Table of Content

05 November 2021, Volume 54 Issue 11

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Evolving Tendency of Electric Supply and Demand Pattern under the Circumstances of High-Quality Energy Development

SHAN Baoguo, JI Xingpei, YAO Li, MA Jie, WU Chenrui, DUAN Jinhui

2021, 54(11):  1-9,18.  DOI: 10.11930/j.issn.1004-9649.202105124

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To fight against climate change, countries around the world are accelerating the energy transition. General Secretary Xi Jinping put forward the “four revolutions, one cooperation” new strategy for energy security and the “carbon emission peaking, carbon neutrality” vision, demanding all efforts to promote high-quality energy development. They will have a profound impact on China’s electric supply and demand pattern. Firstly, this paper refines the connotation and characteristics of high-quality energy development. Secondly, we make the judgment about the transformation direction of the power industry from the perspectives of electric demand, electric supply, technology and market. Finally, through the construction of a multi-regional “energy–economy–power” model system, we analyze the evolving tendency of electric supply and demand pattern from the aspects of electric demand, electric supply, trans-regional power flow, power system pattern, and power market transaction.

Design of the Security Analysis Mechanism with Complex Market Condition for Regional Power Grid

ZHANG Huaiyu, HU Hong, ZHANG Lizi, TANG Chengpeng, LI Yunjian, JIA Xing

2021, 54(11):  11-18.  DOI: 10.11930/j.issn.1004-9649.202009111

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Security analysis is an important part of both the safe operation of regional power system and the normal operation of electricity market. At present regional electricity system in China has come to the complex situation with coexistence of regulation and deregulation, and interweaving of inter provincial transaction energy and planned electricity quantity, which compels the system operators to formulate corresponding security analysis mechanism. Firstly, this paper summarizes the power system security analysis mechanism for the single-mode market clearing and cross-market (country) electricity trading of foreign countries, and then explores the realistic basis, special constraints and requirements for regional power grid security analysis under the complex market environment in China. On this basis, a new security analysis mechanism framework adaptable to existing electricity market form, current power dispatching management system and regional power grid structure is designed, which includes the medium and long-term trans-province(region) electricity trading, day-ahead market pre-clearing generation plan of the pilot provinces and the day ahead generation plan of the non-pilot provinces. For the trans-province and trans-region medium and long-term transactions, this paper put forwards a power checking method based on the typical scenario set of cross-region transaction power curve and an improved security analysis mechanism scheme to elevate security analysis frequency. For the day-ahead period, it puts forward three alternative schemes adaptable to the complex market environment. Based on the comparative analysis, the implementation path of the scheme is proposed.

Mechanism of Peak Regulation Auxiliary Electricity Market in the Presence of High-Penetration Renewable Energy and Its Practice in Northwest China

XUE Chen, REN Jing, MA Xiaowei, CUI Wei, LIU Youbo, WANG Xiaodi

2021, 54(11):  19-28.  DOI: 10.11930/j.issn.1004-9649.202012123

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In the context of power market reform and smart grid development, the source-grid-load flexible interaction, as an inevitable trend of the power system upgrading, can perform as a promising method to address the peak-regulation resources shortage issue in Northwest China. This paper firstly summarizes the key technologies and their practical applications such as the market mechanism and trading varieties of auxiliary service market in the presence of high-penetration renewable energy. Based on the current peak-regulation auxiliary service market in the Northwest China region, a coordinated source-grid-load flexible interaction framework is proposed according to the load characteristics of the northwest grid and the accommodation demand of renewable energy. It is expected to stimulate various market entities to participate in peak-regulation service, so as to maximally consume renewable energy while ensuring the safe and economic operation of the power grid.

