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2010 International Conference on Electrical Machines and systems, ICEMS2010

作者： Tao, Xinghua Li, Yongdong Sun, Min State Key Lab of Control and Simulation of Power System and Generation Equipments Dept. of Electrical Engineering Tsinghua University China Dept. of Electrical Engineering Naval Engineering University China

In this paper, a novel control scheme for cascaded H-Bridge rectifier (CHBR), which can be used as the primary end of high voltage high power multilevel converters, is presented. The controller is similar with the one for single phase rectifier. To improve the performance of the controller, notch filter and proportion resonance (PR) controller are employed and the discrete methods for them are discussed in detail. The different function of CHBR controller from the single rectifier is for voltage balancing. Therefore, the phase-disposition technology, which is used in the multilevel converter, is introduced to eliminate the voltage error from the expected value. With this approach, the states of the switches of the CHBR are decided correctly by the practical condition and then the DC-link capacitors of the cells are controlled to charge or discharge in the way which results to voltage balancing. The effectiveness of the proposed approach is verified by experimental results.

关键词： Cascaded H-bridge rectifier Phase-disposition PWM PR controller Voltage balance

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Evaluation of cascading failure in power system based on the operational reliability theory

Evaluation of cascading failure in power system based on the...

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International Conference on Probabilistic Methods Applied to power systems (PMAPS)

作者： Xin Zou Lin Cheng Yuanzhang Sun State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Department of Electrical Engineering Tsinghua University Beijing China

ISBN: (纸本)9781424457205;9781424457212

According to the characteristics of the cascading failures in power grid, a lot of assessment methods based on the probability theory have been proposed in recent years. However, most of them ignore the influence of the changing operating conditions on the power system planning and operation. This paper assesses the risk of the cascading failure in the power system based on the operational reliability theory which considering the variation of operating states and environment of the power system. The operational reliability of the power system is calculated based on Markov Process which describes the transient probability of states. The key conception of this theory is that the failure rate and the probability of components are changing along with the life of the equipment, the operating states and the environment conditions. A new evaluation procedure is brought up to calculate the operational reliability indices which can provide the specific information of the cascading failure. The evaluating results of the test system confirm that this approach is applicable to analyze the cascading failures in real power system.

关键词： power system faults power system protection power system reliability Reliability theory power system planning power system transients power grids Markov processes Probability System testing

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

Analysis of Application of Superconducting Fault Current Lim...

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International Conference on Advanced power System Automation and Protection (APAP)

作者： Binshu Chen Xinzhou Dong Tsinghua University Key Lab of Control and Simulation of Power Systems and Generation Equipment China

ISBN: (数字)9781728117225

ISBN: (纸本)9781728117232

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.

关键词： Superconducting transmission lines Resistance Superconducting coils Fault currents Magnetic fields Inverters Impedance

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Applications of coordinated automatic voltage control integrated for regional, provincial and prefectural control centers in China Southern power Grid

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Dianli Xitong Zidonghua/Automation of Electric power systems 2014年第13期38卷 208-215页

作者： Wang, Bin Guo, Qinglai Zhou, Huafeng Tang, Lei Gu, Huijie Sun, Hongbin Department of Electrical Engineering Tsinghua University Beijing100084 China State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Tsinghua University Beijing100084 China China Southern Power Grid Dispatching Control Center Guangzhou510623 China

In order to avoid irrational reactive power flow and voltage distribution, the coordinated voltage controlsystem integrated for regional, provincial and prefectural control centers in China Southern power Grid is proposed. The reactive power and voltage operation and control characteristics of China Southern power Grid are analyzed. The hierarchical architecture of coordinated voltage controlsystem integrated for regional, provincial and prefectural control centers is described. Some typical applications are emphasized, including the coordination between regional and provincial control centers, the coordination between provincial and prefectural control centers, the voltage control for substations considering the provincial coordinate constraints, the coordinated voltage control for the high voltage direct current (HVDC) neighboring grids, etc, the exchange data content and mode between regional, provincial and prefectural control centers are described. The coordinated voltage control system is currently in real time operation in China Southern power Grid. © 2014 State Grid Electric power Research Institute Press

关键词： Reactive power

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Substation-control center two-level distributed network modeling

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Dianli Xitong Zidonghua/Automation of Electric power systems 2014年第9期38卷 107-113and151页

