Partial discharge detection method and device based on Rydberg atomic electric field sensor

Abstract

The invention discloses a partial discharge detection method and device based on a Rydberg atomic electric field sensor, belongs to the technical field of partial discharge detection, and solves the problem that the sensor is easily damaged by electrical breakdown in a strong electric field environment in an existing partial discharge detection technology. A ground state cesium atom is excited to a Rydberg state, based on a free space coupling configuration mode, a to-be-measured radio frequency signal is directly propagated into an atomic gas chamber through a free space to be coupled with the Rydberg atom, an atomic energy level is displaced, the transmissivity of an electromagnetically-induced transparent spectrum is changed, electric field information is encoded into an optical signal, and the optical signal is transmitted to the ground state cesium atom. And then the photoelectric detector is used for converting the modulated optical signal into an electric signal, the electric signal is input into the oscilloscope for time domain waveform analysis, and based on an electrical-optical-electric signal conversion mechanism, the common electric breakdown risk in the traditional ultrahigh frequency detection technology is effectively avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of partial discharge detection, and relates to a partial discharge detection method and device based on a Rydberg atom electric field sensor. Background Art

[0002] Partial discharge (PD) refers to the local breakdown phenomenon that occurs in insulating materials under the action of a high-voltage electric field, which may lead to insulation aging and ultimately cause equipment failure. Therefore, early partial discharge detection of high-voltage electrical equipment is of great significance. Partial discharge detection has attracted much attention due to its key role in the condition assessment and fault prediction of power equipment. However, there are still major technical challenges in achieving efficient and accurate acquisition of PD signals. Existing PD detection methods mainly include electrical pulse, acoustic, chemical, optical, and electromagnetic technologies. Among these mainstream technologies, ultra-high frequency (UHF, 0.3–3 GHz) electromagnetic detection technology has attracted much attention. The ultra-high frequency electromagnetic detection technology has the advantages of non-invasive, non-contact measurement, high sensitivity, excellent signal-to-noise ratio, and strong anti-interference ability to external electromagnetic interference. It plays a core role in capturing PD signals and is widely used in PD monitoring of high-voltage electrical equipment, becoming a key method for evaluating the insulation status of power systems.

[0003] Traditional UHF detection technology usually uses metal antennas to capture GHz-band electromagnetic waves generated by partial discharge (PD), and realizes online monitoring through signal processing equipment. For example, the invention patent with the application publication number CN117554759A discloses a multi-signal fusion monitoring method for partial discharge faults of GIS basin insulators, which can monitor the electrical and optical signals of GIS basin insulators in real time under the condition of power-on through a partial discharge detector, a UHF partial discharge sensor, an ultraviolet imaging detector, and a photomultiplier tube, and collect data in combination with an industrial control computer. The UHF partial discharge sensor is an external microstrip antenna structure. However, metal antennas have the following inherent limitations: (1) Electrical breakdown is likely to occur in a strong electric field environment, which may damage the sensor and cause failures in downstream expensive data acquisition and analysis systems. (2) The metal antenna structure is complex and large in volume, which is not conducive to portable applications. (3) Its fixed frequency response characteristic also limits the multi-band detection requirements.

[0004] In recent years, the rapid development of quantum sensing technology has provided a new solution for electric field detection. The electric field sensor based on Rydberg atoms has gradually become a powerful alternative to traditional metal antennas due to its excellent sensitivity and broadband response characteristics. Rydberg atoms are neutral atoms in a highly excited state, and their outer electron states have ultra-sensitive characteristics to external electric fields. The electric field strength and frequency can be accurately detected by measuring the atomic energy level shift through laser spectroscopy technology. Therefore, it is particularly important to overcome the problem that existing partial discharge detection is prone to electrical breakdown and damage to the sensor in a strong electric field environment based on the characteristics of the Rydberg atom electric field sensor. Summary of the Invention

[0005] The technical solution of the present invention is used to solve the problem that existing partial discharge detection technologies are prone to electrical breakdown and damage to sensors in a strong electric field environment.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] A method for detecting partial discharge based on a Rydberg atom electric field sensor, comprising the following steps:

[0008] S1. Use the probe light to pass through the atomic cell. After adjusting the light and the coupling light to be combined, inject them into the atomic cell along the reverse direction of the probe light to prepare ground-state cesium atoms into high Rydberg state atoms.

[0009] S2. Use the PD signal source to emit the radio frequency signal to be measured, and the atomic cell receives the radio frequency signal to be measured based on a free space coupling configuration or a waveguide enhanced coupling configuration.

[0010] S3. Use the Rydberg atom antenna detection area formed by the coincidence of the probe light, the adjusting light and the coupling light in the atomic cell to detect the radio frequency signal to be measured; use a photodetector to measure the transmittance of the probe light to obtain the electromagnetic induced transparency spectrum signal to be detected, and send the output signal of the photodetector to an oscilloscope to obtain the time-domain waveform of the output signal.

