Table of Content

30 April 2020, Volume 0 Issue 4

Previous Issue    Next Issue

Research & Analysis

Degradation Model and Reliability Evaluation of Key Parameters for Electromagnetic Relays’ Contact Spring System

ZHU Xuqing, LIANG Huimin, ZHANG Jiahe, CHEN Hao, TANG Wei

2020, 0(4):  1-6.  doi:10.16628/j.cnki.2095-8188.2020.04.001

Asbtract ( 333 )   HTML ( 4)   PDF (1710KB) ( 442 )  

References | Related Articles | Metrics

To evaluate the reliability of electromagnetic relays,the degradation and failure of a contact spring system for electromagnetic relay under cyclic loading was analyzed.The performance degradation of the contact spring system was then modelled and analysed using stochastic uncertainty theory.Finally,based on the contact gap degradation model,a reliable life evaluation of the electromagnetic relay by considering the degradation of the key assembly parameters of the contact spring system was conducted.The research results lay a foundation for the design of reliable electromagnetic relays.

Research on Railway Relay Contact Performance Based on Correlation Analysis of Macro-Parameters and Micro-Parameters

LÜ Shuyuan

2020, 0(4):  7-10.  doi:10.16628/j.cnki.2095-8188.2020.04.002

Asbtract ( 247 )   HTML ( 3)   PDF (1429KB) ( 361 )  

References | Related Articles | Metrics

The electrical life test of a railway electromagnetic relay was carried out,and the macro-parameter and micro-parameters closely related to contact performance were extracted.The Pearson correlation analysis method was used to analyze the correlation between macro-parameters and micro-parameters.It is concluded that the three-dimensional shape parameters such as surface arithmetic mean deviation have obvious linear relationship with contact resistance.

Research on Control Method of Synthetic Test Based on Recursive Least Square Algorithm

YIN Lijun, CAI Zhiyuan

2020, 0(4):  11-17.  doi:10.16628/j.cnki.2095-8188.2020.04.003

Asbtract ( 224 )   HTML ( 2)   PDF (1779KB) ( 327 )  

References | Related Articles | Metrics

To meet the control requirements of high precision and fast real-time response in large-capacity synthetic test,this paper used recursive least square(RLS) algorithm to predict the zero of short-circuit current,and analyzed the influence of sampling accuracy,sampling frequency,noise,frequency offset and other factors on the calculation accuracy of the prediction algorithm.The method of restraint and improvement was also given.In order to verify the accuracy of the algorithm,a synthetic circuit control system based on DSP was built.The experimental results show that the errors between the actual input time and the setting time of the voltage loop and the arc extension loop are less than 50 ms,which meets the accuracy requirements of the synthesis experiment and ensures the equivalence of the synthesis experiment.

Preliminary Study on Closed Loop Current and Closed Loop Selection in ATSE Parallel Conversion

REN Shanbo, ZHONG Yunpan

2020, 0(4):  18-22.  doi:10.16628/j.cnki.2095-8188.2020.04.004

Asbtract ( 413 )   HTML ( 2)   PDF (1067KB) ( 315 )  

References | Related Articles | Metrics

The calculation method of closed loop surge current in the parallel conversion of automatic transfer switch equipment(ATSE) was introduced.Two kinds of closed loop selection combination with the latest research results both in China and abroad were compared and analyzed.By the practical caladation,the references for the conditional parameter setting of parallel conversion were provided.It can be used for reference significance in the development of parallel conversion products.

Application Research of Intrusion Detection Technology in Intelligent Distribution System

HUANG Shali, GUO Qiyi, LIU Yue, HUANG Shize, TU Xuwei

2020, 0(4):  23-29.  doi:10.16628/j.cnki.2095-8188.2020.05.005

Asbtract ( 257 )   HTML ( 4)   PDF (1251KB) ( 337 )  

References | Related Articles | Metrics

In recent years,the intelligent power distribution systems have developed rapidly in the direction of data,networking and intelligence.With the increasing complexity of the cyberspace security situation,the network security of intelligent power distribution systems is facing enormous challenges.How to detect intrusion behavior against intelligent power distribution systems is a key technical issue that needs to be solved urgently.The intelligent power distribution system with control and protection switch as the terminal equipment was taken as the research object.The key algorithm of system intrusion detection was proposed.Three feature selection algorithms of Relief,MCFS and mRMR,were used to reduce the data respectively.The K nearest neighbor(KNN) algorithm was used as classifiers of the intrusion detection system,and the detection results were compared.The experiment results show that the intrusion detection algorithm proposed can effectively detect illegal attacks on intelligent power distribution systems.

