Dielectric loss determination method and device, equipment, storage medium and program

Abstract

The invention discloses a dielectric loss determination method and device, equipment, a storage medium and a program. The method is applied to the technical field of power grids and comprises the steps that it is determined that the working state of the dielectric loss determination equipment meets a preset condition, and discrete sampling signals of a target submarine cable are measured through the high-voltage side of the dielectric loss determination equipment; performing all-phase time-frequency domain conversion on the discrete sampling signal to obtain a frequency domain signal; and determining a voltage phase and a current phase according to each frequency domain signal, and determining a dielectric loss value of the target submarine cable based on the voltage phase and the current phase. According to the embodiment of the invention, the signal of the target cable is subjected to full-period sampling, the problem of spectrum leakage in the dielectric loss process is solved based on all-phase time-frequency domain conversion, and the accuracy of dielectric loss determination can be improved.

Description

Technical Field

[0001] The present invention relates to the field of power grid technology, and in particular to a method, device, equipment, storage medium and program for determining dielectric loss. Background Art

[0002] Dielectric loss measurement is a method used to evaluate the insulation performance of insulating materials and high-voltage electrical equipment. It determines the energy loss of insulating materials under the action of an electric field by measuring the dielectric loss angle. Currently, existing dielectric loss measurement methods mainly include the bridge balancing method and the harmonic analysis method. Among them, the bridge balancing method adjusts the resistance, capacitance and other parameters of the bridge arm to make the bridge reach a balanced state, that is, the bridge output is zero, and the settlement value is calculated according to the equilibrium condition. However, this dielectric loss measurement method has poor anti-interference ability. In strong electromagnetic interference environments such as substations, the bridge is difficult to balance, resulting in large fluctuations in measurement results, insufficient component stability, and bridge components are easily affected by temperature changes, aging, etc., resulting in parameter drift. The existing harmonic analysis method performs a fast Fourier transform (FFT) on the collected voltage and current signals, extracts the fundamental phase difference through spectrum analysis, and then calculates the dielectric loss angle. However, due to spectrum leakage and the fence effect, there are errors in the phase calculation, resulting in large errors in determining the dielectric loss. The embodiments of the present invention urgently need a high-precision dielectric loss determination method. Summary of the Invention

[0003] The present invention provides a dielectric loss determination method, apparatus, device, storage medium and program to perform full-cycle sampling of the signal of a target cable, solve the spectrum leakage problem during the dielectric loss process, and improve the accuracy of dielectric loss determination.

[0004] According to one aspect of the present invention, a method for determining dielectric loss is provided, wherein the method uses a dielectric loss determination device, and the method includes:

[0005] Determining that the working state of the dielectric loss determination device meets a preset condition, and measuring a discrete sampling signal of the target submarine cable through the high-voltage side of the dielectric loss determination device;

[0006] Performing full-phase time-frequency domain conversion on the discrete sampling signal to obtain a frequency domain signal;

[0007] A voltage phase and a current phase are determined according to each of the frequency domain signals, and a dielectric loss value of the target submarine cable is determined based on the voltage phase and the current phase.

[0008] According to another aspect of the present invention, a dielectric loss determination device is provided, which is applied to a dielectric loss determination apparatus, wherein the device comprises:

[0009] a cable sampling module, configured to determine that the working state of the dielectric loss determination device meets a preset condition, and to obtain a discrete sampling signal of the target submarine cable through the high-voltage side of the dielectric loss determination device;

[0010] A full-phase processing module, configured to perform full-phase time-frequency domain conversion on the discrete sampling signal to obtain a frequency domain signal;

[0011] A dielectric loss determination module is used to determine a voltage phase and a current phase according to each of the frequency domain signals, and determine a dielectric loss value of the target submarine cable based on the voltage phase and the current phase.

[0012] According to another aspect of the present invention, a dielectric loss determination device is provided, the device comprising:

[0013] a low-voltage side controller and a high-voltage side controller, wherein the low-voltage side controller and the high-voltage side controller are connected via an optical fiber; and

[0014] A memory in communication with the low-voltage side controller; wherein,

[0015] The memory stores a computer program executable by the low-voltage side controller. The computer program is executed by the low-voltage side controller so that the low-voltage side controller can perform the dielectric loss determination method described in any embodiment of the present invention.

[0016] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the dielectric loss determination method according to any embodiment of the present invention when executed.

[0017] According to another aspect of the present invention, a computer program product is provided. The computer program product includes a computer program. When the computer program is executed by a processor, the method for determining dielectric loss according to any embodiment of the present invention is implemented.

[0018] The technical solution of the embodiment of the present invention is to call the high-voltage side of the dielectric loss determination device to collect data from the target submarine cable when the working state of the dielectric loss determination device is under preset conditions, perform full-phase time-frequency domain conversion on the discrete sampling signals to obtain frequency domain signals, determine the voltage phase and current phase corresponding to each frequency domain signal, and determine the dielectric loss value of the target submarine cable based on the voltage phase and current phase. The embodiment of the present invention can obtain a frequency domain signal covering the entire signal cycle by performing full-phase time-frequency domain conversion processing on the discrete sampling signals. By calculating the dielectric loss value based on the full-cycle frequency domain signal, spectrum leakage can be greatly suppressed, making the phase used to calculate the dielectric loss value more accurate, and improving the accuracy of dielectric loss determination.