[0011] Further, the preparation of ground-state cesium atoms into high Rydberg state atoms in S1 is specifically as follows: The probe light is incident horizontally and parallel through the atomic cell. After the adjusting light and the coupling light are combined by a beam splitter, they are injected into the atomic cell in a configuration along the opposite direction of the probe light. The ground-state cesium atoms are excited from the ground state to the Rydberg state through an intermediate energy level in the region where the three laser beams overlap in space.

[0012] Further, the radio frequency signal to be measured in S2 is a typical partial discharge signal, and the typical partial discharge signal includes air gap discharge, floating discharge, particle discharge and corona discharge.

[0013] Further, the free space coupling configuration in S2 is specifically as follows: The PD signal source and the atomic cell maintain a preset distance, and the radio frequency signal to be measured propagates through free space and couples with the Rydberg atoms in the atomic cell.

[0014] Further, the waveguide enhanced coupling configuration in S2 is specifically as follows: An integrated waveguide chip is packaged on the surface of the atomic cell, and a coaxial cable is used to connect the integrated waveguide chip and the metal antenna to extend the transmission distance of the radio frequency signal to be measured. The PD signal source and the metal antenna maintain a preset distance, and the radio frequency signal to be measured is received by the antenna, enhanced by the integrated waveguide chip after being transmitted through the coaxial cable, and couples with the Rydberg atoms in the atomic cell.

[0015] Further, the integrated waveguide chip is a plasmonic waveguide, which is used to generate a locally enhanced electric field on the surface of the atomic gas cell to enhance the coupling between the RF signal to be measured and the Rydberg atoms.

[0016] Further, the preset spacing is 5 cm or less, and the coaxial cable extends the transmission distance of the RF signal to be measured to 5 m or less.

[0017] The present invention also provides a partial discharge detection device based on a Rydberg atom electric field sensor, which is applied to the above partial discharge detection method based on a Rydberg atom electric field sensor, and includes an atomic gas cell, a mirror, a first beam splitter, a second beam splitter, a third beam splitter, a photodetector, an integrated waveguide chip, and a PD signal source; the first beam splitter is arranged on one side of the atomic gas cell, and the probe light passes through the first beam splitter and is incident on the atomic gas cell horizontally in parallel, passes through the atomic gas cell and the second beam splitter in sequence, and is received by the photodetector;

[0018] The mirror, the second beam splitter, the third beam splitter, and the photodetector are arranged on the other side of the atomic gas cell. The coupled light is first reflected by the mirror and then combined with the control light through the third beam splitter, and then reflected by the second beam splitter, and is injected into the atomic gas cell in the reverse direction of the probe light, and coincides with the probe light to form a Rydberg atom antenna detection region, and the ground state cesium atoms are prepared into high Rydberg state atoms;

[0019] The integrated waveguide chip is encapsulated on the surface of the atomic gas cell to generate a locally enhanced electric field on the surface of the atomic gas cell.

[0020] Further, it further includes a PD signal source; the PD signal source is spaced from the atomic gas cell by a preset spacing, the PD signal source emits an RF signal to be measured, and the RF signal to be measured propagates through free space and couples with the Rydberg atoms in the Rydberg atom antenna detection region.

[0021] Further, it further includes a PD signal source, a coaxial cable, and a metal antenna; both ends of the coaxial cable are respectively connected to the integrated waveguide chip and the metal antenna, the PD signal source is spaced from the metal antenna by a preset spacing, the metal antenna receives the RF signal to be measured emitted by the PD signal source, is transmitted through the coaxial cable and enhanced by the integrated waveguide chip, and couples with the Rydberg atoms in the Rydberg atom antenna detection region.

[0022] The advantages of the present invention are as follows:

[0023] (1) The present invention uses three lasers to form a coincident detection region in an atomic gas cell, exciting ground-state cesium atoms to the Rydberg state. Based on the free-space coupling configuration, the RF signal to be measured directly propagates through free space into the atomic gas cell to couple with the Rydberg atoms. The atomic energy levels shift, resulting in a change in the transmittance of the electromagnetically induced transparency spectrum. The electric field information is encoded as an optical signal, and then a photodetector is used to convert the modulated optical signal into an electrical signal, which is input into an oscilloscope for time-domain waveform analysis. Based on the electro-optical-electrical signal conversion mechanism, the common electric breakdown risk in traditional ultra-high frequency (UHF) detection technologies is effectively avoided. At the same time, the atomic gas cell, as an insulating material, can effectively isolate the transmission of high-voltage signals and protect the downstream detection equipment from being broken down. By converting the RF signal into a low-frequency spectral output, the Rydberg atom system greatly simplifies the hardware complexity in the signal acquisition and processing link and eliminates the need for high-speed and high-performance electronic components.

