Table of Content

30 July 2024, Volume 0 Issue 7

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Overview

A Comprehensive Review of Electromagnetic Relay Remaining Useful Life Prediction Methods

MA Dongkun, WANG Zhaobin, HE Tianyang

2024, 0(7):  1-8.  doi:10.16628/j.cnki.2095-8188.2024.07.001

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This comprehensive review focuses on the technological advancements in predicting the remaining useful life (RUL) of electromagnetic relays,offering an insightful overview of the current research landscape.The existing methodologies for predicting the RUL of electromagnetic relays are systematically organized and contrasted.The application status and efficacy of various prediction techniques is delved into,including grey system models,statistical analysis,and neural networks.By examining recent scholarly articles,the review highlights the strengths and limitations of these diverse methods,emphasizing their role in enhancing the reliability of power systems.While each approach contributes to some extent in predicting the RUL of electromagnetic relays,significant variations persist in terms of accuracy,applicability,and user-friendliness.The future research direction is pointed that the hybrid models integrated multiple prediction technologies and the practical prediction systems incorporated real-time monitoring data are developed to augment the precision and applicability of RUL predictions.

Research & Analysis

Research on Analysis Method of Multi-Physical Fields Bidirectional Interaction Coupling in HSER

CUI Xiangqian, YOU Jiaxin, DING Ding, XUE Yutong, SHI Libing, TIAN Cong

2024, 0(7):  9-18.  doi:10.16628/j.cnki.2095-8188.2024.07.002

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When the hermetically sealed electromagnetic relay (HSER) operates,it involves multiple physical processes such as mechanical,electrical,and magnetic processes.The traditional analysis methods based on static data tables are difficult to meet the efficiency and accuracy requirements of reliability analysis.The meshless node flexible body model is introduced as the core of the multi-body dynamics model to build a real-time interaction channel between transient mechanical torque,electromagnetic force,and position parameters.The implicit integration algorithms for nonlinear contact and collision problems in the rigid flexible coupling model and electromagnetic finite element methods based on Maxwell’s equations are introduced.A multi-body dynamics electromagnetic finite element bidirectional interaction coupling calculation model is established to achieve real-time coupling calculation analysis of HSER mechanical electrical magnetic dynamic characteristics.An HSER electrical parameter,time parameter and force parameter testing system is built.The test data of the prototype is compared with the analysis and calculation results.The average error of the end attractive dynamic pressure of contact is 2.21%,which verifies the effectiveness of the method.

Wireless Energy Transmission System Based on Coupled Resonance and Novel Space Omnidirectional Coupling Mechanism

CHEN Wei, DONG Zhenyu, CHEN Chong, LI Zhi

2024, 0(7):  19-27.  doi:10.16628/j.cnki.2095-8188.2024.07.003

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Aiming at the problem that the transmission power and efficiency drop sharply when the relative positions of the transmitting and receiving bodies in the traditional wireless energy transmission system are offset, a wireless energy transmission system based on coupled resonance and a new type of spatial omnidirectional coupling mechanism is proposed. Firstly, the magnetic field distribution characteristics of the transmitting mechanism are analyzed by finite element simulation, and the receiving mechanism adapted to its magnetic field distribution is designed. The mathematical model of the system is established based on the series-series resonance compensation structure, and the transmission characteristics of the system are analyzed. The optimal output selection method and the transmission characteristics optimization method are put forward on the basis of the system. Finally, the feasibility and validity of the system for multi-degree-of-freedom transmission are verified by experiments. The experimental results show that the output power of the system is maintained at more than 35 W and the transmission efficiency is stable at 60%~75% in the case of multiple angles of the receiving mechanism.