[0019] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 This is a flow chart of a method for determining dielectric loss provided in accordance with the first embodiment of the present invention;

[0022] Figure 2 is a flow chart of another dielectric loss determination method provided in accordance with the second embodiment of the present invention;

[0023] Figure 3 This is an example diagram of a step-by-step voltage boost test process provided according to the second embodiment of the present invention;

[0024] Figure 4 This is an example diagram of a signal acquisition circuit provided according to the second embodiment of the present invention;

[0025] Figure 5 is a flow chart of another dielectric loss determination method provided in accordance with the third embodiment of the present invention;

[0026] Figure 6 2 is a schematic structural diagram of a dielectric loss determination device provided in accordance with a fourth embodiment of the present invention;

[0027] Figure 7 This is a schematic diagram of full-cycle sampling provided according to the fourth embodiment of the present invention;

[0028] Figure 8 This is an example diagram of a signal full-phase processing process provided according to the fourth embodiment of the present invention;

[0029] Figure 9 This is an example diagram of a windowed all-phase FFT calculation process provided according to a fourth embodiment of the present invention;

[0030] Figure 10 2 is a schematic diagram of a dielectric loss angle calculation process according to a fourth embodiment of the present invention;

[0031] Figure 11 2 is a schematic structural diagram of a dielectric loss determination device provided according to a fifth embodiment of the present invention;

[0032] Figure 12 It is a structural diagram of an electronic device for implementing the dielectric loss determination method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0034] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0035] Example 1

[0036] Figure 1 This is a flow chart of a dielectric loss determination method provided according to the first embodiment of the present invention. This embodiment is applicable to the case of dielectric loss measurement of submarine cables. The method can be executed by a dielectric loss determination device. The dielectric loss determination device can be implemented in the form of hardware and / or software. The dielectric loss determination device can be configured in a dielectric loss determination device. Figure 1 As shown, the method includes:

[0037] Step 110: Determine whether the working state of the dielectric loss determination device meets a preset condition, and obtain a discrete sampling signal of the target submarine cable through the high-voltage side of the dielectric loss determination device.

[0038] Among them, the dielectric loss determination device can be a device for measuring dielectric loss. The dielectric loss determination device can include a low-voltage side and a high-voltage side. The low-voltage side can include a controller, which can be used to configure the initial signal frequency and amplitude, and the high-voltage side can be used to receive the low-voltage signal and linearly amplify the signal. The high-voltage side can be configured with a signal acquisition circuit, which can collect signals such as voltage and current in the cable. The working state can reflect the state of the dielectric loss determination device when it is working. The working state can be determined by the value state of the level signal received by the high-voltage side of the dielectric loss determination device. The preset condition can be a critical value for judging whether the dielectric loss determination device can accurately measure the dielectric loss. The preset condition can include the high-voltage side of the dielectric loss determination device receiving at least one cycle of high-level pulses. The preset condition can ensure that the internal components of the device operate within a safe working range and delay the service life of the dielectric loss determination device.

[0039] In embodiments of the present invention, the operating status of a dielectric loss determination device can be monitored. For example, the output signal of the dielectric loss determination device can be monitored to determine whether it meets the operating status requirements, or the signal collected by the dielectric loss determination device can be monitored to determine whether it meets the operating status requirements. When it is determined that the operating status of the dielectric loss determination device meets preset conditions, the dielectric loss determination device can be determined to be operating normally. This not only ensures the accuracy of the signals measured by the dielectric loss determination device, but also ensures that the dielectric loss determination device operates within a safe range, preventing safety threats to the device or operators. When it is determined that the operating status of the dielectric loss determination device meets the preset conditions, the high-voltage side of the dielectric loss determination device can be controlled to measure the target submarine cable, and at least two signals can be obtained as discrete sampling signals. It is understood that the discrete sampling signals can be a series of signals collected at a specified sampling frequency for the target submarine cable. The discrete sampling signals can include the current signal and voltage signal of the target submarine cable, and the current signal and voltage signal are in a discrete state. Furthermore, the target submarine cable can be part of the submarine cable to be tested. The dielectric loss determination device can directly collect the discrete sampling signals on the target submarine cable, without collecting signals from the cable sheath, thereby improving the signal-to-noise ratio and enhancing the accuracy of the dielectric loss measurement.

[0040] Exemplarily, determining that the working state of the dielectric loss determination device meets the preset conditions may include determining that the signal strength collected by the dielectric loss determination device on the high-voltage side is at least greater than the threshold strength, that is, the voltage of the collected output signal reaches the maximum value. In this case, the starting zero crossing point of each sine wave of the signal output by the dielectric loss determination device can generate a high-level pulse, that is, high-level pulses are generated at both ends of a signal cycle, thereby ensuring that the collected signal can cover the entire signal cycle, thereby improving the accuracy of the dielectric loss determination.

[0041] Step 120: Perform full-phase time-frequency domain conversion on the discrete sampling signal to obtain a frequency domain signal.

[0042] Among them, the full-phase time-frequency domain conversion can be a processing process of obtaining at least one sampling signal covering the entire phase within a discrete sampling signal for time domain conversion. The full-phase sampling signal can be obtained by periodically extending the truncated phasor of the discrete sampling signal or weighting the discrete sampling signal through a convolution window and then shifting and adding it.

[0043] In an embodiment of the present invention, a discrete sampling signal covering at least one full phase can be extracted from the discrete sampling signal to form a full-phase signal. The frequency domain signal can be obtained by performing time-frequency domain conversion on the full-phase signal. Specifically, the full-phase signal can be obtained by periodically extending the truncated phasor of the discrete sampling signal or weighting the discrete sampling signal through a convolution window and then performing shift addition. For example, a convolution window with the same number of sampling points as the number of signals of the discrete sampling signal can be obtained. The discrete sampling signal can be weighted through the convolution window, and shift addition is performed on each signal value generated after the weighted processing. The shift number can be configured as needed, and its value can be 2, 3, 4, 5, etc. The processing result can be used as the full-phase signal.

[0044] Step 130: Determine the voltage phase and the current phase according to each frequency domain signal, and determine the dielectric loss value of the target submarine cable based on the voltage phase and the current phase.

[0045] Among them, the voltage phase and the current phase can be the signal phase belonging to the current signal and the signal phase belonging to the voltage signal in the frequency domain signal. The voltage phase and the current phase can be obtained by calculating the phase spectrum of the frequency domain signal or the amplitude angle of the complex part of the frequency domain signal.

[0046] Specifically, the frequency domain signals of current and voltage can be processed separately. The voltage phase and current phase can be determined by calculating the phase spectrum of the current or voltage frequency domain signal, and the dielectric loss value of the target submarine cable corresponding to the voltage phase and current phase can be determined. For example, the frequency phase and amplitude information of each generated frequency domain signal can be statistically analyzed. A phase spectrum can be created based on the phase, amplitude and other information. The voltage phase and current phase corresponding to the current signal and voltage signal can be searched in the phase spectrum. The complementary angle of the phase difference between the voltage phase and the current phase can be used as the dielectric loss angle, and the tangent value of the dielectric loss angle can be calculated as the dielectric loss value of the target submarine cable.