[0024] (2) The present invention encapsulates an integrated waveguide chip on the surface of the atomic gas cell and uses a coaxial cable to connect the integrated waveguide chip to a metal antenna, expanding the detection range of the atomic sensing system from centimeter level to several meters. The transmission distance of the RF signal to be measured is extended. The RF signal to be measured is received by the antenna, transmitted through the coaxial cable, and then a local enhanced electric field is generated on the surface of the atomic gas cell through the integrated waveguide chip, enhancing the efficient coupling between the RF signal to be measured and the Rydberg atoms. Based on the waveguide coupling enhancement configuration, the interaction strength between the RF signal and the atomic system is significantly enhanced, enabling the atomic sensing system to effectively detect the electric field within a large spatial range, especially showing excellent performance at a detection distance of several meters, providing a practical technical path for the detection of PD signals over long distances and in on-site deployments.

[0025] (3) Based on the above two coupling configurations, the Rydberg atom electric field sensor can accurately measure classical partial discharge signals including air-gap discharge, floating discharge, particle discharge, and corona discharge, precisely capturing the periodic and random characteristics of various PD signals, providing an optically readable alternative solution for traditional ultra-high frequency detection technologies and a highly efficient and reliable new means for the detection of partial discharges in high-voltage power equipment. Description of the Drawings

[0026] Figure 1 is a flowchart of the partial discharge detection method based on the Rydberg atom electric field sensor in Embodiment 1 of the present invention;

[0027] Figures 2(a) to 2(c) is a structural diagram of the partial discharge detection device based on the Rydberg atom electric field sensor in Embodiment 1 of the present invention;

[0028] Figure 3 is a schematic diagram of the energy level structure of cesium atoms in Embodiment 1 of the present invention;

[0029] Figure 4 It is the spectrogram of the typical partial discharge signal in the first embodiment of the present invention;

[0030] Figure 5 It is the time-domain waveform diagram of the partial discharge signal after detection in the first embodiment of the present invention;

[0031] Figure 6 It is the schematic diagram of the signal-to-noise ratio performance after detecting various partial discharge signals in the first embodiment of the present invention;

[0032] Figure 7 It is the schematic diagram of the single-pulse characteristic analysis of the partial discharge signal in the first embodiment of the present invention;

[0033] Reference numerals: 10, atomic gas cell; 11, integrated waveguide chip; 20, first beam splitter; 30, mirror; 31, second beam splitter; 32, third beam splitter; 33, photodetector; 40, PD signal source; 50, metal antenna; 51, coaxial cable. Detailed implementation manners

[0034] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, 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 part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings of the specification and specific embodiments:

[0036] Embodiment 1

[0037] As Figure 1 shown, specifically, a partial discharge detection method based on a Rydberg atom electric field sensor is disclosed, including the following steps:

[0038] S1, using the probe light to pass through the atomic gas cell, after regulating the light and the coupling light to be combined, injecting them into the atomic gas cell in the reverse direction of the probe light, and preparing the ground-state cesium atoms into high-Rydberg-state atoms.

[0039] Further, the preparation of the ground-state cesium atoms into high-Rydberg-state atoms is specifically as follows: the probe light is incident parallelly in the horizontal direction through the atomic gas cell, after the regulating light and the coupling light are combined by the beam splitter, they are injected into the atomic gas cell in a configuration opposite to the direction of the probe light, and the ground-state cesium atoms are excited from the ground state to the Rydberg state through the intermediate energy level in the region where the three laser beams overlap in space. As shown in Figure 2(a), the three photon excitation paths adopted in this embodiment can be seen.

[0040] As shown Figure 3 is the energy level structure of cesium atoms involved in the excitation from the ground state to the Rydberg state. Specifically, the probe light drives cesium atoms from the ground state 6S 1 / 2 to the first intermediate state 6P 3 / 2 in a resonant transition, and the control light drives cesium atoms from 6P 3 / 2 to transition to the second intermediate state 7S 1 / 2 , and the coupling light drives cesium atoms from 7S 1 / 2 to transition to the Rydberg state 49P with a higher principal quantum number 3 / 2 , a total of three resonant transitions, which are realized by lasers with different wavelengths and involve four energy levels of cesium atoms.

[0041] Furthermore, the wavelength of the probe light is 852 nm, the wavelength of the control light is 1470 nm, and the wavelength of the coupling light is 780 nm.

[0042] S2, using a PD signal source to emit a radio frequency signal to be measured, and the atomic gas cell receives the radio frequency signal to be measured based on a free space coupling configuration or a waveguide enhanced coupling configuration for interaction with Rydberg atoms.

[0043] The present invention provides two ways for the atomic gas cell to receive the radio frequency signal to be measured sent by the PD signal source, specifically the free space coupling configuration and the waveguide enhanced coupling configuration. The free space coupling configuration is specifically: the PD signal source and the atomic gas cell maintain a preset distance, and the radio frequency signal to be measured propagates through free space and couples with the Rydberg atoms in the atomic gas cell, as shown in Fig. 2(b).

