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Electrical Engineering and Automation (IFEEA), International Forum on

作者： Zhou Shaoliang Chen Li Shen Jian Sun Jianping State Key Laboratory of Smart Grid Protection and Control NARI Group Corporation (State Grid Electric Power Research Institute) Co. Ltd Nanjing China NARI Group Corporation (State Grid Electric Power Research Institute) Co. Ltd NARI Technology Corporation Co. Ltd Nanjing China

ISBN: (数字)9781728196275

ISBN: (纸本)9781728196282

In view of the shortage of direct measurement method for shafting of large generator sets, this paper proposes a sensor monitoring technology based on illumination emphasis. The article first introduces the research status of the shaft torque of thermal power units, and expounds the theory of mode interference and the theory of twist sensing. Then, the LP mode simulation of single-mode fiber and two-mode fiber is carried out, which is an effective method for symmetrical higher-order mode. Finally, the simulation of the mode interferometer, the spectrum and the phase during twisting is carried out. It is clarified that the non-circular symmetrical mode with π phase difference electric field distribution is the key inducement of the interferometric phase jump and spectrum flipping in twisting measurement. This article provides theoretical guidance for subsequent device fabrication and spectral distortion analysis.

关键词： Optical fiber sensors Optical interferometry Phase measurement Perturbation methods Optical distortion Distortion Optical fiber theory

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A Fast Blocking Method of Bus protection when CT Disconnected Based on Braking Current and Zero Sequence Current

A Fast Blocking Method of Bus Protection when CT Disconnecte...

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Sustainable Power and Energy Conference (iSPEC)

作者： Yincheng Wang Jie Zhu Wei Dai Xiang Zhu Xiaohong Wang Kaiyu Zhang NARI Technology Co. Ltd NARI Group Corporation Nanjing China Maintenance company of State Grid Tibet Electric Power Co. Ltd State Grid Tibet Electric Power Company Lhasa China State Key Laboratory of Smart Grid Protection and Control NARI Group Corporation Nanjing China

ISBN: (数字)9781728191645

ISBN: (纸本)9781728191652

Current transformer (CT) disconnection of bus is prone to maloperation of bus differential protection. The existing criteria for CT disconnection do not fully consider the distinction between heavy load high impedance fault and external metal fault transfer to internal high impedance fault. And not fully consider the influence of one-half wiring circulation and unbalanced impedance on CT disconnection zero sequence criterion. Based on the theoretical analysis of the characteristics of braking current variation and zero sequence current distribution in the event of internal fault, this paper puts forward a fast blocking criterion of CT disconnection based on braking current and zero sequence current, and carries out simulation verification. Both the theory and the simulation show that there is a drop of braking current in the event of internal fault. The distribution of zero sequence current in the event of CT disconnection is obviously different from that in the event of internal fault. The criterion proposed in this paper can effectively and reliably distinguish CT disconnection from internal fault.

关键词： Wiring Analytical models Current transformers Reliability theory Current distribution Impedance Load modeling

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An analytic method of calculating rotor and stator short-circuit current of DFIG with RSC control

An analytic method of calculating rotor and stator short-cir...

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IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC)

作者： Jinhua Zhang Baohui Zhang Bingqing Wu Jin Wang Shaanxi Key Laboratory of Smart Grid Xi'an Jiaotong University Xi'an China Electric Power Dispatching and Control Center State Grid Shandong Electric Power Company Jinan China

ISBN: (纸本)9781509054190

To investigate the fault features of doubly-fed induction generator (DFIG) with rotor side converter (RSC) control, an analytic method of calculating the DFIG short-circuit current is proposed in this paper. Based on the space vector model of DFIG with RSC control, the dynamic equation of rotor current reflecting both the machine transient process and the impact of RSC control is derived, and analytic expressions of rotor and stator fault current in time-domain are obtained. The calculation result is certified by being compared with the PSCAD simulation result. According to the derived analytic expressions, the components of the DFIG short-circuit current are analyzed. It indicates that the machine terminal voltage dip of DFIG, the current reference value, the orientation angle, and the proportional-integral value of RSC controller are main factors influencing the short-circuit current characteristics.

关键词： Damping Indexes Power grids Frequency control Time-frequency analysis Stators

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A hybrid model based on convolutional neural network and long short-term memory for short-term load forecasting

A hybrid model based on convolutional neural network and lon...

