Fault arc signal detection method and device based on Rydberg atoms

Abstract

A fault arc signal detection method and device based on Rydberg atoms belong to the technical field of power fault detection and solve the problem of how to improve the responsiveness of Rydberg atoms to fault arc signals under non-resonant conditions. The present invention adopts a two-photon cascade excitation method to transition cesium atoms from a ground state to an excited state via a Rydberg state, constructs an EIT spectrum linear model, and adjusts the Rabi frequency of the detection light by changing the detection light power so that the spectrum shows an intermediate state in the process of transition from EIT to EIA, thereby increasing the slope of the spectrum with respect to the fault arc response position, improving the responsiveness of the Rydberg atom system to the fault arc electromagnetic signal under non-resonant conditions, and significantly improving the performance of the Rydberg atom microwave sensing system. The method is applied to the detection of fault arc signals under high-voltage environments and is of great significance for reducing the risk of personal injury and property loss caused by localized discharge faults in various power facilities.

Description

Technical Field

[0001] The present invention belongs to the technical field of power fault detection, and relates to a method and device for detecting a fault arc signal based on Rydberg atoms. Background Art

[0002] Arc faults are a high-power discharge between conductors, commonly seen in various power facilities due to localized insulation discharge failures. These include aging insulation in high-voltage transmission cables, single-phase ground faults in distribution networks, internal transformer short circuits, and fast transient overvoltages (VFTOs) in gas-insulated substations (GIS). With the increase in residential electricity consumption nationwide, the frequency of electrical fires has also risen accordingly. Approximately 80% of electrical fires each year are related to arc faults. Detecting arc faults is crucial to the safety of life and property of power users and businesses.

[0003] Existing arc fault detection methods mainly include the following methods: (1) Intrusive detection based on time-frequency domain analysis of voltage and current data and pattern recognition algorithms, such as the document "Research on the Influence of Different Electrode Materials on DC Arc Fault Detection Characteristics" (Wang J, Meng Y, Li X, Chen S. 2021 IEEE 66th Holm Conference on Electrical Contacts (HLM). San Antonio, TX, USA, 2021: 89-94. DOI: 10.1109 / HLM51431.2021.9671187.), which analyzes and compares the differences in arc fault currents based on different materials from a time domain perspective, discusses the reasons for the differences in arc fault phenomena of different materials, uses wavelet transform method to find the differences in arc fault detection characteristics, compares them from the perspective of time-frequency domain, and summarizes the influence of different materials on DC arc fault detection characteristics. (2) Non-invasive detection methods that analyze the acoustic signals, optical signals, electromagnetic radiation signals, thermal signals, etc. emitted by the fault arc circuit system based on its physical characteristics, such as the document "ASeries DC Arc Fault Detection Method Based on Steady Pattern of High-Frequency Electromagnetic Radiation" (Zhao S, Wang Y, Niu F, Zhu C, Xu Y, Li K. IEEE Transactions on Plasma Science, 2019, 47(9): 4370-4377. DOI: 10.1109 / TPS.2019.2932747.), use the electromagnetic radiation (EMR) emitted by the arc as the test basis, calculate patterns such as the structural similarity index (SSIM) and 6dB bandwidth bins (dB BWBs), accurately identify arc faults in different DC systems, and distinguish arc faults from normal operation.

[0004] Currently, research on arc fault detection based on arc RF signals often uses traditional metal antennas to receive the RF signals emitted by the arc fault, identifying the arc fault using the arc RF signal's characteristic frequency band at the MHz level. However, in environments with extremely high electric field strength, such as when detecting electromagnetic signals emitted from a power transformer's arc fault in free space, the inherent metal content of traditional antennas can easily lead to circuit overload, resulting in heating, short circuits, and even burnout of the arc detector circuit.

[0005] In recent years, microwave sensing systems based on Rydberg atoms have gradually gained traction in power companies and related research institutes due to their high sensitivity, high precision, wide operating bandwidth, and real-time multi-frequency demodulation and monitoring. They have become a hot topic in the field of quantum precision measurement. Because the probe portion of a Rydberg atom sensing system is entirely optical, the metal component can be completely removed by constructing a fiber-coupled gas chamber. This allows the atomic system to utilize its non-destructive measurement capabilities to resist interference even in extremely high electric field strengths, safely detecting electromagnetic signals.

