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RECEIVER SPURIOUS RESPONSES - COMPUTER IMPROVES RECEIVER DESIGN

IEEE TRANSACTIONS ON VEHICULAR COMMUNICATIONS 1966年第1期VC15卷 13-&页

作者： MYERS, RT MCKEE, TA General Electric Company Limited Lynchburg VA USA

This paper will review the processes of spurious response generation in land-mobile receivers. The various types of spurious responses will be discussed. Formulas required to calculate the spurious response frequencies will be presented, and the use of a computer for spurious-response frequency prediction will be outlined. These computer spurious-response frequency predictions can be used as an aid in designing systems to avoid spurious. In addition, these predictions may be used by the receiver designer to minimize spurious. Several different methods of minimizing receiver spurious responses will be discussed since the various spurious mechanisms require different methods of reduction.

关键词： Receivers Mixers Design engineering power engineering and energy Systems engineering and theory power engineering computing Frequency conversion Interference elimination Dictionaries Physics

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Methods of image recognition of overhead power line insulators and ice types based on deep weakly-supervised and transfer learning

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IET GENERATION TRANSMISSION & DISTRIBUTION 2022年第11期16卷 2140-2153页

作者： Hao, Yanpeng Liang, Wei Yang, Lin He, Jinqiang Wu, Jianrong South China Univ Technol Sch Elect Power Guangzhou 510640 Peoples R China China Southern Power Grid Co Ltd Elect Power Res Inst Guangzhou Peoples R China China Southern Power Grid Co Ltd Guizhou Elect Sci Inst Guiyang Guizhou Peoples R China

Insulator icing endangers the safe operation of overhead power lines. The current measures for image monitoring of icing overhead power lines rely on manual observation. There is an urgent need for image intelligent analysis methods with strong generalisation, accuracy, and efficiency to improve power grid decision-making. Based on the icing monitoring data from China Southern power Grid, this paper first proposes rules for insulator image data cleaning, classification, and annotation, establishing a dataset of insulator icing monitoring images during 2014-2018. Then, based on Yolo (You only look once) v5, a weakly supervised and phased transfer learning method is proposed to recognise insulators and ice types such as snow, rime, mixed rime, glaze, and the normal. This method reduces the interference of icing background, uneven illumination, and camera occlusion through multidimensional feature fusion. The precision, recall, and mean average precision of the recognition can reach 86.6%, 91.3%, and 90.1%, respectively, and the recognition speed is as fast as 8 ms/image. Using image pseudo-labelling based on weakly supervised learning enables the intellectualisation of image annotation, which significantly changes the inefficiency of manual labelling.

关键词： image classification object detection image intelligent analysis methods image annotation image monitoring insulators power grids image recognition supervised learning power grid decision-making China Southern power Grid overhead power lines deep weakly-supervised transfer learning overhead power line insulators convolutional neural nets weakly supervised learning icing monitoring data transfer learning method insulator image data cleaning feature extraction power overhead lines deep learning (artificial intelligence) ice types image pseudolabelling power engineering computing learning (artificial intelligence)

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Real-time distributed economic dispatch scheme of grid-connected microgrid considering cyberattacks

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IET RENEWABLE power GENERATION 2020年第14期14卷 2750-2758页

作者： Huang, Chongxin Wang, Jing Deng, Song Yue, Dong Nanjing Univ Posts & Telecommun Coll Automat Nanjing 210023 Peoples R China Nanjing Univ Posts & Telecommun Coll Artificial Intelligence Nanjing 210023 Peoples R China Nanjing Univ Posts & Telecommun Inst Adv Technol Nanjing 210023 Peoples R China

Cyber security of microgrids attracts increasing attention since the relatively open communication network of the microgrids is vulnerable to hacker attacks. This study proposes a real-time distributed economic dispatch scheme for the grid-connected microgrid against the cyberattacks. Firstly, a virtual leader agent is placed at the point of common coupling to measure the real-time power tracking error for achieving the power supply-demand balance, and then the optimal solution of the economic dispatch model is solved by the consensus algorithm of the multi-agent system theory. Subsequently, a set of detection algorithms is designed for each generator to determine whether its neighbouring generators suffer from the cyberattacks. The attacked generator is gradually marginalised from the communication network through updating the weight in the communication adjacency matrix based on its reputation value, thereby the impact of the attacked generator on the whole system is reduced greatly. Finally, the numerical simulations are carried out to verify the effectiveness of the proposed cyberattack-resilient distributed economic dispatch scheme.