Mechanism and Strategy for Distributed Photovoltaic Coordinated Electricity-Sale in Electricity Market

LIU Jingqing, MA Wei, HE Nan, XIE Xiaolin, CHEN Jing, XIA Qing

2021, 54(11):  29-36.  DOI: 10.11930/j.issn.1004-9649.202010100

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Promoting distributed generation to participate in power market transaction is the inevitable requirement of energy development and market development, while the distributed generation can participate in the market through the agent of electricity retailers. Under the background of spot market, by taking distributed photovoltaic (PV) generation as an example, a transaction decision-making model is proposed for coordinated electricity-sale mode with the minimum electricity purchasing cost of retailers as objective. This paper designs a "double-price" contract pricing mechanism for electricity retailers to determine the optimal decision price and settlement price based on the predicted and actual electricity prices respectively. The optimal decision price is used for model optimization, while the settlement price is used for contract settlement, thus realizing the balance of interests of both parties. The proposed mechanism and strategy for coordinated electricity-sale can provide some ideas for the electricity retailers to manage the distributed photovoltaic power generation and promote the effective utilization of distributed photovoltaic power in electricity market, and also can provide the basis for the electricity retailers to participate in the spot market under the new agent relationship.

Strategic Investment and Business Models of Large Centralized Data Centers under the New Power System Reform

LIN Zhengchong, QI Sirui, GOU Jiwei, XU Te, LIU Xuefei, NI Meng, WANG Beibei

2021, 54(11):  37-46.  DOI: 10.11930/j.issn.1004-9649.202103078

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With the rapid development of advanced technologies such as 5G, Internet of Things and edge computing, large centralized data centers are constantly being built. However, the traditional business model of large centralized data centers still has a series of problems such as a single profit model and excessive operating costs, which leads to poor participation of stakeholders in the construction of large centralized data centers. This article starts with the practice of large centralized data centers in China. Then, four new business models of large centralized data centers are analyzed, and an index system is set to evaluate the business models. Finally, some suggestions are put forward for the large centralized data center operators based on the evaluation and analysis.

Three-Stage Bidding Strategy of Generation Company Based on Double Deep Q-Network under Incomplete Information Condition

YANG Pengpeng, WANG Beibei, XU Peng, WANG Gaoqin, ZHENG Yaxian

2021, 54(11):  47-58.  DOI: 10.11930/j.issn.1004-9649.202103163

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In power market with incomplete information, a generation company only knows its own relevant information, while biddings of other market members and market environment may affect the market clearing result, which impacts the generation company’s revenue, so its bidding strategy should consider multi-dimensional market information. On the basis of deep learning reinforcement method, this paper proposes a framework based on the multi-agent DDQN (Double Deep Q-Network) algorithm to simulate the bidding strategy of generation company in the spot market. Firstly, the elements of the Markov Decision Process and action-value function in the model is defined. Secondly, the framework of the generator’s double deep Q network is established and the ε-greedy algorithm and Experience Replay Memory is adopted to train the neural network. The proposed model can make decisions based on multi-dimensional continuous states such as the market clearing price and load levels. Finally, a PJM 5-bus test case is used to compare the rewards obtained by DDQN and traditional Q-learning algorithm. The results shows that the DDQN algorithm can make appropriate decisions according to the complex state while the Q-learning algorithm has poor performance. This paper also analyzes the effectiveness of the generation company’s adoption of the DDQN algorithm for generating market strategy in terms of selection of different state vector, network generalization ability and adaptability to larger-scale calculation examples.

A Comprehensive Evaluation Method for Market Power of Generation Companies Based on Improved Critic-G1 Algorithm

LI Xuesong, JIANG Yu, LIU Xuwen, WANG Yang, DING Yu

2021, 54(11):  59-67.  DOI: 10.11930/j.issn.1004-9649.202101085

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In the field of electricity market, the existence of market power of generation companies will lead to inefficient allocation of electricity resources, harm social welfare, and reduce the efficiency of market competition. This article analyzes the behaviors of generation companies, and establishes a market power risk evaluation index system for generation companies, and applies the improved Critic-G1 comprehensive weighting method to evaluate the market power risk of generation companies in a region. The results of the case study show that the market power levels of generation companies in this region are different. The proposed method in this paper has been applied in a province of East China and achieved good results, which can provide a reference for market operators to effectively identify the market power risks of generation companies.