[0006] In fact, cesium atoms, a common experimental target for Rydberg atom systems, have adjacent energy levels with relatively low principal quantum numbers (20-60) that have resonant frequencies (above 1 GHz) that are 1 to 3 orders of magnitude greater than the primary frequency of arc fault signals (below 100 MHz). Furthermore, cesium atoms with higher principal quantum numbers (above 60) are more difficult to excite with lasers, resulting in a relatively small number of successfully excited atoms. Therefore, two-photon excitation is generally rarely considered. Therefore, Rydberg atom sensing systems can only detect arc signals using the AC Stark effect in a non-resonant manner. Compared to resonant microwave superheterodyne detection of electromagnetic signals, the bandwidth in this non-resonant method is one order of magnitude smaller, the sensitivity is three orders of magnitude smaller, and the overall responsiveness is inferior to that of the resonant method. Therefore, overcoming the low responsiveness of Rydberg atoms to arc fault signals in the non-resonant condition is particularly important. Summary of the Invention

[0007] The technical problem to be solved by the present invention is how to improve the responsiveness of Rydberg atoms to fault arc signals under non-resonant conditions.

[0008] The present invention solves the above technical problems through the following technical solutions:

[0009] The method for detecting arc fault signals based on Rydberg atoms includes the following steps:

[0010] S1. Split the laser output by the first laser into a first probe light and a second probe light through a polarization beam splitter cube. The first probe light is incident on the first cesium atomic gas chamber to couple the cesium atoms from the ground state to the excited state. The second probe light is incident on the saturation spectrum optical path for wavelength locking.

[0011] S2, the laser output from the second laser is used as coupling light, which is incident in reverse on the first cesium atomic gas chamber, and the coupled cesium atoms transition from the excited state to the Rydberg state. The gain photoelectric probe scans the detuning amount of the coupling light to generate an EIT spectrum;

[0012] S3, constructing an EIT spectrum linear model based on the first detection light and the coupled light;

[0013] S4. Adjust the parameters of the EIT spectrum linear model to obtain the intermediate state spectrum;

[0014] S5. Loading a fault arc signal to the first cesium atomic gas chamber, obtaining a slope of a response position of the fault arc signal in the spectrum based on the intermediate state spectrum, and calculating a response amplitude of the fault arc signal.

[0015] Furthermore, the ground state of the cesium atom is 6S 1 / 2 , the excited state is 7P 3 / 2 , the Rydberg state is 31D 5 / 2 .

[0016] Furthermore, the laser wavelength of the first laser is 456 nm, and the laser wavelength of the second laser is 1072 nm.

[0017] Furthermore, the step S3 includes the following steps:

[0018] S31, writing the first detection light Rabi frequency, the first detection light detuning amount, the coupling light Rabi frequency, and the coupling light detuning amount into a Hamilton matrix, and simplifying the Hamilton matrix;

[0019] S32, writing the dephasing frequency of the excited state of the cesium atom into the dephasing matrix, constructing the optical Bloch equations based on the Hamilton matrix and the dephasing matrix, and calculating the density matrix element of the detection light absorption coefficient;

[0020] S33. Solve the relationship between the repolarizability and the density matrix element;

[0021] S34. The linear model expression of EIT spectrum is obtained based on electrodynamics.

[0022] Furthermore, the Hamilton matrix is ​​represented by the following logic in S31:

[0023]

[0024] Where H represents the Hamilton matrix, represents the reduced Planck constant.

[0025] Furthermore, the optical Bloch equations are represented by the following logic in S32:

[0026]

[0027] ρ 11 +ρ 22 +ρ 33 =1

[0028] Where γ2 represents the dephasing frequency of the excited state of the cesium atom, ΔP represents the detuning amount of the first detection light, Δ C Denotes the coupling light detuning amount, Ω P represents the first detection light Rabi frequency, Ω C represents the coupled light Rabi frequency, i represents the imaginary unit, ρ xy represents the matrix element at row x and column y of the density matrix ρ, Represents the time derivative of the matrix element, x∈[1,3], y∈[1,3].

[0029] Furthermore, the relationship between the complex polarizability and the density matrix element is solved using the following logic in S33:

[0030]

[0031] Where, χ 21 represents the repolarization rate, N a Indicates the number of atoms per unit space in the area where the laser interacts with atoms, μ 21 represents the detection light transition matrix element, and ε0 represents the vacuum dielectric constant.

[0032] Furthermore, the EIT spectrum linear model expression in S34 is as follows:

[0033]

[0034] Where P represents the transmitted light power of the first detection light, Exp{·} represents the exponential operation, and C represents the constant term composed of system parameters and physical constants.

[0035] Furthermore, the response amplitude of the arc fault signal is calculated using the following logic in S5:

[0036] A=κδ

[0037] Where A represents the response amplitude of the fault arc signal, κ is the slope of the fault arc signal response position in the intermediate state spectrum, and δ represents the energy level offset.

