A current measurement method based on a double-channel NV color center quantum magnetic field sensing structure and related equipment

Abstract

This application discloses a current measurement method and related equipment based on a dual-channel NV center quantum magnetic field sensing structure. The method includes: setting an NV center quantum magnetic field sensing structure, comprising a first sensing channel and a second sensing channel, within a preset range of the conductor under test, and performing laser pumping; driving the two sensing channels with a microwave driving signal, and performing phase-locked detection and closed-loop feedback based on the fluorescence signal to obtain two resonant signals, thereby obtaining a frequency difference signal; applying a reference AC magnetic field to the magnetic field sensing structure to determine the gain correction factor; and determining the current signal of the conductor under test based on the corrected frequency difference signal, the reference resonant frequency, and the magnetic field-current transfer function. The embodiments of this application can simultaneously suppress common-mode magnetic field interference, temperature drift, and photoelectric signal chain gain drift, thereby obtaining high-precision and reliable real-time current measurement results. This application can be widely applied in the field of current measurement technology.

Description

Technical Field

[0001] This application relates to the field of current measurement technology, and in particular to a current measurement method and related equipment based on a dual-channel NV color center quantum magnetic field sensing structure. Background Technology

[0002] With the development of power grid digitalization, new energy power electronic devices, and high-end drive systems, higher requirements are being placed on the bandwidth, accuracy, and long-term stability of online current measurement. Traditional solutions such as current transformers (CTs) and Hall current sensors are limited by factors such as core saturation, nonlinearity, and temperature drift, resulting in shortcomings in high-frequency broadband measurement and long-term stability. Furthermore, they are difficult to simultaneously meet the requirements of high insulation, miniaturization, and low power consumption.

[0003] Quantum magnetometers based on diamond nitrogen-vacancy (NV) color centers can achieve high-sensitivity magnetic field detection at room temperature. They offer advantages such as wide bandwidth, small size, easy integration, and electrical insulation, and are considered a promising new current sensing technology. By arranging the NV color centers within a predetermined range of the conductor being measured, and using Ampere's law to establish a correspondence between the magnetic field generated by the current and the magnitude of the current, quantum current measurement can be achieved.

[0004] However, existing NV color core current sensing solutions typically have the following problems: 1) Most of them adopt a single-channel structure. The sensor is highly sensitive to the external magnetic field, electromagnetic interference and common-mode magnetic field caused by temperature changes, resulting in a large zero drift. 2) The NV resonant frequency is affected by lattice temperature, stress, etc., and drifts slowly with environmental changes. This will introduce systematic measurement deviations during long-term operation. 3) Changes in laser power, photodetector gain, and temperature drift in analog amplifier circuits can cause a slow change in the overall gain of the optical and electronic signal chains, making the output amplitude corresponding to the same magnetic field no longer constant. 4) Existing calibration methods mostly adopt the form of shutting down and comparing with external current standards or external magnetic field standards, which can only be calibrated intermittently and cannot achieve in-situ, real-time gain correction during continuous system operation.

[0005] The aforementioned factors collectively limit the widespread adoption of NV center quantum current sensors in long-term online monitoring and metrology applications. Therefore, there is an urgent need for a current measurement method and system suitable for NV center quantum current sensors, capable of suppressing environmental common-mode magnetic field interference and temperature drift while performing in-situ, real-time self-calibration of gain changes in the optical and electronic signal chains, thereby significantly improving the long-term stability and accuracy of current measurement.

[0006] In summary, the technical problems existing in the relevant technologies need to be improved. Summary of the Invention

[0007] The main objective of this application is to propose a current measurement method and related equipment based on a dual-channel NV color center quantum magnetic field sensing structure. By using a composite calibration architecture composed of dual-channel differential magnetic field measurement and heterodyne calibration signal, the method simultaneously suppresses common-mode magnetic field interference, temperature drift, and photoelectric signal chain gain drift, thereby obtaining high-stability and high-precision real-time current measurement results.

[0008] To achieve the above objectives, one aspect of this application proposes a current measurement method based on a dual-channel NV color center quantum magnetic field sensing structure, the method comprising: An NV color center quantum magnetic field sensing structure, including a first sensing channel and a second sensing channel, is set within a preset range of the conductor under test, and the first sensing channel and the second sensing channel are laser-pumped. The first sensing channel and the second sensing channel are driven by microwaves using a first microwave driving signal and a second microwave driving signal containing periodic modulation signals, respectively. The first NV fluorescence signal of the first sensing channel and the second NV fluorescence signal of the second sensing channel are obtained. The first microwave driving signal and the second microwave driving signal are subjected to phase-locked detection and closed-loop feedback based on the first NV fluorescence signal and the second NV fluorescence signal, respectively, to obtain a first resonance signal and a second resonance signal. The first resonance signal is subtracted from the second resonance signal to obtain a first frequency differential signal. A reference AC magnetic field with a known frequency and amplitude is applied to the NV color center quantum magnetic field sensing structure, and a gain correction factor is determined based on the reference AC magnetic field and the first frequency differential signal. The first frequency differential signal is corrected according to the gain correction factor to obtain the second frequency differential signal. The current signal of the conductor under test is determined according to the second frequency differential signal, the preset reference resonant frequency, and the pre-calibrated magnetic field-current transfer function. The first sensing channel and the second sensing channel are set in the same common-mode disturbance environment. The first response value of the first sensing channel to the target magnetic field of the conductor under test in the preset NV axis is higher than the second response value of the second sensing channel to the target magnetic field in the NV axis.