关键词： power generation economics security of data power generation dispatch multi-agent systems distributed power generation matrix algebra power engineering computing real-time systems grid-connected microgrid cyber security open communication network hacker attacks real-time distributed economic dispatch scheme virtual leader agent real-time power tracking error power supply-demand balance economic dispatch model consensus algorithm multiagent system theory neighbouring generators attacked generator communication adjacency matrix cyberattack-resilient distributed economic dispatch scheme numerical simulations

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Harmonic contribution determination based on change-point monitoring and shape context algorithm

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IET GENERATION TRANSMISSION & DISTRIBUTION 2022年第3期16卷 453-466页

作者： Liu, Hang Ma, Tiefeng Zhang, Yi Liu, Shuangzhe Wang, Youran Guo, Junyu Southwestern Univ Finance & Econ Sch Stat Chengdu Peoples R China Fuzhou Univ Coll Elect Engn & Automat Fuzhou Peoples R China Univ Canberra Fac Sci & Technol Canberra ACT Australia

In the power system, the harmonic is one of the important concerns of power quality, which has a significant impact on the safe operation of power grids and the energy efficiency for users. When there are not enough special harmonic monitoring devices installed on public transport, it is important to identify the harmonic source and assess the harmonic contribution based on the load data of the user's electricity meter. This paper proposes a data selection and matching idea based on change-point monitoring (CPM), canonical correlation analysis (CCA) and dynamic adjusted shape context (DASC) for determining the harmonic contributions of individual customers and utilities. In the proposed approach, the CPM is used to select the valuable data by detecting the violent fluctuation area of harmonic voltage and the DASC to determine the harmonic contribution of individual customers by matching the user load sequence and harmonic voltage sequence based on CCA, filtering the harmonic contribution from the utility side. Simulation data is used to evaluate the performance of the method and a real-world case study is also conducted. It is found that the proposed technique can be used to reveal the harmonic impact of the loads if data is selected resonably.

关键词： harmonic voltage sequence power system harmonics power system special harmonic monitoring devices change-point monitoring power supply quality harmonic contribution determination correlation methods dynamic adjusted shape context harmonic source power grids harmonic impact matching idea data selection power engineering computing shape context algorithm power quality

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Edge-cloud collaborative architecture based multi-time scales rolling optimization of regional integrated electrical and natural gas energy system considering wind power uncertainty

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IET GENERATION TRANSMISSION & DISTRIBUTION 2021年第19期15卷 2684-2709页

作者： Cao, Zhiao Zhao, Qiang Wang, Jia Wang, Jinkuan Han, Yinghua Northeastern Univ Coll Informat Sci & Engn Shenyang Peoples R China Northeastern Univ 143 Taishan Rd Qinhuangdao 066004 Hebei Peoples R China

With the serious energy crisis and speedy development of natural gas utilization, regional integrated electrical and gas energy system is an efficient way to improve energy potency. This paper studies the energy scheduling of integrated electrical and gas energy system with bi-directional energy conversion at distribution network level, considering wind power uncertainty. To realize independent autonomy of energy networks, meantime adjusting scheduling strategies of integrated energy system from system-level perspective, innovative edge-cloud collaborative operation architecture is proposed. In edge servers, electrical and gas networks are optimized severally for scheduling strategies. In cloud server, the uncertainty of wind power are processed with robust optimization method, strategies of energy conversion units are updated for re-optimization. Cooperated with edge-cloud architecture, a novel multi-time scales rolling optimization framework is proposed, electrical and gas networks are optimized under day-ahead time scale in corresponding edge servers, and electrical network is further adjusted under intraday time scale in electrical edge server. Case studies show that edge-cloud collaborative operation architecture can ensure the practical feasibility of optimization, which is more suitable for energy scheduling of integrated electrical and gas energy system. Multi-time scales rolling optimization framework have significant efficiency on reducing the impact of wind power uncertainty.

关键词： Wind power plants Optimisation techniques Optimisation techniques power system management, operation and economics Distribution networks power engineering computing

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NEW PWM SWITCHING STRATEGY FOR MICROPROCESSOR CONTROLLED INVERTER DRIVES

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IEE PROCEEDINGS-B ELECTRIC power APPLICATIONS 1986年第4期133卷 237-254页

作者： BOWES, SR MIDOUN, A Department of Electrical and Electronic Engineering University of Bristol Bristol UK

A new high-voltage suboptimal (HVSO) pulse-width modulation (PWM) switching strategy is presented which can be used at high fundamental PWM voltages to achieve a smooth, transient-free, low harmonic distortion, transition from the PWM to quasisquare-wave mode. The design philosophy underlying the development of the new HVSO strategy is aimed at reproducing the special features and desirable characteristics of the optimised PWM strategy, using a simple and efficient microprocessor implementation. The full theoretical development of the new HVSO strategy is presented; and experimental results, from a microprocessor controlled PWM inverter drive, are provided which confirm this theoretical development. It is shown that the new HVSO strategy is superior to all existing PWM strategies, and can be implemented simply and efficiently on a microprocessor controller with only minor modifications to the existing PWM microprocessor implementations. In addition, a new hybrid PWM strategy is proposed and demonstrated, which combines the HVSO strategy with a previously developed suboptimal strategy. It is shown that this new hybrid PWM strategy can be used to cover the complete voltage/frequency range of the drive system up to and including the quasisquare wave mode, with minimised total harmonic distortion.