[0038] A fault arc signal detection device based on Rydberg atoms, comprising a first laser, a second laser, a polarization beam splitter cube, a first cesium atom gas chamber, a saturation spectrum optical path, a gain photoelectric probe and an arc lighter;

[0039] The laser light output by the first laser is split into a first probe light and a second probe light by the polarization beam splitter cube, the first probe light is incident on the first cesium atomic gas chamber, and couples the cesium atoms to transition from the ground state to the excited state, and the second probe light is incident on the saturation spectrum optical path for wavelength locking;

[0040] The laser light output by the second laser is used as coupling light and is incident in reverse on the first cesium atomic gas chamber, coupling the cesium atoms to transition from the excited state to the Rydberg state, and the gain photoelectric probe scans the detuning amount of the coupling light to generate an EIT spectrum;

[0041] The first cesium atomic gas cell is used to construct an EIT spectrum linear model based on the first detection light and the coupled light;

[0042] The gain photoelectric probe is used to adjust various parameters of the EIT spectrum linear model to obtain the intermediate state spectrum;

[0043] The arc lighter is used to load a fault arc signal to the first cesium atomic gas chamber, obtain the slope of the fault arc signal response position in the spectrum based on the intermediate state spectrum, and calculate the response amplitude of the fault arc signal.

[0044] The advantages of the present invention are:

[0045] The present invention uses a two-photon cascade excitation method to transition cesium atoms from the ground state to the excited state to the Rydberg state, constructs an EIT spectrum linear model, and adjusts the Rabi frequency of the detection light by changing the detection light power, so that the spectrum shows an intermediate state in the transition process from EIT to EIA, increases the slope of the fault arc response position on the spectrum, improves the responsiveness of the Rydberg atom system to the fault arc electromagnetic signal under non-resonant conditions, significantly improves the performance of the Rydberg atom microwave sensing system, and is applied to the detection of fault arc signals in high-voltage environments. It is of great significance to reducing the risk of personal injury and property loss caused by local discharge faults in various power facilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a flow chart of a fault arc signal detection method based on Rydberg atoms according to the first embodiment of the present invention;

[0047] Figure 2 Schematic diagram of the energy levels of the Rydberg atom excitation path according to the first embodiment of the present invention;

[0048] Figure 3 1 is a spectrum diagram of the EIT, intermediate state and EIA cases of Example 1 of the present invention;

[0049] FIG4( a ) is a schematic diagram of the detection light transmission spectrum at different detection light Rabi frequencies when no arc fault signal is applied according to the first embodiment of the present invention;

[0050] FIG4( b ) is a schematic diagram showing the response of different detection light Rabi frequencies to a fault arc signal according to the first embodiment of the present invention;

[0051] Figure 5 It is a structural diagram of a fault arc signal detection device based on Rydberg atoms according to the second embodiment of the present invention. DETAILED DESCRIPTION

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0053] The technical solution of the present invention is further described below with reference to the accompanying drawings and specific embodiments:

[0054] Example 1

[0055] like Figure 1-2 Specifically, a method for detecting arc fault signals based on Rydberg atoms is disclosed, comprising the following steps:

[0056] S1. Split the laser output by the first laser into a first probe light and a second probe light through a polarization beam splitter cube. The first probe light is incident on the first cesium atomic gas chamber to couple the cesium atoms from the ground state to the excited state. The second probe light is incident on the saturation spectrum optical path for wavelength locking.

[0057] S2, the laser output from the second laser is used as coupling light, which is incident in reverse on the first cesium atomic gas chamber, and the coupled cesium atoms transition from the excited state to the Rydberg state. The gain photoelectric probe scans the detuning amount of the coupling light to generate an EIT spectrum;

[0058] Furthermore, the ground state of the cesium atom is 6S 1 / 2 , the excited state is 7P 3 / 2 , the Rydberg state is 31D 5 / 2 .

[0059] Furthermore, the laser wavelength of the first laser is 456 nm, and the laser output by the first laser is used as a probe light to couple the cesium atoms from the ground state 6S 1 / 2 Transition to the excited state 7P 3 / 2 , make the first level transition.

[0060] In this embodiment, the probe light is split into two beams by a polarization beam splitter. The first probe light is incident on the first cesium atomic gas cell. The first probe light passes through the first cesium atomic gas cell and enters the gain photoelectric probe, which reads the transmittance information of the first probe light through the first cesium atomic gas cell. The first probe light interacts with the cesium atoms when passing through the first cesium atomic gas cell. The gain photoelectric probe reads the intensity and spectral shape of the transmitted light, which can provide relevant information about the cesium atomic transition and energy level structure. The second probe light is incident on the saturation spectrum optical path for wavelength locking. The saturation absorption characteristic of the saturation spectrum optical path is utilized to match the probe light with the energy level of the cesium atom transition from the ground state to the excited state, precisely locking the probe light to the resonant frequency of the cesium atom transition from the ground state to the excited state, thereby improving detection accuracy and sensitivity.

[0061] Furthermore, the laser wavelength of the second laser is 1072nm, and the laser output by the second laser is used as coupling light to couple cesium atoms from the excited state 7P 3 / 2 Transition to Rydberg state 31D 5 / 2 , and make the second-level transition.

