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2nd IET Renewable power Generation Conference, RPG 2013

作者： Feng, G. Xu, Y. Chen, Y. Gao, H. Chen, L. State Key Lab of Control and Simulation of Power Systems and Generation Equipments Dept. of Electrical Engineering Tsinghua University Beijing 100084 China

ISBN: (纸本)9781849197588

Due to the power electronic devices in doubly fed induction generators (DFIG), it is very time consuming to simulate the electromagnetic transients of DFIG using its detailed model. Thus it is necessary to have appropriately simplified model of DFIG that maintains desirable accuracy. In this paper, the piecewise averaged model of PWM converters is introduced and applied to the modelling of DFIG. The proposed model divides the simulation time interval into switching periods and recalculates the averaged state equations of PWM converters in each switching cycle. In addition, a predictorcorrector based EMTP algorithm is designed to iteratively solve the model. Instead of treating switching events at the time points when they happen, the new algorithm solves all the switching instants in a switching cycle at the same time, which avoids frequency modification of the system conductance matrix and speeds up EMT simulations of DFIG. simulation results of a single-machine infinity bus system with a DFIG show that the proposed model and algorithm can achieve satisfactory accuracy and efficiency.

关键词： Equations of state

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Effect of UV radiation aging on creepage discharge characteristics of high temperature vulcanized silicon rubber at high altitude

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Plasma Science and Technology 2019年第5期21卷 23-33页

作者： Fubao JIN Yuanxiang ZHOU Bin LIANG Xidong LIANG Zhongliu ZHOU Ling ZHANG Key Laboratory of Plateau Ecology and Agriculture College of Agriculture and Animal HusbandrySchool of Water Resources and Electric PowerQinghai UniversityXining 800016People's Republic of China State Key Lab of Control and Simulation of Power Systems and Gen eration Equipments Departme nl of Electrical EngineeringTsinghua UniversityBeijing 100084People's Republic of China

The physicochemical properties and creepage discharge characteristics of aged high temperature Vulca nized(HTV)silicone rubber materials were investigated by ultraviolet radiati on(UV)aging method in this *** experimental results show that as the aging time increases,the creepage discharge flashover voltage increases first and then *** the aging time has little effect on the creepage discharge inception *** the aging time prolonged,the discharge endurance time of HTV silicone rubber is shortened,and the creepage discharge development velocity is *** the short time of applying voltage to aging material,the magnitude of discharge in creases *** to the partial discharge characteristic parameters of creepage discharge,the whole creepage discharge process is partitioned into four *** with unaged HTV silicone rubber,the aged HTV silicone rubber has less fluctuation in performance parameters and a clear *** study found that UV aging not only affects the physicochemical and hydrophobic properties of the HTV silicone rubber,but also accelerates the development of creepage discharge under AC voltage.

关键词： high temperature vulcanized silicone rubber creepage discharge UV aging inception voltage flashover voltage high altitude characteristic parameters

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Evaluation Method of Wind power Consumption Limitation in power System with High Proportion of Wind power 4

Evaluation Method of Wind Power Consumption Limitation in Po...

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4th IEEE China International Electrical and Energy Conference, CIEEC 2021

作者： Wang, Hongye He, Li Lin, Xuelong Ma, Jing An, Baihui Yang, Weixiang Xu, Fei Hou, Tao Li, Jing Feng, Changsheng Li, Junhui Co. Ltd Beijing China State Key Lab of Control and Simulation of Power Systems and Generation Equipment Tsinghua University Beijing China

ISBN: (纸本)9781728171494

In order to study the reasonable capacity of power grid to absorb wind power, a new calculation method is proposed for the combined system of thermal power and wind power. In this paper, the probability and statistics method is used to analyze the output characteristics of wind farm, and the influence of characteristic index on wind farm is studied. A new calculation method of wind power limit is proposed, and the influence of seasonal factors is introduced to study the situation of wind power limit in summer and winter. Through the actual example, the idea and method are provided to formulate the control principle of wind power output, and the rationality and effectiveness of the proposed method are verified. © 2021 IEEE.

关键词： Electric power utilization

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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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Coordinated Wholesale and Retail Market Mechanism for Providing Demand-side Flexibility

Coordinated Wholesale and Retail Market Mechanism for Provid...

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2019 IEEE Sustainable power and Energy Conference, iSPEC 2019

作者： Luo, Gang He, Yujun Zhao, Chen Zhang, Xuan Lin, Shaohua Zhao, Yue Guangdong Power Grid Co. Ltd Dispatch and Control Center Guangzhou China Tsinghua University State Key Lab of Control and Simulation of Power Systems and Generation Equipments Beijing China

ISBN: (纸本)9781728149301

With the trend of electricity market deregulation for recent decades, the consumers at demand-side are progressively encouraged to trade the power in competitive market environment. Conventionally, only large-scale consumers participate directly in the wholesale market that adopts spot energy pricing. Most small-scale consumers are involved in the retail market that offers non-varying tariff predefined by retailers or utility companies. In this work, we investigate a framework of coordinated wholesale and retail market structure that enables consumers in the retail market to reflect the spot price and improve the power system flexibility for the high penetration of renewables. Then, market behaviors of demand-side participants with the proposed market mechanism and some related business models are discussed. The following participation modes for consumers could be opted including: direct trade, trade agented by retailers or organized in virtual power plant (VPP). For a pool-based trade at demand-side, a bi-level market clearing mechanism at transmission and distribution levels is explained. This mechanism seeks to optimize the global demand profile for hosting renewables while solving the operating constraint of loads and local networks. This study can offer constructive advises to promote further development of China's electricity market. © 2019 IEEE.