[0009] In some embodiments, the first sensing channel and the second sensing channel are disposed on the same diamond substrate, or the first sensing channel and the second sensing channel are disposed on the same thermal coupling structure.

[0010] In some embodiments, the first projected distance value of the first sensing channel relative to the conductor under test in the NV axis is less than the second projected distance value of the second sensing channel relative to the conductor under test in the NV axis.

[0011] In some embodiments, the step of performing phase-locked detection and closed-loop feedback on the first microwave drive signal and the second microwave drive signal based on the first NV fluorescence signal and the second NV fluorescence signal, respectively, to obtain the first resonance signal and the second resonance signal, includes: The first error signal is determined based on the first NV fluorescence signal to the center of the resonance peak of the first microwave drive signal relative to the optical detection magnetic resonance of the first sensing channel. The first microwave drive signal is adjusted by feedback based on the first error signal to obtain the first resonance signal; A second error signal is determined based on the second NV fluorescence signal to indicate the center of the resonance peak of the second microwave drive signal relative to the optical detection magnetic resonance of the second sensing channel; The second microwave drive signal is adjusted by feedback based on the second error signal to obtain the second resonance signal.

[0012] In some embodiments, determining the gain correction factor based on the reference AC magnetic field and the first frequency differential signal includes: Obtain the calibration frequency and calibration amplitude of the reference AC magnetic field; The heterodyne calibration component measurement signal is obtained by separating it from the first frequency differential signal according to the calibration frequency; The gain correction factor is determined based on the amplitude of the heterodyne calibration component measurement signal and the calibration amplitude.

[0013] In some embodiments, determining the current signal of the conductor under test based on the second frequency differential signal, a preset reference resonant frequency, and a pre-calibrated magnetic field-current transfer function includes: The resonant frequency offset is determined based on the second frequency differential signal and the reference resonant frequency; The target magnetic field strength of the target magnetic field is determined based on the resonant frequency offset and the preset NV color center electron spin-gyromagnetic ratio parameter. The current signal of the conductor under test is determined based on the target magnetic field strength and the magnetic field-current transfer function.

[0014] In some embodiments, the magnetic field-current transfer function is determined by the following steps: Obtain the assembly geometric parameters of the conductor under test and the NV color center quantum magnetic field sensing structure; The geometric coefficients of the magnetic field-current transfer function are determined based on the assembly geometry parameters. The magnetic field-current transfer function is determined based on the geometric coefficients.

[0015] To achieve the above objectives, another aspect of this application proposes a current measurement device based on a dual-channel NV color center quantum magnetic field sensing structure, the device comprising: The sensing channel setting module is used to set an NV color center quantum magnetic field sensing structure including a first sensing channel and a second sensing channel within a preset range of the conductor under test, and to laser pump the first sensing channel and the second sensing channel. The frequency differential module is used to drive the first sensing channel and the second sensing channel with microwaves through a first microwave driving signal and a second microwave driving signal containing a periodic modulation signal, respectively, to obtain a first NV fluorescence signal of the first sensing channel and a second NV fluorescence signal of the second sensing channel. Based on the first NV fluorescence signal and the second NV fluorescence signal, phase-locked detection and closed-loop feedback are performed on the first microwave driving signal and the second microwave driving signal, respectively, to obtain a first resonant signal and a second resonant signal. The first resonant signal is subtracted from the second resonant signal to obtain a first frequency differential signal. A gain correction module is used to apply a reference AC magnetic field of known frequency and amplitude to the NV color center quantum magnetic field sensing structure, and to determine a gain correction factor based on the reference AC magnetic field and the first frequency differential signal. The current measurement module is used to correct the first frequency differential signal according to the gain correction factor to obtain the second frequency differential signal, and to determine the current signal of the conductor under test according to the second frequency differential signal, the preset reference resonant frequency and the pre-calibrated magnetic field-current transfer function. The first sensing channel and the second sensing channel are set in the same common-mode disturbance environment. The first response value of the first sensing channel to the target magnetic field of the conductor under test in the preset NV axis is higher than the second response value of the second sensing channel to the target magnetic field in the NV axis.

[0016] To achieve the above objectives, another aspect of this application provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the methods described above.