[0062] In this embodiment, the coupling light is incident on the first cesium atomic gas cell in the opposite direction of the detection light. The coupling light and the first detection light work together to produce the EIT effect. By scanning the detuning amount Δ of the coupling light C , the formation of the electromagnetically induced transparent window can be precisely controlled to produce the EIT spectrum.

[0063] Furthermore, the first detection light Rabi frequency Ω P ~1MHz, the coupled light Rabi frequency Ω C =10.9MHz, indicating that the intensity of the coupled light is much greater than that of the probe light, satisfying the condition of weak probe light and strong coupled light, further ensuring that the coupled light dominates the EIT effect. The transmittance change of the first probe light is caused by the detuning of the coupled light.

[0064] Furthermore, since the cesium atom is converted from the ground state 6S 1 / 2 to the excited state 7P 3 / 2 The two energy level transition dipole moments are small and meet the weak detection light strong coupling light condition. The first level transition probability is low. In this embodiment, the cesium atomic gas chamber is heated to 400K and the first detection light transmission spectrum signal intensity is improved by increasing the atomic vapor density.

[0065] In this embodiment, the EIT effect (Electromagnetically Induced Transparency) is a quantum interference effect. This embodiment adopts a two-photon cascade excitation method. Through the synergistic effect of the first detection light and the coupling light, the cesium atom is transitioned from the ground state to the excited state via the Rydberg state. The first detection light, with the help of the coupling light, causes the atom to enter a coherent energy level structure, forming an electromagnetically induced transparent window. The transmittance information of the first detection light passing through the first cesium atom gas chamber is read by the gain photoelectric probe, effectively enhancing the signal intensity of the cesium atom excitation and providing high-precision EIT spectrum measurement.

[0066] S3, constructing an EIT spectrum linear model based on the first detection light and the coupled light;

[0067] In this embodiment, S3 includes the following steps:

[0068] S31, writing the first detection light Rabi frequency, the first detection light detuning amount, the coupling light Rabi frequency, and the coupling light detuning amount into a Hamilton matrix, and simplifying the Hamilton matrix;

[0069] In this embodiment, the first probe light is pulled higher by the frequency Ω P , the first detection light detuning amount Δ P 、Coupled light Rabi frequency Ω C and the coupling light detuning amount Δ C The non-diagonal terms of the Hamilton matrix are written, and the Hamilton matrix is ​​subjected to unitary transformation and swirl approximation to eliminate the time-dependent factors in the Hamilton matrix. In this embodiment, the Hamilton matrix is ​​represented by the following logic:

[0070]

[0071] Where H represents the Hamilton matrix, represents the reduced Planck constant.

[0072] S32, writing the dephasing frequency of the excited state of the cesium atom into the dephasing matrix, constructing the optical Bloch equations based on the Hamilton matrix and the dephasing matrix, and calculating the density matrix element of the detection light absorption coefficient;

[0073] In this embodiment, because the spontaneous emission frequency of the Rydberg state of the cesium atom is much lower than the spontaneous emission frequency of the excited state, this embodiment only considers the dephasing frequency γ2 of the excited state of the cesium atom and writes it into the dephasing matrix. Based on the Hamilton matrix and the dephasing matrix, the optical Bloch equations are constructed. This embodiment uses the following logic to represent the optical Bloch equations:

[0074]

[0075] ρ 11 +ρ 22 +ρ 33 =1

[0076] Where γ2 represents the dephasing frequency of the excited state of the cesium atom, Δ P represents the detuning amount of the first detection light, Δ C Denotes the coupling light detuning amount, Ω P represents the first detection light Rabi frequency, Ω C represents the coupled light Rabi frequency, i represents the imaginary unit, ρ xy represents the matrix element at row x and column y of the density matrix ρ, Represents the time derivative of the matrix element, x∈[1,3], y∈[1,3].

[0077] In this embodiment, a dephasing matrix is ​​used to represent the non-Hermitian part of the density matrix evolution equation of the Rydberg atom microwave sensing system. In this embodiment, the optical Bloch equations are constructed as the density matrix evolution equation, and the dephasing matrix is ​​used to represent the irreversible time evolution caused by factors such as spontaneous radiation, collisions, and transitions. By adjusting the parameters in the dephasing matrix, the behavior of the quantum system under different environments is simulated, the experimental conditions are changed, and the experimental results are optimized.

[0078] The construction of the optical Bloch equations can describe the dynamic behavior of the two energy levels of the cesium atom under the interaction with the detection light field and the coupling light field. In this embodiment, by solving the optical Bloch equations under the steady-state approximation, the density matrix element ρ of the corresponding first detection light absorption coefficient can be obtained. 21 .

