Transmission Line Security Research Articles

Research on detection of transmission line corridor external force object containing random feature targets

With the objective of achieving “double carbon,” the power grid is placing greater importance on the security of transmission lines. The transmission line corridor has complex situations with external force targets and irregularly featured objects including smoke. For this reason, in this paper, the high-performance YOLOX-S model is selected for transmission line corridor external force object detection and improved to enhance model multi-object detection capability and irregular feature extraction capability. Firstly, to enhance the perception capability of external force objects in complex environment, we improve the feature output capability by adding the global context block after the output of the backbone. Then, we integrate convolutional block attention module into the feature fusion operation to enhance the recognition of objects with random features, among the external force targets by incorporating attention mechanism. Finally, we utilize EIoU to enhance the accuracy of object detection boxes, enabling the successful detection of external force targets in transmission line corridors. Through training and validating the model with the established external force dataset, the improved model demonstrates the capability to successfully detect external force objects and achieves favorable results in multi-class target detection. While there is improvement in the detection capability of external force objects with random features, the results indicate the need to enhance smoke recognition, particularly in further distinguishing targets between smoke and fog.

Detection of bird species related to transmission line faults based on lightweight convolutional neural network

Efficient bird damage prevention of transmission lines is a long-term challenge for power grid operation and maintenance. An approach combined lightweight convolutional neural network (CNN), image processing and object detection is presented in this paper to detect typical bird species related to transmission line faults. An image dataset of 20 bird species that threaten transmission line security is constructed. The YOLOv4-tiny algorithm model is constructed and trained combining stage-wise training, mosaic data enhancement, cosine annealing, and label smoothing. The mean average precision (mAP) can reach 92.04% on the test set by adjusting the parameters of the training process. Then, the validity of the proposed method is verified according to the test results and performance indexes by comparing with other methods, including Faster RCNN, SSD, YOLOv4 etc. Some image pre-processing methods such as motion blur, defocus blur, contrast and brightness adjustment are used to simulate the scenarios in practical engineering applications. The proposed method can detect bird species perched around transmission lines with high-efficiency, which is useful for differential prevention of bird-related outages of power grids.

Fuzzy Dynamic Thermal Rating System-Based SIPS for Enhancing Transmission Line Security

The increased integrations of intermittent renewable energy sources into power systems cause more power grid congestions and therefore system operators need more advanced control to relieve this pressure. The dynamic thermal rating (DTR) system is able to increase the thermal constraint and subsequently maximum loading of existing lines. This dynamic rating is achieved through real-time considerations of weather data and it is usually much higher than the traditional static thermal rating system. The operational tripping scheme (OTS), a variant of the wider system integrity protection scheme, also relieves line congestions but it does this by tripping pre-selected generators and this have the unwanted consequence of reducing power adequacy. This paper proposes the novel integration of DTR and OTS, while considering the inherent uncertainties of their sensors based on fuzzy numbers, to avoid unnecessary generation tripping due to conservative line ratings. This novel Fuzzy-DTR-OTS delays the tripping of generations, enhances the adequacy of power supply, improves system security and avoids high risk cascading black out inducing events.

An Efficient Perspective of Neuro Fuzzy on Fog Net work for Latency Driven View Point

In the present milieu, changes in guidelines and the opening of intensity markets have showed as enormous measure of intensity move across transmission lines with visit changes in stacking conditions dependent on advertise cost. Since ordinary separation transfers may consider power swing as a shortcoming, stumbling in view of such breaking down would prompt genuine ramifications for power framework strength. A recurrence area approach for advanced handing-off of transmission line flaws relieving the unfriendly impacts of intensity swing on customary separation handing-off is introduced. A wavelet-neuro-fluffy consolidated methodology for deficiency area is likewise exhibited. It is not the same as customary calculations that depend on deterministic calculations on a well-characterized model for transmission line security. The wavelet change catches the dynamic qualities of flaw signals utilizing wavelet multi goals examination coefficients. The fluffy surmising framework and the versatile neuro fluffy derivation frameworkare both used to extricate significant highlights from wavelet MRA coefficients and in this manner to arrive at resolutions with respect to blame location.The results contained here approve the prevalence of the methodology over the for deficiency area.