[0017] To achieve the above objectives, another aspect of the embodiments of this application proposes a computer-readable storage medium storing a computer program that, when executed by a processor, implements the methods described above.

[0018] To achieve the above objectives, another aspect of the embodiments of this application proposes a computer program product, including a computer program that, when executed by a processor, implements the methods described above.

[0019] The embodiments of this application include at least the following beneficial effects: This application provides a current measurement method and related equipment based on a dual-channel NV color center quantum magnetic field sensing structure. This scheme sets a first sensing channel and a second sensing channel within a preset range of the conductor under test, and places the two sensing channels in the same common-mode disturbance environment. At the same time, the first sensing channel responds stronger to the target magnetic field than the second sensing channel. Thus, by differentially dividing the resonant frequencies of the two channels, common-mode drift caused by changes in the environmental magnetic field and temperature can be suppressed, and high-precision target magnetic field information can be extracted. By laser pumping and microwave driving of the two sensing channels, and by performing phase-locked detection and closed-loop feedback on the microwave driving signal based on the fluorescence signal, the microwave driving signals of the two sensing channels can track the corresponding resonant frequencies respectively, providing an accurate data basis for subsequent signal processing. By applying a reference AC magnetic field with a known frequency and amplitude, and determining the gain correction factor based on the reference AC magnetic field and the frequency difference signal, and then using the gain correction factor to correct the frequency difference signal, the influence of measurement link gain changes on the current measurement results can be compensated. This method is suitable for long-term online applications such as power grid monitoring, new energy power electronics, and precision current metering. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating the steps of a current measurement method based on a dual-channel NV color center quantum magnetic field sensing structure provided in this application embodiment; Figure 2 This is a schematic diagram of the arrangement of the NV color center quantum magnetic field sensing structure near the conductor being measured, provided in an embodiment of this application. Figure 3 This is a schematic diagram of the dual-channel differential measurement principle provided in the embodiments of this application; Figure 4 This is a flowchart illustrating the dual-channel closed-loop frequency tracking and heterodyne self-calibration current measurement method provided in the embodiments of this application. Figure 5 This is a schematic diagram illustrating the conversion principle from the corrected frequency signal to the target magnetic field and the measured current provided in the embodiments of this application; Figure 6 This is a schematic diagram of a current measurement device based on a dual-channel NV color center quantum magnetic field sensing structure provided in an embodiment of this application; Figure 7 This is a schematic diagram of the hardware structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit it. In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application; they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this application as detailed in the appended claims.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0023] To address the problems of high sensitivity to environmental common-mode magnetic fields, significant temperature drift, unstable gain in optical and electronic signal chains, and lack of in-situ real-time calibration mechanisms in continuous operation of existing NV center quantum current sensing technologies during long-term online measurements, this application provides a current measurement method and related equipment based on a dual-channel NV center quantum magnetic field sensing structure. This method, without altering the basic physical structure and measurement mechanism of the NV center, utilizes a composite calibration architecture composed of dual-channel differential magnetic field measurement and heterodyne calibration signals to simultaneously suppress common-mode magnetic field interference, temperature drift, and optoelectronic signal chain gain drift, thereby obtaining highly stable and accurate real-time current measurement results. This application provides a current measurement method based on a dual-channel NV center quantum magnetic field sensing structure, relating to the field of information technology. This method can be applied to terminals, servers, or software running on either. In some embodiments, the terminal can be a smartphone, tablet, laptop, desktop computer, smart speaker, smartwatch, or in-vehicle terminal, but is not limited thereto. The server can be configured as an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms. The server can also be a node server in a blockchain network. The software can be an application implementing a current measurement method based on a dual-channel NV center quantum magnetic field sensing structure, but is not limited to the above forms.

[0024] This application can be used in a wide variety of general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices. This application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform specific tasks or implement specific abstract data types. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0025] Figure 1 This is an optional flowchart of a current measurement method based on a dual-channel NV color center quantum magnetic field sensing structure provided in an embodiment of this application. Figure 1 The method may include, but is not limited to, steps S101 to S104.

[0026] S101. An NV color center quantum magnetic field sensing structure containing a first sensing channel and a second sensing channel is set within a preset range of the conductor to be tested, and the first sensing channel and the second sensing channel are laser-pumped. In some embodiments, the first sensing channel and the second sensing channel are disposed on the same diamond substrate, or the first sensing channel and the second sensing channel are disposed on the same thermal coupling structure.

[0027] In some embodiments, the first projected distance value of the first sensing channel relative to the conductor under test in the NV axis is less than the second projected distance value of the second sensing channel relative to the conductor under test in the NV axis.