Multi-time Scale Adaptive Reactive Voltage Control for Distribution Networks Based on Voltage Tendency Coefficient

JIN Ziran, WU Hongbin, ZHOU Yiyao, XU Bin, DING Jinjin, WEI Wei

2021, 54(11):  69-75.  DOI: 10.11930/j.issn.1004-9649.202009131

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With a high proportion of distributed photovoltaic connected to the distribution network, the mismatch between source and load may lead to voltage overlimit. Based on the deviation and fluctuation of the voltage, the voltage tendency coefficient (VTC) for evaluating different operation scenarios of the distribution network is defined and an multi-time scale adaptive reactive voltage control method is proposed in this paper. For the long time scale, a day-ahead optimal dispatch strategy aiming at the optimization of economy and security satisfaction is constructed based on VTC. And for the short time scale, the fixed slope of the traditional droop control is dynamically modified by VTC for releasing the reactive power margin of the photovoltaic inverter. In addition, a feedback correction for the long time scale is added to the short time scale optimization control. With the simulation of the example system, the effectiveness of the proposed reactive voltage control method is verified.

Active Distribution Network Optimal Operation Considering Conservation Voltage Reduction

XING Haijun, XIE Baojiang, QIN Jian, LUO Yangfan, LOU Weiming

2021, 54(11):  76-81.  DOI: 10.11930/j.issn.1004-9649.202103146

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With the goal of carbon neutralization clear, reducing the social energy cost through technical means is of great significance for energy low-carbon transformation. Based on this background, this paper proposes a Conservation Voltage Reduction (CVR) operation method for medium-voltage power distribution system. CVR refers to operating under a lower voltage range on the premise of satisfying the supply voltage deviation, so as to achieve the purpose of energy saving and consumption reduction. The method proposed in this paper adopts the load exponential model and realizes the voltage reduction and energy saving operation through the adjustment of On-Load Tap Changer (OLTC). Coupled with the reactive compensation of the capacitor bank, network reconstruction, and distributed generations (DGs), the regulation guarantees that the voltage reduction operation meets the power quality requirements of the power supply to achieve the minimum total energy consumption of the distribution system within a period of time. Through the analysis of IEEE 33 node distribution system examples, the effectiveness and rationality of the proposed method are verified.

Improvement of Operational Flexibility for Active Distribution Networks Based on Soft Open Points

XU Quan, YUAN Zhiyong, LEI Jinyong, LIN Yuehuan, BAI Hao, LI Peng

2021, 54(11):  82-90.  DOI: 10.11930/j.issn.1004-9649.202003159

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With the high penetration of distributed generators (DGs), it is more complicated for the operational scenarios and puts a higher requirement for the operational flexibility in active distribution networks (ADNs). The operational flexibility of ADNs is based on the controllable resources in it. The increasing integration of flexible resources such as soft open point (SOP) provides opportunities for further improvement of operational flexibility in distribution networks. In this paper, to quantify the improvement of flexibility by SOP, a quantification method of operational flexibility in ADNs is proposed. The definition of operational flexibility is proposed firstly. By constructing a multi-dimensional state space, state equations of operational constraints and an analytical framework for quantifying improvement of operational flexibility are proposed. Then the mathematical expressions of SOP are proposed and the mechanism of improving operational flexibility is discussed. Finally, based on the Monte-Carlo simulation, case studies are performed on the modified IEEE 33-node system to quantify the improvement of operational flexibility by integration of SOP.

Faulted Line Segment Location Method for Low-Voltage Distribution Network Based on Adjacency Matrix

YAO Yongfeng, WANG Qizhe, WANG Huiping, JIA Jia, XIA Xibin

2021, 54(11):  91-96,114.  DOI: 10.11930/j.issn.1004-9649.202105071

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The low-voltage distribution network is characterized by short feeder line sections, a large number of line branches, and a complex and changeable topology, and the integration of distributed generation further complicates the faulted line segment location problem. This paper investigates a novel faulted line segment location algorithm by combining the graph theory and artificial intelligence algorithm. Firstly, the adjacency matrix corresponding to the configuration of the fault monitoring units in distribution network is built, then the connectivity equivalent model of fault current in the topology of fault monitoring units is established. The monitoring information of the fault monitoring unit is calculated according to the shortest path from the power source to the estimated fault line section. Based on these works, the fault line segment location model of low-voltage distribution network considering multiple faults is developed, and the particle swarm optimization algorithm is used to solve the model. The results of simulation examples show that the proposed method can effectively improve the efficiency and accuracy of fault location.