作者： Wang, Jing Sun, Hongbin Chen, Runze Zhang, Yang Wu, Wenchuan Guo, Qinglai Department of Electrical Engineering Tsinghua University Beijing100084 China State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Tsinghua University Beijing100084 China National Electric Power Dispatching and Control Center Beijing100031 China

As the traditional centralized network modeling for energy management system (EMS) in control center is error prone, heavily reliant on maintenance, and lacking in self-healing ability while unable to satisfy the needs of the distributed application of future transmission grid, a method of substation-control center two-level distributed network modeling is presented. The information model including the network model as well as one-line diagram is built in the substation, transferred to the control center after transformation, and then merged to form an entire network model in control center. The architecture and key technologies such as substation modeling, model transferring and transforming, model joining are discussed in detail. The proposed method has been successfully implemented in China Eastern Grid as shown in the field-application results. ©2014 State Grid Electric power Research Institute Press.

关键词： Energy management systems

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power Reconstructing Method of Distributed Photovoltaic Based on the Temporal and Spatial Correlation 10

Power Reconstructing Method of Distributed Photovoltaic Base...

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2020 10th International Conference on power, Energy and Electrical Engineering, CPEEE 2020

作者： Li, Shangqiang Sun, Rongfu Qiao, Ying Lu, Zongxiang State Key Lab of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University Haidian District in Beijing100084 China State Grid Jibei Electric Power Company Xicheng District in Beijing100031 China

55GW distributed photovoltaic have been installed in China, but nearly half are connected to the low voltage level of 380V, without real-time power data acquisition. The sequential power data is needed to be reconstructed based on some related monitoring data. Current researches focus on outliers recovery, but not reconstruction from none. This paper explores the temporal and spatial correlation of power between adjacent centralized photovoltaic stations and proposes a large-scale missing power data reconstructing method based on the time-delay power correlation, the spatial geometric characteristics of stations and the thought of ensemble learning. Finally, we verify the effectiveness of the proposed method by simulation based on the real photovoltaic power data. The proposed method can get the better effect of data reconstructing compared with the traditional method, which only use the power curves of the nearest CP station to reconstruct the power curves of the DP station according the capacity conversion. © 2020 The Authors, published by EDP Sciences.

关键词： Data acquisition

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Effect of UV Radiation Aging on Creepage Discharge Characteristics of High Temperature Vulcanized Silicon Rubber at High Altitude

Effect of UV Radiation Aging on Creepage Discharge Character...

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中国物理学会第二十二届全国静电学术年会

作者： JIN Fu-bao LIANG Bin ZHOU Yuang-xiang ZHONG Liu ZHANG Ling School Of Water Resources and Electric Power Qinghai University Xining80016China State Key Lab of Control and Simulation of Power Systems and Generation Equipments Department of Ele

Aiming at the special working environment of composite insulators at high altitude area,we investigate the creepage discharge characteristics of aged HTV(High Temperature Vulcanized,HTV)silicone rubber materials by UV(ultraviolet radiation,UV)aging method in this *** results show that the creepage discharge flashover voltage first increased,then decreased as aging time increasing,whereas the creepage discharge initial voltage was not significantly affected by aging *** aging time has little effect on creepage discharge *** aging time contributed to shorter endurance time and higher creepage discharge development *** magnitude of discharges increase rapidly in a short time after *** partial discharge detection system was used to detect the whole creepage discharge development *** to the partial discharge characteristics parameters of creepage discharge,we divided the development process of creepage discharge into initial stage,developmental stage,accelerating stage,and critical breakdown *** with characteristic parameters of unaged HTV silicone rubber,the characteristic parameters for the aged HTV silicone rubber exhibited less fluctuation and clear *** aging not only has an effect on the physicochemical and hydrophobic properties of the materials,but also accelerates the development process of creepage discharge under AC *** should be given enough attention in engineering practice,especially at high altitude area.