[0028] Specifically, in this embodiment, referring to Figure 2 A dual-channel quantum magnetic field sensing structure based on diamond NV centers was fabricated near the conductor under test. The first sensing channel and the second sensing channel were formed by laser pumping and microwave driving, respectively, so that the first channel could simultaneously sense the target magnetic field generated by the measured current. and environmental common-mode magnetic field The second channel primarily senses the common-mode magnetic field of the environment. The two channels are fabricated on the same diamond substrate or in the same thermally coupled structure, so that the NV zero-field splitting drift caused by temperature changes and lattice stress acts on both channels in the same way. Optically Detected Magnetic Resonance (ODMR) measurements are performed on both channels, and the first resonant frequency is obtained through phase-locked servo control. Second resonant frequency And calculate the frequency differential signal. This physically suppresses common-mode frequency drift caused by temperature changes and environmental magnetic field disturbances, thus enabling... It mainly reflects the target magnetic field generated by the current in the conductor being measured.

[0029] For example, the first channel is positioned close to the conductor being measured to simultaneously sense the target magnetic field generated by the current in the conductor being measured. and environmental common-mode magnetic field The second channel is positioned relatively far from the conductor or in a region with a small magnetic field gradient, making it more effective for... The response was significantly reduced, primarily perceptible. The two channels can be fabricated on the same diamond substrate or the same thermal coupling carrier and placed in the same packaging and temperature environment. This ensures that the zero-field splitting drift caused by temperature changes is essentially consistent in both channels, and can be considered a common mode and eliminated in subsequent frequency differential processing. A reference calibration coil is placed near the diamond chip, positioned close to or around the NV probe. Its geometry and position are pre-designed to ensure that the magnetic field generated by the coil has a stable projected component along the NV axis. A reference calibration current with known amplitude and frequency is injected into the coil to generate a reference AC magnetic field in the region of the NV ensemble, the nominal amplitude of which is denoted as... The calibration frequency is denoted as . The values ​​can be obtained through analytical calculations or electromagnetic simulations during the system's factory calibration phase and stored in the control unit as reference values ​​for subsequent heterodyne self-calibration. In the NV ensemble, the equivalent magnetic field sensed by the first channel can be understood as a superposition of three parts: the target magnetic field... Environmental common-mode magnetic field and reference calibration magnetic field For ease of explanation, the total magnetic field of the first channel can be denoted as: (1) The total magnetic field of the second channel is denoted as: (2) Because the NV orientation and spatial position of the two channels are similar, and The changes in the two channels are highly correlated and will appear in common-mode form in subsequent frequency differential operations.

[0030] For example, refer to Figure 3 This invention utilizes dual-channel ODMR measurement and common-mode suppression principles to achieve the conversion of magnetic field to frequency. Two NV ensembles generate optically detected magnetic resonances under microwave excitation. When the magnetic field along the NV axis changes, its resonant frequency also changes. For any channel, its resonant frequency can be written in the form of "center frequency + offset caused by the magnetic field," for example, the first channel is: (3) The second channel is: (4) in, , The center frequency is given by the reference magnetic field and the ambient magnetic field. and These represent the frequency shifts caused by minute changes in the target magnetic field and the common-mode magnetic field, respectively. Within the approximately linear interval of the Zeeman effect, the frequency shift of the first channel is related to the total magnetic field. The frequency offset of the second channel is directly proportional to the total magnetic field. Proportional, that is: (5) The first resonant frequency was obtained by performing ODMR measurements on both channels and using a phase-locked servo motor. Second resonant frequency Further construct the frequency differential signal: (6) From equation (6) and , As can be seen from the expression, the common-mode frequency changes caused by temperature drift and environmental magnetic field disturbances are highly similar in both channels and are significantly canceled out in the differential operation. Mainly retain and The relevant components, and also include The resulting narrowband heterodyne component.

[0031] S102. The first sensing channel and the second sensing channel are driven by microwaves using a first microwave driving signal and a second microwave driving signal containing a periodic modulation signal, respectively, to obtain the first NV fluorescence signal of the first sensing channel and the second NV fluorescence signal of the second sensing channel. The first microwave driving signal and the second microwave driving signal are subjected to phase-locked detection and closed-loop feedback according to the first NV fluorescence signal and the second NV fluorescence signal, respectively, to obtain the first resonance signal and the second resonance signal. The first resonance signal is subtracted from the second resonance signal to obtain the first frequency differential signal. In some embodiments, phase-locked detection and closed-loop feedback are performed on the first microwave drive signal and the second microwave drive signal based on the first NV fluorescence signal and the second NV fluorescence signal, respectively, to obtain the first resonance signal and the second resonance signal, including: S1021. Determine the first error signal of the resonance peak center of the optical detection magnetic resonance of the first microwave drive signal relative to the first sensing channel based on the first NV fluorescence signal. S1022. The first microwave drive signal is adjusted by feedback according to the first error signal to obtain the first resonance signal; S1023. Determine the second error signal of the resonance peak center of the optical detection magnetic resonance of the second microwave drive signal relative to the second sensing channel based on the second NV fluorescence signal; S1024. The second microwave drive signal is adjusted by feedback according to the second error signal to obtain the second resonance signal.

