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2025 Vol. 46, No. 1
Published: 2025-01-28
 
1 Research and Establishment of the New Generation Inductance Primary Standard
YANG Yan, CHEN Yan, WANG Wei, HUANG Lu, DAI Dongxue, LU Wenjun
DOI: 10.3969/j.issn.1000-1158.2025.01.01
The new inductance primary standard adopts the modified Maxwell-Wien bridge method， and proposes a method of non-inductive resistance to compensate for the influence of the time constant of bridge’s standard resistors， and independently develops a new inductance coaxial bridge. Based on the equivalent replacement of capacitive reactance and inductive reactance， a new method is proposed to directly trace the inductance value to the capacitance unit， which shortens the traceability chain. The new inductance primary standard reduces the uncertainty and expands the traceability range of the inductance value. It achieves the uncertainty in the reproduction of 100 mH and 10 mH inductance values to be better than 2 μH/H （k=1） at 1 kHz. The establishment of national new inductance primary standard has improved the national impedance measurement traceability system， which can unify the national inductance quantity values and will be used in a new round of international key comparisons of inductance （CCEM-K3）.
2025 Vol. 46 (1): 1-6 [Abstract] ( 67 ) HTML (1 KB)  PDF (2005 KB)  ( 25 )
7 The Research and Establishment of the AC Resistance Standard
HUANG Lu, YANG Yan, WANG Wei, ZHANG Jiangtao
DOI: 10.3969/j.issn.1000-1158.2025.01.02
The composition and principle of the ac resistance standard is introduced. One set of the four terminal-pair （4TP） ac resistance bridge is developed. In comparison with the quadrifilar reversed resistor traced to the new national calculable cross-capacitor standard and the quantum hall resistance standard， the precision dissemination of the ac resistance and time constant with the range from 1 Ω to 1 MΩ at the frequency between 400 Hz and 10 kHz can be performed. The relative standard uncertainty of the ac resistance is evaluated between 0.1 μΩ/Ω and 6.0 μΩ/Ω.
2025 Vol. 46 (1): 7-13 [Abstract] ( 42 ) HTML (1 KB)  PDF (3431 KB)  ( 11 )
14 Research on On-chip Small Capacitance Standard Cell Based on Interdigital Structure
ZHAO Shuo, RAN Zixuan, CHEN Jian, YANG Yan
DOI: 10.3969/j.issn.1000-1158.2025.01.03
The interdigital capacitance is theoretically calculated using the Schwarz-Christoffel transform method. Through a combination of theoretical calculations and simulation analysis， the study investigates the influence of the geometric size of the interdigital capacitor structure and the number of electrodes on the on-chip small capacitance standard cell. The preparation and test verification of interdigital capacitor standard units with capacitance values ranging from 10 fF to 100 fF have been realized. Test results indicate that the on-chip small capacitance standard cells become more linearly dependent on the changes in capacitance as the length and number of interdigitated electrodes increase. In the range of 10 fF to 100 fF， the standard uncertainty of an on-chip small capacitance standard cell is better than 0.5% × C + 100 aF （where C is the capacitance）. It provides a research basis for the further production of a wider range of on-chip small capacitance standard cells.
2025 Vol. 46 (1): 14-18 [Abstract] ( 36 ) HTML (1 KB)  PDF (827 KB)  ( 4 )
19 Development of Error Measuring Instrument for Broadband Current Transformer
JIN Haibin, HU Zhiyuan, LIANG Shengzhi, REN Xiuwei
DOI: 10.3969/j.issn.1000-1158.2025.01.04
Based on the principle of measuring small error current by current comparator， the embedded control module is adopted. The working voltage generated by the current signal from the standard current loop in the error calibration circuit of the current transformer is used to produce weak error currents with high accuracy， both in-phase and orthogonal to the working voltage， through a program-controlled conductance box and capacitance box. These weak error currents， along with the error current of the tested current transformer， are simultaneously fed into the winding of the current comparator. And then autonomous balance measurement is performed using a high-resolution digital null detector， achieving ratio error and phase error measurements for wideband current transformers within a wide error range of 0.00001% to 10% and a wide frequency band of 50 Hz to 1 kHz. Compared with traditional current transformer calibrators， this method offers advantages such as higher accuracy， a wider measurement range， and faster measurement speeds.
