Software-defined networking (SDN) has emerged in recent years as a form of Internet architecture. Its scalability, dynamics, and programmability simplify the traditional structure. This architecture realizes centralized management by separating control plane data-forwarding network. However, due to this feature, SDN is more vulnerable attacks than networks can cause entire network collapse. DDoS attacks, also known distributed denial-of-service are most aggressive all attacks. These generate...

The rapid development of the power Internet Things (IoT) has greatly enhanced level security, quality and efficiency in energy production, consumption, related fields. However, it also puts forward higher requirements for security privacy data. Ciphertext-policy attribute-based encryption (CP-ABE) is considered a suitable method to solve this issue can implement fine-grained access control. its internal bilinear pairing operation too expensive, which not IoT with limited computing resources....

Renewable energy power plants (REPPs) offer unique fault characteristics that are greatly influenced by the converters. This might cause malfunction of traditional relays. The inverter-interfaced REPPs considered in this paper and their influences to current differential protection configured on transmission line analyzed detail. Firstly, features renewable generators (IIREGs) considering typical controls. Then operation performance is different types capacity IIREPPs. It revealed angular...

With the growing concern about energy and environment, smart grid has been proposed as a standard of future with high power quality, reliability, flexibility efficient access to distributed generations (DG) micro-grids. This paper presents opportunities advantages VSC-based DC technology improve city distribution systems. Conventional CSC-HVDC is costly not feasible in network. Comparison between VSC prevailing AC analyzed detail takes both technically economically. At last, practical...

This paper introduced a feature selection algorithm, used random forest classifier for recursive elimination, and selected the top 49 features according to order of importance ranking, then proposed an attack detection model based on LeNet-5 convolutional neural network named it as LeNet-4 model. In its structure, first pooling layer last fully connection original were removed, which reduced model's computational load complexity, self-learning ability was strengthened through structure...

A dc circuit breaker (DCCB), which can interrupt a fault current, is the key equipment in voltage source converter-based high-voltage (VSC-HVDC) transmission system. However, existing DCCBs cannot balance economy and high reliability, thus preventing their large-scale application. This article proposes new type of forced resonant mechanical (FR-MCB) that generate an unlimited number zero crossings to meet requirements low cost performance. To improve performance interrupting control strategy...

This paper proposes a new scheme of substation area backup protection system based on range information. A configuration relay in smart was proposed firstly, the structure (SABP) introduced, information matrix SABP which can reflect topology established, algorithm proposed, fault-tolerance performance also analyzed. According to analysis fault direction information, current differential as well matrix, carry out location and make reasonable tripping strategy. The result case studies shows...

Reliability is one of the critical issues for a modular multilevel converter (MMC) since it consists large number series-connected power electronics submodules (SMs). In this paper, complete control strategy including fault detection, localization, and tolerant operation proposed MMC under an insulated gate bipolar transistor (IGBT) open circuit fault. According to output characteristics SM with open-circuit IGBT, detection method based on circulating current observation used. order further...

To study the influence of environmental factors such as temperature, humidity, wind speed, and air pressure on detection corona discharge using ultraviolet imaging, rod‐plate gap model was used, video signals AC under different conditions were recorded by CoroCAM504 imager, affecting UV from electrical equipment analyzed. The experimental results show that area spot increases nonlinearly with temperature. decreases increasing a power‐law relationship governs this behavior. At humidity 40 to...

To study the effectiveness of infrared and UV imaging technology to detect zero‐value insulators, thermal images videos insulators at different positions on insulator strings were collected humidities levels pollution. The heat discharge characteristics analyzed. thermal‐electric multi‐physics simulation models established with COMSOL Multiphysics finite element analysis software. temperature electric field distributions string under conditions verified. shows that, dry pollution, did not...

This paper presents a PMU-based state estimation algorithm that considers the presence of voltage source converter-based high direct current (VSC-HVDC) links. The network model VSC-HVDC link with its control modes is developed and then combined an AC to accomplish hybrid AC/DC model. measurement in this properties PMU measurements, thus separating measurements. Additionally, DC measurements are assumed be sampled synchronously, time-stamped reported at same rate as Then, by applying...

The dc circuit breaker (DCCB) is the core equipment for ensuring safe and stable operation of transmission system. It often requires high response times. In recent years, a new type DCCB topology called forced resonant (FR-DCCB) has attracted widespread attention. only small amount power electronic devices to provide mechanical switch zero crossing with <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LC</i> circuit. And this offers...

The inter-transmission of sub-synchronous electrical parameters between AC and DC sides HVDC power transmission system is analyzed by switching functions converter, in term frequency the mechanism oscillations (SSO) grid caused control expounded. By use complex torque coefficients time-domain simulation damping characteristic AC/DC researched detail, principle suppression SSO supplementary controller (SSDC) emphatically discussed, then design approach for modal control-based SSDC proposed....

Automatic Question Answer System (QAS) is a kind of high-powered software system based on Internet. Its key technology the interrelated natural language understanding, including construction knowledge base and corpus, Word Segmentation POS Tagging text, Grammatical Analysis Semantic sentences etc. This thesis dissertated mainly denotation knowledge-information semantic network in QAS, stochastic syntax-parse model named LSF structure constitution QAS. And parameters were exercised; it proved...

Reducing greenhouse gas emissions and governing pollutant would cause real synergy.Therefore, China has proposed achieving the target of reducing fine particulate matter (PM 2.5 ) concentrations to 35 ug/m 3 , as it pollutes most.The prioritized purpose this dissertation is aimed at constructing a comprehensive framework by integrating PM target, influencing factors, countermeasures together shed some new light on problem.A computable general equilibrium (CGE) model containing pollution...

A novel dual-band decoupling method is proposed and applied to millimeter-wave phased array for wide-angle scanning. By introducing comb-shaped branch, "I"-shaped branch grounded vias simultaneously, two kinds of extra paths are generated cancel the inherent couplings at frequencies, respectively, thus achieving decoupling. To verify structure, a broadband magneto-electric (ME) dipole antenna designed, ranging from 24.13 45.17 GHz (60.7 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...

In recent years, the gate driven on array (GOA) has become increasingly popular in a‐Si TFT‐LCD industry. this study, a new GOA circuit was designed by adjusting ratio of inverter TFT size, and operation principle studied detail. The K/P point voltage effectively optimized, which could avoid sharp drop margin during reliability testing at high temperature humidity (60°C/90%, HTHH). used to drive 55” LCD panels that passed 1500‐hour HTHH test, with only 6 V loss compared original circuit's 13...

Abstract This article presents an innovative method for predicting transformer temperature and faults in distribution substations using a digital twin model combined with deep learning techniques. By constructing of the transformer, real-time monitoring precise simulation its operating status are achieved. In prediction process, convolutional neural networks (CNN) long short-term memory (LSTM) fused to mine data features deeply predict future state transformer. The results show that this...