[0047] In an embodiment of the present invention, when the working state of the dielectric loss determination device is under preset conditions, the high-voltage side of the dielectric loss determination device is called to collect data from the target submarine cable, and a full-phase time-frequency domain conversion is performed on the discrete sampling signals to obtain a frequency domain signal. The voltage phase and current phase corresponding to each frequency domain signal are determined, and the dielectric loss value of the target submarine cable is determined based on the voltage phase and current phase. By performing a full-phase time-frequency domain conversion on the discrete sampling signals, the embodiment of the present invention can obtain a frequency domain signal covering the entire signal cycle. By calculating the dielectric loss value using the full-cycle frequency domain signal, spectrum leakage can be greatly suppressed, making the phase used to calculate the dielectric loss value more accurate, and improving the accuracy of dielectric loss determination.

[0048] Example 2

[0049] Figure 2 This is a flow chart of another dielectric loss determination method provided in accordance with the second embodiment of the present invention. This embodiment of the present invention is a refinement of the above-mentioned embodiment of the present invention, and describes the acquisition process of discrete sampling signals. Figure 2 The method provided in the embodiment of the present invention specifically includes the following steps:

[0050] Step 210: When the high-voltage signal of the dielectric loss determination device is gradually boosted to a maximum voltage threshold, it is determined that the working state of the dielectric loss determination device meets a preset condition.

[0051] The high-voltage signal may be a voltage signal collected by the high-voltage side of the dielectric loss determination device within the target submarine cable. The voltage signal may be output by the dielectric loss determination device to the target submarine cable. The maximum voltage threshold may be a critical judgment value for measuring whether the high-voltage signal of the dielectric loss determination device has reached a maximum value. When the high-voltage signal is greater than or equal to the maximum voltage threshold, it can be determined that the high-voltage signal of the dielectric loss determination device has reached its maximum voltage.

[0052] In an embodiment of the present invention, the high-voltage signal output by the dielectric loss determination device can be monitored to determine whether the high-voltage signal is gradually increased, and whether the final voltage value is greater than the maximum voltage threshold. If so, it can be determined that the dielectric loss determination device has reached the maximum voltage after gradual increase, and it can be considered that the dielectric loss determination device is working normally and its working state meets the preset conditions. Specifically, the gradual increase process of the high-voltage signal of the dielectric loss determination device can be as follows Figure 3As shown, this prevents instantaneous insulation breakdown caused by the direct application of high voltage, improving user safety. The gradual voltage increase allows the dielectric loss determination device's insulation material to adapt to the increased voltage, allowing weak points such as tiny air gaps to self-adjust through partial discharge at lower voltages. This reduces the risk of sudden insulation breakdown and ensures the safety of the device and operators. Furthermore, the gradual voltage increase allows the dielectric loss determination device to output a stable voltage according to the set voltage increase rate, ensuring that its internal components operate within a safe operating range and extending the test equipment's service life.

[0053] Step 220: Control dielectric loss according to the configured sampling cycle number to determine the voltage signal and current signal of the target submarine cable of the signal acquisition circuit on the high-voltage side of the device.

[0054] The number of sampling cycles can be pre-configured as the number of cycles for collecting signals from the target submarine cable. The number of sampling cycles can be input into the low-voltage side of the dielectric loss determination device, thereby controlling the number of signals collected by the dielectric loss determination device from the target submarine cable.

[0055] In an embodiment of the present invention, a pre-configured number of sampling cycles can be obtained, and the dielectric loss determination device can be controlled according to the number of sampling cycles, so that the signal acquisition circuit on the high-voltage side of the dielectric loss determination device collects the target submarine cable, thereby collecting voltage signals and current information of at least the number of sampling cycles. The signal acquisition circuit can be as follows: Figure 4 As shown, the voltage signal can be collected by using a parallel resistor divider. The small voltage signal is collected on the low-resistance resistor, and the actual voltage value is inferred from the resistor ratio. The current signal is realized by using a series sampling resistor. The calculation formula for the sampled voltage and current is as follows:

[0056] or

[0057] U=IR or

[0058] Where R1 is the voltage sampling resistor, R2 is the voltage divider resistor, U1 is the sampled voltage signal, U2 is the voltage divider resistor voltage, R is the current sampling resistor, U is the current sampling resistor voltage, and I is the sampled current signal.

[0059] Step 230: The collected voltage signals and current information are used as discrete sampling signals.

[0060] Specifically, the collected voltage signal and current information can be used as discrete sampling signals respectively.

[0061] Step 240: Perform full-phase time-frequency domain conversion on the discrete sampling signal to obtain a frequency domain signal.

[0062] Step 250: Determine the voltage phase and the current phase according to each frequency domain signal, and determine the dielectric loss value of the target submarine cable based on the voltage phase and the current phase.

[0063] In an embodiment of the present invention, the high-voltage signal of the dielectric loss determination device is gradually boosted to a maximum voltage threshold, so that the working state of the dielectric loss determination device meets preset conditions. The signal acquisition circuit configured on the high-voltage side of the dielectric loss determination device is controlled to collect the voltage and current signals of the target submarine cable according to the number of sampling cycles, thereby obtaining discrete sampling signals. The discrete sampling signals are subjected to full-phase time-frequency domain conversion to obtain frequency domain signals, and the voltage and current phases corresponding to each frequency domain signal are determined. The dielectric loss value of the target submarine cable is determined based on the voltage and current phases. By controlling the output process of the high-voltage signal of the dielectric loss determination device, the embodiment of the present invention ensures that the dielectric loss determination device meets the preset conditions of safety testing, thereby improving the safety of the dielectric loss determination device during dielectric loss measurement, ensuring that the components within the device are within a safe operating range, and extending the service life of the dielectric loss determination device. By calculating the dielectric loss value using full-phase sampling signals, spectrum leakage can be greatly suppressed, making the phase used to calculate the dielectric loss value more accurate, and improving the accuracy of dielectric loss determination.