[0044] Furthermore, the preset distance is 5 cm and within 5 cm. Since the atomic gas cell needs to be closely integrated with a complex optical system in the experiment, keeping the distance between the PD signal source and the atomic gas cell within 5 cm and 5 cm in the actual engineering environment can achieve the in-situ detection of the radio frequency signal to be measured directly through free space propagation into the atomic gas cell.

[0045] In this embodiment, the method of directly propagating the partial discharge signal through free space into the atomic gas cell based on the free space coupling configuration has the characteristics of simple structure, facilitating experimental assembly and optical path calibration, and can effectively verify the direct response characteristics of Rydberg atoms to external electric fields in an open environment.

[0046] The waveguide enhanced coupling configuration is specifically: a waveguide chip is encapsulated and integrated on the surface of the atomic gas cell, a coaxial cable is used to connect the integrated waveguide chip and the metal antenna to extend the transmission distance of the radio frequency signal to be measured, the PD signal source and the metal antenna maintain a preset distance, the radio frequency signal to be measured is received by the antenna, enhanced by the integrated waveguide chip after being transmitted through the coaxial cable, and couples with the Rydberg atoms in the atomic gas cell, as shown in Fig. 2(c).

[0047] Furthermore, the metal antenna can adopt an Archimedes spiral antenna. The PD signal source and the antenna maintain a preset distance. The to-be-detected radio frequency signal emitted is first received by the receiving end of the Archimedes spiral antenna. The coaxial cable is used to extend the transmission distance of the to-be-detected radio frequency signal to the atomic gas cell, and the to-be-detected radio frequency signal is sent to the integrated waveguide chip encapsulated on the surface of the atomic gas cell, generating a local enhanced electric field on the surface of the atomic gas cell to enhance the efficient coupling between the to-be-detected radio frequency signal and the Rydberg atoms.

[0048] The Archimedes spiral antenna adopted in this embodiment is made of a printed circuit board with a diameter of 30 cm, and has excellent broadband characteristics. Its operating frequency band covers 100 MHz to 6 GHz, completely covering the main radio frequency spectrum of the PD signal, meeting the requirements of the waveguide enhanced coupling configuration. When the operating bandwidth of the metal antenna can cover the frequency band range of the ultra-high frequency detection method UHF, other types of metal antennas can also be used to receive the to-be-detected radio frequency signal.

[0049] In this embodiment, the preset distance maintained between the PD signal source and the antenna is also 5 cm or less, and the transmission distance of the to-be-detected radio frequency signal extended by the coaxial cable is 5 m or less. If longer coaxial lines are used for transmission, signal transmission over longer distances can be achieved. To improve the applicability and deployment flexibility of the Rydberg atom-based system in real scenarios, this embodiment adopts a combination of a spiral antenna and a waveguide structure to efficiently couple the PD radio frequency (RF) signal received over a long distance into the atomic system to achieve stable optical readout. This new signal coupling method significantly enhances the interaction strength between the radio frequency signal and the atomic system, providing a practical technical path for the detection of PD signals over long distances and in on-site deployments.

[0050] Furthermore, the integrated waveguide chip is specifically an artificial surface plasmon polariton waveguide, which is used to generate the local oscillator microwave field and the to-be-detected radio frequency signal field, concentrating the microwave field in a small area inside the atomic gas cell to enhance the field intensity. Figures 2(a) to 2(c) All the integrated waveguide chips described above are encapsulated on the surface of the atomic gas cell, which is not shown in Fig. 2(a).

[0051] Furthermore, the atomic gas cell is a cesium atomic vapor cell, and the size of the atomic gas cell is 5×1×1 cm 3 .

[0052] Furthermore, the to-be-detected radio frequency signal is a typical partial discharge signal emitted by a professional partial discharge signal source, and the typical partial discharge signal includes air gap discharge, floating discharge, particle discharge, and corona discharge.

[0053] In this embodiment, the PD signal source uses a JD-CL20 professional PD signal generator produced by JuDian-Electric Company, which can generate nanosecond-level UHF pulse signals and effectively simulate various typical partial discharge signals (including air gap discharge, floating discharge, particle discharge, and corona discharge). The typical partial discharge signals can be radiated through the rod antenna integrated in the generator or transmitted wired through a standard SMA connector. For spectral analysis, the PD signal source is directly connected to the spectrum analyzer through a coaxial cable to measure the power spectral density of the generated PD signal.

[0054] As Figure 4 shown, the four typical types of RF signals to be measured all exhibit broadband characteristics in the frequency domain, and there is a significant power peak at about 200 MHz, indicating that this frequency band is the main area where energy is concentrated; as the frequency increases, the signal power gradually decays and approaches the noise floor of the analyzer near 5 GHz. The above spectral analysis results provide a key frequency band reference for subsequent effective detection.