2025 Vol. 46 (1): 19-24 [Abstract] ( 29 ) HTML (1 KB)  PDF (1320 KB)  ( 9 )
25 Development of 150 mV Pulse-driven AC Quantum Voltage Chip
XU Sisi, CHENG Qianshuo, LI Xiaoyu, HAN Qina, ZHONG Qing, LI Jinjin, CAO Wenhui, ZHONG Yuan
DOI: 10.3969/j.issn.1000-1158.2025.01.05
The superconducting chip is the core part of the Josephson arbitrary waveform synthesizer （JAWS） system. In the JAWS chip developed by the National Institute of Metrology （NIM）， tapered coplanar waveguide is utilized to compensate for variations in the driving pulse intensity experienced by Josephson junctions at different positions within the array. The electrical performance of the chip is verified through testing its I-V curves and synthesizing AC signals driven by pulses. In this chip， a Josephson junction array consisted by 4000 2-stack Nb/NbxSi1–x/Nb junctions， so there are totally 8000 junctions in serially connection. An oversampled delta-sigma pulse modulation system is used to generate a 14.4 Gbps bitstream to drive this Josephson junctions array. This array is capable to provide a 150 mV rms 1 kHz ac voltage output. The highest harmonic is the second， which is suppressed by at least 105 dBc.
2025 Vol. 46 (1): 25-29 [Abstract] ( 45 ) HTML (1 KB)  PDF (1095 KB)  ( 4 )
30 Research on the Key Technology of the AC Digital Ratio Bridge
WANG Zhiwei, LI Chengong, YANG Yan, HUANG Lu
DOI: 10.3969/j.issn.1000-1158.2025.01.06
Based on an automatic auxiliary balancing algorithm for bridges， the digital proportional AC bridge device is improved. The improved digital proportional AC bridge can effectively reduce the influence of the central branch potential on the measurement results， and realize automatic and fast measurement. A high-precision voltage follower is introduced to effectively isolate the analog switch from the bridge and the acquisition card to improve the measurement accuracy. The voltage ratio collected by the capture card is corrected， and the corrected voltage relative proportional error is less than 10 μV/V. The improved digital proportional AC bridge device is compared with the traditional four-terminal AC resistance bridge， and the measurement uncertainty of the digital proportional AC bridge is better than 1×10-5 at typical frequencies.
2025 Vol. 46 (1): 30-35 [Abstract] ( 51 ) HTML (1 KB)  PDF (1255 KB)  ( 11 )
36 Research on kA Level Wideband AC High Current Calibration System
CHEN Shaohua, YU Hezhen, WANG Shuqiang, JIN Haibin, HUANG Chen
DOI: 10.3969/j.issn.1000-1158.2025.01.07
The kA level wideband AC high current calibration system is introduced to stress the calibration of AC high current with a maximum range of 2 kA and frequency of 50 Hz~1 kHz. To ensure the integrity of the AC high current traceability chain, the calibration method of compensated AC current ratio standard has been studied. A set of AC current ratio calibration devices that can cover ratios up to 1000:1 and frequencies up to 1 kHz has been developed, solving the key issue of non-power frequency current ratio standard traceability. Related tests have been conducted to verify the reliability of the quantity transmission of the AC current ratio self-calibration system. Through the establishment of wideband AC high current calibration system, calibration experiments were conducted on the tested AC high current source. It was verified that the expanded uncertainty of the system is about 2.4×10-4, which could meet the calibration requirements of most wideband AC high current devices.