[0064] Example 3

[0065] Figure 5 This is a flowchart of another dielectric loss determination method provided in accordance with the third embodiment of the present invention. This embodiment of the present invention is a refinement of the above embodiment and describes the sampling and processing of discrete sampling signals. Figure 5 The method provided in the embodiment of the present invention specifically includes the following steps:

[0066] Step 310: Determine whether the working state of the dielectric loss determination device meets a preset condition, and obtain a discrete sampling signal of the target submarine cable through the high-voltage side of the dielectric loss determination device.

[0067] Step 320: Construct at least three groups of truncated phasors for the discrete sampling signal, wherein the at least three groups of truncated phasors have at least one identical reference sampling signal.

[0068] The truncated phasor may be a signal group obtained by truncating a discrete sampled signal according to a specified signal length. The truncated phasor may include signals at at least two sampling positions within the discrete sampled signal. The base station sampled signals may be signals at the same sampling position within different truncated phasors.

[0069] In an embodiment of the present invention, a discrete sampled signal can be truncated according to a preset signal length. The preset signal length can be a window length for performing time-frequency domain conversion. The preset signal length can be preconfigured and ensures that all truncated phasors generated after truncation have at least one identical reference sampled signal. For example, the discrete sampled signal can be truncated using a window of the preset signal length. After each truncation of the discrete sampled signal, the window can be moved with a step size of 1, thereby obtaining at least two truncated phasors having the same reference sampled signal.

[0070] Step 330: Obtain at least three groups of truncated phasors and perform period extension on each of them to generate period extension signals.

[0071] The cycle extension may be a process of extending multiple cycles based on each group of truncated phasors, and the signal composed of the truncated phasors after the cycle extension may be used as the cycle extension signal.

[0072] In an embodiment of the present invention, a period extension of at least three periods may be performed on each group of truncated phasors obtained. It can be understood that the number of periods of the period extension may be determined by the number of truncated vectors. For example, a period extension of at least three periods may be performed on each of the three truncated vectors. A signal generated after the period extension of each truncated phasor may be used as a period-extended signal.

[0073] For example, the truncated phasors are: x':x(0)x(-1)x(-2), x":x(1)x(0)x(-1), and x':x(2)x(1)x(0). The truncated phasors can be periodically extended to obtain the following three periodically extended signals:

[0074]

[0075] Step 340 : Align each cycle-extended signal with the reference sampling signal and then add them together to obtain a full-phase cycle-extended signal.

[0076] In an embodiment of the present invention, the cycle extension signals may be aligned based on the reference sampling signal, and the aligned cycle extension signals may be added at the same position to obtain a full-phase cycle extension signal.

[0077] Step 350: Perform time-frequency domain conversion on the full-phase periodic extension signal to obtain a frequency domain signal.

[0078] Specifically, the acquired full-phase periodic extension signal can be converted into a time-frequency domain, and the full-phase periodic extension signal in the time domain can be transformed into the frequency domain to obtain a frequency domain signal. The time-frequency domain conversion can be achieved through DFT or FFT.

[0079] Step 360: Extract the voltage frequency domain signal and the current frequency domain signal from the frequency domain signal, and determine the amplitude spectrum and phase spectrum of the voltage frequency domain signal and the current frequency domain signal.

[0080] The amplitude spectrum represents the amplitude of the current and voltage frequency domain signals at corresponding frequencies, and may include the modulus of the current and voltage frequency domain signals in the frequency domain. The phase spectrum represents the phase information of the current and voltage frequency domain signals at different frequencies, and includes the phase portion of the current and voltage frequency domain signals.

[0081] Specifically, the voltage frequency domain signal corresponding to the voltage and the current frequency domain sign corresponding to the current are extracted from the frequency domain signal. The amplitude spectrum and phase spectrum of the voltage frequency domain signal and the current frequency domain signal can be statistically calculated respectively. The modulus values ​​of the voltage frequency domain signal and the current frequency domain signal can be extracted respectively to form an amplitude spectrum, and the phases of the voltage frequency domain signal and the current frequency domain signal can be extracted respectively to form a phase spectrum.

[0082] Step 370 : Generate phase spectra corresponding to the voltage frequency domain signal and the current frequency domain signal according to the amplitude spectrum and the phase spectrum.

[0083] Specifically, corresponding phase spectra can be drawn for voltage and current according to their corresponding amplitude spectra and phase spectra respectively. For example, the drawing process can be implemented by customizing the drawing program or calling common drawing tools. For example, the Matplotlib drawing tool can be called to draw the phase spectrum according to the amplitude spectrum and phase spectrum.

[0084] Step 380 : extract the current peak spectrum line and the voltage peak spectrum line from the phase spectrograms of the voltage frequency domain signal and the current frequency domain signal, respectively.

[0085] In an embodiment of the present invention, corresponding peak spectrum lines can be identified in the phase spectrum diagrams of the voltage frequency domain signal and the current frequency domain signal, respectively. The peak spectrum lines can be recorded as current peak spectrum lines and voltage peak spectrum lines, respectively. It can be understood that the peak spectrum lines can be spectrum lines corresponding to the packaging position in the phase spectrum diagram. For example, the peak spectrum lines can be identified in the phase spectrum diagram through a peak detection algorithm.

[0086] Step 390: Extract the current phase corresponding to the current peak spectrum line and the voltage phase corresponding to the voltage peak spectrum line in the phase spectrum diagram.

[0087] Specifically, the phase value corresponding to the voltage peak spectrum line in the phase spectrum diagram of the voltage frequency domain signal can be extracted as the voltage phase, and the phase value corresponding to the current peak spectrum line in the phase spectrum diagram of the current frequency domain signal can be extracted as the current phase.

[0088] Step 3100: The complementary angle of the difference between the voltage phase and the current phase is used as the dielectric loss angle, and the tangent value of the dielectric loss angle is obtained as the dielectric loss value.

[0089] In the embodiment of the present invention, the phase difference between the voltage phase and the current phase can be determined, the complementary angle corresponding to the phase difference can be used as the dielectric loss angle, and the tangent value of the dielectric loss angle can be used as the dielectric loss value of the target submarine cable.