[0079] S33. Solve the relationship between the repolarizability and the density matrix element;

[0080] The complex polarization intensity is a complex representation of the electric dipole moment, capturing the polarization behavior of cesium atoms in a medium induced by an external electromagnetic field. When the probe light and the coupled light field illuminate the cesium atoms, the particles generate an induced electric dipole moment driven by the light field, and the complex polarization intensity directly represents this induced polarization phenomenon.

[0081] In this embodiment, according to the definition of repolarization intensity And the repolarization intensity and the first detection light Rabi frequency Ω P relationship Use the following logic to solve the relationship between the complex polarizability and the density matrix element:

[0082]

[0083] Where, χ21 represents the repolarization rate, N a Indicates the number of atoms per unit space in the area where the laser interacts with atoms, μ 21 represents the detection light transition matrix element, and ε0 represents the vacuum dielectric constant.

[0084] S34, based on electrodynamics, the linear model expression of EIT spectrum is obtained;

[0085] In this embodiment, based on the known electrodynamics, the approximate relationship between the power of the first probe light before and after passing through the cesium atomic gas cell is: Among them, k P represents the first detection light wave number, L represents the length of the interaction between the cesium atoms and the laser in the cesium atom gas chamber, and P0 represents the initial optical power of the incident light. Based on the above relationship, this embodiment ignores the Doppler averaging effect and obtains the expression of the EIT spectrum linear model:

[0086]

[0087] Where P represents the transmitted light power of the first detection light, Exp{·} represents the exponential operation, and C represents the constant term composed of system parameters and physical constants. In this embodiment, C=1 is taken to simplify the theoretical model.

[0088] According to the above expression, the EIT spectrum line shape is related to the detuning amount of the first detection light Δ P , the first detection light Rabi frequency Ω P 、Coupled light Rabi frequency Ω C and the excited state dephasing frequency γ2.

[0089] S4. Adjust the parameters of the EIT spectrum linear model to obtain the intermediate state spectrum;

[0090] In this embodiment, the detuning amount Δ of the first detection light is adjusted P 、Coupled light Rabi frequency Ω C and the excited state dephasing frequency γ2, so that the EIT spectrum is transformed into the EIA spectrum. When the amplitudes of the transmission peak and the absorption peak in the spectrum are basically the same and the maximum slope of the spectrum line reaches a maximum value, it is recorded as an intermediate state and the intermediate state spectrum is obtained.

[0091] In this embodiment, the various parameters of the EIT spectrum linear model are adjusted. When the first detection light detuning amount Δ P = 0MHz, the obtained detection light transmission spectrum shows the detuning amount of coupling light Δ C =0MHz position symmetrical EIT peak; however, this embodiment changes the cesium atom from 6S 1 / 2 →7P 3 / 2When the first detection light is frequency-locked by the transition saturation spectrum, the Rabi frequency of the first detection light is simply locked in the Doppler absorption background by PID control for 6S. 1 / 2 ,F=3→7P 3 / 2 , near the transition frequency of the hyperfine structure energy level of F=4.

[0092] When cesium atoms are excited in the cesium atomic cell, it is difficult to avoid the situation where the detuning amount of the first detection light is not zero due to environmental interference and PID parameter settings. In addition, under the external heating of the cesium atomic cell, some atoms still transition to other hyperfine energy levels of the intermediate state, and some of them participate in the transition, resulting in the result that the detuning amount of the detection light is not zero. In this embodiment, the detuning amount of the first detection light Δ P After setting it to non-zero, the detection light transmission spectrum is no longer symmetrical. P After gradually increasing, the absorption peak amplitude gradually increases, eventually exceeding the transmission peak amplitude and becoming the main feature of the detection light transmission spectrum, indicating a transition from EIT to EIA. During the EIT to EIA transition, there is a state where the transmission peak and absorption peak amplitude are comparable, recorded as the intermediate state. The slope of the detection light transmission spectrum corresponding to the intermediate state is much higher than that of the detection light transmission spectra corresponding to EIT and EIA, which can effectively improve the detection performance of non-resonant fault arc signal detection based on the AC Stark effect.

[0093] In fact, the condition for inducing the transition from EIT to EIA is not only determined by adjusting the detuning amount Δ P By adjusting the coupling light Rabi frequency Ω C The process of EIT to EIA transformation can also be realized by the excited state dephasing frequency γ2.

[0094] like Figure 3 As shown, in this embodiment, the first detection light detuning amount Δ P =2MHz, coupled light Rabi frequency Ω C =10MHz, excited state dephasing frequency γ2 = 2MHz, detection light Rabi frequency Ω P From left to right, they are 8MHz, 1.8MHz, and 0.4MHz, corresponding to EIT, intermediate state, and EIA spectra, respectively.

