The shielding frame is made of double-layer aluminum magnesium alloy and is combined with a metal machine frame to form a composite shielding system. And the data processing module regulates and controls parameters in real time through the touch screen, analyzes response data of the tested equipment based on an FFT algorithm, and generates a visual evaluation report.

The invention discloses a high-precision voltage and current characteristic quantity extraction and anti-interference sampling circuit compensation method, and belongs to the technical field of voltage and current sampling, and the method comprises the steps: employing a 24-bit ADC to collect voltage and current signals at the sampling frequency of 1 kHz to 10 kHz; electromagnetic interference is inhibited through the metal shielding cover and the wave absorbing material; dynamically correcting the sampling data through a temperature compensation model; dynamically correcting the sampling data based on an LMS algorithm; voltage and current effective values are calculated through a root mean square algorithm in a sliding window mode, a processing result is output in real time, and the problems that existing sampling precision is low and the error compensation effect is limited are solved.

A current sensor (2) comprising a differential magnetic field transducer (4) having at least two magnetic field sensor portions (14) configured to measure a main current flowing in a main conductor positioned adjacent and proximate to the differential magnetic field transducer (4), and a housing (10) housed in the housing, characterized in that the differential magnetic field transducer (4) is configured to measure the main current flowing in the main conductor. The current sensor further comprises a magnetic shield (8) having lateral branches (16a) joined together to the bridge branches (16b) at one end thereof such that the magnetic shield (8) has a generally U-shaped shape. The magnetic shield surrounds a main conductor channel (5) through which the main conductor (1) is mounted in use, and the differential magnetic field transducer is positioned adjacent and close to the bridge branch (16b) between the bridge branch (16b) and the main conductor channel (5).

The invention relates to the technical field of test fixtures, in particular to a radio frequency power amplifier board test fixture which comprises a fixed seat, telescopic guide rods which are symmetrical to each other are fixedly connected to one side of the top of the fixed seat, a pressing plate is fixedly connected to the top ends of the telescopic guide rods, and an electric push rod is fixedly connected between the fixed seat and the pressing plate. A placing groove is formed in the top of the fixing base, a plurality of elastic probe pieces are installed on the pressing plate, the pressing plate which is pressed downwards can drive the elastic probe pieces to move and move towards a radio frequency power amplifier board placed in the placing groove, the elastic probe pieces are made to make contact with the radio frequency power amplifier board, and the radio frequency power amplifier board is placed in the placing groove through elastic components in the elastic probe pieces. The elastic probe piece can be in contact with each element on the radio frequency power amplifier board, so that the phenomenon that the elastic probe piece is not in contact with the element in place is reduced, the test error caused by the fact that the elastic probe piece is not in contact with the element is eliminated to the maximum extent, and the test accuracy of the radio frequency power amplifier board is improved.

The invention discloses a direct current comparator for quantum magnetic balance monitoring and a method thereof, and the method is characterized in that the method comprises the following steps: employing a diamond NV color center as a quantum magnetic sensor, so as to read an initial fluorescence signal outputted by the quantum magnetic sensor; feeding the initial fluorescence signal back to a microwave source and a secondary winding side of a proportion coil, adding microwave resonance frequency to the diamond NV color center by using the microwave source, and adding a feedback modulation magnetic field to the diamond NV color center by using the proportion coil; a fluorescence signal of the diamond NV color center under the action of the feedback modulation magnetic field is collected, and the state of the to-be-detected direct current input into the proportion coil is analyzed based on the fluorescence signal intensity. The problems of leakage flux errors, ampere-turn balance errors, feedback control errors and the like in the prior art are solved, the accuracy and stability of current measurement are remarkably improved, and the requirements of high-precision current measurement and calibration are met.

The invention discloses an electromobile electromagnetic compatibility testing device, and relates to the technical field of electromagnetic compatibility testing, the electromobile electromagnetic compatibility testing device comprises a shielding box, the upper side of the shielding box is fixedly connected with a control box, and one side of the control box is provided with a manipulator used for clamping an electromobile motor to go in and out of the shielding box; one side of the manipulator is provided with an opening and closing mechanism used for opening and closing the entrance, the lower side of the control box is slidably connected with a load simulation circuit box used for regulating and controlling a power supply and emitting high-energy pulses through a circuit, and one side of the load simulation circuit box is fixedly connected with a second handle. One side of the second handle is provided with a wiring terminal, and the wiring terminal is fixedly connected with the load simulation circuit box. A dynamic test platform capable of highly simulating a real world complex scene is created, and the tested motor is driven to move along a U-shaped track in the shielding box through a precise mechanical structure; and working conditions such as straight running, steering and backing of the vehicle can be accurately reproduced.