[0090] In an embodiment of the present invention, when the working state of the dielectric loss determination device meets a preset condition, the high-voltage side of the dielectric loss determination device can be called to collect a discrete sampling signal of the target submarine cable, and at least three groups of truncated phasors with the same reference sampling signal are obtained in the discrete sampling signal. The truncated vectors are periodically extended to obtain periodically extended signals, each group of periodically extended signals is aligned with the reference sampling signal, and each group of periodically extended signals is added in aligning positions to obtain a full-vector periodically extended signal. The full-vector periodically extended signal is converted into a time-frequency domain to obtain a frequency domain signal, and the voltage frequency domain signal and the current frequency domain signal are extracted from the frequency domain signal. The amplitude spectrum and the phase spectrum corresponding to the voltage frequency domain signal and the current frequency domain signal are determined, and a phase spectrum diagram is constructed based on the amplitude spectrum and the phase spectrum corresponding to the voltage frequency domain signal and the current frequency domain signal. The current peak spectrum line and the voltage peak spectrum line are respectively extracted from the phase spectrum diagram, and the complementary angle of the difference between the current phase and the voltage phase corresponding to the current peak spectrum line and the voltage peak spectrum line is used as the dielectric loss angle, and the tangent value of the dielectric loss angle is used as the dielectric loss value. The embodiment of the present invention calculates the dielectric loss value through a full-cycle signal sequence, which can greatly suppress spectrum leakage, make the phase of the full-cycle signal sequence more accurate, and improve the accuracy of dielectric loss determination.

[0091] Furthermore, based on the above-mentioned embodiment of the invention, a secondary windowing process is performed on the full-phase period extension signal, and the window function of the secondary windowing process includes a Hanning window that has undergone self-convolution.

[0092] Among them, the secondary windowing process can be a process of windowing the periodic extension signal generated by window truncation and periodic extension again. The generation of the truncated phasor and the secondary windowing process can be understood as double-window processing of the discrete sampling signal. The double-window processing can have a more balanced window function, which can reduce the sidelobe effect of the window function and reduce spectrum leakage. The window function used in the secondary windowing process can be a Hanning window that has been convolved with itself. This window function is equivalent to windowing the signal twice, making the signal more balanced and further preventing spectrum leakage. The Hanning window, also known as the cosine square window, can balance the transition to zero, which is expressed as:

[0093] w(n)=0.5[1-cos(2πn / N-1)]

[0094] Wherein, N represents the number of sampling points of the window function, and n represents a discrete time index in the discrete sampling signal, and the discrete time index represents the sampling point position of the current discrete sampling signal.

[0095] In an embodiment of the present invention, a Hanning window can be constructed based on the signal length of the full-phase period-extended signal, and self-convolution can be performed based on the Hanning window. Thus, a window function for secondary windowing can be used to perform windowing on the full-phase period-extended signal. Furthermore, the signal sequence generated by the secondary windowing process can be converted to the time-frequency domain to obtain a frequency domain signal. It is understood that the window function for secondary windowing can also be generated by self-convolution of a Heyman window or a rectangular window.

[0096] Example 4

[0097] Figure 6 Schematic diagram of the structure of the dielectric loss determination device provided by the fourth embodiment of the present invention, see Figure 6 The dielectric loss determination device may include a low-voltage side, a high-voltage side, and an optical fiber. The low-voltage side controls the high-voltage side to output an ultra-low-frequency sinusoidal signal, which is used to measure the dielectric loss of the cable. To ensure device parameters, reliability, and safety of equipment operation, the low-voltage and high-voltage sides cannot be electrically connected. Therefore, communication between the low-voltage and high-voltage sides can be achieved through optical fiber communication, optical couplers, transformers, or electrical isolators. Specifically, the low-voltage side, acting as the control end, converts electrical signals into optical signals and transmits them to the low-frequency, high-voltage output end of the high-voltage side. The high-voltage side then converts the corresponding optical signals into electrical signals to achieve electrical isolation. The low-voltage side may use a single-chip microcomputer as the main controller, and communicate via a serial communication unit and a multi-channel optical fiber signal transmission circuit. The serial communication unit primarily performs data exchange and quality analysis between the host computer and the low-voltage side main controller, configuring information such as the frequency, period, and amplitude of the sinusoidal signal serving as the initial signal. The multi-channel optical fiber signal transmission circuit primarily converts the sinusoidal wave data output by the low-voltage side into optical signals and transmits them to the high-voltage side. The high-voltage side can also choose a single-chip microcomputer as the main controller. The optical signal analysis circuit can use a fiber optic module to convert the received sinusoidal waveform data into an analog signal through the built-in DAC, and transmit the corresponding signal to the input side of the analog amplifier circuit at the high-voltage end through the signal conditioning unit, ultimately realizing the transmission and amplification of the low-voltage sinusoidal signal.

[0098] When measuring the dielectric loss of a cable, this device measures the voltage across the cable and the small current flowing through the insulation. The voltage signal can be collected using a parallel resistor divider. The small voltage signal is sampled across a low-value resistor, and the actual voltage value is inferred from the resistor ratio. The current signal is obtained using a series sampling resistor. The formulas for calculating the sampled voltage and current are as follows:

[0099] or

[0100] U=IR or

[0101] Among them, R1 is the voltage sampling resistor, R2 is the voltage divider resistor, U1 is the sampling voltage, U2 is the voltage divider resistor, R is the current sampling resistor, U is the current sampling resistor voltage, and I is the sampling current.

[0102] In an embodiment of the present invention, the insulation of the submarine cable can be tested by frequency domain dielectric response, by measuring the weak current signal flowing through the insulating medium. Common methods for micro-current detection include the following: capacitance integration method, sampling resistor differential detection method, etc. When the capacitance integration method is used, due to the existence of capacitor leakage current, a certain error is inevitable. In addition, due to the existence of stray capacitance on the circuit board, uncontrollable phase shift is often added when measuring AC micro-current. The sampling resistor differential detection method has the advantages of simple structure and can effectively remove common mode interference. This design uses BWL EE high-precision non-inductive resistors, which have high stability and reliability, as well as very small temperature coefficients that can even be controlled to a single-direction temperature coefficient. They are widely used in the field of precision instruments.