[0095] S5. Loading a fault arc signal to the first cesium atomic gas chamber, obtaining a slope of a response position of the fault arc signal in the spectrum based on the intermediate state spectrum, and calculating a response amplitude of the fault arc signal;

[0096] In this embodiment, the response amplitude of the arc fault signal is calculated using the following logic:

[0097] A=κδ

[0098] Where A represents the response amplitude of the fault arc signal, κ is the slope of the fault arc signal response position in the intermediate state spectrum, and δ represents the energy level offset.

[0099] The existing technology is based on the non-resonant detection method, which relies on the energy level shift of the atomic energy level under the ACStark effect, which is related to the electric field strength E(t) of the external electromagnetic wave. Among them, α represents the electrical susceptibility of the entire atomic vapor, which is related to the atomic principal quantum number n by α~n 7 The high principal quantum number n of the Rydberg atom can ensure that the detection of the arc fault signal based on the non-resonant detection method has a high detection response. When the amplitude of E(t) is smaller than the EIT peak width, it can be approximately considered that the response amplitude of the arc fault signal sensed in the detection light transmission spectrum is A. By adjusting the detuning amount Δ of the first detection light P 、Coupled light Rabi frequency Ω C and the excited state dephasing frequency γ2, adjusting the atoms to the intermediate state with a large slope, thereby improving the responsiveness of the Rydberg atom microwave sensing system to fault arc signals.

[0100] In this embodiment, a commercial dual-arc pulse lighter is used to simulate the fault arc in an actual power instrument. After the fault arc signal is loaded into the cesium atomic gas chamber, a modulated oscillation caused by the time-varying characteristics of the fault arc signal can be observed in the signal peak of the detection light transmission spectrum. The oscillation wave packet usually has a maximum value at the center of the spectrum signal, resulting in that in the EIT and EIA spectra of traditional technologies, the fault arc signal usually takes a response maximum at the peak with a smaller slope. In the intermediate state spectrum, the sweep width can be set to zero at the coupling light detuning point with the largest slope in the intermediate state spectrum, thereby obtaining a relatively higher response.

[0101] like Figures 4(a) to 4(b) As shown, the detection light Rabi frequency Ω P From the left to the right, they are 2.5MHz, 0.9MHz, and 0.5MHz. In the specific implementation of this embodiment, the coupling light power is set to 280mW, corresponding to the theoretical coupling light Rabi frequency Ω C =10.9MHz, in this example, the detection light power of the first cesium atom gas cell is changed by adjusting the filter, thereby adjusting the first detection light Rabi frequency Ω P , when the detection laser power is 970μW, 133μW and 46μW respectively, the corresponding first detection light Rabi frequency Ω P The EIT, intermediate state and EIA spectra of the EIT spectrum linear model are obtained at 2.5 MHz, 0.9 MHz and 0.5 MHz respectively, as shown in Figure 4(a).

[0102] When Ω P=2.5MHz, the EIT spectrum signal shows a transmission state, and the actual EIT transmission peak is asymmetric. Moreover, due to the increase of the detection light power, the EIT transmission peak undergoes power broadening, resulting in the overall line width being significantly larger than that of other spectra.

[0103] When Ω P =0.9MHz, the spectrum signal presents an intermediate state, and the slope between the signal center and the non-resonant fault arc response position is significantly larger than that in other cases;

[0104] When Ω P When =0.5MHz, the EIA spectrum signal shows an absorption state, and three sharp absorption peaks appear in the spectrum.

[0105] Depend on Figures 4(a) to 4(b) It can be seen that the fault arc spectrum signals output under the EIT and EIA spectra decay rapidly with increasing frequency, and are annihilated by the noise floor at 827kHz and 702kHz respectively. However, the output signal of the intermediate state maintains a signal-to-noise ratio of more than 10dBm up to 1.5MHz in response to the stronger of the two sets of electromagnetic signals generated by the dual-arc pulse lighter; for the peak with the highest intensity at about 32.5kHz in the fault arc signal, the signal-to-noise ratios of the three spectra are 30dBm, 46dBm, and 38.2dBm respectively, and the signal-to-noise ratio of the intermediate state spectrum is 46dBm, which is at least 7.8dBm higher in fault arc signal power sensitivity than the other two states.

[0106] Example 2

[0107] like Figure 5 As shown, the present invention also discloses a fault arc signal detection device based on Rydberg atoms, comprising a first laser 11, a second laser 12, a polarization beam splitter cube 21, a first cesium atomic gas chamber 31, a saturation spectrum optical path, a gain photoelectric probe 41 and an arc lighter 51;

[0108] The laser light output by the first laser 11 is split into a first probe light and a second probe light by the polarization beam splitter cube 21. The first probe light is incident on the first cesium atom gas chamber 31 to couple the cesium atoms to transition from the ground state to the excited state. The second probe light is incident on the saturation spectrum optical path to perform wavelength locking.

[0109] The laser light output by the second laser 12 is used as coupling light and is incident on the first cesium atom gas chamber 31 in reverse, so that the coupled cesium atoms transition from the excited state to the Rydberg state. The gain photoelectric probe 41 scans the detuning amount of the coupling light to generate an EIT spectrum.