Electrical Design & Discussion

Development of Innovation Operation Mechanism for Automatic Transfer Switch Equipment

LIN Zeming

2020, 0(4):  30-37.  doi:10.16628/j.cnki.2095-8188.2020.04.006

Asbtract ( 340 )   HTML ( 15)   PDF (5009KB) ( 424 )  

References | Related Articles | Metrics

As automatic transfer switch equipment(ATSE) needs a quick action,two-way points close,safety and reliability,a kind of new operation mechanism compatible with both two work and three bits of position was put forwdrd.The operating mechanism was driven by a magnet coil.An innovative changement mechanism to implement two-way transformation was adopted.By spring energy storage and release the independent manual break-brake closing and opening operation was implemented.The mechanism is simple and reliable,of fast conversion.It not only can realize two work positian operation,but also can be extended to three work position.The experimental results verify the feasibility and effectiveness of the mechanism.

Discussion on Short Conductor Series Connection Structure of DC Moulded Case Circuit Breaker

ZHANG Yan, WANG Yang

2020, 0(4):  38-41.  doi:10.16628/j.cnki.2095-8188.2020.04.007

Asbtract ( 536 )   HTML ( 10)   PDF (2982KB) ( 626 )  

References | Related Articles | Metrics

The commonly used series connection forms of the DC moulded case circuit breaker(MCCB) short conductor were enumerated.The advantages and disadvantages of these series connection forms were analyed.Combined with the actual improvement demand of the product,a new series structure of DC MCCB short conductor was proposed,which has the advantages of increasing the current limiting capacity,reducing the temperature rise,reducing the volume and enhancing the insulation.

Design and Experimental Research of Electromagnetic Jettison System Without an Armature

SHEN Lu, XIA Yuming, WANG Xiaochuang, CHEN Jianmei, DONG Yongjun, GUO Jingfu

2020, 0(4):  42-46.  doi:10.16628/j.cnki.2095-8188.2020.04.008

Asbtract ( 240 )   HTML ( 1)   PDF (1924KB) ( 403 )  

References | Related Articles | Metrics

A novel electromagnetic jettison system without an armature was developed to resolve and complete the self-compensating buoyancy regulation of the towed marine profile buoy.In this paper,the design parameters of DC plunger electromagnet were determined through the theoretical analysis and calculation of the electromagnet structure,and the simple and reliable power trigger circuit was designed according to the analysis of the power supply characteristics of the electromagnet.Then,multiple experiments of the prototype were done to test its performance.The results show that this design meets the requirements,which verifies the feasibility of this proposal.In conclusion,comparing with the electromagnet with an armature,the proposed device has many advantages,such as simple structure,low power consumption,easily sealing,and so on.Therefore,it can be applied for the buoyancy regulation of small-scale towed buoy and also can provide references for the jettison system of other underwater equipments.

Study on Operation Mechanism and Stress Analysis of MCCB

TANG Ting, WANG Taiyu, XU Pengsheng, XIE Lingfeng

2020, 0(4):  47-53.  doi:10.16628/j.cnki.2095-8188.2020.04.009

Asbtract ( 503 )   HTML ( 13)   PDF (1657KB) ( 576 )  

References | Related Articles | Metrics

According to the connecting rod transformation characteristics and static characteristics of the moulded case circuit breaker(MCCB) operation mechanism,the mechanism sketches of each key state were drawn,and the movement principle of the operation mechanism was elaborated in detail.On the other hand,the force analysis of the links of the operation mechanism in some stable and specific transient positions was carried out by graphic method,and the key mechanical parameters of MCCB were calculated by using the principle of mechanical balance and the theorem of positive rotation.These five mechanical parameters are the re-buckling force of the handle,the closing force of the handle,the main spring force,the final contact pressure and the release force.It provides a theoretical reference was provided for the force optimization of the existing MCCB operating mechanism and the design of a new operating mechanism.

Simulating Calculation of Short-Circuit Dynamic Stability for Air Circuit Breaker

ZHANG Guangzhi, YIN Jiacan, ZHAO Peng, WANG Wanlu

2020, 0(4):  54-61.  doi:10.16628/j.cnki.2095-8188.2020.04.010

Asbtract ( 273 )   HTML ( 4)   PDF (4399KB) ( 409 )  

References | Related Articles | Metrics

The calculation principle and verification method of the short-circuit dynamic stability of the air circuit breaker contact system were expounded.The establishment of the contact bridge mathematical model was introduced.The finite element electromagnetic simulation analysis based on Ansys was carried out by using the contact bridge model.The simulation results were compared with the experimental results to verify the feasibility of the simulation method.The method of analyzing the short-circuit dynamic stability of the contact system can provide a reference for engineers to design the contact system.