Research on Evaluation Method of Low Voltage Multi-Area Flexible Interconnected Operation Based on Improved TOPSIS Algorithm

HUANG Shiting, MIAO Xiren

2024, 0(7):  28-35.  doi:10.16628/j.cnki.2095-8188.2024.07.004

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To address the issues of voltage over-limit and three-phase imbalance in low-voltage distribution areas with high photovoltaic penetration,an energy storage-inclusive Fault Indication Device (FID) is introduced to facilitate power mutual aid and optimize the operation of the distribution areas.In response to the operational assessment challenges of flexible interconnection in multiple low-voltage distribution areas,an improved TOPSIS evaluation model based on AHP-CRITIC combination weighting is proposed.Firstly,an evaluation system is established from three aspects:improvement in operating voltage,operating power,and operating economy,with the introduction of energy storage-inclusive FID.Secondly,the main and objective weights are determined using the AHP and CRITIC methods,and Nash equilibrium theory is employed for AHP-CRITIC combination weighting.Subsequently,the TOPSIS method is enhanced based on weighted grey relational degree to further reflect the internal changes of indicators.Finally,the effectiveness of the proposed method is analyzed using an actual distribution area as a case study.

Electrical Design & Discussion

Research on Portable Transponder Based on Partial Discharge TDR Method of High Voltage Cable

WANG Jianwei, ZHENG Xiang

2024, 0(7):  36-41.  doi:10.16628/j.cnki.2095-8188.2024.07.005

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Aiming at the attenuation problem of partial discharge signal in the transmission of high voltage cable,a portable GSM short message communication repeater based on FPGA time domain reflectometry (TDR) method is designed.It is mainly used for data acquisition,filtering out narrow band interference,white noise and other interference in partial discharge,detecting accurate partial discharge signal and transmitting its amplitude.The characteristic information such as the average discharge time is fed back to the local detection device in the form of short messages,and a larger pulse is generated to replace the partial discharge signal reflected by the far end.Then the computer simulates the local signal noise environment for the denoising experiment.Finally,the experiment shows that this device not only enhances the strength of local signal,but also improves the positioning accuracy. The test results meet the requirements.

Design on Semi-Bridgeless Boost PFC Converter in Discontinuous Conduction Mode

HUANG Kang, MAO Xingkui

2024, 0(7):  42-49.  doi:10.16628/j.cnki.2095-8188.2024.07.006

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The semi-bridgeless Boost power factor correction (PFC) converter is favored for its low risk of direct conduction in the bridge arm,making it ideal for high-reliability applications like military and medical fields.Operating in discontinuous conduction mode (DCM),this converter offers advantages such as zero-current turn-off and diode reverse recovery elimination.Addressing the issue of current distortion and reduced power factor caused by excessive input voltage under traditional control methods, a variable duty cycle control strategy based on constant duty cycle control is elaborated,enhancing the power factor across the entire input range.Additionally,to solve the challenges associated with traditional semi-bridgeless Boost PFC converters,such as large system volume and board footprint due to dual power inductors,an integrated magnetic coupling approach is adopted to enhance power density.Finally,a 150 W semi-bridgeless Boost PFC converter based on fully integrated magnetic coupling is constructed and experimentally validated for its efficacy.

Design and Analysis on Operating Mechanism of Smart Miniature Circuit Breakers

SHENG Yongbing, TANG Fulong, ZHANG Jin, RU Dezhi, LI Junting, YUE Kang

2024, 0(7):  50-53.  doi:10.16628/j.cnki.2095-8188.2024.07.007

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For smart miniature circuit breakers,a schematic diagram of the mechanism motion is drawed,the size of the four connecting rods of the operating mechanism is adjusted, and the motion trajectory of the operating mechanism is analyzed.Combined with the static analysis to analyze the force situation of the operating mechanism at certain steady-state positions,the contact parameters of the smart miniature circuit breaker (opening distance,overtravel,final pressure,driving unit force) are calculated,which provides a new design direction for the design and analysis of the operating mechanism of smart miniature circuit breakers.

Design on Electronic Release of Molded Case Circuit Breaker

ZHANG Zhenyang

2024, 0(7):  54-59.  doi:10.16628/j.cnki.2095-8188.2024.07.008

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With the construction of smart grid in China,the application of electronic circuit breaker is widely used.A dual core current transformer is used to sample the main circuit current,and an electronic release equipped with a LCD screen and buttons that can continuously adjust protection parameters is designed.Practice has shown that the designed release has high accuracy,a wide variety of protection types,and functions such as status display,self diagnosis,auxiliary input and output,historical logs,and communication,which meet the intelligent requirements of the smart grid for circuit breakers.

