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Diagnosis method for rub-impact fault of rotating machinery based on EMD and Hilbert envelop spectrum

Diagnosis method for rub-impact fault of rotating machinery ...

Joint Conference on Machinery Failure Prevention Technology Conference, MFPT 2016 and ISA's 62nd International Instrumentation Symposium, IIS 2016

作者： Wang, Nan-Fei Jiang, Dong-Xiang Han, Te State Key Laboratory of Control and Simulation of Power System and Generation Equipments Departments of Thermal Engineering Tsinghua University Beijing100084 China

Aiming at the characteristics of the casing vibration acceleration signal of rotating machinery with rubbing fault, a diagnosis method based on EMD (empirical mode decomposition) and Hilbert envelop spectrum is put forward. When the rubbing fault occurs between the rotor and the stator, the vibration acceleration signals from the casing of the rooting machinery will present amplitude-modulated feature due to the periodical rub-impact between the rotor and the stator. However, it is relatively difficult to extract the rub-impact feature since the rub-impact signal in the process of transferring to the casing is always buried in the noise and background signals. In this paper, by means of the powerful capability of EMD and Hilbert envelop spectrum in processing nonlinear signal can accurately describe nonlinear behaviours, the fault signal is adaptively decomposed by EMD to acquire intrinsic mode functions (IMF) containing obvious feature of amplitude modulation. Then some of the sensitive IMF components are transformed by FFT and their Hilbert spectrum are analysed. The analysis results from the experimental signal show that the EMD provides an effective and adaptive method to obtain 'purified' casing vibration acceleration signal, which demonstrates the transient casing vibration more precisely and vividly, decreasing misinterpretation of the machine running condition. Therefore, the EMD approach can be applied to the single-point rubbing fault diagnosis of the rotor systems efficiently. © 2016, Society for Machinery Failure Prevention Technology. All rights reserved.

关键词： Empirical mode decomposition

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Series-connected HV-IGBTs using active voltage control with status feedback circuit

Series-connected HV-IGBTs using active voltage control with ...

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作者： Ji, Shiqi Lu, Ting Zhao, Zhengming Yu, Hualong Yuan, Liqiang State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing100084 China

ISBN: (纸本)9781479956982

The transient voltage unbalance is the major problem that limits the application of series-connected IGBTs in high voltage and high power converters. The asynchronous gate delay which causes that series-connected IGBTs do not turn-on and turn-off at the same time results in the most serious unbalanced voltage sharing. The active voltage control technique is proposed in this paper to solve the asynchronous gate delay problem. By sampling the feedback signal caused by unbalanced voltage, the microcontroller generates a time delay for gate driver to compensate the asynchronous gate delay. The most vital part of active voltage control is the status feedback circuit which is also given in detail in this paper. The function of the status feedback circuit and the effect of active voltage control are verified in a two series-connected HV-IGBTs platform in rated operation (5kV bus voltage and 600A load current). © 2014 IEEE.

关键词： Insulated gate bipolar transistors (IGBT)

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Nonlinear E-field simulation of HVDC Converter Transformer Busing and Its Structure Optimization With RBF Neural Network and NSGA-II Algorithm 13

Nonlinear E-field Simulation of HVDC Converter Transformer B...

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13th International Conference on power and Energy systems, ICPES 2023

作者： He, Yongsheng Zhang, Shiling Lu, Zongxiang Wang, Pengbo State Grid Chongqing Electric Power Company Chongqing Electric Power Research Institute Chongqing China State Key Lab of Control and Simulation of Power Systems and Generation Equipment Haidian China Transmission Equipment and System Security and New Technology Dept Name of State Key Laboratory of Power Chongqing China

ISBN: (纸本)9798350345063

Static DC and PR are typical operation conditions of HVDC converter transformer bushing outlet device, moreover, the electrical parameters of RIP, transformer oil and OIP have the nonlinear relationship with E-field stress and temperature. Under the temperature gradient, the electrical parameters will modify the static DC and PR E-field distribution of the composite insulation. In order to simulate static DC and PR electric field of the composite insulation structure, this paper established the full model of the converter transformer outlet. Then, the structure parameters of converter transformer outlet have been optimized using combined RBF neural network and NSGA-II algorithm. Moreover, electric field verification calculation has been carried out under AC and PR conditions. The results show that under uniform temperature condition, E-field strength is larger than that under iso-thermal condition. The overshoot coefficient of the bushing end and barrier reach 65% and 45%, respectively. The study can provide reference for the design of outlet structure of the converter transformer. © 2023 IEEE.

关键词： DC transformers

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Modeling and simulation analysis of dual-rotor vibration system with multiple faults

Modeling and simulation analysis of dual-rotor vibration sys...