Wireless power transfer technology

Nonlinear Parity-Time-Symmetric Wireless Power Transfer Based on Switching Devices

ZHENG Yitian, ZHENG Zonghua, CHEN Qingbin

2020, 0(4):  62-66.  doi:10.16628/j.cnki.2095-8188.2020.04.011

Asbtract ( 232 )   HTML ( 2)   PDF (1307KB) ( 304 )  

References | Related Articles | Metrics

Wireless power transfer system based on nonlinear parity-time-symmetry is a robust system which can maintain high efficiency at a certain distance.Current systems use operational amplifiers to balance gain and loss,resulting in low transmission power.To solve this problem,a method of using switching devices as nonlinear saturation gain components was proposed.Full bridge,half bridge and class E power amplifier circuits were used to construct parity-time-symmetric wireless power transfer system.The circuit model was established and analyzed by coupling mode theory.Finally,the effectiveness and feasibility of the proposed method were proved by simulation.

Analysis of Multi-Coil Wireless Power Transfer Characteristics

PAN Leilei, ZHU Xiangou

2020, 0(4):  67-70.  doi:10.16628/j.cnki.2095-8188.2020.04.012

Asbtract ( 232 )   HTML ( 1)   PDF (1212KB) ( 330 )  

References | Related Articles | Metrics

The power characteristics and transfer efficiency characteristics of multi-coil wireless power transfer were analyzed,and the relationship between maximum output power and working frequency and the relationship between transfer efficiency and working frequency and load were obtained.Through the multi-coil wireless power transfer equivalent circuit model,the composite insulator of the embedded resonant coil was modeled and analyzed by Maxwell software to analyze the multi-coil wireless power transfer characteristics.This transfer characteristic provides the basis for the power management module design of the receiving coil,and can also be applied to multi-coil wireless power transfer of 35 kV,66 kV,220 kV.

Research on Topology and Control of ICPT Based on Bilateral Dynamic Capacitance Compensation

WANG Qiting

2020, 0(4):  71-76.  doi:10.16628/j.cnki.2095-8188.2020.04.013

Asbtract ( 228 )   HTML ( 2)   PDF (1640KB) ( 359 )  

References | Related Articles | Metrics

In the traditional inductive coupled power transfer(ICPT) system which is compensated with fixed compensation capacity,its output voltage fluctuates with the change of load.Aiming at this shortcoming,a new ICPT topology based on bilateral dynamic capacitance compensation with magnetic energy recovery switch(MERS) was proposed,which makes the compensation link of the ICPT system controllable.The topological analysis and modeling were conducted by mutual inductance theory and loosely coupled transformer leakage inductance model,and the mathematical relationship between MERS,output voltage and power factor of inverter was established.By using the dynamic compensation of transmitter,the reactance component of the system input impedance can be offset,and the power factor was increased.Through the dynamic compensation of receiving terminal,the influence of load variation on output voltage can be weakened,so that the output voltage remained stable.At last,an experimental device for 5 V voltage output was set up,the power factor of the inverter was stable around 0.9 in the range of load change,which proves the voltage regulation and power factor adjustment function of this topology when the load was changeable.

Non-Ideal Model and Efficiency Optimization of Buck Converter in Electric Vehicle Wireles Power Transfer System

XIAO Jing, WU Ning, FENG Yubin, YAO Zhiyang, GUO Xiaoxuan

2020, 0(4):  77-82.  doi:10.16628/j.cnki.2095-8188.2020.04.014

Asbtract ( 239 )   HTML ( 5)   PDF (1222KB) ( 293 )  

References | Related Articles | Metrics

In order to improve the efficiency of Buck converter in electric vehicle wireles power transfer(EV-WPT) system and further the overall efficiency of the whole system,a piecewise linear state space model with parasitic parameters and switching process were established based on the original two simplified models,which was closer to the actual non-ideal Buck converter.Based on the stroboscopic mapping and phase trajectory theory,the steady-state working points of the three models were analyzed and compared by simulation.Finally,based on the non-ideal model,the efficiency optimization of the Buck converter was realized.