Study on Properties of Pure Iron and Soft Magnetic Material of Relay and Selection of Heat Treatment Process

SHI Lei, WU Duanjian, LIAO Yushen, WU Yuanjin

2024, 0(7):  60-64.  doi:10.16628/j.cnki.2095-8188.2024.07.009

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The magnetic properties of the pure iron affect the core function of relays.The differences in magnetic properties of several pure iron materials are investigated primarily under various heat treatment processes and the impact on relay related performane is simulated.Finally, based on the actual usage scenarios of relays,the recommendations on the selection of pure iron materials and heat treatment processes of relay are put forward.

Simulation Technology Application

Simulation Design of Contact Wear Sensor for ACB

ZHOU Yingzi, CHEN Zhengxin, WANG Bingqing

2024, 0(7):  65-68.  doi:10.16628/j.cnki.2095-8188.2024.07.010

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The contact system is a key component of the air circuit breaker (ACB),and the degree of contact wear is a key parameter reflecting the lifespan of ACB,but it is difficult to measure directly online.A method is proposed to indirectly measure the degree of contact wear by directly measuring the spindle rotation speed.Firstly,using the principle of electromagnetic induction the sensors is designed to measure the rotational speed of the spindle.Then,the finite element electromagnetic simulation is used to optimize the specific parameters of the sensor.Finally,a model prototype is processed and the experimental comparisons are conducted on the different levels of contact wear.The experimental results verified the effectiveness of the designed sensor.

Research on Accuracy of Secondary Signal of Electronic Voltage Transformer

ZHI Jiaojiao, SHI Jinqiang

2024, 0(7):  69-73.  doi:10.16628/j.cnki.2095-8188.2024.07.011

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Electronic voltage transformer plays an important role in intelligent distribution equipment,and the accuracy of the secondary signal of the electronic voltage transformer is the key to intelligent distribution equipment.The 10 kV resistance type electronic voltage transformer as the example,the simulation model is built.The simulation analysis on the influence of cable length on secondary signal accuracy of electronic voltage transformer is carried out.Then the electronic voltage transformer accuracy test environment is set up and the accuracy test under different lengths cable is completed.Through the simulation and test data analysis,the influence of cable length on the accuracy of secondary signal is obtained.The research results have practical significance for the reasonable selection of cable length and the improvement of accuracy.

Simulation of Tripping Process of Miniature Circuit Breaker Based on Maxwell 3D/ADAMS

WANG Bingqing, ZHANG Senlin

2024, 0(7):  74-78.  doi:10.16628/j.cnki.2095-8188.2024.05.012

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To improve the accuracy of traditional dynamic simulation,the virtual prototyping technology is used to simulate the instantaneous trip process of circuit breaker based on Maxwell 3D and ADAMS.Firstly,the electromagnetic transient dynamic simulation finite element model of the tripper is established by using Maxwell 3D,and the simulation results of the transient electromagnet motion characteristics are obtained by calculation.Then the calculation results are imported into ADAMS to simulate the instantaneous tripping process of circuit breaker.Finally,the instantaneous release test of the actual prototype is taken by high-speed photography.The correctness of the simulation is verified.The co-simulation can improve the accuracy of dynamic simulation.

Simulation Study on High Temperature Vibration Failure of Electrical Connector

ZHU Ning, ZHAI Guofu

2024, 0(7):  79-86.  doi:10.16628/j.cnki.2095-8188.2024.07.013

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The dynamic response of electrical connector in high temperature vibration environment is analyzed with Ansys software.The influence of the quality of the cable at the tail of the contact piece,temperature,separation force,stress relaxation,etc.on the micro motion amplitude is deeply analyzed.Based on the simulation,it is concluded that the original design will fail in high temperature vibration.The design of the contact positive pressure and the quality of the tail cable are optimized.Combined with the simulation analysis results and the relevant calculation,the design index range for the electrical connector to not fail under the specified high temperature vibration conditions is obtained,which means that the separation force should be as close as possible to the upper limit of 2.5 N,and the quality of the cable at the tail of each contact should be controlled within 1.2 g.The correctness of the simulation and optimization is verified by the test,which provides the design and optimization ideas for the high temperature vibration resistance of the electrical connector.