[0055] S3, detecting the RF signal to be measured using the detection area of the Rydberg atom antenna formed by the coincidence of the detection light, the control light, and the coupling light in the atomic gas cell; measuring the transmittance of the detection light using a photodetector to obtain the electromagnetic induced transparency spectral signal to be detected, and sending the output signal of the photodetector to an oscilloscope to obtain the time-domain waveform of the output signal.

[0056] In this embodiment, the electromagnetic induced transparency (EIT) effect generated by the three-photon excitation technique is used to realize the spectral response readout of cesium Rydberg atoms to PD RF signals, and the response of the Rydberg atom electric field sensor to typical partial discharge signals is studied through the cesium atom EIT spectrum. During the experiment, the detection light, the control light, and the coupling light coincide and pass through the cesium atom vapor cell, forming a detection area of the Rydberg atom antenna in the cesium atom vapor cell. The cesium atoms are not only excited to high principal quantum number Rydberg states but also coupled to the external PD RF field through non-resonant dipole interactions. This interaction causes significant modulation in the EIT transmission spectrum, thus providing a measurable optical signal for RF field sensing.

[0057] Taking Figures 2(a) to 2(b) as an example, the transmitted detection light is collected by a photodetector and recorded in the time domain by a high-speed oscilloscope to indirectly obtain the dynamic response of the Rydberg atoms to the applied RF field. Its physical mechanism can be attributed to the AC Stark effect, which describes the phenomenon of the frequency-dependent shift of atomic energy levels under the action of an external alternating electric field. For a non-resonant field far detuned from the atomic transition, the energy level shift is mainly dominated by second-order perturbation theory. In this embodiment, the photodetector can use an avalanche photodiode (APD) to receive the detection light transmission signal.

[0058] When an external radio frequency electric field acts on Rydberg atoms, through non-resonant dipole interaction, the atomic energy levels are shifted due to the AC Stark effect. The shift amount is proportional to the square of the electric field amplitude and is modulated by the dynamic polarizability. The energy level shift of Rydberg atoms is represented by the following logic:

[0059]

[0060] Among them, ΔE represents the energy level shift of Rydberg atoms, α(ω) represents the dynamic polarizability of the atom at angular frequency ω, and E represents the amplitude of the applied radio frequency electric field.

[0061] Since the actual partial discharge signal usually contains multiple frequency components, when the radio frequency electric field contains multiple frequency components (i.e., a composite radio frequency signal), the amplitudes, frequencies, and phases of multiple frequency components jointly determine the dynamic response characteristics of the atomic system to the electric field. The time-domain expression of the composite radio frequency electric field amplitude is represented by the following logic:

[0062]

[0063] Among them, E(t) represents the instantaneous amplitude of the composite radio frequency electric field at time t in the time domain, E i represents the electric field amplitude of the i-th frequency component, ω i represents the angular frequency of the i-th frequency component, represents the initial phase of the i-th frequency component.

[0064] Based on the AC Stark effect, the PD radio frequency signal modulates the energy levels of Rydberg atoms, resulting in a change in the transmittance of the electromagnetically induced transparency spectrum. The electric field information is encoded into an optical signal, and the modulated optical signal is converted into an electrical signal by a photodetector and input into an oscilloscope for time-domain waveform analysis. Based on the electro-optical-electrical signal conversion mechanism, the electrical breakdown risk commonly found in traditional ultra-high frequency (UHF) detection technologies is effectively avoided; at the same time, the atomic gas chamber, as an insulating material, can effectively isolate the transmission of high-voltage signals and protect the downstream detection equipment from being broken down; by converting the radio frequency signal into a low-frequency spectral output, the signal acquisition and processing link hardware complexity is greatly simplified using the Rydberg atom system, eliminating the need for high-speed and high-performance electronic components.

[0065] Rydberg atoms are neutral atoms in a highly excited state. Their outer electron states have ultra-sensitive characteristics to external electric fields, and the electric field strength and frequency can be accurately detected by measuring the atomic energy level shift through laser spectroscopy technology. Compared with traditional metal antennas, quantum sensors have an ultra-wideband response (covering the DC to terahertz frequency bands) and detection sensitivities far exceeding the physical limits of metal probes. Their all-optical measurement method fundamentally eliminates the electrical breakdown risk of metal probes, simplifies the sensor structure, and provides feasibility for miniaturization.