[0110] The first cesium atomic gas cell 31 is used to construct an EIT spectrum linear model based on the first detection light and the coupled light;

[0111] The gain photoelectric probe 41 is used to adjust the parameters of the EIT spectrum linear model to obtain the intermediate state spectrum;

[0112] The arc lighter 51 is used to load the first cesium atomic gas chamber 31 with a fault arc signal, obtain the slope of the fault arc signal response position in the spectrum based on the intermediate state spectrum, and calculate the response amplitude of the fault arc signal.

[0113] Furthermore, the ground state of the cesium atom is 6S 1 / 2 , the excited state is 7P 3 / 2 , the Rydberg state is 31D 5 / 2 .

[0114] Furthermore, the laser wavelength of the first laser 11 is 456 nm, and the laser wavelength of the second laser 12 is 1072 nm.

[0115] Furthermore, the arc lighter 51 is a commercial double arc pulse lighter, which is used to simulate the fault arc in an actual power instrument.

[0116] Furthermore, it also includes a first half-wave plate 61, a filter 71, a first lens 81, and a first dichroic mirror 91; the first laser 11 passes through the first half-wave plate 61 and the polarization beam splitter cube 21 to output a first detection light, and the first detection light passes through the filter 71, the first lens 81, and the first dichroic mirror 91 once, and is incident on the first cesium atomic gas chamber 31, coupling the cesium atoms to transition from the ground state to the excited state.

[0117] Furthermore, the saturation spectrum optical path includes a double-sided mirror 96, a second cesium atomic gas chamber 32, a third half-wave plate 63, a first PBS22, a second mirror 94, a third mirror 95 and a balanced photoelectric probe 42; the second detection light is reflected in the direction of the second cesium atomic gas chamber 32 and the second mirror 94 respectively through the double-sided mirror 96, and the second detection light reflected in the direction of the second cesium atomic gas chamber 32 passes through the third half-wave plate 63 and the first PBS22 in sequence, and is incident on the balanced photoelectric probe 42; the second detection light reflected in the direction of the second reflector 94 passes through the third reflector 95 and the first PBS22 in sequence, and is divided into two laser beams by the first PBS22, and is incident on the balanced photoelectric probe 42 and the third half-wave plate 63 respectively. The laser light incident on the third half-wave plate 63 passes through the second cesium atomic gas chamber 32 and is incident on the double-sided mirror 96, thereby realizing wavelength locking of the second detection light in the saturation spectrum optical path.

[0118] Furthermore, it also includes a second half-wave plate 62, a second PBS23, a second lens 82, a first reflector 93, a second dichroic mirror 92 and a third lens 83; the laser output by the second laser 12 is used as coupling light, which passes through the second half-wave plate 62 and the second PBS23 in sequence. The second PBS23 divides the coupling light into two beams, one beam is incident on the wavelength meter for monitoring the actual wavelength of the coupling light, and the other beam passes through the second lens 82, the first reflector 93 and the second dichroic mirror 92 in sequence and then is reversely incident on the first cesium atomic gas chamber 31, and the coupled cesium atoms transition from the excited state to the Rydberg state. The coupling light passes through the first cesium atomic gas chamber 31 and is combined with the first detection light through the first dichroic mirror 91 and then is incident on the light receiving tube. The second dichroic mirror 92 combines the first detection light and the coupling light and then passes through the third lens 83 to be incident on the gain photoelectric probe 41.

[0119] like Figure 5 As shown in the figure, HWP represents a half-wave plate, and the first half-wave plate 61, the second half-wave plate 62, and the third half-wave plate 63 are all used to change the polarization direction of the laser and cooperate with the PBS to adjust the light intensity distribution; PBS represents a polarization beam splitter cube, and the polarization beam splitter cube 21, the first PBS 22, and the second PBS 23 are all used to separate or merge light beams according to the polarization state; DM represents a dichroic mirror, and the first dichroic mirror 91 and the second dichroic mirror 92 are all used to separate or merge light beams according to the wavelength; PDA represents a gain photoelectric probe 41, which is used to convert the optical signal into an amplified electrical signal; PDB represents a balanced photoelectric probe 42, which is used to detect signal differences and suppress noise; the first lens 81, the second lens 82, and the third lens 83 are all used to focus the laser to an intensity sufficient to excite atomic transitions; the filter 71 is used to change the detection light power of the first cesium atomic gas chamber 31, thereby adjusting the Rabi frequency of the first detection light.