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Society for Machinery Failure Prevention Technology Conference 2018: Intelligent Technologies for Equipment and Human Performance Monitoring, MFPT 2018

作者： Yang, Yizhou Liu, Chao Jiang, Dongxiang Yang, Wenguang State Key Lab. of Control and Simulation of Power Systems and Generation Equipment Department of Thermal Engineering Tsinghua University Beijing100084 China

Dual-rotor system is an important rotor form in rotating machinery like gas turbine engine. Its complex structure results in rich dynamical behaviors and more probability to failure. The modeling and simulation of the dual-rotor system can help to understand its dynamic characteristics and provide theoretical support for the design, operation and maintenance. In this paper, a dynamic model of a dual-rotor system with multiple rotor faults is established. The dual-rotor vibration model without any fault is built by finite element method, where the two shafts are connected by an inter-shaft bearing and nonlinear models of rolling element bearing and squeeze film damper are considered. The numerical integration method of Newmark-β is used to obtain the steady-state vibration response of the system. Then rotor faults are introduced to the system model, including unbalance, misalignment, looseness and rub-impact. The steady-state responses of single faults in the dual-rotor system are analyzed and typical fault features are obtained. Then coupling characteristics between different rotor faults, and the influences of the squeeze film dampers on the dynamic characteristics and fault features of the system are studied. © 2018 Proceedings of the 9th International Symposium on Imprecise Probability.

关键词： Rotating machinery

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Finite element analysis on damping characteristics for vibro-impact of integral shroud blade

Finite element analysis on damping characteristics for vibro...

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Joint Conference on Society for Machinery Failure Prevention Technology Conference, MFPT 2015 and ISA's 61st International Instrumentation Symposium, IIS 2015 - Technology Evolution: Sensors to systems for Failure Prevention

作者： Wang, Nan-Fei Jiang, Dong-Xiang Chen, Jing-Ming State Key Laboratory of Control and Simulation of Power System and Generation Equipments Department of Thermal Engineering Tsinghua University Beijing100084 China

By using theoretical and experimental methods, dynamic characteristics of turbine blades with integral shrouds are studied, and the mechanism of vibro-impact and the effective factors of integrally shrouded blades are mainly presented. By means of finite element calculation, the dynamic frequencies and vibration mode shapes of single shrouded blade are explored under different rotating speeds. The three-dimensional entity unit integral dynamics equation of blades with vibro-impact are established by using nonlinear damping model in this paper. With the help of 3D software Solidworks, the solid model of blade is built. With the aid of FEA software ANSYS, the dynamics and static characteristics of single blade are obtained. Meanwhile, by building the model to set different shroud clearance and exciting force amplitude, the relationships between displacement of blade tip and influence of such as blade shroud clearance and exciting force amplitude are demonstrated. The results of the analysis indicate that the collision structural is an ideal damping structure. As the clearance between blade shrouds is smaller, the damping effect is better. Moreover, results show that blades adopting collision damping mechanism can achieve good damping effect when the blades are subjected to greater exciting force.

关键词： Finite element method

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Short-Term Prediction of Wind power Based on NWP Error Correction with TimeGAN and LSTM-TCN 4th

Short-Term Prediction of Wind Power Based on NWP Error Corre...

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4th International Conference on Energy power and Automation Engineering, ICEPAE 2023

作者： Li, Shuona Ma, Wei Liu, Zhao Duan, Yuge Tian, Chengwei School of Electrical Engineering Beijing Jiaotong University Beijing China State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments of Electrical Engineering Tsinghua University Beijing China

ISBN: (纸本)9789819988778

The data quality of numerical weather prediction has a great influence on the accuracy of wind power prediction technology. In order to improve the short-term forecasting effect of wind power, we proposed a combined LSTM-TCN forecasting model based on NWP error correction model with TimeGAN. First, minimal redundancy maximal relevance (mRMR) algorithm is used to extract original NWP features and measured meteorological features, respectively. Then, TimeGAN is used to correct initial NWP data according to the internal hidden associations with the measured weather features. After that, the corrected NWP features combined with historical wind power are applied to establish a wind power short-term prediction hybrid model based on LSTM and TCN network. Finally, the performance of the hybrid model is tested by a wind farm dataset in China, which verified effectiveness of this method. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.

关键词： Wind power

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Concept and analysis of discrete energy internet

Concept and analysis of discrete energy internet

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2017 IEEE Conference on Energy Internet and Energy System Integration, EI2 2017

作者： Zhang, Fang Cheng, Lin Ci, Song Huang, Renle Wang, Cunping State Key Laboratory of Control and Simulation of Power System and Generation Equipments Tsinghua University Beijing China State Grid of China Beijing Electric Power Company Beijing China

ISBN: (纸本)9781538614273

The future power system will be the integration of multiple energy systems, cyber-physical system, and multiple markets. This paper presents an architecture of energy-discretized multi-energy microgrids. This architecture can achieve the point-to-point (P2P)transmission of discrete energy with the physical system level, which solves the problem of energy flow tracking and measurement. In this architecture, the real-time transaction-and-control-combined mechanism can ensure the dynamic and fully customized energy supply. This paper draws the architecture of a new generation of energy supply system, and may provide an idea for the integration of energy, information, and value in energy supply system. © 2017 IEEE.