[0066] This embodiment is illustrated by taking the detection result of partial discharge signals by a Rydberg atom electric field sensor under a free space coupling configuration as an example:

[0067] As Figure 5 shown, Figure 5 (a) to Figure 5 (d) disclose the three-dimensional time-domain response waveforms output after the atomic system receives radio frequency (RF) signals emitted by different types of partial discharges (PDs) under free space coupling conditions, respectively showing the characteristic time-domain waveforms of four typical PD types, corresponding to void discharge, floating discharge, particle discharge, and corona discharge. In Figure 5 (a), the void discharge shows two distinct discharge clusters in each 50 Hz power frequency cycle, corresponding to the positive and negative half-cycles respectively. Each discharge cluster consists of multiple discharge pulses, showing strong periodicity and highly consistent discharge characteristics; in Figure 5 (b), the floating discharge usually generates an isolated, high-amplitude pulse in each half-cycle. The event frequency is lower than that of the void discharge, but still maintains a relatively regular time distribution; Figure 5 (c) shows that the particle discharge appears randomly or is completely absent in each cycle, showing significant randomness and lacking obvious periodicity; Figure 5 (d) shows the waveform of the corona discharge, where the discharge cluster composed of high-frequency pulses is mainly concentrated in the positive half-cycle, and there is no obvious discharge activity in the negative half-cycle, showing a unipolar discharge characteristic and having a certain time consistency. The above time-domain waveforms prominently demonstrate the unique characteristics of different types of partial discharges in the time domain, providing important information for identifying the discharge type using a Rydberg atom electric field sensor.

[0068] To verify the accuracy of the partial discharge signal results received by the atomic system, the PD signal source is directly connected to a high-bandwidth oscilloscope through a coaxial cable to obtain a reference time-domain waveform, as Figure 5 (e) to Figure 5 (h) shown. The observed waveform characteristics are the same as those in Figure 5 (a) to Figure 5(d) The responses of the atomic system are highly consistent. By analyzing the time-domain waveforms of each RF signal to be measured, it is found that air-gap discharges present two distinct discharge clusters in each power cycle, suspended discharges generate a high-amplitude pulse within each half-cycle, particulate discharges are extremely random in time, and corona discharges mainly occur in the positive half-cycle. The above comparison results indicate that the Rydberg atom-based RF electric field sensing system can effectively detect partial discharge signals propagating through free space and accurately reconstruct their time-domain characteristics. The high consistency between the detection results of the atomic sensor and those measured by a traditional high-bandwidth oscilloscope further verifies the effectiveness and reliability of this atomic sensing method.

[0069] This embodiment is illustrated by taking the detection results of detecting the original partial discharge signal, detecting the partial discharge signal through the free-space coupling configuration, and detecting the partial discharge signal through the waveguide-enhanced coupling configuration as examples:

[0070] Figure 6 The results of the signal-to-noise ratio (SNR) performance comparison experiment for three different signal reception methods, namely directly collecting the original PD RF signal (Test 1), detecting the partial discharge signal through the free-space coupling configuration (Test 2), and detecting the partial discharge signal through the waveguide-enhanced coupling configuration (Test 3). The results show that the original PD RF signal has high quality and the SNR is not less than 29.6; although there is a certain degree of attenuation in the signals of the atom-based detection method, their SNRs are all higher than 3.4, and the performance of the two partial discharge signal detection methods of the free-space coupling configuration and the waveguide-enhanced coupling configuration is comparable.

[0071] Therefore, compared with the free-space coupling configuration, the waveguide-enhanced coupling configuration extends the effective detection distance from the centimeter level to the meter level. This embodiment verifies that stable signal sensing can be achieved within a maximum distance of 5 m. In addition, this embodiment adopts an electro-optical-electrical conversion mechanism, effectively avoiding the common electrical breakdown risk in traditional ultra-high frequency (UHF) detection technologies. By converting the RF signal into a low-frequency spectral output, the atomic system greatly simplifies the hardware complexity in the signal acquisition and processing link, eliminating the need for high-speed and high-performance electronic components, providing a feasible and scalable path for the deployment of atom-based RF sensing technology in practical engineering.

[0072] When further analyzing the single-pulse characteristics of the PD signal, significant distortion in the response of the atomic system is observed, as shown in Figure 7 (a)~ Figure 7 (d). Figure 7 (a) The pulse width of the original PD signal is approximately 200 ns, containing rich time characteristics; Figure 7(b) shows the response of the atomic system to a single corona discharge pulse, which is significantly broadened to about 15 μs, far exceeding the time scale of the original PD signal, and the detailed waveform information is no longer distinguishable; Figure 7 (c) measures the instantaneous bandwidth of the atomic system to explore the cause of signal distortion in the atomic system. The experimental results show that the 3 dB instantaneous bandwidth of the atomic system is about 170 kHz, significantly lower than the 4 MHz bandwidth of the photodetector, indicating that the signal distortion is mainly due to the limited bandwidth of the atomic system itself, which limits its ability to accurately reconstruct the high-frequency components in the original PD signal. Figure 7 (d) shows the electric field sensitivity test of the atomic system in the frequency range from 100 MHz to 5 GHz under non-resonant conditions. The results show that the atomic system can achieve an optimal sensitivity of 19 μV / cm·Hz in this frequency band –1 / 2 , and the atomic system still has a high response ability to weak RF signals in a wide frequency range.