关键词： power markets

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A VCG Payment Scheme for Energy Storages in the Spot Market Considering Levelized-Cost-of-Storage 8

A VCG Payment Scheme for Energy Storages in the Spot Market ...

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8th Asia Conference on power and Electrical Engineering, ACPEE 2023

作者： Liu, Jianing Zhao, Yue Su, Zhuo Wang, Ke He, Yujun Guangdong Province Power Grid Co. Ltd Power Dispatching and Control Center Guangzhou China Tsinghua Univeristy State Key Lab of Control and Simulation of Power Systems and Generation Equipments Beijing China

ISBN: (纸本)9798350345520

Energy storages are considered as a key solution in the novel energy system with high penetration of renewables. However, the current power markets are not designed for the participation of energy storage as it has a variable cost. This paper investigates an efficient mechanism in which the energy storage submits his levelized cost of storage, then the storage receives a Vickrey-Clark-Grove payment equal to the increase in social welfare attributable to his presence. This mechanism can encourage the storage to truthfully submit the true operating cost and thus help to optimize the system operation. Moreover, the increments of the storage's own interests and the social welfare are coincidental, so it is incentive compatible. Numerical tests show the advantages of the proposed mechanism over the marginal pricing mechanism. © 2023 IEEE.

关键词： Energy storage

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Analysis of Application of Superconducting Fault Current Limiter to AC Line of HVDC 8

Analysis of Application of Superconducting Fault Current Lim...

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8th IEEE International Conference on Advanced power System Automation and Protection, APAP 2019

作者： Chen, Binshu Dong, Xinzhou Tsinghua University Key Lab of Control and Simulation of Power Systems and Generation Equipment Dept. of Electrical Engineering China

ISBN: (纸本)9781728117225

In LCC-HVDC hybrid grid, commutation failure is an important factor affecting system stability. When there is a fault or a large voltage fluctuation in AC line of LCC-HVDC, a commutation failure will occur. Fault current limiter (FCL) can limit the fault current and prevent commutation failure. Superconducting current limiters using superconducting materials as the core component, have no power loss and do not affect the dynamic performance of the system during normal operation. This article analyze how SFCL acts to suppress commutation failure in AC/DC hybrid systems, and describes the various types of SCFCLs and their limitations for this scene. By building simulation models of SCFCLs applied to AC line of LCC-HVDC invert, the author analyzes the effect of SCFCL on the hybrid grid. © 2019 IEEE.

关键词： Superconducting fault current limiters

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H∞ analysis method for the small signal stability of power system

H∞ analysis method for the small signal stability of power ...

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26th Chinese control Conference, CCC 2007

作者： Mei, Shengwei Che, Wenyan State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Dept. of Electrical Engineering Tsinghua University Beijing 100084 China

ISBN: (纸本)7900719229

This work is concerned with the small signal stability problem in multi-machine systems. By means of H∞ theory, firstly the math model with disturbances is constructed;and secondly, the excitation control law for each generator is designed based on solving Riccati Equation. Finally, simulations performed on 4-machine system shows that the proposed H ∞ method has more advantages over LQR method in both damping ratio and H∞ norm of the corresponding closed-loop system and so can enhance the small signal stability of power system greatly.

关键词： Electric power systems

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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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Application and Practice of Digital Twin Technology in Monitoring Status of power Equipment in Converter Valve Hall

Application and Practice of Digital Twin Technology in Monit...

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2023 International Conference on Intelligent Communication and Computer Engineering, ICICCE 2023

作者： Yongsheng, He Baojia, Deng Zongxiang, Lu Shiling, Zhang Liangjun, Dai State Grid Chongqing Electric Power Company Electric Power Research Institute China State Key Lab of Control and Simulation of Power Systems and Generation Equipment Deptartment of Electrical Engineering Tsinghua University China

ISBN: (纸本)9798350395617

The internal power equipment of ultrahigh voltage converter valve hall is numerous and complex in structure, involving the various information elements such as the temperature and vibration. Moreover, the gas inside ultra-high voltage converter bushing is SF6 gas. Under the current over-load condition of the converter bushing, SF6 gas will decompose. This article focuses on the SF6 gas equipment inside the ultrahigh pressure converter valve hall as the research object, and analyzes specific types and content of SF6 gas decomposition products. In order to effectively detect gas content in the digital twin model of the converter transformer bushing, the new portable SF6 gas chromatograph, laser detection technology and device for HF gas, and partial discharge detection technology research using the acoustic electric coupling method are carried out, providing the effective means for onsite detection of hidden faults in operating equipment. Research has shown the digital twin technology can effectively detect the absorption spectra of gases such as O2, H20, CO, CO2, CF4, SO2, H2S, SOF2, and SO2F2. On the other hand, through digital twin partial discharge detection technology, it is effectively found that the SO2 inside the UHV converter sleeve is 29μL/L, H2S is 4μL/L, CO is 36μL/L, HF=0, detected SO2 and H2S components, determined as the insulation heating defect. The research results of paper provide theoretical and data support for operation status monitoring of SF6 gas insulated power equipment inside the ultra-high voltage converter valve hall. © 2023 IEEE.

关键词： Sulfur hexafluoride

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