2025 Vol. 46 (1): 36-41 [Abstract] ( 42 ) HTML (1 KB)  PDF (2118 KB)  ( 4 )
42 A DC Dynamic Energy Measurement Method Based on Frequency Adaptive Multi⁃order Quasi⁃Synchronization Algorithm
CEN Wei, DUAN Yongxian, DUAN Xiaomeng, LI Xiaojun, ZHANG Zhijie, GENG Ailing
DOI: 10.3969/j.issn.1000-1158.2025.01.08
In the new power system， the rapid development of DC power distribution technology such as electric vehicle charging， photovoltaic， energy storage had put forward higher requirements for the accuracy of DC energy measurement. The quasi-synchronous algorithm was one of the most effective algorithms for solving aperiodic signal measurement， and can reduce the impact of dynamic frequency fluctuations on measurement accuracy by increasing the recursive valence. Aiming at the random time-varying dynamic characteristics of ripple components in DC signals， a new DC dynamic energy measurement method based on frequency adaptive multi-order quasi-synchronization algorithm was proposed. The instantaneous frequency of DC dynamic signal was quickly locked based on finite impulse response filtering and differential zero cross frequency monitoring method， and the average periodic sampling number and sampling frequency of the quasi-synchronous algorithm were dynamically adjusted according to the instantaneous frequency， so that the error of the adaptive quasi-synchronous algorithm was about equal to the n power of the reciprocal of the number of periodic wave samples （n is the quasi-synchronous iteration number）. It achieved the accurate tracking and separation of DC energy and ripple energy， and effectively improved the accuracy of DC energy measurement under complex dynamic conditions. In order to verify the performance of the algorithm， a DC dynamic power test was carried out. The test results showed that the accuracy of DC and active power was better than 0.01%， and the accuracy of ripple power was better than 0.1%， which can be applied to the electric energy measurement under DC dynamic conditions.
2025 Vol. 46 (1): 42-52 [Abstract] ( 30 ) HTML (1 KB)  PDF (1420 KB)  ( 7 )
53 Power Quality Disturbance Identification Based on Optimized Generalized S⁃transform and Hybrid Input Neural Network
LIU Haitao, WU Xiang, ZHANG Shuqing, LIU Dapeng, LIU Yong, MU Yong
DOI: 10.3969/j.issn.1000-1158.2025.01.09
Based on the correlation between the time maximum value curve and frequency maximum value curve of generalized S-transform time-frequency matrix and the amplitude and spectrum envelope of power quality signal， a method of optimizing generalized S-transform is proposed to select the parameters of Gaussian window function adaptively， which fully preserves the amplitude and frequency characteristics of power quality disturbance. Then， a hybrid input neural network framework is proposed to automatically extract the features of the original time series and the time-frequency matrix obtained from the optimized generalized S-transform. Finally， the features extracted from the two inputs are combined and the disturbance types are identified by the fully connected layer. Through the training and verification of the simulation data set containing 26 types of power quality disturbance， the results show that the disturbance recognition accuracy of the proposed method is 99.77%， and then the two kinds of actual grid disturbance signals are tested， and the disturbance recognition accuracy can still reach 92.5%， which is higher than the traditional single input neural network.
2025 Vol. 46 (1): 53-61 [Abstract] ( 28 ) HTML (1 KB)  PDF (2595 KB)  ( 2 )
62 Virtual Measurement Method For Grid-Connected Inverter Parameters Based on Frequency Response
ZHENG Di, HU Tianyu, WANG Ying, QIAN Lijuan, SHAO Haiming
DOI: 10.3969/j.issn.1000-1158.2025.01.10
Aiming at the problem that most of the existing methods need to obtain internal electrical quantities of grid-connected inverter （GCI） to realize the measurement of control parameters， which imposes high demands on the testing conditions， a virtual measurement method for GCI parameters based on frequency response is proposed， which just applies disturbance and measures output currents at the common coupling point of the grid-connected inverter. Firstly， the operational principles and mathematical models of GCIs are analyzed， establishing corresponding transfer functions and obtained their frequency response characteristics. On this basis， an optimization model for virtual measurement of GCIs is constructed， and the particle swarm optimization is utilized to calculate the parameters that approximate the actual frequency response characteristics of the GCI. Simulation results indicate that， this algorithm realizes the virtual measurement of the control parameters of the inner loop， outer loop and phase-locked loop only by using the measurement information of the terminal voltage and current of the GCI， and the maximum error does not exceed 2.6%.