[0120] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A fault arc signal detection method based on Rydberg atoms, characterized in that: The following steps are involved: S1. Split the laser output by the first laser into a first probe light and a second probe light through a polarization beam splitter cube. The first probe light is incident on the first cesium atomic gas chamber to couple the cesium atoms from the ground state to the excited state. The second probe light is incident on the saturation spectrum optical path for wavelength locking. S2, the laser output from the second laser is used as coupling light, which is incident in reverse on the first cesium atomic gas chamber, and the coupled cesium atoms transition from the excited state to the Rydberg state. The gain photoelectric probe scans the detuning amount of the coupling light to generate an EIT spectrum; S3, constructing an EIT spectrum linear model based on the first detection light and the coupled light; S4. Adjust the parameters of the EIT spectrum linear model to obtain the intermediate state spectrum; S5. Loading a fault arc signal to the first cesium atomic gas chamber, obtaining a slope of a response position of the fault arc signal in the spectrum based on the intermediate state spectrum, and calculating a response amplitude of the fault arc signal.

2. The arc fault signal detection method based on Rydberg atoms according to claim 1, characterized in that: The ground state of the cesium atom is , the excited state is , the Rydberg state is .

3. The arc fault signal detection method based on Rydberg atoms according to claim 1, characterized in that: The laser wavelength of the first laser is 456 nm, and the laser wavelength of the second laser is 1072 nm.

4. The arc fault signal detection method based on Rydberg atoms according to claim 1, characterized in that: The S3 includes the following steps: S31, writing the first detection light Rabi frequency, the first detection light detuning amount, the coupling light Rabi frequency, and the coupling light detuning amount into a Hamilton matrix, and simplifying the Hamilton matrix; S32, writing the dephasing frequency of the excited state of the cesium atom into the dephasing matrix, constructing the optical Bloch equations based on the Hamilton matrix and the dephasing matrix, and calculating the density matrix element of the detection light absorption coefficient; S33. Solve the relationship between the repolarizability and the density matrix element; S34. The linear model expression of EIT spectrum is obtained based on electrodynamics.

5. The method for detecting arc fault signals based on Rydberg atoms according to claim 4, characterized in that: The Hamilton matrix is ​​represented by the following logic in S31: Where, represents the Hamilton matrix, represents the reduced Planck constant, represents the first probe light Rabi frequency, represents the coupled light Rabi frequency, represents the detuning amount of the first detection light, Indicates the coupling light detuning amount.

6. The arc fault signal detection method based on Rydberg atoms according to claim 5, characterized in that: The optical Bloch equations are represented by the following logic in S32: Where, represents the dephasing frequency of the excited state of the cesium atom, i represents the imaginary unit, Represents the density matrix The matrix element of the xth row and yth column of represents the time derivative of the matrix element, , .

7. The method for detecting arc fault signals based on Rydberg atoms according to claim 6, characterized in that: In S33, the relationship between the complex polarizability and the density matrix element is solved using the following logic: Where, represents the repolarization rate, It represents the number of atoms per unit space in the area where the laser interacts with atoms. represents the detection light transition matrix element, represents the dielectric constant of vacuum.

8. The method for detecting arc fault signals based on Rydberg atoms according to claim 7, characterized in that: The linear model expression of the EIT spectrum in S34 is as follows: Where, represents the transmitted light power of the first detection light, represents the initial optical power of the incident light, represents exponential operation, represents the constant term consisting of system parameters and physical constants, , represents the first detection light wave number, It represents the length of interaction between cesium atoms and laser in the cesium atom gas cell.

9. The method for detecting arc fault signals based on Rydberg atoms according to claim 8, characterized in that: In S5, the response amplitude of the arc fault signal is calculated using the following logic: Where, Indicates the response amplitude of the fault arc signal, is the slope of the fault arc signal response position in the intermediate state spectrum, Indicates energy level shift.

10. The arc fault signal detection device based on Rydberg atoms is characterized by: The device comprises a first laser, a second laser, a polarization beam splitter cube, a first cesium atomic gas chamber, a saturation spectrum optical path, a gain photoelectric probe and an arc lighter; The laser light output by the first laser is split into a first probe light and a second probe light by the polarization beam splitter cube, the first probe light is incident on the first cesium atomic gas chamber, and couples the cesium atoms to transition from the ground state to the excited state, and the second probe light is incident on the saturation spectrum optical path for wavelength locking; The laser light output by the second laser is used as coupling light and is incident in reverse on the first cesium atomic gas chamber, coupling the cesium atoms to transition from the excited state to the Rydberg state, and the gain photoelectric probe scans the detuning amount of the coupling light to generate an EIT spectrum; The first cesium atomic gas cell is used to construct an EIT spectrum linear model based on the first detection light and the coupled light; The gain photoelectric probe is used to adjust various parameters of the EIT spectrum linear model to obtain the intermediate state spectrum; The arc lighter is used to load a fault arc signal to the first cesium atomic gas chamber, obtain the slope of the fault arc signal response position in the spectrum based on the intermediate state spectrum, and calculate the response amplitude of the fault arc signal.

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