Operation and Application of Flexible Distribution Multi-state Switch With Three Teminals

ZENG Yonghao, FAN Xinming, PENG Yuanquan, LI Xin, ZHANG Ziqi, SONG Guanyu

2021, 54(11):  97-103.  DOI: 10.11930/j.issn.1004-9649.202009103

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The integration of distributed energy resources, such as distributed generators (DGs) can lead to serious operational problems including voltage violations and network congestion in distribution networks. Flexible distribution multi-state switch (FDS) is a novel power electronic device to realize flexible connection among feeders with high operational flexibility. FDS can regulate the power flow in a more secure, reliable and rapid manner. In this paper, a unified mathematical model of active distribution networks (ADNs) is established to analyze the operation optimization and self-healing control with FDS integration. Based on the pilot project with FDS in Foshan, Guangdong, this paper introduces the topology of FDS and the fault self-healing control strategy of the distribution network with FDS. The results show that FDS can effectively improve the network voltage profile and enhance the reliability of power supply.

Cause Analysis and Suppression Strategy of Power System Low-Frequency Oscillation Based on Recording Curves

FANG Risheng, LIN Yaodong, XU Zhenhua, HUANG Ting, HUANG Daoshan, JIANG Wei, LIN Jikeng, ZHANG Jian

2021, 54(11):  104-114.  DOI: 10.11930/j.issn.1004-9649.201911097

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How to swiftly determine the cause of the power system low-frequency oscillation and suppress it effectively is always a subject of great concern. A novel integrated solution is proposed to analyze and suppress the power system low-frequency oscillation based on the recording curves. Firstly, the eigenvalues of the system are analyzed, and the type of the low-frequency oscillation is determined according to whether the system has an oscillation mode consistent with the recording curves. And then, different suppression strategies are adopted according to the type of the oscillation. If the oscillation is a forced one, detect the disturbance source, and eliminate it to suppress the oscillation. If it is caused by the poor damping, determine whether the poor damping is caused by excitation system or governor through analysis of the damping torque of the system. And a power system stabilizer and the optimized governor parameters are proposed respectively to solve the poor damping caused by the excitation system and the governor. The validity of the solution is verified by its application to an actual power system.

Theory and Application of Agricultural Energy Internet Considering Coupling of Agriculture, Meteorology and Energy

MA Lingxi, FU Xueqian

2021, 54(11):  115-124.  DOI: 10.11930/j.issn.1004-9649.202006239

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Under the background of vigorously developing energy internet and building facility agriculture in China, meteorology is an important factor affecting the seasonality of agricultural power load side and the uncertainty of agricultural new energy power generation side. In order to provide new ideas for the mutual promotion of new energy development and agricultural development, it is necessary to study the agricultural energy internet (AEI) of agriculture-meteorology-energy coupling. Based on an investigation of the research status of energy meteorology, agrometeorology and agricultural energy internet, the coupling mechanism of agriculture, energy and meteorology is summarized. The impact of their coupling is studied. The application scenarios of important technologies for dealing with the impact of energy meteorology and agrometeorology are elaborated under the framework of agricultural energy internet system. And the agricultural energy internet of agriculture-meteorology-energy coupling is analyzed from three levels. The results of this paper can provide a reference for the future research of agricultural energy internet.

Distribution Network Fault Type Identification Method Based on Feature-summarizing Matrix

FU Jinwei, SHI Changkai, YIN Hui, GUAN Shilei, WANG Anqi, WANG Yue

2021, 54(11):  125-132.  DOI: 10.11930/j.issn.1004-9649.202003220

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Fast identification of short-circuit fault types of distribution network is the basis for accurate fault removal. A method for detecting short-circuit fault types in distribution networks is proposed based on comprehensive feature-summarizing matrix. This method comprehensively considers the difficulties in short-circuit fault-type identification of distribution networks in the case of long-distance transmission, non-linear load switching, incomplete data volume, noise and high-impedance grounding, and the fault types are identified based on the voltage RMS value obtained by Hilbert transform, the voltage harmonics obtained from the Discrete Fourier transform and the converted voltage information by the Hilbert-Huang transform. The proposed feature-summarizing matrix method was verified through a Simulink simulation test system of a 10kV radial network consisting of three feeders, and compared with the traditional methods, which has proved the accuracy advantages of the proposed method.