关键词： Cyber Physical System

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Model Predictive control Strategy of Multi-Port Interline DC power Flow controller

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Energy Engineering 2023年第10期120卷 2251-2272页

作者： He Wang Xiangsheng Xu Guanye Shen Bian Jing Key Laboratory of Modern Power System Simulation and Control&Renewable Energy Technology Ministry of Education(Northeast Electric Power University)Jilin132012China Marketing Department State Grid Jilin Electric Power Co.Ltd.Changchun130061China

There are issues with flexible DC transmission system such as a lack of control freedom over power *** order to tackle these issues,a DC power flow controller(DCPFC)is incorporated into a multi-terminal,flexible DC power *** recent years,a multi-port DC power flow controller based on a modular multi-level converter has become a focal point of research due to its simple structure and robust *** work proposes a model predictive control(MPC)strategy for multi-port interline DC power flow controllers in order to improve their steady-state dynamic ***,the mathematical model of a multi-terminal DC power grid with a multi-port interline DC power flow controller is developed,and the relationship between each regulated variable and control variable is determined;The power flow controller is then discretized,and the cost function and weight factor are built with numerous control *** module sorting method and nearest level approximation modulation regulate the power flow controller;Lastly,theMATLAB/Simulink simulation platformis used to verify the correctness of the establishedmathematicalmodel and the control performance of the suggestedMPC ***,it is demonstrated that the control strategy possesses the benefits of robust dynamic performance,multiobjective control,and a simple structure.

关键词： DC power flow controller model predictive control modular multi-level converter control strategy dynamic performance

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An Internet of Energy Things Based on Wireless LPWAN

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Engineering 2017年第4期3卷 460-466页

作者： Yonghua Song Jin Lin Ming Tang Shufeng Dong State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University. Beijing 100084 China College of Electrical Engineering Zhejiang University Hangzhou 310027 China Center of Internet of Energy Things Tsinghua-Sichuan Energy Internet Institution Chengdu 610213 China

Under intense environmental pressure, the global energy sector is promoting the integration of renewable energy into interconnected energy systems. The demand-side management （DSM） of energy systems has drawn considerable industrial and academic attention in attempts to form new flexibilities to respond to variations in renewable energy inputs to the system. However, many DSM concepts are still in the experimental demonstration phase. One of the obstacles to DSM usage is that the current information infrastructure was mainly designed for centralized systems, and does not meet DSM requirements. To overcome this barrier, this paper proposes a novel information infrastructure named the lnternet of Energy Things （IoET） in order to make DSM practicable by basing it on the latest wireless communication technology： the low-power wide-area network （LPWAN）. The primary advantage of LPWAN over general packet radio service （GPRS） and area Internet of Things （loT） is its wide-area coverage, which comes with minimum power consumption and maintenance costs. Against this background, this paper briefly reviews the representative LPWAN tech- nologies of narrow-band Internet of Things （NB-IoT） and Long Range （LORa） technology, and compares them with GPRS and area IoT technology. Next, a wireless-to-cloud architecture is proposed for the IoET, based on the main technical features of LPWAN. Finally, this paper looks forward to the potential of IoET in various DSM application scenarios.

关键词： Low-power wide-area network Internet of Things Narrow-band lnternet of Things LoRa technology Demand-side management

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Measurement techniques on transient process of lightning striking overhead transmission lines

Measurement techniques on transient process of lightning str...

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CIGRE Session 46

作者： Xie, S.J. Li, J.M. Zhang, Y. Zeng, R. Zhuang, C.J. Wang, H. State Grid Sichuan Electric Power Research Institute State Grid Sichuan Electric Power Company China State Key Lab. of Control and Simulation of Power Systems and Generation Equipment Tsinghua University China

Obtaining the lightning strike density along an overhead transmission line and identifying the lightning strike types are the key to evaluating the lightning protection performance and proposing reasonable protection schemes of transmission lines. In addition, the waveform characteristics of lightning invasion overvoltage are the basis to establish the standard on the insulation tests of power equipment. Measuring the transient process of lightning striking overhead transmission lines is the basis to carry out the work mentioned above. In this paper, a distributed measurement method of transient current on conductors caused by lightning strikes is proposed. The measuring units are installed on the field conductors of transmission lines every 30 km to obtain less-distorted transient current waveforms. In order to enable measuring units to work in field isolated environment, a power supply coil using Faraday electric-magnetic effect and a wireless communication module is designed and developed. By far, 4776 measuring units have been installed on 597 transmission lines of China's power grid. According to measured transient current waveforms, the lightning strike point can be located using the double-end or single-end travelling wave location method, and the lightning strike type can also be identified. Moreover, a novel measurement method of lightning transient voltage based on the integrated optical electric field sensor (IOEFS) is proposed. In this method, the transient voltage waveforms are inversed from space electric field waveforms measured by IOEFSs. A series of performance tests of IOEFS have been carried out. The test results indicate that the response speed can reach several nanoseconds, and the frequency response can cover 5Hz∼100MHz which is wide enough for the measurement of the lightning transient voltage. In order to test the field measurement effect, the measurement equipment is used to measure a transient voltage when a group of capacitor voltage trans

关键词： Frequency response

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