[0103] Because the cable is a capacitive load, changes in the test frequency will cause changes in the current amplitude. At a certain test frequency, if the current is too small, the dielectric loss calculation results will fluctuate greatly and the settlement results will be inaccurate. Therefore, it is necessary to design a range switching circuit to meet different test frequency requirements. The sampling terminal is designed on the high-voltage side because low-voltage side sampling will couple various noise signals in the ground wire, and filtering is difficult and the signal-to-noise ratio is low. The high-voltage side sampling method directly collects current signals from the high-voltage wire core instead of collecting signals from the lead sheath of the submarine cable, which improves the signal-to-noise ratio. The sampling circuit on the high-voltage side can be as follows: Figure 4 As shown, in some embodiments of the invention, the voltage divider resistors and current sampling resistors in the circuit can be replaced by digital sensors such as Hall sensors to achieve direct digital signal acquisition, reduce the analog signal processing process, and simplify the measurement equipment structure.

[0104] Since the sampling is on the high-voltage side, the collected signal on the high-voltage side is transmitted to the host computer for data analysis. In the embodiment of the present invention, optical fiber can be used for data transmission. After the sampled signal passes through the sampling resistor, operational amplifier and single-chip microcomputer, the optical fiber transmitter completes the conversion of the electrical signal to the optical signal. The optical fiber transmits the optical signal to the low-voltage side for further signal conversion. The low-voltage side signal receiving module realizes the conversion of the optical signal to the electrical signal and sends the data to the host computer. The data conversion is completed by the optical receiver, and the converted electrical signal is transmitted to the PC end via the USB data cable.

[0105] When dielectric loss determination equipment measures dielectric loss of submarine cables, it can perform full-cycle sampling to avoid the problem of spectrum leakage and dielectric loss error caused by non-full-cycle sampling. Specifically, when sampling mechanical energy in full cycles, since directly applying high voltage may cause instantaneous breakdown of the equipment insulation, for safety reasons, the high-voltage signal is boosted in a step-by-step manner. The boosting process is as follows: Figure 3 As shown. Gradual voltage boosting allows the insulating material in the device to adapt to the voltage increase, giving weak points such as tiny air gaps a chance to self-regulate by performing partial discharge at a lower voltage, thereby reducing the risk of sudden insulation breakdown and ensuring the safety of the equipment and operators. At the same time, gradual voltage boosting allows the device to output voltage smoothly according to the set voltage boost rate, ensuring that its internal components operate within a safe operating range and extending the service life of the test equipment. In some embodiments of the invention, a high-voltage source is directly used in conjunction with a high-voltage fuse or overload protection circuit to prevent the device from breaking down at high voltage.

[0106] The synchronous sampling of the entire cycle of the device based on dielectric loss determination may include the following process:

[0107] Set the frequency and amplitude information of the ultra-low frequency signal of the dielectric loss determination device and start the ultra-low frequency dielectric loss measurement. At the beginning of the measurement, the output signal gradually reaches the maximum value in a step-by-step voltage-increasing manner. When the output signal reaches the maximum value, a high-level pulse will be generated at the starting zero crossing point of each sine wave. Figure 7 The device's signal receiving interrupt receives the first high-level pulse and begins signal acquisition according to the set number of sampling cycles, stopping acquisition when the last high-level pulse signal is received. Sampling the entire cycle of signals ensures the accuracy of the FFT transform during signal processing and improves the accuracy of dielectric loss measurement. In other embodiments of the invention, a sampling system with phase-locked loop (PLL) control is used instead of full-cycle synchronous sampling. The PLL can adjust the sampling frequency based on the input signal frequency, thereby ensuring sampling synchronization.

[0108] The collected signal is processed based on the full-phase FFT. Conventional FFT methods suffer from uneven sampling and spectrum leakage when calculating phase, reducing phase measurement accuracy. The present invention leverages the phase invariance of the phase FFT, eliminating the need for additional phase correction measures and accurately calculating the phase information of the collected signal.

[0109] Specifically, the dielectric loss determination device in the embodiment of the present invention samples the analog signal at a certain sampling frequency to obtain a discrete sampling signal x(n), where n = 1-N,…,-1,0,1,…,N-1, with a total of 2N-1 sampling points. Discrete Fourier transform (DFT) is a mathematical tool that converts discrete signals from the time domain to the frequency domain. It processes the periodic extension signal of the truncated signal x(n), extracts valuable features from the DFT spectrum for tasks such as classification and recognition, and by analyzing the spectrum after DFT, it is possible to determine which frequency components are contained in the signal, as well as their relative amplitude and phase. When N = 3, for the same sampling point, there are three truncated phasors that contain the sampling point. By periodically extending these three truncated phasors and then adding them together, a new full-phase periodic extension signal can be obtained. The processing process is as follows, taking the x(0) sampling point as an example:

[0110] x':x(0)x(-1)x(-2)

[0111] x”:x(1)x(0)x(-1)

[0112] x”':x(2)x(1)x(0)

[0113] The three truncated phasors mentioned above are periodically extended respectively to obtain the following three periodically extended signals.

[0114]

[0115] Taking x(0) as the sampling starting point, the three periodic extension signals are added together to obtain the full-phase periodic extension signal, as shown in the following formula:

[0116] 3x(0)2x(-1)+x(2)x(-2)+2x(1)

[0117] The above calculation process can be simplified as Figure 8 , full phase processing is equivalent to using a convolution window w to weight the 2N-1 data centered on x(0), and then shift and add them. Figure 8 This is the processing process when there is no window.