Power Quality

Research on Parallel Method of Active Power Filter

JIANG Rui, ZHAO Cheng, YANG Wei, HUANG Haihong

2020, 0(4):  83-88.  doi:10.16628/j.cnki.2095-8188.2050.04.015

Asbtract ( 255 )   HTML ( 3)   PDF (5802KB) ( 337 )  

References | Related Articles | Metrics

The active power filter (APF) has been widely used in power grid harmonic control due to its high control accuracy and good dynamic compensation.In order to apply APF to high-power applications,this paper describes several APF parallel technologies,and selects the capacity ratio scheme and carrier phase shift multiplexing scheme to build a system simulation model under MATLAB/Simulink platform,and the experimental prototype was produced.The simulation and experiment of the compensation of the two APF parallel systems were carried out.The results reach the network requirements,which verifies the feasibility of the proposed method.

Research on Drop Detection Method Adapted to Dynamic Voltage Recovery Control of Distribution Network

JIANG Hua, BAI Jinhua, SHEN Xinglai, TENG Song, HU Sheng

2020, 0(4):  89-92.  doi:10.16628/j.cnki.2095-8188.2020.04.016

Asbtract ( 202 )   HTML ( 2)   PDF (1259KB) ( 309 )  

References | Related Articles | Metrics

The problems of voltage sag detection of the industrial park distribution network after a large number of DGs were analyzed.The detailed design research based on the positive-negative sequence separation method of multi-dq coordinate rotation transformation and the S-transform method was carried out.Finally,in order to verify the correctness of the method,a simulation model was built in MATLAB/Simulink.The results show that the positive and negative sequence separation detection method based on multi-dq coordinate rotation transformation meets the real-time requirements of voltage recovery control,which lays a theoretical foundation for engineering design.

Transient Analysis of Switching Low Voltage Power Capacitors

XIA Wu, XIA Wen

2020, 0(4):  93-98.  doi:10.16628/j.cnki.2095-8188.2020.04.017

Asbtract ( 193 )   HTML ( 1)   PDF (1250KB) ( 382 )  

References | Related Articles | Metrics

The low voltage common type and the harmonic suppression type split-phase compensation power capacitors were taken as research target.Considering the factors of system impedance and load impedance,the equivalent single-phase mathematical model of the low voltage split-phase power capacitors was established,and then the transient process of switching the capacitors was analyzed.The optimum ideal condition for switching the capacitors was obtained,which provided the theoretical support for the intelligent control of the power capacitors.Finally,the correctness of the above analysis was verified by the calculation examples and simulation.

Energy Management

General Representation of the Energy Relationship of Energy Systems and Its Influence Factors

ZHU Yongqiang, GAO Chenge

2020, 0(4):  99-105.  doi:10.16628/j.cnki.2095-8188.2020.04.018

Asbtract ( 306 )   HTML ( 1)   PDF (1236KB) ( 341 )  

References | Related Articles | Metrics

The variety of energy-using appliances leads to different energy relationships.In this paper,a general representation of the energy relationship of an energy system was illustrated,then general expressions of efficient energy output and energy loss were deduced.Moreover,the influences of proportional links,energy-storage links,feedback links,etc.on efficient energy output of energy-using sysfem were analyzed.This paper provides a theoretical basis for the future analysis of specific energy-using system,and is on benefit to make the targeted energy-saving strategy.

Low Carbon Economic Dispatching of Electric-Gas Interconnection Integrated Energy Source System Considering Carbon Capture Equipment

ZHOU Yang, WANG Jin, REN Shengnan, GONG Luowen, LIU Ting

2020, 0(4):  106-112.  doi:10.16628/j.cnki.2095-8188.2020.04.019

Asbtract ( 328 )   HTML ( 6)   PDF (1148KB) ( 440 )  

References | Related Articles | Metrics

The combination of carbon capture equipment and comprehensive energy system can effectively improve the wind power consumption capacity of the system.A low-carbon economic dispatch model including electricity to gas,gas turbine,carbon capture power plant and wind farm combined operation was proposed,and the carbon trading mechanism was introduced.The objective function was the lowest comprehensive economic cost of the system.The decision variables are electricity to gas power,active power of gas turbine,active power of unit and carbon capture rate.The correlation constraint between power network and natural gas network is considered,including electric-gas balance and unit climbing constraints,etc.Through the example simulation,the carbon dioxide emission,comprehensive economic cost and abandoned air volume of the system were analyzed and compared to verify that the proposed model can effectively improve the capacity of wind power consumption and reduce the carbon dioxide emission and comprehensive economic cost.Finally,the impact of carbon trading price on carbon dioxide emission and operation of the system was analyzed.