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IEEE Power and Energy Society General Meeting

作者： Jixiang LU Zhihong YANG Qipei ZHANG Mengfu TU Technology Research Center NARI Group Corporation Nanjing China State Key Laboratory of Intelligent Power Grid Protection and Operation Control Nanjing China

To better mine the effective information contained in massive data and improve the accuracy of short-term load forecasting, this paper proposes a hybrid model based on convolutional neural network and long short-term memory network (CNN-LSTM) for short-term load forecasting (STLF), which takes massive historical load data, meteorological data, date information, and peak-valley electric price data as input by constructing continuous feature maps with time sliding window. Convolutional neural network (CNN) is used to extract features and reshape them into vectors. The feature vectors are constructed in temporal and fed into long short-term memory network (LSTM) which is used to predict STLF. To the best of our knowledge, this is the first work to predict STLF using deep learning in both spatial and temporal domains. It is shown that the forecasting accuracy can be notably improved by CNN-LSTM hybrid model method. The effectiveness of the proposed method is validated through extensive comparison studies on a real-world dataset.

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The propagation characteristics of electromagnetic wave generated from partial discharges in power transformer by FDTD simulation

The propagation characteristics of electromagnetic wave gene...

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2007 Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP

作者： Tang, Zhiguo Li, Chengrong Wang, Wei Wang, Hui Wang, Li Ding, Yansheng Beijing Key Laboratory of High Voltage and EMC Ministry of Education North China Electric Power University Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control Ministry of Education North China Electric Power University State Grid Corporation of China 100081 Beijing China Beijing Key Laboratory of High Voltage and EMC School of Electric and Electronic Engineering North China Electric Power University P.O. No.88 Beijing 102206 China

The radiation and propagation of electromagnetic (EM) waves generated from PD caused by the obstruction of main transformer components are studied by FDTD simulation in order to get more information for PD location and diagnosis. Current filament, perfect conductive cylinder and perfect conductive spiral coil models are used to simulate the radiation and the influences of iron-core and transformer coil to the propagation of EM *** results demonstrate dynamic propagation process of EM waves in time order, and prove the correctness of the shortest optical path principle. But the attenuation and distortion of EM waves-especially the first peak amplitude-caused by the obstruction of large solid conductive obstacle like iron-core are quite intensive that it may cause great difficulties to identify exact arriving time position of incident waves coming along the shortest optical path. While the influences of the coil to the propagation of EM waves are so little that HF EM waves can penetrate it in almost linear path. ©2007 IEEE.

关键词： Electromagnetic waves

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A Flame Detection Algorithm Based on Improved YOLOv3 and Thermograph Generation 5

A Flame Detection Algorithm Based on Improved YOLOv3 and The...

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5th International Conference on Computing and Big Data, ICCBD 2022

作者： Zhang, Yong Zhang, Jiaqing Zhang, Jianhua Xing, Weijie Xcmg Fire-fighting Safety Equipment Co. Ltd. Xuzhou China State Grid Anhui Electric Power Research Institute Anhui Province Key Laboratory of Electric Fire and Safety Protection Hefei China School of Information and Control Engineering China University of Mining and Technology Xuzhou China

ISBN: (纸本)9781665457163

Aiming at the low accuracy of flame detection in complex environment, a new flame detection method based on improved YOLOv3 and gray thermograph is proposed. For the insufficient thermograph of actual flame data sets, a temperature filling algorithm based on radial basis function is proposed. Based on the open data sets, the actual flame image and thermograph are added to build the initial flame data sets, which improves the model training efficiency and generalization performance. The obtained flame gray scale thermograph and R, G, B image are combined to form a four-channel data and input into the improved YOLOv3 network convolution network layer to obtain the multi-channel characteristics of the data. The experimental results on public and self-built data sets show that the algorithm combines gray thermal image to expand image data and improves the detection accuracy of flame recognition. © 2022 IEEE.

关键词： Image enhancement

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Study on Robust Estimation of Combined Heat and Power Networks based on Huber Estimation

Study on Robust Estimation of Combined Heat and Power Networ...

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Sustainable Power and Energy Conference (iSPEC)

作者： Yunlong Hu Qi Wang Ming Ni Yi Yang Yongkang Zhu Xiecheng Yao College of Electrical and Automation Engineering Nanjing Normal University Nanjing China State Key Lab of Smart Grid Protection and Control NARI Group Corporation Nanjing China State Grid Jiangsu Electric Power Research Institute Nanjing China

ISBN: (纸本)9781665414401

Combined heat and power state estimation is the basis for safety assessment, optimal dispatching and other functions in multi-flow energy management centers, and has important theoretical value and practical significance. The measurement system inevitably has gross errors or bad data. The traditional weighted least squares method can’t restrain its influence, so the robust estimation method of combined heat and power network based on Huber estimation is proposed. The results of calculation examples show that the proposed method has good robustness and can restrain the influence of gross errors on the estimation accuracy.