关键词： Control engineering computing high voltage suboptimal pulse width modulation electric drives Drives PWM inverter drive switching PWM switching strategy HVSO strategy computerised control power convertors and power supplies to apparatus power engineering computing microprocessor controlled inverter drives invertors pulse width modulation Control of electric power systems

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STATE FORECASTING IN ELECTRIC-power SYSTEMS

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IEE PROCEEDINGS-C GENERATION TRANSMISSION AND DISTRIBUTION 1983年第5期130卷 237-244页

作者： DASILVA, AML DOCOUTTO, MB DEQUEIROZ, JF FED UNIV RIO DE JANEIRO DEPT ELECT ENGNRIO DE JANEIRORJBRAZIL

The state vector of a power system varies with time owing to the dynamic nature of system loads. Therefore, it is necessary to establish a dynamic model for the time evolution of the state vector. The dynamic state estimation approach consists of predicting the state vector based on past estimations, followed by a filtering process performed when a new set of measurements is available. This paper presents a new algorithm for forecasting and filtering the state vector, using exponential smoothing and least-squares estimation techniques. The proposed algorithm is compared with another one based on standard Kalman filtering theory. Numerical results showing the performance for both dynamic estimators under different operational conditions are presented and discussed. Detection and identification of multiple bad data are also included. The new dynamic estimator exploiting state forecasting is extremely useful to real-time monitoring of power systems.

关键词： eigenvalues and eigenfunctions least squares approximations Simulation, modelling and identification dynamic model state estimation filtering power engineering computing Algebra Interpolation and function approximation (numerical analysis) state vector electric power systems least-squares estimation techniques real-time monitoring time evolution algorithm identification multiple bad data power system analysis computing power system management, operation and economics forecasting Numerical analysis exponential smoothing

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INTEGRATION OF HVDC LINKS WITH FAST-DECOUPLED LOAD-FLOW SOLUTIONS

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PROCEEDINGS OF THE INSTITUTION OF ELECTRICAL ENGINEERS-LONDON 1977年第5期124卷 463-468页

作者： ARRILLAGA, J BODGER, P UNIV CANTERBURY DEPT ELECT ENGNCHRISTCHURCHNEW ZEALAND

A model of the high-voltage direct-current transmission link suitable for incorporation in fast decoupled a.c. load-flow programs is described. The model is not restricted to a particular control made and provision is made to alter the control equations according to prespecified constraints for the variables. The versatility of decoupled programs is increased with this addition and it is shown that their reliability and computational efficiency are maintained.

关键词： DC power transmission transmission link d.c. transmission HVDC decoupled programs control equations Network and transmission line calculations integration with fast decoupled load flow solutions reliability power system analysis computing high voltage direct current power engineering computing computational efficiency load distribution

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NEWTON-RAPHSON ALGORITHM FOR 3-PHASE LOAD FLOW

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PROCEEDINGS OF THE INSTITUTION OF ELECTRICAL ENGINEERS-LONDON 1974年第7期121卷 630-638页

作者： WASLEY, RG SHLASH, MA UNIV MANCHESTER INST SCI TECHNOLPOB 88MANCHESTER M60 1QDENGLAND

One of the problems encountered in power-systems operation is the generation of unbalanced voltages and currents in the presence of long transmission lines with few or no transpositions, including possible unbalances arising in source and load conditions, or indeed any items of plant such as shunt and series reactors. To improve or investigate these unbalance effects in any detail, a 3-phase-load-flow solution that allows representation of all possible unbalances as they exist in the power-systems network without making any assumptions is essential. Consequently, a working Newton-Raphson algorithm is presented, which forms the basis of a computer program developed for the specific purpose of solving the 3-phase-load-flow problem. An indication of program facilities is given, together with sample results for illustration.

关键词： Newton Raphson algorithm computer program three phase load flow load (electric) Network and transmission line calculations electrical engineering application of computers unbalance effects power system operation power engineering computing electrical engineering applications of computers transmission network calculations

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Factorial analysis for ageing assessment of in-service transformers

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IET GENERATION TRANSMISSION & DISTRIBUTION 2018年第13期12卷 3177-3185页

作者： Wang, Dongmiao Tee, Sheng Ji Liu, Qiang Wang, Zhongdong Univ Manchester Sch Elect & Elect Engn Manchester M13 9PL Lancs England

Condition monitoring data in the form of oil test results are important for transformer ageing assessment and asset management. Analysis of variance-based factorial analysis was demonstrated as a data mining technique for identifying the influence of different factors on transformer ageing. Using a UK oil test database of 33/11(or 6.6) kV transformers, studies were performed to assess the influence of in-service age, manufacturer, year of manufacture, load and environment on the measured oil acidity. This methodology can reduce the workload of manually performing pairwise comparisons to understand the influence of each factor. In addition, it can also consider any interaction effect present among the factors. As a demonstration, influence of the year of manufacture on oil acidity was revealed, which was confirmed by identifying a change in design for late 1960s units and an early degradation phenomenon for late 1980s units.

关键词： maintenance engineering transformer oil condition monitoring ageing data mining power transformer insulation asset management power engineering computing UK oil test database kV transformers in-service age manufacturer measured oil acidity factorial analysis in-service transformers condition monitoring data oil test results transformer ageing assessment asset management data mining technique

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