2025 Vol. 46 (1): 62-68 [Abstract] ( 33 ) HTML (1 KB)  PDF (1607 KB)  ( 2 )
69 The Research on the Superconducting Films for X-ray Superconducting Transition Edge Sensors
JIA E, LI Wan, HU Jiahao, BAI Haijun, CHEN Jian, XU Xiaolong, GUO Siming, SUN Tianbao, ZHAO Xiaobo, LI Jinjin, WANG Xueshen1.College of Information Engineering， Shenyang University of Chemical Technol
DOI: 10.3969/j.issn.1000-1158.2025.01.11
Ultra-high vacuum DC magnetron sputtering technology was employed to fabricate both superconducting Mo films and Mo/Au bilayer films， The influence of varying sputtering powers and pressures on film stress， surface roughness， and superconducting transition temperature was investigated. The results for superconducting Mo films revealed a stress range from -421 MPa to 163 MPa， surface roughness below 1 nm， critical temperatures between 1.06 K and 1.10 K. For the Mo/Au films， the stress varied from -38 MPa to 26 MPa， with critical temperatures ranging from 80 mK to 350 mK. The developed Mo/Au bilayer film provides a technical reserve for the development of single-energy X-ray superconducting transition edge sensors（TES）.
2025 Vol. 46 (1): 69-74 [Abstract] ( 34 ) HTML (1 KB)  PDF (1944 KB)  ( 10 )
75 Time Constant Measurement of AC Shunt by Impedance Bridge
FENG Jian, SHI Leibing, ZHOU Bihong, HU Junjie, XU Feng
DOI: 10.3969/j.issn.1000-1158.2025.01.12
The equivalent model of four-terminal AC shunt is introduced. An AC impedance bridge using the zero flux current transformer（ZCT） as the current proportional standard is constructed to measure the main parameter of the AC shunt. A multi-decade two-stage inductive voltage divider is used to divide the voltage of the standard ac resistor. The differential measurement circuit measures the voltage difference between the shunt under test and the standard AC resisor. The bridge signals are sampled by the dual-channel synchronous sampling system and the voltage amplitude ratio and phase difference are calculated by the discrete Fourier transform algorithm. Then the resistance and time constant of the AC shunt can be computed. Verification experiments show that the measuring device can achieve precise measurement of AC shunts below 100 A in the frequency range of 20 Hz~3 kHz. The optimum expanded uncertainty of time constant is 8 ns.
2025 Vol. 46 (1): 75-79 [Abstract] ( 34 ) HTML (1 KB)  PDF (984 KB)  ( 8 )
80 Test and Calibration Method for High Accuracy Vector Atomic Magnetometer in Near Zero⁃field
WU Shuang, XUE Hongbo, FU Jiqing, SONG Wei, TAO Ran, MIN Zewen, ZHANG Wei, WANG Jindong, LI Hui, LI Lei
DOI: 10.3969/j.issn.1000-1158.2025.01.13
Vector atomic magnetometers for deep space magnetic field detection applications not only need to have high sensitivity in weak fields， but also need to have long-term accurate measurement capabilities. Therefore， it is necessary to test and calibrate the sensitivity and linearity of the vector atomic magnetometer in the near zero field， especially the performance of accuracy. At present， there is no device that can directly test and calibrate the magnetometer under weak magnetic field in the national standards and metrology institution. An indirect test and calibration device and method under near zero field is proposed. In the magnetic shielding cylinder， the magnetic field generating coil is calibrated by the calibrated CPT atomic magnetometer. The calibrated coil generates a weak artificial magnetic field. Combined with the zero-point rotation test calibration method， the accuracy of the magnetometer is calibrated. The test calibration and uncertainty analysis of the near zero-field high precision atomic magnetometer sensor are completed. The linearity within the ±5 nT range is 0.03%， the zero-point uncertainty is 12.90 pT， and the accuracy is 15.80 pT.