[0032] Specifically, in this embodiment, to achieve high-precision tracking of the NV resonance center, a small-amplitude frequency modulation is superimposed on the two-channel microwave drive signals, and an ODMR closed-loop servo is constructed. The NV fluorescence signal is sent to a lock-in amplifier after photodetection, and an error signal related to the microwave carrier frequency deviating from the resonance center is obtained by synchronous detection at the modulation frequency. The error signal is then used to adjust the microwave frequency via a proportional-integral (PI) or proportional-integral-derivative (PID) controller, so that... and Locked at the center of their respective ODMR resonance peaks, a closed-loop servo structure is formed to track the NV resonance frequency in real time. The specific changes of the two-channel microwave carrier frequencies over time are shown in the following equation: (7) (8) In equations (7) and (8), and To be close to the center frequency of the microwave carrier at their respective NV resonance centers, For the frequency modulation amplitude, it is preferable to be less than half the ODMR linewidth to ensure that the phase-locked detection operates in the linear region; The modulation angular frequency corresponds to the modulation frequency. They often choose to avoid the frequency range of power frequency and its low-order harmonics.

[0033] Subsequently, the NV fluorescence signal is sent to a lock-in amplifier after photodetector input, to... Synchronous detection is performed for reference, yielding an error signal proportional to the current microwave carrier's deviation from the resonant center. This error signal is then processed by a proportional-integral-derivative (PID) controller for feedback adjustment. and ,make and It locks onto its respective ODMR resonance center in real time, thereby achieving closed-loop tracking of the resonance frequencies of the two channels. During closed-loop steady-state operation, and It drifts slowly with changes in the applied magnetic field, and the difference is... This is the differential frequency signal in the time domain.

[0034] S103. Apply a reference AC magnetic field with a known frequency and amplitude to the NV color center quantum magnetic field sensing structure, and determine the gain correction factor based on the reference AC magnetic field and the first frequency differential signal. In some embodiments, determining a gain correction factor based on a reference alternating magnetic field and a first frequency differential signal includes: S1031. Obtain the calibration frequency and calibration amplitude of the reference AC magnetic field; S1032. The heterodyne calibration component measurement signal is obtained by separating it from the first frequency differential signal according to the calibration frequency; S1033. Determine the gain correction factor based on the amplitude of the heterodyne calibration component measurement signal and the calibration amplitude.

[0035] Specifically, in this embodiment, to compensate for optical pump power drift, changes in optical path coupling efficiency, changes in photodetector responsivity, and analog amplification link gain drift, a reference AC magnetic field with pre-calibrated amplitude and frequency is injected near the NV color center. The amplitude is denoted as... The frequency is denoted as The reference magnetic field and the target magnetic field act together on the NV ensemble, at the differential frequency signal. Formed in the middle The nearby heterodyne calibration component, whose amplitude has been transmitted through optical, electrical, analog, and digital signal chains, thus carries information about the overall system gain over time. Therefore, in the frequency domain of the first frequency differential signal, In addition to including and In addition to the corresponding low-frequency components, the calibration frequency is also being adjusted. The vicinity contains a reference magnetic field. The introduced narrowband heterodyne calibration component has an amplitude that is proportional to the overall gain of the system's optical and electronic signal chains.

[0036] Reference Figure 4 To utilize this heterodyne calibration component for online self-calibration of the system gain, this embodiment uses the differential frequency signal... Perform digital signal processing. First, [the process involves...] Perform Fast Fourier Transform or Digital Down-Conversion processing, in order to Perform digital bandpass filtering over a narrow frequency range centered on the filter, and the filter output is... In an ideal situation, It can be represented as: (9) in, The equivalent transfer gain from the reference magnetic field to the differential frequency includes factors such as NV's intrinsic sensitivity, laser pump efficiency, photodetector response, analog amplifier gain, and digital processing gain. When the system is in its initial calibration state, the transfer gain is... The calibration component measured at this time can be recorded as .Will Considered a multiple quantity, actually part This represents the nominal amplitude under the system's rated gain.

[0037] During normal operation, factors such as optical coupling, device aging, or temperature changes can cause problems. It will slowly deviate ,lead to and They are no longer equal. In this embodiment, the instantaneous amplitude is measured and compared with the reference amplitude stored during the system initialization phase. By comparison, the gain correction factor can be constructed using the following formula. : (10) This allows us to obtain a real-time scaling factor characterizing the overall gain change of the signal chain. When the system gain decreases, Get smaller Greater than 1; when the system gain increases, Get bigger Less than 1.

[0038] S104. Correct the first frequency differential signal according to the gain correction factor to obtain the second frequency differential signal. Determine the current signal of the conductor under test according to the second frequency differential signal, the preset reference resonant frequency and the pre-calibrated magnetic field-current transfer function. The first sensing channel and the second sensing channel are set in the same common-mode disturbance environment. The first response value of the first sensing channel to the target magnetic field of the conductor under test in the preset NV axis is higher than the second response value of the second sensing channel to the target magnetic field in the NV axis.