Fault Location for Active Distribution Network Based on Improved LMD and Energy Relative Entropy

XU Yanchun, ZHAO Caicai, SUN Sihan, MI Lu

2021, 54(11):  133-143.  DOI: 10.11930/j.issn.1004-9649.202106040

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In view of the characteristics of distribution network with large-scale integration of distributed generation when single-phase grounding fault occurs, such as complex structure and operation mode, obscure electrical quantity after fault, weak fault characteristics and so on, this paper proposes a new fault location method for active distribution network based on improved local mean decomposition (ILMD) and energy relative entropy. Firstly, the mirror extension is used to extend the signals at both ends to eliminate the endpoint effect of LMD. At the same time, the adaptive noise is added to the signal to overcome the mode aliasing problem of LMD, and the ILMD is used to decompose the transient zero sequence current of each section. Then the energy relative entropy of all product functions (PF) after decomposition is calculated. The sum of relative energy entropy of all PF components is the relative energy entropy between sections. The fault section is judged by the positioning criteria set in this paper. Simulation results show that the proposed algorithm has high accuracy in fault location for 10 kV small current grounding system and improved IEEE 33 node system under different simulation conditions, which verifies the accuracy of the proposed method.

Electrochromic and Dielectric Characteristics of Advanced Insulating Polymer under Various Electric Fields

NIE Yongjie, JING Yu, ZHANG Meng, CHEN Haopeng, ZHAO Xianping, ZHAO Tengfei, XIANG Enxin, WANG Ke, LU Guanghao, ZHU Yuanwei

2021, 54(11):  144-152.  DOI: 10.11930/j.issn.1004-9649.202106016

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In order to identify the charged states of power equipment through electrochromism of insulating materials, a regular/irregular poly(3-hexylthiophene) (reg-P3HT/irreg-P3HT) blend film is prepared. The experiment study shows that the reg-P3HT is evenly distributed as nano-scale crystallite morphology on top of the blend film. As the content of irreg-P3HT increases, the blend film shows better insulating performance in the direction of film thickness. When the content of irreg-P3HT reaches 95%, the blend film has a power frequency dielectric constant of 5.86, a volume resistivity of 3.2×10¹² Ω·cm, and a DC breakdown strength of 113 kV/mm. By applying charge accumulation spectroscopy, it is found that when the field strength reaches over 40 kV/mm, the space charges mainly accumulate in irreg-P3HT, and the blend film’s absorption intensity increases with the field strength at 450 nm, triggering the electrochromism of the insulating film. This work provides a new path for testing the charged states of insulating materials of power equipment.

Review on Comprehensive Evaluation of Multi-energy Complementary Integrated Energy Systems

QU Xiaoyun, WU Ming, LI Qi, DING Baodi, ZHAO Fengzhan, KOU Lingfeng

2021, 54(11):  153-163.  DOI: 10.11930/j.issn.1004-9649.202009121

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The integrated energy system is a viable way to deal with the energy and environment crisis, owing to its high comprehensive energy utilization rate, flexible energy supply capability, and environmental friendliness. In this paper, the basic concepts and comprehensive evaluation research progress of multi-energy complementary integrated energy systems are summarized, where the index selection principles, main evaluation indicators and typical application scenarios are highlighted. A conclusion is presented to point out future research directions.

Power-Data-Asset Trading Platform Architecture Based on Double-chained Blockchain

LIN Jieyu, CUI Weiping

2021, 54(11):  164-170,180.  DOI: 10.11930/j.issn.1004-9649.202007119

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This article aims to solve the existing problems of power data asset management in data sharing, data transaction, data security, etc., so as to achieve intelligent control and realize value of power data asset. In the first sector, we discussed data collection and transaction of present power system, and its defects on data management. We then discussed applications of blockchain-data-control and put forward the concept of interactive double-chained blockchain based on principles of genetics. The mechanism and control strategy of interactive double-chained blockchain is analogous to process of transcription, interpretation, expression & regulation and reverse transcription of gene heredity. Interactive double-chained blockchain platform can solve security and complexity issues during power system data transactions, while offering effective scheme to the platform structure.