2025 Vol. 46 (1): 80-86 [Abstract] ( 37 ) HTML (1 KB)  PDF (1328 KB)  ( 15 )
87 Feasible Scheme of Bell⁃Bloom Cs⁃4He Optically Pump Magnetometer
CHEN Haoran, FU Jiqing, KONG Jia
DOI: 10.3969/j.issn.1000-1158.2025.01.14
With its high accuracy， the Cs-4He optically pump magnetometer has an important position in the field of magnetic field measurement. However， its sensitivity is still not ideal， which greatly limits its applications. Based on the magnetic response experimental data of the Cs-4He optically pumped magnetometer，the practical limitations of its sensitivity， primarily due to radiofrequency （RF） broadening is analyzed. To improve its sensitivity， a research approach that combines the Bell-Bloom principle with the Cs-4He optically pumped magnetometer is proposed. Here using optical field modulation instead of RF magnetic field modulation， which is expected to reduce the impact of RF broadening， thereby significantly enhancing the magnetometer’s magnetic field detection sensitivity. Theoretical calculations suggest that this approach could improve the sensitivity of the Cs-4He optically pumped magnetometer by one-third. In addition， the mentioned research also focuses on the analysis and discussion of the feasible working range of the scheme. By comparing the angular momentum exchange rate formed by spin-exchange collision， Penning ionization and the Ramel precession frequency caused by the magnetic field， the working magnetic field range of the Bell-Bloom Cs-4He optical pump magnetometer is given.
2025 Vol. 46 (1): 87-91 [Abstract] ( 39 ) HTML (1 KB)  PDF (852 KB)  ( 9 )
92 Measurement Method for Supercapacitor’s Serial Resistance Based on Goertzel Algorithm
WU Shuangshuang, BAI Wenqi, ZHANG Bin, HUANG Guoliang
DOI: 10.3969/j.issn.1000-1158.2025.01.15
A new method for measuring the equivalent serial resistance （ESR） of supercapacitor based on the Goertzel algorithm and the alternating current（AC） injection method was proposed. In this method， the complex impedance of supercapacitor was firstly obtained by using the AC injection method. Then， by using the Goertzel algorithm， the phase difference between the excitation signal and the output signal of the supercapacitor is calculated to obtain the ESR of the supercapacitor. This method only requires calculating the spectral information of specific frequency points of the excitation signal， which significantly reduces the computational complexity compared to traditional Fast Fourier Transform （FFT） methods. The experimental results show that the measurement error of the Goertzel algorithm is equivalent to that of the FFT algorithm， both of which can meet the requirement of an error less than 5%. However， the computational complexity of the Goertzel algorithm is much smaller than that of the FFT algorithm.
2025 Vol. 46 (1): 92-98 [Abstract] ( 29 ) HTML (1 KB)  PDF (1537 KB)  ( 10 )
99 Research on 10 V Programmable Josephson Array and Its Bias Current System
WANG Zengmin, LI Honghui, DUAN Meimei, WU Ran, WANG Siyun, LIAO Fujian, WANG Lei
DOI: 10.3969/j.issn.1000-1158.2025.01.16
The structure of a 10 V programmable Josephson junction array and its superconducting characteristics was researched in detail. The bias algorithm and the bias electronics of the 10 V programmable Josephson array were studied. A new I-V curve scanning method by using a digital voltmeter instead of the oscilloscope was proposed， which greatly improves the evaluation accuracy of the superconducting characteristics. The experimental results showed that the critical current of each subarray was greater than 4 mA， and the minimum quantum voltage step width of each subarray is 1.5 mA， which is important for the research of cryocooled 10 V quantum voltage system.