[0039] In some embodiments, determining the current signal of the conductor under test based on a second frequency differential signal, a preset reference resonant frequency, and a pre-calibrated magnetic field-current transfer function includes: S1041. Determine the resonant frequency offset based on the second frequency differential signal and the reference resonant frequency; S1042. Determine the target magnetic field strength based on the resonance frequency offset and the preset NV color center electron spin-gyromagnetic ratio parameter. S1043. Determine the current signal of the conductor under test based on the target magnetic field strength and the magnetic field-current transfer function.

[0040] In some embodiments, the magnetic field-current transfer function is determined by the following steps: S201. Obtain the assembly geometric parameters of the conductor under test and the NV color center quantum magnetic field sensing structure; S202. Determine the geometric coefficients of the magnetic field-current transfer function based on the assembly geometry parameters; S203. Determine the magnetic field-current transfer function based on the geometric coefficients.

[0041] Specifically, in this embodiment, the real-time gain correction factor characterizing the overall gain change of the signal chain can be obtained from the aforementioned digital bandpass filtering and gain correction factor generation process. , gain correction factor Acting on differential frequency signals The gain drift introduced by the optical and electronic signal chains is compensated to obtain the corrected differential resonant frequency: (11) From a physical perspective, It is equivalent to the differential frequency that should be obtained when the system gain is constant at the initial state, and therefore is more suitable as the basis signal for subsequent magnetic field and current conversion.

[0042] like Figure 5 As shown, the ground state spin level of the NV color center undergoes Zeeman splitting under the influence of an external magnetic field. For the target magnetic field component along the selected NV axis... Its resonant frequency shift and They approximately satisfy a linear relationship: (12) In equation (12), This represents the gyromagnetic ratio of the electron spin. In the measurement process of this embodiment, the frequency change after heterodyne self-calibration... This is the change in the differential resonant frequency relative to the reference value, which can be regarded as the Zeeman frequency shift. Therefore, within the operating bandwidth range From equation (12), the relationship between the target magnetic field and the corrected differential frequency can be obtained: (13) In the initial stage of the system, based on the geometric dimensions of the conductor under test, the cross-sectional shape of the conductor, the relative position of the NV probe and the conductor, and the NV axial direction, the geometric coefficients can be determined through analytical calculation or electromagnetic simulation. This ensures that the target magnetic field along the NV axis and the current in the measured conductor approximately satisfy the following relationship: (14) in, Given the time series of the current in the conductor being measured, the above equation is the magnetic field-current transfer function in this embodiment. Geometric coefficients. It characterizes the magnetic field strength generated by a unit current along the NV axis and can be considered a constant once calibrated.

[0043] By combining equations (13) and (14), we can obtain the time series expression for the current in the conductor being measured: (15) Therefore, this embodiment suppresses common-mode magnetic field and temperature drift through dual-channel differential measurement, and constructs a gain correction factor through heterodyne calibration components. And the corrected differential resonance frequency is obtained. Combined with the Zeeman effect and geometric coefficients Establish , and The quantitative relationship between them enables in-situ, real-time, and highly stable measurement of the current in the conductor being measured.

[0044] It can be recognized that this embodiment, by employing a dual-channel differential structure composed of the first and second NV color center channels near the conductor under test and operating in the same substrate or thermal coupling environment, makes environmental magnetic field disturbances and temperature changes appear as common-mode components in both channels. The signal obtained after resonant frequency differential significantly reduces zero-point drift and baseline drift. Combined with microwave frequency modulation, lock-in amplification, and closed-loop servo, the fluorescence amplitude readout, which is susceptible to light intensity fluctuations, is transformed into a stable frequency reading, improving the measurement accuracy and anti-drift capability for DC and low-frequency currents. Furthermore, by injecting a reference AC magnetic field with pre-calibrated amplitude and frequency in the NV region, a heterodyne calibration component is obtained at the differential frequency, and digital bandpass filtering and gain correction factors are used. Online compensation is performed on the gain drift of the entire optical and electronic signal chain, so that the corrected frequency change can be stably mapped to the target magnetic field and the measured current. This enables the NV color center quantum current sensor to perform in-situ, real-time self-calibrated current measurement under continuous operation conditions, which is suitable for long-term online applications such as power grid monitoring, new energy power electronics and precision current metering.