[0118] In other embodiments of the invention, double windowing can be used to further improve the accuracy of phase measurement by the full-phase FFT. Taking the Hanning window as an example, first, an N-point Hanning window is constructed. The Hanning window w(n) is convolved with itself to obtain a 2N-1-point convolution window H. Each element h(n) in the convolution window H is the weight value of the signal after the sampled signal is periodically extended. The processing process is shown in the following formula:

[0119] Assume the Hanning window is: Where n = 0, 1, ..., N-1;

[0120] Convolve the Hanning window w(n) with itself:

[0121]

[0122] Through the calculation of the above process, the result of Hanning window self-convolution can be obtained. Multiply the 1:2N-1 item of the data after full phase processing by the convolution window to obtain the windowed 2N-1 item. After phase shifting and adding, the N-point signal sequence after full phase processing is obtained. The calculation flow chart is as follows Figure 9 shown.

[0123] Specifically, a phase spectrum of an N-point signal sequence that has undergone full phase processing can be obtained, a peak spectrum line can be found from the phase spectrum, and the phase value corresponding to the peak spectrum line can be measured to obtain the theoretical phase value of the input signal.

[0124] Perform full-phase FFT on the voltage sampling signal and current sampling signal in the signal sequence respectively, and obtain the phase spectrum. From it, find the peak spectrum line of voltage and current. After obtaining the phase value, take the remaining angle to obtain the dielectric loss angle δ, and thus calculate the dielectric loss value. The calculation process is as follows: Figure 10 After the dielectric loss angle is determined, its tangent is taken as the dielectric loss value, which can be used to evaluate the insulation condition of power equipment such as cables. This embodiment of the present invention uses a dielectric loss determination device and a full-phase FFT to accurately calculate the dielectric loss value of power equipment. This simple data processing requires minimal computation, and the resulting dielectric loss value is highly accurate.

[0125] Example 5

[0126] Figure 11 FIG. 1 is a schematic diagram of a dielectric loss determination device according to a fifth embodiment of the present invention. Figure 11 As shown, the device includes:

[0127] The cable sampling module 410 is used to determine whether the working state of the dielectric loss determination device meets a preset condition, and to obtain a discrete sampling signal of the target submarine cable through the high-voltage side of the dielectric loss determination device.

[0128] The full-phase processing module 420 is used to perform full-phase time-frequency domain conversion on the discrete sampling signal to obtain a frequency domain signal.

[0129] The dielectric loss determination module 430 is configured to determine the voltage phase and the current phase according to each frequency domain signal, and determine the dielectric loss value of the target submarine cable based on the voltage phase and the current phase.

[0130] In an embodiment of the present invention, when the working state of the dielectric loss determination device is in a preset condition, the cable sampling module calls the high-voltage side of the dielectric loss determination device to collect data from the target submarine cable. The full-phase processing module performs full-phase time-frequency domain conversion on the discrete sampling signal to obtain a frequency domain signal. The dielectric loss determination module determines the voltage phase and current phase corresponding to each frequency domain signal, and determines the dielectric loss value of the target submarine cable based on the voltage phase and current phase. By performing full-phase time-frequency domain conversion processing on the discrete sampling signal, the embodiment of the present invention can obtain a frequency domain signal covering the entire signal cycle. By calculating the dielectric loss value using the full-cycle frequency domain signal, spectrum leakage can be greatly suppressed, making the phase used to calculate the dielectric loss value more accurate, and improving the accuracy of dielectric loss determination.

[0131] Based on the above embodiments of the invention, the cable sampling module 410 includes:

[0132] The signal measuring unit is used to determine whether the working state of the dielectric loss determination device meets the preset conditions, and to measure the discrete sampling signal of the target submarine cable through the high-voltage side of the dielectric loss determination device.

[0133] The full-phase processing unit is used to perform full-phase time-frequency domain conversion on the discrete sampling signal to obtain a frequency domain signal.

[0134] The dielectric loss determination unit is used to determine the voltage phase and the current phase according to each frequency domain signal, and determine the dielectric loss value of the target submarine cable based on the voltage phase and the current phase.

[0135] In some inventive embodiments, the full phase processing module 420 includes:

[0136] The signal truncation unit is used to construct at least three groups of truncated phasors for discrete sampling signals, wherein the at least three groups of truncated phasors have at least one same reference sampling signal.

[0137] The cycle extension unit is used to obtain at least three groups of truncated phasors and perform cycle extension on each of them to generate a cycle extension signal.

[0138] The alignment processing unit is used to align each period extension signal with the reference sampling signal and then add them together to obtain a full-phase period extension signal.

[0139] The time-frequency conversion unit is used to perform time-frequency domain conversion on the full-phase periodic extension signal to obtain a frequency domain signal.

[0140] On the basis of the above-mentioned embodiment of the invention, it further comprises: a secondary windowing unit, which is used to perform secondary windowing processing on the full-phase period extension signal, and the window function of the secondary windowing processing comprises a Hanning window that has been convolved with itself.

[0141] Based on the above embodiments of the invention, the dielectric loss determination module 430 includes:

[0142] The information extraction unit is used to extract the voltage frequency domain signal and the current frequency domain signal from the frequency domain signal, and determine the amplitude spectrum and phase spectrum of the voltage frequency domain signal and the current frequency domain signal.

[0143] The spectrum construction unit is used to generate phase spectrum diagrams corresponding to the voltage frequency domain signal and the current frequency domain signal according to the amplitude spectrum and the phase spectrum respectively.

[0144] The peak recognition unit is used to extract the current peak spectrum line and the voltage peak spectrum line in the phase spectrum diagram of the voltage frequency domain signal and the current frequency domain signal respectively.

[0145] The phase determination unit is used to extract the current phase corresponding to the current peak spectrum line and the voltage phase corresponding to the voltage peak spectrum line in the phase spectrum diagram.

[0146] The dielectric loss determination unit is configured to use the complementary angle of the difference between the voltage phase and the current phase as the dielectric loss angle, and obtain the tangent value of the dielectric loss angle as the dielectric loss value.