The invention provides an EMC test fixture special for an LRM module, and relates to the field of electromagnetic compatibility testing, and the EMC test fixture comprises a main body structure box, a module installation frame, a cable accessory and an LRM normal temperature test board. The main body structure box is a metal shielding box body, one end of the main body structure box is provided with a module socket hole, the other end of the main body structure box is communicated with a cable threading pipe, the inner wall of the cable threading pipe is filled with a layer of shielding filling copper net, an LRM socket is installed in the module socket hole, and the LRM normal temperature test board is installed on the inner side wall of the main body structure box. The electromagnetic compatibility of the LRM module can be more comprehensively and deeply verified, problems encountered by the LRM module in a test can be accurately analyzed, system fault hidden dangers caused by the electromagnetic compatibility problem are avoided, the main body structure box adopts the metal shielding box body, the inner wall of the cable threading pipe is filled with the shielding filling copper net, the electromagnetic compatibility of the LRM module is improved, the electromagnetic compatibility of the LRM module is improved, and the electromagnetic compatibility of the LRM module is improved. And shielding reeds are arranged around the module socket holes, so that external electromagnetic interference can be effectively shielded.

The invention provides a resonant electric field sensor and a detection method, and a sensitive structure comprises a first vibration part, a second vibration part, and a first induction electrode and a second induction electrode which are located in different planes and between a first vibration assembly and a second vibration assembly. When the first vibration part and the second vibration part periodically vibrate to shield the first induction electrode and the second induction electrode, a first current signal and a second current signal with a signal difference value are generated, and the first vibration part comprises a first vibration beam and a first shielding structure; the first vibration part comprises a first vibration beam and a first shielding structure, the first shielding structure covers at least one part of the first induction electrode and / or the second induction electrode, the second vibration part comprises a second vibration beam and a second shielding structure, and the second shielding structure covers at least one part of the first induction electrode and / or the second induction electrode. The sensitivity of the first sensing electrode and the second sensing electrode can be improved, so that the strength and the accuracy of the first current signal and the second current signal are improved.

The utility model, which relates to the technical field of the LED, discloses a leakage protection circuit comprising a power supply circuit, a step-down circuit, an LED circuit and a detection circuit. The input end of the power supply circuit is connected to the output pin of the power supply end, the output end of the power supply circuit is connected with the input end of the step-down circuit and the input end of the LED circuit, and the power supply circuit is used for rectifying the output power supply of the power supply end so as to output the power supply to the step-down circuit and the LED circuit; the output end of the step-down circuit is connected with the detection circuit, and the step-down circuit is used for carrying out step-down processing on the power supply output by the power circuit to output reference voltage to the detection circuit; and the detection circuit is respectively connected with the output pins of the power supply end and the LED circuit, and is used for controlling the working state of the LED circuit according to the real-time voltage difference and the real-time voltage between the output pins of the power supply end and the reference voltage output by the step-down circuit. According to the utility model, the working state of the LED circuit can be controlled according to the real-time voltage difference, the real-time voltage and the reference voltage, thereby realizing anti-creeping protection.

The invention relates to a vertical magnetic field interference resistant inductor which comprises a Rogowski coil and a vertical magnetic field counteracting coil located on one side of the Rogowski coil and connected with the Rogowski coil, the Rogowski coil comprises a plurality of hollow coils connected end to end, and the wire diameter, the number of turns, the number of layers, the inner diameter and the outer diameter of each hollow coil are consistent. The number of the hollow coils is not less than 4 and is an even number, the hollow coils are used for being symmetrically distributed on the same horizontal plane with a circle as the center, and output ends are arranged on the Rogowski coil and the vertical magnetic field counteracting coil. Therefore, the technical problem that the current common Rogowski coil is easy to be interfered by an external power frequency electromagnetic field when being used for small current detection, so that the actual current cannot be normally reflected by a large measurement error is solved, and the application limitation of the current Rogowski coil is broken through.

The invention provides an alternating-current weak current high-precision detection system and method, and the system comprises a copper-nickel alloy shielding cover which is used for inhibiting space power frequency radiation interference and power system broadband noise, and a magnetic sensitive element which is used for converting the detected magnetic field change into a corresponding initial current signal, the trans-impedance amplifier is used for converting the initial current signal into a voltage signal; the adaptive noise suppression module collects a power frequency fundamental wave reference signal and a harmonic wave reference signal, generates a harmonic wave anti-phase counteracting signal, and performs anti-phase counteracting on real noise of the initial current signal; the analog-to-digital converter is used for converting the voltage signal into a discretized digital signal, and the discretized digital signal comprises a target signal and a random noise signal; and the FPGA coherent demodulation module is used for carrying out cross-correlation operation and narrow-band filtering on the target signal and the random noise signal to separate out a micro-current signal. The technical problems that in the prior art, composite noise covering is limited, the frequency fluctuation adaptability is poor, and microvolt-level signals are difficult to capture are solved.