关键词： Couplings Cogeneration Measurement uncertainty Robustness Safety Power systems state estimation

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Ultra-short-term wind speed forecasting method based on spatial and temporal correlation models

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The Journal of Engineering 2017年第13期2017卷 1071-1075页

作者： Zhou Haiqiang Xue Yusheng Guo Jizhu Chen Jiehui Energy and Electrical Engineering School Hohai University Nanjing 211100 Jiangsu Province People's Republic of China NARI Group Corporation (State Grid Electric Power Research Institute) Nanjing 211106 People's Republic of China State Key Laboratory of Smart Grid Protection and Control Nanjing 211106 People's Republic of China

An ultra-short-term wind speed forecasting method based on spatial and temporal correlation models is proposed. Firstly, the temporal correlation model was studied. The generalised distance of wind speed time series is defined based on the dynamic time warping distance and correlation coefficient. Samples with similar wind dynamic patterns are classed into the same group. Time series in one group are depicted with a representative time series which is modelled by an autoregressive moving average (ARMA) model. For time series which cannot be classed to any of these groups, a special group was defined. It was modelled by artificial neural network (ANN). Secondly, the spatial correlation between the target wind farm and the reference wind farm was investigated with the meteorological data taking into consideration. The grey prediction method is utilised to predict the wind speed. Finally, the combined ultra-short-term wind speed forecasting method is proposed. It takes into account the inherent time correlation of the target wind speed and its spatial correlation with reference wind farm. The wind speed prediction of wind farms in northwest USA verifies the effectiveness and feasibility of the proposed method.

关键词： wind neural nets time series grey systems autoregressive moving average processes wind power plants power engineering computing ultra-short-term wind speed forecasting method wind farms wind speed prediction target wind speed inherent time correlation ultra-short-term wind speed combination forecasting method corresponding spatial correlation model grey prediction method reference wind farm target wind farm ARMA model representative time series similar wind dynamic patterns sliding time window correlation coefficient dynamic time warping distance wind speed time series temporal correlation model temporal correlation models spatial correlation models

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Design and Implementation of Integrated Service Penetration Technology Cross Security Region

Design and Implementation of Integrated Service Penetration ...

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IEEE Conference on Energy Internet and Energy System Integration (EI2)

作者： Qiang Yi Shupeng Wan Kai Zhang Peng Chen Hailong Guo Baoshan Gao System R&D Center NARI Group Corporation NARI Technology Co. Ltd Nanjing China System R&D Center State Key Laboratory of Smart Grid Protection and Control Nanjing China

In the power dispatching automation system, production control security region and management information security region adopt forward and backward isolation devices for physical isolation, with the enhancement of the functional relevance between the security regions and the expansion of the system functions, one-way synchronization of production control security region to management information security region has been unable to meet the requirements of application expansion of supervisory control. In accordance with the principles of safety protection standards, it is urgent to establish a data transmission mechanism that can cross the forward and backward isolation, realize service penetration cross the security region. In this paper, a scheme of integrated service invocation across the security region is proposed, which can be invoked by the service bus that can be transparent and unaware service bus, encapsulate cross domain service protocol, establish virtual access, and complete service invocation. Through the signature verification technology, the service message is tampered in the communication, the communication security of the service invocation is guaranteed, the rights of the service are obtained through the authorization and the security of the service invocation cross the security region. The integrated service invocation technology cross the security region has been applied in Jiangsu Province, Beijing and Hangzhou. It provides a safe and stable support for the construction of the grand operation system, and provides a powerful guarantee for the efficient operation of the power grid.

关键词： Security Production control Power systems Safety Servers Synchronization Dispatching

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Virtual Inertia Enhancement of DC Microgrid Based on Adaptive Motor Load control 8

Virtual Inertia Enhancement of DC Microgrid Based on Adaptiv...

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8th International Conference on Power and Renewable Energy, ICPRE 2023

作者： Hu, Sizhe Li, Yong Fan, Cheng Feng, Zheng He, Yangyang Tai, Nengling Liu, Qi Shanghai Jiao Tong University Key Laboratory of Control of Power Transmission and Conversion Ministry of Education Shanghai China Xinjiang Silk Road Kunyuan Energy Co. Ltd China Shanghai Jiao Tong University College of Smart Energy Shanghai China State Grid Shanghai Electric Power Company Shanghai China

ISBN: (纸本)9798350328813

To enhance the dynamic stability and security of voltage and improve the inertial response of the DC microgrid after disturbances, this paper proposes a model predictive control (MPC) based method for regulating the speed of motor load, effectively utilizing controllable load resources without the need for additional energy storage devices. Firstly, a linear discrete model of the DC microgrid with motor load is established to predict the future trends of various system state variables. Secondly, a controller is designed with the objective of restraining the rate of DC voltage variation, and constraints are imposed on the rate of change of motor speed and their maximum response range. At each sampling time, the optimal speed adjustment is computed to achieve active response of the motor load. Finally, the feasibility and effectiveness of the proposed method are validated through MATLAB/Simulink simulation under typical operating conditions. © 2023 IEEE.

关键词： DC microgrid model predictive control motor load virtual inertia

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