[0045] Please see Figure 6 This application also provides a current measurement device based on a dual-channel NV color center quantum magnetic field sensing structure, which can implement the above-mentioned method. The device includes: The sensing channel setting module is used to set an NV color center quantum magnetic field sensing structure including a first sensing channel and a second sensing channel within a preset range of the conductor under test, and to laser pump the first sensing channel and the second sensing channel. The frequency differential module is used to drive the first sensing channel and the second sensing channel with microwaves through a first microwave driving signal and a second microwave driving signal containing a periodic modulation signal, respectively, to obtain the first NV fluorescence signal of the first sensing channel and the second NV fluorescence signal of the second sensing channel. Based on the first NV fluorescence signal and the second NV fluorescence signal, phase-locked detection and closed-loop feedback are performed on the first microwave driving signal and the second microwave driving signal, respectively, to obtain the first resonant signal and the second resonant signal. The first resonant signal is subtracted from the second resonant signal to obtain the first frequency differential signal. The gain correction module is used to apply a reference AC magnetic field with a known frequency and amplitude to the NV color center quantum magnetic field sensing structure, and to determine the gain correction factor based on the reference AC magnetic field and the first frequency differential signal. The current measurement module is used to correct the first frequency differential signal according to the gain correction factor to obtain the second frequency differential signal, and to determine the current signal of the conductor under test according to the second frequency differential signal, the preset reference resonant frequency and the pre-calibrated magnetic field-current transfer function. The first sensing channel and the second sensing channel are set in the same common-mode disturbance environment. The first response value of the first sensing channel to the target magnetic field of the conductor under test in the preset NV axis is higher than the second response value of the second sensing channel to the target magnetic field in the NV axis.

[0046] It is understood that the content of the above method embodiments is applicable to the present device embodiments. The specific functions implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0047] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described method. This electronic device can be any smart terminal, including tablet computers, in-vehicle computers, etc.

[0048] It is understood that the content of the above method embodiments is applicable to this device embodiment. The specific functions implemented by this device embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0049] Please see Figure 7 , Figure 7 The hardware structure of an electronic device according to another embodiment is illustrated. The electronic device includes: The processor 901 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this application. The memory 902 can be implemented as a read-only memory (ROM), static storage device, dynamic storage device, or random access memory (RAM). The memory 902 can store the operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 902 and is called and executed by the processor 901 using the methods described in the embodiments of this application. The input / output interface 903 is used to implement information input and output; The communication interface 904 is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.). Bus 905 transmits information between various components of the device (e.g., processor 901, memory 902, input / output interface 903, and communication interface 904); The processor 901, memory 902, input / output interface 903, and communication interface 904 are connected to each other within the device via bus 905.

[0050] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0051] It is understood that the content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented in this storage medium embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0052] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0053] It is understood that the content of the above method embodiments is applicable to the embodiments of this program product. The specific functions implemented by the embodiments of this program product are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0054] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0055] This application provides a current measurement method and related equipment based on a dual-channel NV center quantum magnetic field sensing structure. The method involves setting a first and second sensing channel within a preset range of the conductor under test, placing both channels in the same common-mode disturbance environment, and ensuring the first sensing channel responds more strongly to the target magnetic field than the second. This allows for the suppression of common-mode drift caused by changes in the ambient magnetic field and temperature by differentiating the resonant frequencies of the two channels, thus extracting high-precision target magnetic field information. By laser pumping and microwave driving of the two sensing channels, and using phase-locked detection and closed-loop feedback based on fluorescence signals, the microwave driving signals of the two sensing channels can track their respective resonant frequencies, providing an accurate data foundation for subsequent signal processing. By applying a reference AC magnetic field with known frequency and amplitude, and determining a gain correction factor based on this reference AC magnetic field and the frequency difference signal, the frequency difference signal can be corrected using this gain correction factor. This method compensates for the impact of measurement link gain changes on the current measurement results and is suitable for long-term online applications such as power grid monitoring, new energy power electronics, and precision current metering.

[0056] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0057] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0058] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0059] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0060] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0061] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0062] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0063] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0064] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0065] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0066] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A current measurement method based on a dual-channel NV color center quantum magnetic field sensing structure, characterized in that, include: An NV color center quantum magnetic field sensing structure, including a first sensing channel and a second sensing channel, is set within a preset range of the conductor under test, and the first sensing channel and the second sensing channel are laser-pumped. The first sensing channel and the second sensing channel are driven by microwaves using a first microwave driving signal and a second microwave driving signal containing periodic modulation signals, respectively. The first NV fluorescence signal of the first sensing channel and the second NV fluorescence signal of the second sensing channel are obtained. The first microwave driving signal and the second microwave driving signal are subjected to phase-locked detection and closed-loop feedback based on the first NV fluorescence signal and the second NV fluorescence signal, respectively, to obtain a first resonance signal and a second resonance signal. The first resonance signal is subtracted from the second resonance signal to obtain a first frequency differential signal. A reference AC magnetic field with a known frequency and amplitude is applied to the NV color center quantum magnetic field sensing structure, and a gain correction factor is determined based on the reference AC magnetic field and the first frequency differential signal. The first frequency differential signal is corrected according to the gain correction factor to obtain the second frequency differential signal. The current signal of the conductor under test is determined according to the second frequency differential signal, the preset reference resonant frequency, and the pre-calibrated magnetic field-current transfer function. The first sensing channel and the second sensing channel are set in the same common-mode disturbance environment. The first response value of the first sensing channel to the target magnetic field of the conductor under test in the preset NV axis is higher than the second response value of the second sensing channel to the target magnetic field in the NV axis.