Key Technologies and Business Model of Shared Towers for Power and Communication

ZHAO Weibo, DONG Yuming, MO Juan, FANG Zhenggang, LIU Rui

2021, 54(11):  171-180.  DOI: 10.11930/j.issn.1004-9649.202002097

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The arrival of 5G communication era provides new opportunities for the development of communication operators, but also brings new challenges. The construction of 5G communication needs more and more iron tower resources. However, the tower companies also face many difficulties such as limited land resources, long construction period and large capital pressure. By mounting the antenna of the communication base station on the power tower, the wider coverage of communication signals can be achieved without building a new communication tower. The shared tower construction needs to consider many issues, such as equipment installation, operation and maintenance, lightning protection and grounding, electromagnetic interference and so on. Based on the analysis of key technologies, this paper firstly proposes three kinds of business models for shared towers, namely, direct leasing, brief leasing and joint venture construction. Based on the actual calculation example and the difference net present value method, this paper analyzes the rental costs under the direct leasing mode, and analyzes the income of the grid company, the tower company and the third-party company in the different business modes. By comparing the income differences of different parties under different rents and contribution shares, the change rule and feasible range of annual rents and contribution shares of the sharing tower are summarized.

Influence of Temperature on Initiation Mechanism of Partial Discharge at the Interface Defects of Cable Accessories

LI Weiwei, ZHU Ke, DENG Yuanshi, WANG Zikang, HUANG Yonglu, ZHOU Kai

2021, 54(11):  181-189.  DOI: 10.11930/j.issn.1004-9649.202010129

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Temperature has an important influence on the partial discharge (PD) development, but the effect of temperature on the PD initiation mechanism is still not fully understood. Thus, this paper investigated the influence of temperature on the PD initiation mechanism at the interface defects of cable accessories. First, the interface unit and defects of cable accessories were designed and simulated, and the PD features of air-gap defects under different temperature were measured. Then, an electrothermal aging platform for cables with semi-conductive-layer protrusion defects was constructed, simulating the influence of cooling and heating loads on the operating temperature of cables through the on-off current. Afterward, the partial discharge inception voltage (PDIV) and the phase resolved partial discharge (PRPD) spectrum of samples were analyzed comparatively. Obtained results showed that, as the test temperature applied on the unit increased, PDIV would decrease from 8.3 kV to 6.9 kV accordingly, and the PRPD spectrum presented obvious internal discharge characteristics. Meanwhile, tests on the actual defects of the cable accessory showed that when the temperature rose quickly, the temporary PD excitation occurred and the number and amplitude of PD increased significantly. When the temperature was stabilized, however, the increment slowed down. The phenomenon can be interpreted through the space charge distribution of the interface due to temperature changes and the “breathing effect” caused by the thermal expansion and contraction of the interface material. The research reveals that PD signals in the interface defect are easier to be detected when cable accessories are operating under high temperature gradient, which may provide theoretical references for the unreliability of traditional PD detection.

Fault Diagnosis Method of Wind Turbine Pitch Angle Based on PCA-KNN Fusion Algorithm

CHEN Xi, LI Luping, LIU Rui, YANG Bo, DENG Zihao, LI Zhonggui

2021, 54(11):  190-198.  DOI: 10.11930/j.issn.1004-9649.202009083

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With regard to the four main fault types of the pitch angle of a wind turbine pitch system and the data analysis of the wind turbine, an identification method of abnormal pitch angles of a wind turbine is proposed, depending on nonparametric kernel density estimation and Relief-F based feature extraction for data processing and the PCA-KNN fusion algorithm for fault diagnosis. Firstly, the SCADA data is preprocessed according to nonparametric kernel density estimation, and seven categories (thirteen) of characteristic parameters of pitch angle faults are extracted by the Relief-F algorithm. Then, the PCA-KNN fusion algorithm is used to identify the state of pitch angle faults, and the results show that the proposed method can accurately identify the four main fault types of pitch angles. Finally, the improved PCA-KNN fusion algorithm is compared with the KNN algorithm, the PCA-KNN algorithm and BP neural network, which proves that the improved PCA-KNN fusion algorithm has a higher recognition rate.