2025 Vol. 46 (1): 99-105 [Abstract] ( 34 ) HTML (1 KB)  PDF (1122 KB)  ( 5 )
106 Interlayer Dielectric Planarization in Quantum Voltage Chip Fabrication
CAO Yue, XU Sisi, ZHONG Yuan, LI Jinjin, ZHONG Qing, CAO Wenhui, CAI Jinhui
DOI: 10.3969/j.issn.1000-1158.2025.01.17
In the fabrication of quantum voltage chips， thin films of silicon dioxide are used as interlayer dielectric layers （IDL） to realize the electrical connections of Josephson junctions. However， typically silicon dioxide film is conformally deposited and subsequent niobium wire layers are prone to form grain boundary cracks near the rectangular steps. Planarization of the IDL is necessary for lithography and chip reliability considerations. Compared to other planarization schemes， the etch-back method has simple process steps and is suited for research work. A thick photoresist layer is spin-coated over the IDL to fill the trenches in the pattern and form a planar interface. Then， a reactive ion etching system is used to etch back the photoresist and SiO2 at the same speed. A planar dielectric layer surface can be obtained when the photoresist layer is etched up. The same etching rate of photoresist and SiO2 is realized by adjusting the oxygen flow and RF power. Additionally， in order to monitor the planarization status， an end-point detection system is applied in the etch-back process. Based on the light intensity reflected from the substrate surface， one can determine the etching depth and decide when to stop the process. The above method was successfully used to form a planarized dielectric layer above the junction area. By applying this etch-back method in the chip fabrication process， no crack is formed in the niobium wiring layer， and good I-V curves are obtained for the chip. The reliability of the chip is effectively improved.
2025 Vol. 46 (1): 106-111 [Abstract] ( 35 ) HTML (1 KB)  PDF (2339 KB)  ( 3 )
112 Research on High Accuracy Current Comparator and Self-calibration Methods
WANG Wei, LIU Xia, HUANG Lu, YANG Yan
DOI: 10.3969/j.issn.1000-1158.2025.01.18
The structure and working principle of a new type of high accuracy current comparator are introduced， and the circuit structure of "shielded directional drainage" is proposed. The structure can basically eliminate the secondary winding capacitive leakage error， and eliminate the additional error introduced in the combination of the secondary winding， and improve the accuracy of the current comparator. In the range of current ratio 5 A/5 A ~ 5 000 A/5 A， the technical index achieved is better than 1×10-6. According to the characteristics of the "shielded directional drainage" circuit structure， the self-calibration method of multi-ratio current comparator is further proposed， and its calibration uncertainty is better than 2×10-7. This method has the advantages of high accuracy， good stability， simple operation and short time operation， which can effectively solve the long distance transportation and inspection problems of transformers in the past.
2025 Vol. 46 (1): 112-118 [Abstract] ( 27 ) HTML (1 KB)  PDF (1885 KB)  ( 6 )
119 Research on Precision Angle Position Signal Digital Measurement System
YOU Li, WANG Shuqiang, JIN Haibin, LI Yalu, GUAN Zhenyu
DOI: 10.3969/j.issn.1000-1158.2025.01.19
Resolver and synchro are a type of angle position sensors based on electromagnetic induction， which widely used in automatic control or servomechanism. Their output signals are a series of AC voltage signals that change proportionally with the angle position. In order to measure or calibrate these signals， precision angle position indicators （API） are required， which are very expensive with single function. We developed a precision angle position signal digital measurement system based on universal digitizers， and realized resolver and synchro signal measurement with 0.000 1° resolution and 0.001°（k=2） uncertainty. The measurement system can be applied in metrology of Resolver/Synchro Simulator or sensors， and related technologies can also be applied in design of domestically precision angle position indicators， has good application prospect.