[0073] In this invention, by adopting a three-photon excitation scheme and utilizing the electromagnetically induced transparency (EIT) effect in a cesium vapor cell, the time-domain response characteristics of Rydberg atoms to four typical PD types are successfully obtained. The results show that the atomic system can accurately capture the periodicity (such as the double-cluster periodicity of air-gap discharge) and randomness (such as the intermittency of particle discharge) characteristics of various PD signals, providing an optically readable alternative solution for traditional ultra-high frequency (UHF) detection techniques. To meet the requirements of engineering deployment, the detection range of this invention is extended from centimeter level to 5-meter level (through coaxial transmission), while maintaining the signal-to-noise ratio (SNR) performance. Although the limited instantaneous bandwidth of the atomic system (3 dB bandwidth is about 170 kHz) causes the single-pulse response to be broadened to 15 μs (the original signal is 200 ns), its high sensitivity (the optimal sensitivity in the 100 MHz–5 GHz frequency band reaches 19 μV / cm·Hz -1 / 2 ) and wide-band characteristics are still suitable for conventional PD monitoring.

[0074] As Figures 2(a) to 2(b) shown, this invention also provides a partial discharge detection device based on a Rydberg atom electric field sensor, which is applied to the partial discharge detection method based on a Rydberg atom electric field sensor described in Embodiment 1, and includes an atomic gas cell 10, a mirror 30, a first beam splitter 20, a second beam splitter 31, a third beam splitter 32, a photodetector 33, an integrated waveguide chip 11, and a PD signal source 40.

[0075] The first beam splitter 20 is arranged on one side of the atomic gas cell 10. The probe light passes through the first beam splitter 20 and is incident on the atomic gas cell 10 horizontally in parallel, passes through the atomic gas cell 10 and the second beam splitter 31 in sequence, and is received by the photodetector 33.

[0076] The reflector, the second beam splitter 31, the third beam splitter 32, and the photodetector 33 are arranged on the other side of the atomic gas cell 10. The coupling light is first reflected by the mirror 30 and then combined with the control light through the third beam splitter 32, and then reflected by the second beam splitter 31 and injected into the atomic gas cell 10 along the reverse direction of the detection light, overlapping with the detection light to form a Rydberg atom antenna detection region, and preparing the ground-state cesium atoms into high-Rydberg-state atoms.

[0077] The surface of the atomic gas cell 10 is encapsulated with an integrated waveguide chip 11 to generate a local enhanced electric field on the surface of the atomic gas cell 10.

[0078] The PD signal source 40 is spaced apart from the atomic gas cell 10 by a preset distance. The PD signal source 40 emits a radio frequency signal to be measured, and the radio frequency signal to be measured propagates through free space and couples with the Rydberg atoms in the Rydberg atom antenna detection region.

[0079] The above implementation can realize the detection of partial discharge signals based on the free space coupling configuration. This embodiment also provides an implementation for realizing the detection of partial discharge signals based on the waveguide enhanced coupling configuration.

[0080] As shown in Fig. 2(c), the partial discharge detection device based on the Rydberg atom electric field sensor provided by the present invention further includes a coaxial cable 51 and a metal antenna 50. The two ends of the coaxial cable 51 are respectively connected to the integrated waveguide chip 11 and the metal antenna 50. The PD signal source 40 is spaced apart from the metal antenna 50 by a preset distance. The metal antenna 50 receives the radio frequency signal to be measured emitted by the PD signal source 40, is enhanced by the integrated waveguide chip 11 after being transmitted through the coaxial cable 51, and couples with the Rydberg atoms in the Rydberg atom antenna detection region.

[0081] Further, the photodetector 33 is an avalanche photodiode, the PD signal source 40 uses a JD-CL20 type professional PD signal generator produced by JuDian-Electric Company, and the radio frequency signal to be measured includes air gap discharge, floating discharge, particle discharge, and corona discharge.

[0082] Further, the atomic gas cell 10 is a cesium atom vapor cell, and the size of the atomic gas cell 10 is 5×1×1 cm 3 , and the integrated waveguide chip 11 is an artificial surface plasmon polariton waveguide.

[0083] Further, the metal antenna 50 is an Archimedean spiral antenna, and the working frequency band is 100 MHz to 6 GHz.