Economic Research on Peak Shaving of Thermal Power Units Considering Safety-Environmental Protection and Compensation

CHAI Youguo, HE Xiaoyan, SU Yongjian, DING Banglin, HU Weiming, YANG Zhiping

2021, 54(11):  199-205.  DOI: 10.11930/j.issn.1004-9649.202010096

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Deep peak regulation of thermal power units is an effective way for renewable energy penetration. Considering the rising coal price, a comprehensive cost model of power generation is established to study the economy of thermal power units participating in peak regulation. The cost of power generation under peak shaving condition is analyzed considering fuel consumption, investment and operation fees, life expenditure and environmental compensation. The model is extended as a benefit analysis model for peak shaving operation by coupling with peak shaving compensation policy. The peak shaving benefits of case study under different loads and coal prices are analyzed by calculating the comprehensive cost of power generation. Moreover, compensation quotation strategies are obtained with different peak shaving benefits.

Security Management and Traceability of Substation Software Versions

LI Jin, ZHANG Ximing, HU Rong, XU Ai, ZHOU Huafeng, QIU Rongfu

2021, 54(11):  206-213.  DOI: 10.11930/j.issn.1004-9649.202007090

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At present, the software and configuration of substation automation equipment have not undergone rigorous testing and verification or centralized management, which has brought great risks to the safe operation and maintenance of substation automation systems. A three-level (network-provincial-local) automated operation and maintenance management system architecture is designed in this paper to realize the centralized and unified management and control of equipment software and other software versions. Based on the digital authentication technology and national secret algorithm, the integrity and traceability of software versions are achieved through digital signature and verification of equipment software in substations. The key contents and innovation in this paper include: (1) the centralized and unified management and control of the substation equipment software and configuration files are achieved through designing a three-level automated operation and maintenance management system; (2) the integrity and traceability of software versions in each process is realized through step-by-step digital signature and verification of equipment software and configuration files using digital authentication technology and national encryption algorithm.

Real-Time Path Planning for Power Tower Inspection Based on Hybrid Algorithm

HUANG Zheng, WANG Hongxing, ZHOU Hang, ZHANG Xingwei, ZHAO Hongwei

2021, 54(11):  214-220.  DOI: 10.11930/j.issn.1004-9649.202003201

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The sequence of conventional shooting viewpoints for power tower is fixed and the inspection distance of multi-rotor UAV is not optimal. In addition, as the dimension increases, the path planning algorithm cannot meet the requirements of real-time path planning because the space complexity increases exponentially. Aiming at those problems, a three-dimensional path planning method for power tower inspection is proposed based on ant colony optimization and A * (ACO-A*) hybrid algorithm. The method is composed of global planning and local planning. Firstly, the global planning uses the ant colony optimization algorithm to find a relatively optimal path that covers all viewpoints, and to judge whether the path passes through obstacles. And then the A* algorithm is used for local planning. The simulation results show that the path length planned by the proposed ACO-A* algorithm is reduced by 16.68% compared to that stipulated in the Shooting Manual for UAV Inspection Images of Overhead Transmission Lines, and the path planning time is reduced by 99.68% compared to that of the A* algorithm. Therefore, the proposed method not only reduces the energy consumption for inspection, but also enhances the efficiency of path planning.

Substation Modelling and Network Security Monitoring Based on Scene Replication Technology

WANG Xiaohu, Guo Guangxin, DONG Jiahan, WANG Lei, CAO Can

2021, 54(11):  221-228.  DOI: 10.11930/j.issn.1004-9649.202004053

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In view of the intelligent demand of the SGCC for safety operation of power grid equipment, a real scene reproduction technology is proposed. A novel substation safety monitoring platform is constructed using deep network architecture displayed with global and local point cloud features. The internet of things (IOT) network directly uses the original point cloud as the input data of the network without the voxel or rendering operation. For power equipment objects, the local geometric dominant subspace of point cloud data is extracted to realize fast data processing, improve the data quality and estimate the point cloud normal vector. The repetition structures in the IOT safety scenario are automatically recognized to realize data augmentation and structure modelling. The proposed algorithm can minimize the fitting error between the model and the original point cloud, so that the three-dimensional model of the power equipment objects can be obtained quickly, and the intelligent understanding and high quality reconstruction of the large scene of transmission and transformation can be realized finally. On this basis, a substation IOT security monitoring platform is established, which can realize accurate modeling and simulation, visual analysis, intelligent management of substations, effectively enhancing the IOT safety monitoring capability of substations.