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

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Capacity Configuration of Hybrid CSP/PV Plant for Economical Application of Solar Energy

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Chinese Journal of Electrical Engineering 2020年第2期6卷 19-29页

作者： Fei Li Canbing Li Kai Sun Jiamei Zhang Hua Li State Grid Henan Electric Power Company Economic Research Institute Zhengzhou 450000China College of Electrical and Information Engineering Hunan UniversityChangsha 410082China Department of Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Lab of Control and Simulation of Power Systems and Generation Equipment Tsinghua UniversityBeijing 100084China Zhangjiakou Power Supply Company Zhangjiakou 075000China

Concentrating solar power(CSP)technology has received increasing attention in recent years because of its distinct advantage for dispatchable power generation from solar ***,owing to its highly levelized costs of electricity,CSP plants are less competitive than photovoltaic(PV)power *** overcome this drawback and suppress PV power fluctuations,the concept of a hybrid CSP/PV power plant is proposed and developed.A capacity configuration method based on filtering and checking is proposed to seek a relationship between the capacity configuration of a hybrid CSP/PV system and the cost of solar ***-content hybrid systems with different ratios of CSP capacity and PV capacity are modeled,and their comprehensive performance is *** and comparisons with a standalone CSP system focused on annual energy generation,capacity factor,levelized cost of electricity,and possibility for loss of power supply show that the hybrid CSP/PV systems possess different features depending on their capacity *** results indicate that the proposed method can supply a convenient and simple operation pattern that favors engineering utilization and extension.

关键词： Concentrating solar power photovoltaic capacity configuration levelized cost of electricity

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Surface Partial Discharge Characteristics of Oil-paper Insulation Under Combined AC-DC Voltage

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高电压技术 2013年第8期39卷 1902-1910页

作者： SHA Yanchao ZHOU Yuanxiang NIE Dexin WU Zhirong DENG Jiangang LU Licheng State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Department of Electrical Engineering Tsinghua University Beijing 100084 China State Key Laboratory of Electrical Insulation and Power Equipment Department of Electrical Engineering State Grid Electric Power Research Institute Wuhan 467001 China State Grid Corporation of China Beijing 100031 China

The valve side windings of converter transformers bear AC, DC, impulse, and reversal-polarity voltages during operation, which could result in serious insulation problems of the equipment. By performing experiments with surface discharge model of oil-paper insula- tion at 80 ℃ under combined AC-DC voltage for 200 h, we studied the spectrums and statistical parameters of partial discharges at different discharge stages. Furthermore, some fingerprint parameters were calculated in order to estimate the development situation of par- tial discharge, while the characteristic gases dissolved in the transformer oil were measured by gas chromatography. The surface discharges in the experiments were observed using a high speed camera, and a full discharge process could be marked off into four stages as follows. ①The elementary stage. When a partial discharge occurs near electrodes, electrical charges are injected into the region near electrodes and causing bubble generation. ②Due to their high resistivity and low dielectric constant, the bubbles would bare the major part of the voltage applied to samples. Therefore, discharge happens inside the small bubbles, and it emits a lot of light. ③Micromolecules of gas are produced in discharge, and further ionization in the transformer oil takes place simultaneously when high-energy electrons collide with oil molecules. ④The carrier charge moves forward to electrodes driven by the applied electric field, till they neutralize with the charge from electrodes, and hence discharge channels are formed subsequently.

关键词： AC-DC 放电特性绝缘表面电压油纸油中溶解气体换流变压器合作

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Effects of Temperature on Creepage Discharge Characteristics in Oil-Impregnated Pressboard Insulation under Combined AC-DC Voltage

Effects of Temperature on Creepage Discharge Characteristics...

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中国物理学会第二十二届全国静电学术年会

The characteristics of oil-impregnated pressboard(OIP)insulation in converter transformer are different with that in traditional AC transformers due to the complication of voltage applied on valve side windings of converter *** is a serious lack of empirical research on effect of temperature on creepage discharge characteristics in OIP under combined AC-DC ***,this study investigates the characteristics spectrum of creepage discharge in OIP under combined AC-DC voltage,and explores the effect of temperature on creepage discharge characteristics under different temperature from 70 to 110℃.The experimental results show that the partial discharge inception voltage and flashover voltage decrease as temperature *** times of low amplitude discharge(LAD)decrease and amplitude of LAD *** temperature had an accelerating effect on the development of creepage discharge in the OIP under combined AC-DC voltage Meanwhile,the times of high amplitude discharge(HAD)gradually increase at each stage of creepage discharge with higher *** analysis indicates that the charge carriers easily accumulate and quickly migrate directional movement along the electric field ahead of *** residual charge carriers are more easily dissipated after ***'hump'region of LAD moves to the direction of higher discharge *** interval time between two consecutive discharges drastically *** HAD intensively appear,result in accelerating the development of creepage discharge in OIP insulation.

关键词： Oil-impregnated pressboard insulation temperature combined AC-DC voltage creepage discharge inception voltage flashover voltage

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