2. The current measurement method based on a dual-channel NV color center quantum magnetic field sensing structure according to claim 1, characterized in that, The first sensing channel and the second sensing channel are disposed on the same diamond substrate, or the first sensing channel and the second sensing channel are disposed on the same thermal coupling structure.

3. The current measurement method based on a dual-channel NV color center quantum magnetic field sensing structure according to claim 1, characterized in that, The first projection distance value of the first sensing channel relative to the conductor under test in the NV axis is less than the second projection distance value of the second sensing channel relative to the conductor under test in the NV axis.

4. The current measurement method based on a dual-channel NV color center quantum magnetic field sensing structure according to claim 1, characterized in that, The step of performing phase-locked detection and closed-loop feedback on the first microwave drive signal and the second microwave drive signal based on the first NV fluorescence signal and the second NV fluorescence signal, respectively, to obtain the first resonance signal and the second resonance signal, includes: The first error signal is determined based on the first NV fluorescence signal to the center of the resonance peak of the first microwave drive signal relative to the optical detection magnetic resonance of the first sensing channel. The first microwave drive signal is adjusted by feedback based on the first error signal to obtain the first resonance signal; A second error signal is determined based on the second NV fluorescence signal to indicate the center of the resonance peak of the second microwave drive signal relative to the optical detection magnetic resonance of the second sensing channel; The second microwave drive signal is adjusted by feedback based on the second error signal to obtain the second resonance signal.

5. The current measurement method based on a dual-channel NV color center quantum magnetic field sensing structure according to claim 1, characterized in that, The step of determining the gain correction factor based on the reference AC magnetic field and the first frequency differential signal includes: Obtain the calibration frequency and calibration amplitude of the reference AC magnetic field; The heterodyne calibration component measurement signal is obtained by separating it from the first frequency differential signal according to the calibration frequency; The gain correction factor is determined based on the amplitude of the heterodyne calibration component measurement signal and the calibration amplitude.

6. The current measurement method based on a dual-channel NV color center quantum magnetic field sensing structure according to claim 1, characterized in that, The step of determining the current signal of the conductor under test based on the second frequency differential signal, the preset reference resonant frequency, and the pre-calibrated magnetic field-current transfer function includes: The resonant frequency offset is determined based on the second frequency differential signal and the reference resonant frequency; The target magnetic field strength of the target magnetic field is determined based on the resonant frequency offset and the preset NV color center electron spin-gyromagnetic ratio parameter. The current signal of the conductor under test is determined based on the target magnetic field strength and the magnetic field-current transfer function.

7. The current measurement method based on a dual-channel NV color center quantum magnetic field sensing structure according to claim 1, characterized in that, The magnetic field-current transfer function is determined by the following steps: Obtain the assembly geometric parameters of the conductor under test and the NV color center quantum magnetic field sensing structure; The geometric coefficients of the magnetic field-current transfer function are determined based on the assembly geometry parameters. The magnetic field-current transfer function is determined based on the geometric coefficients.

8. A current measurement device based on a dual-channel NV color center quantum magnetic field sensing structure, characterized in that, The device includes: The sensing channel setting module is used to set an NV color center quantum magnetic field sensing structure including a first sensing channel and a second sensing channel within a preset range of the conductor under test, and to laser pump the first sensing channel and the second sensing channel. The frequency differential module is used to drive the first sensing channel and the second sensing channel with microwaves through a first microwave driving signal and a second microwave driving signal containing a periodic modulation signal, respectively, to obtain a first NV fluorescence signal of the first sensing channel and a second NV fluorescence signal of the second sensing channel. Based on the first NV fluorescence signal and the second NV fluorescence signal, phase-locked detection and closed-loop feedback are performed on the first microwave driving signal and the second microwave driving signal, respectively, to obtain a first resonant signal and a second resonant signal. The first resonant signal is subtracted from the second resonant signal to obtain a first frequency differential signal. A gain correction module is used to apply a reference AC magnetic field of known frequency and amplitude to the NV color center quantum magnetic field sensing structure, and to determine a gain correction factor based on the reference AC magnetic field and the first frequency differential signal. The current measurement module is used to correct the first frequency differential signal according to the gain correction factor to obtain the second frequency differential signal, and to determine the current signal of the conductor under test according to the second frequency differential signal, the preset reference resonant frequency and the pre-calibrated magnetic field-current transfer function. The first sensing channel and the second sensing channel are set in the same common-mode disturbance environment. The first response value of the first sensing channel to the target magnetic field of the conductor under test in the preset NV axis is higher than the second response value of the second sensing channel to the target magnetic field in the NV axis.

9. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the method according to any one of claims 1 to 7.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1 to 7.

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