[0084] Further, the wavelength of the detection light is 852 nm, the wavelength of the control light is 1470 nm, and the wavelength of the coupling light is 780 nm. The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for detecting partial discharge based on a Rydberg atom electric field sensor, characterized in that It includes the following steps: S1. The probe light passes through the atomic cell. After the light is regulated and combined with the coupling light, it is injected into the atomic cell in the reverse direction of the probe light, and the ground-state cesium atoms are prepared into highly Rydberg atoms; S2. The PD signal source emits the RF signal to be measured, and the atomic cell receives the RF signal to be measured based on the free-space coupling configuration or the waveguide-enhanced coupling configuration; S3. The RF signal to be measured is detected in the Rydberg atom antenna detection area formed by the coincidence of the probe light, the regulated light and the coupling light in the atomic cell; the transmittance of the probe light is measured by a photodetector to obtain the electromagnetic-induced transparency spectrum signal to be detected, and the output signal of the photodetector is sent to an oscilloscope to obtain the time-domain waveform of the output signal.

2. The partial discharge detection method based on a Rydberg atom electric field sensor according to claim 1, characterized in that The specific process of preparing the ground-state cesium atoms into highly Rydberg atoms in S1 is as follows: the probe light is incident horizontally and parallel through the atomic cell. After the regulated light and the coupling light are combined by a beam splitter, they are injected into the atomic cell in a configuration opposite to the direction of the probe light. The ground-state cesium atoms are excited from the ground state to the Rydberg state through an intermediate energy level in the region where the three laser beams overlap in space.

3. The partial discharge detection method based on a Rydberg atom electric field sensor according to claim 1, wherein The RF signal to be measured in S2 is a typical partial discharge signal, and the typical partial discharge signal includes air-gap discharge, floating discharge, particle discharge and corona discharge.

4. The partial discharge detection method based on a Rydberg atom electric field sensor according to claim 1, characterized in that The specific free-space coupling configuration in S2 is as follows: the PD signal source and the atomic cell maintain a preset distance, and the RF signal to be measured propagates through free space and couples with the Rydberg atoms in the atomic cell.

5. The partial discharge detection method based on a Rydberg atom electric field sensor according to claim 4, characterized in that The specific waveguide-enhanced coupling configuration in S2 is as follows: an integrated waveguide chip is packaged on the surface of the atomic cell, and a coaxial cable is used to connect the integrated waveguide chip and the metal antenna to extend the transmission distance of the RF signal to be measured. The PD signal source and the metal antenna maintain a preset distance, and the RF signal to be measured is received by the antenna, enhanced by the integrated waveguide chip after being transmitted through the coaxial cable, and couples with the Rydberg atoms in the atomic cell.

6. The partial discharge detection method based on a Rydberg atom electric field sensor according to claim 5, characterized in that The integrated waveguide chip is a plasmonic waveguide, which is used to generate a local enhanced electric field on the surface of the atomic cell to enhance the coupling between the RF signal to be measured and the Rydberg atoms.

7. The partial discharge detection method based on a Rydberg atom electric field sensor according to claim 5, wherein The preset distance is 5 cm or less, and the coaxial cable extends the transmission distance of the RF signal to be measured by 5 m or less.

8. A partial discharge detection device based on a Rydberg atom electric field sensor, characterized in that, Applied to the partial discharge detection method based on the Rydberg atom electric field sensor according to any one of claims 1-7, it includes an atomic cell, a mirror, a first beam splitter, a second beam splitter, a third beam splitter, a photodetector, an integrated waveguide chip and a PD signal source; the first beam splitter is arranged on one side of the atomic cell, and the probe light passes through the first beam splitter and is incident horizontally and parallel into the atomic cell, passes through the atomic cell and the second beam splitter in sequence, and is received by the photodetector; The mirror, the second beam splitter, the third beam splitter and the photodetector are arranged on the other side of the atomic cell. The coupling light is first reflected by the mirror and then combined with the regulated light by the third beam splitter, and then reflected by the second beam splitter and injected into the atomic cell in the reverse direction of the probe light, and coincides with the probe light to form a Rydberg atom antenna detection area, and the ground-state cesium atoms are prepared into highly Rydberg atoms; The surface of the atomic cell is packaged with an integrated waveguide chip to generate a local enhanced electric field on the surface of the atomic cell.

9. The partial discharge detection device based on a Rydberg atom electric field sensor according to claim 8, wherein, It further includes a PD signal source; the PD signal source is spaced apart from the atomic gas cell by a preset distance, the PD signal source emits a radio frequency signal to be measured, the radio frequency signal to be measured propagates through free space and couples with Rydberg atoms within the detection region of the Rydberg atom antenna.

10. The partial discharge detection device based on a Rydberg atom electric field sensor according to claim 8, wherein It further includes a PD signal source, a coaxial cable and a metal antenna; two ends of the coaxial cable are respectively connected to the integrated waveguide chip and the metal antenna, the PD signal source is spaced apart from the metal antenna by a preset distance, the metal antenna receives the radio frequency signal to be measured emitted by the PD signal source, is enhanced by the integrated waveguide chip after being transmitted through the coaxial cable, and couples with Rydberg atoms within the detection region of the Rydberg atom antenna.

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