2025 Vol. 46 (1): 119-125 [Abstract] ( 36 ) HTML (1 KB)  PDF (1387 KB)  ( 7 )
126 Research on Error Estimation Method of Electric Vehicle Charging Meter Based on Spatio-temporal network
DAI Xuanding, HE Yuchen, QIAN Lijuan, ZHANG Huanghui, SHAO Haiming, LIN Guoqiang, LIN Qiang
DOI: 10.3969/j.issn.1000-1158.2025.01.20
The performance of smart meters usually declines with time， and on-site verification requires a lot of manpower and material resources. Therefore， an error estimation method based on the combination of high-speed convolutional neural network（CNN） and bidirectional long short-term memory（BiLSTM） network is proposed. Firstly， the data characteristics of charging facilities collected by smart meters are preprocessed. Secondly， the spatial features between variables are extracted based on the convolution module added to the high-speed network， and part of the original information is retained. Finally， the performance of the proposed method is verified in the data set of an energy vehicle charging station in a certain place. Experimental results show that the proposed method outperforms the other state-of-the-art methods in error analysis of electric meters. The experimental results show that the proposed method has significant advantages in error estimation accuracy of charging meters， and the three performance evaluation indicators have at least 13.68% improvement.
2025 Vol. 46 (1): 126-132 [Abstract] ( 25 ) HTML (1 KB)  PDF (2376 KB)  ( 5 )
133 Low Frequency Oscillatory Transients Detection Method Based on Optimization Window Function Modified S-Transform
JIANG Qingliu, LIANG Chengbin, CHEN Guanggui, WANG Rongyu, HE Qing
DOI: 10.3969/j.issn.1000-1158.2025.01.21
Low-frequency oscillation transient is a common type of power quality disturbance in power system， directly affecting the safe and stable operation of power system. A low-frequency oscillation transient detection method based on an improved S-transform using an optimized window function is proposed. Firstly， the changing characteristics of the window function with detection frequency in time-frequency analysis algorithms are analyzed， identifying an optimized window function suitable for detecting low-frequency oscillation transients. This optimized window function is then utilized to construct an improved S-transform algorithm. Secondly， through the application of the convolution theorem， Fourier transform， and its inverse transform， a computational expression for the fast implementation of the improved S-transform algorithm is derived， resulting in a two-dimensional time-frequency matrix containing signal amplitude and phase information. The implementation process of the improved algorithm is provided. Finally， the improved algorithm is tested using power grid signals containing low-frequency oscillation transients. The algorithm demonstrates relatively optimal time-frequency energy concentration performance for low-frequency oscillation transients. In practical experiment， the detected disturbance center frequency is 600 Hz， consistent with the generation frequency of the disturbance， verifying the feasibility and effectiveness of the improved algorithm.
2025 Vol. 46 (1): 133-140 [Abstract] ( 32 ) HTML (1 KB)  PDF (1381 KB)  ( 9 )
141 Progress of Fiber Optic Current Sensing Technology for New Power Systems
BAI Jingfen, ZENG Feitong, MENG Jing, LI Qilin, CEN Wei, CAI Junyi, DUAN Yongxian
DOI: 10.3969/j.issn.1000-1158.2025.01.22
Current sensing measurements play a crucial role in the fields of metering， protection， and control within power systems. With the introduction and increasing level of intelligence and digitization in China's new power system construction plan， there is a growing demand for current sensors with wide bandwidth， high dynamics， and miniaturization. Compared to traditional electromagnetic transformers， the advanced current measurement technologies based on the Faraday effect， magnetostriction， magnetofluids， and thermal effects offer unique advantages in terms of wide amplitude range， wide bandwidth， and electromagnetic immunity. On the other hand， the deployment， accuracy requirements， and reliable operation of sensors face significant challenges in meeting the future scenario demands of the new power systems. From the perspective of current measurement mechanisms， current sensing technologies is introduced based on the Faraday effect， Thermo-optical effect， magnetofluids， and magnetostriction，. Building upon this foundation， it highlights the challenges in sensing methods， frequency characteristics， environmental adaptability， and DC measurement， emphasizing the need for new sensing materials and topological structures to improve its measurement performance. Furthermore， the development trends suggestions for optical fiber current measurement standards is proposed， technical guidance for the wide application of fiber optic current sensor with high accuracy and good adaptability in the construction of new power system is provided.
2025 Vol. 46 (1): 141-150 [Abstract] ( 36 ) HTML (1 KB)  PDF (1446 KB)  ( 17 )
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