[0147] The dielectric loss determination device provided in the embodiment of the present invention can execute the dielectric loss determination method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0148] Example 6

[0149] Figure 12 A schematic diagram of a dielectric loss determination device 10 that can be used to implement an embodiment of the present invention is shown. The dielectric loss determination device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The dielectric loss determination device can also represent various forms of mobile devices, such as personal digital assistants, cellular phones, smartphones, wearable devices (such as helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0150] like Figure 12As shown, the dielectric loss determination device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores a computer program executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the read-only memory (ROM) 12 or loaded from the storage unit 18 into the random access memory (RAM) 13. RAM 13 can also store various programs and data required for the operation of the dielectric loss determination device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0151] Multiple components in the dielectric loss determination device 10 are connected to an I / O interface 15, including an input unit 16, such as a keyboard and mouse; an output unit 17, such as various types of displays and speakers; a storage unit 18, such as a magnetic disk and optical disk; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the dielectric loss determination device 10 to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks.

[0152] The processor 11 can be any general-purpose and / or specialized processing component with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various specialized artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any other suitable processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the dielectric loss determination method.

[0153] In some embodiments, the dielectric loss determination method can be implemented as a computer program tangibly embodied in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on dielectric loss determination device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the dielectric loss determination method described above can be performed. Alternatively, in other embodiments, processor 11 can be configured to execute the dielectric loss determination method in any other suitable manner (e.g., via firmware).

[0154] Various embodiments of the systems and techniques described herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), system-on-chip systems (SOCs), programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include being implemented in one or more computer programs that are executable and / or interpreted on a programmable system that includes at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0155] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when the computer program is executed by the processor, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The computer program may be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0156] In the context of the present invention, computer-readable storage media can be tangible media that can contain or store a computer program for use with an instruction execution system, device or equipment or used in combination with an instruction execution system, device or equipment. Computer-readable storage media can include but are not limited to electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, computer-readable storage media can be machine-readable signal media. More specific examples of machine-readable storage media can include electrical connections based on one or more lines, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0157] To provide interaction with a user, the systems and techniques described herein can be implemented on a dielectric loss determination device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the dielectric loss determination device. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0158] The systems and techniques described herein can be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0159] A computing system may include clients and servers. The clients and servers are typically remote from each other and typically interact via a communication network. This client-server relationship arises through computer programs running on the respective computers, creating a client-server relationship. The server may be a cloud server, also known as a cloud computing server or cloud host. This server is a hosting product within the cloud computing service ecosystem that addresses the management difficulties and limited scalability of traditional physical hosting and VPS services.

[0160] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0161] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A method for determining dielectric loss, characterized in that: Applied to a dielectric loss determination device, the method comprises: Determining that the working state of the dielectric loss determination device meets a preset condition, and measuring a discrete sampling signal of the target submarine cable through the high-voltage side of the dielectric loss determination device; Performing full-phase time-frequency domain conversion on the discrete sampling signal to obtain a frequency domain signal; A voltage phase and a current phase are determined according to each of the frequency domain signals, and a dielectric loss value of the target submarine cable is determined based on the voltage phase and the current phase.

2. The method according to claim 1, characterized in that Determining that the working state of the dielectric loss determination device meets a preset condition, and measuring a threshold number of discrete sampling signals of the target submarine cable through the high-voltage side of the dielectric loss determination device, includes: When the high-voltage signal of the dielectric loss determination device is gradually boosted to a maximum voltage threshold, determining that the working state of the dielectric loss determination device meets a preset condition; Controlling the voltage signal and current signal of the target submarine cable by the signal acquisition circuit on the high-voltage side of the dielectric loss determination device according to the configured sampling cycle number; The collected voltage signals and current information are used as the discrete sampling signals.

3. The method according to claim 1, characterized in that The performing full-phase time-frequency domain conversion on the discrete sampling signal to obtain a frequency domain signal includes: constructing at least three groups of truncated phasors for the discrete sampled signals, wherein the at least three groups of truncated phasors have at least one same reference sampled signal; Obtaining the at least three groups of truncated phasors and performing period extension on each of them to generate period extension signals; Aligning each of the period-extended signals with the reference sampling signal and then adding them together to obtain a full-phase period-extended signal; Performing time-frequency domain conversion on the full-phase periodic extension signal to obtain the frequency domain signal.

4. The method according to claim 3, characterized in that Also includes: A secondary windowing process is performed on the full-phase period extension signal, wherein the window function of the secondary windowing process includes a Hanning window that has undergone self-convolution.

5. The method according to claim 1, characterized in that: The determining of the voltage phase and the current phase according to each of the frequency domain signals includes: Extracting a voltage frequency domain signal and a current frequency domain signal from the frequency domain signal, and determining an amplitude spectrum and a phase spectrum of the voltage frequency domain signal and the current frequency domain signal; Generating the phase spectrum diagrams corresponding to the voltage frequency domain signal and the current frequency domain signal respectively according to the amplitude spectrum and the phase spectrum; Extracting a current peak spectrum line and a voltage peak spectrum line from the phase spectrograms of the voltage frequency domain signal and the current frequency domain signal, respectively; The current phase corresponding to the current peak spectrum line and the voltage phase corresponding to the voltage peak spectrum line are respectively extracted from the phase spectrum diagram.

6. The method according to claim 5, characterized in that The determining the dielectric loss value of the target submarine cable based on the voltage phase and the current phase includes: The complementary angle of the difference between the voltage phase and the current phase is used as a dielectric loss angle, and the tangent value of the dielectric loss angle is obtained as the dielectric loss value.

7. A dielectric loss determination device, characterized in that: Applied to a dielectric loss determination device, the device comprises: a cable sampling module, configured to determine that the working state of the dielectric loss determination device meets a preset condition, and to obtain a discrete sampling signal of the target submarine cable through the high-voltage side of the dielectric loss determination device; A full-phase processing module, configured to perform full-phase time-frequency domain conversion on the discrete sampling signal to obtain a frequency domain signal; A dielectric loss determination module is used to determine a voltage phase and a current phase according to each of the frequency domain signals, and determine a dielectric loss value of the target submarine cable based on the voltage phase and the current phase.

8. A dielectric loss determination device, characterized in that: The dielectric loss determination device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor. The computer program is executed by the at least one processor to enable the at least one processor to perform the dielectric loss determination method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the dielectric loss determination method according to any one of claims 1 to 6 when executed.

10. A computer program product, characterized in that The computer program product comprises a computer program, which, when executed by a processor, implements the dielectric loss determination method according to any one of claims 1 to 6.

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