Modeling and Analysis of Progressive Ice Shedding along a Transmission Line during Thermal De-Icing

Progressive ice shedding (PIS) along transmission lines is a common type of ice shedding during thermal de-icing that requires investigation to ensure the security of transmission lines. In current research, PIS is commonly analyzed using a constant speed for ice detaching from the conductor, which is not accurate for PIS simulation. Therefore, a mechanical model of PIS is established in this study to analyze PIS during thermal de-icing. First, an ice detachment model during thermal de-icing is built to determine the detachment times of the initial ice and remaining ice. Then, a two-node isoparametric truss element is employed to derive the static and dynamic equilibrium equations of an iced conductor to simulate the dynamic response of PIS. Relative to commercial software, these equations can easily accommodate the changing mass of ice with the flow of melted water. The dynamic equilibrium equations are then solved using the ice detachment model to obtain the dynamic response of PIS. Finally, small-scale and full-scale experimental results are employed to verify the proposed method. The simulation results show that the results of the proposed method are more consistent with the experimental results than are the results of existing methods that assume a constant propagation speed. The proposed method can be further applied to optimize transmission line designs and evaluate the application of thermal de-icing devices.

Dynamic Network Topology Control of Branch-Trimming Robot for Transmission Lines

With the development of engineering technology, the distributed design-based Branch-Trimming Robot (BTR) has been used to ensure the power supply security of transmission lines. However, it remains difficult to combine distributed BTRs with a wireless sensor network to build an efficient multi-robot system. To achieve this combination, a dynamic network topology control method was proposed, combining the motion characteristics of robots with the structure of a distributed wireless sensor network. In addition, a topology-updating mechanism based on node signal strength was adopted as well. To achieve efficient data transmission for distributed multi-robot systems, the present study focused on the design of a distributed network model and a dynamic network topology control strategy. Several simulation and test scenarios were implemented, and the changes of network performance under different parameters were studied. Furthermore, the real scene-based dynamic topology control method considers the relationship between network performance and antenna layout.

Gravitational search algorithm applied to fixed head hydrothermal power system with transmission line security constraints

Optimal operation and production planning are important problems for electric power generation systems. Optimal operation of an energy generation system conventionally refers to the minimization of total thermal fuel cost (TTFC). However, the presence of thermal and hydraulic generation units in a power system requires that hydraulic as well as thermal constraints be added to a problem, which is referred to as a short term hydrothermal coordination problem (STHCP). STHCPs assume that the amount of water in the reservoirs of a hydraulic generation unit has no effect on power generation when its net heads are fixed. This study applied a gravitational search algorithm (GSA) for the solution of a STHCP with fixed head. The probable electrical and hydraulic constraints of the problem have been provided by punishment function method. Line losses of the power system were calculated using the Newton-Raphson load flow method. Two different cases, where transfer capacities of transmission lines were neglected and included, were set up, and the problem was solved for both cases. Transfer capacities of transmission lines were included to make the problem more complex and realistic. Solutions for both cases were discussed.

A Model for Calculating Core Temperature of Bare Overhead Conductor Based on Neural Network

Operation Security of transmission line is affected by operating temperature of bare overhead conductors. IEEE Standard Model has reflected that the current of a conductor should be decreased when the temperature difference between the core and surface exceed the special value. In order to accurately estimate the operating risk of bare overhead conductors, a model is proposed to calculate core temperature of a conductor based on BP neural network in this paper. An experimental plate was designed to validate the proposed model under the free convection and forced convection condition. The experimental and calculated results are analyzed and discussed.

Study on Remote Monitoring System of Crossing and Spanning Tangent Tower

In order to grasp the vibration state of overhead transmission line and ensure the operational security of transmission line, the remote monitoring system of crossing and spanning tangent tower was studied. By use of this system, the displacement, velocity and acceleration of the tower, and the local weather data are collected automatically, displayed on computer of remote monitoring centre through wireless network, real-time collection and transmission of vibration signals are realized. The applying results show that the system is excellent in reliability and accuracy and so on. The system can be used to remote monitoring of transmission tower of UHV power transmission lines and in large spanning areas.

Atmospheric icing status and type of southwest China networks

Transmission line disconnection, tower collapse and insulator flashover caused by icing seriously threaten power system security. Ice type and state of transmission lines, which vary a lot with terrain and climate, in typical areas such as Daqing-ridge, Yak Mountain and Erlang Mountain in Sichuan Province in South China were investigated in this paper. It is shown that mixed-phase ice with obvious layered structure, low density, strong adhesive force and windward-side growth is the main type of ice threatening the security of transmission lines and insulators. There is more ice on the ends of insulators than other areas in severe cases, where all sheds of the insulator is bridged by ice. Besides, temperature, humidity and precipitation intensity are main factors influencing the icing process. As a result, terrain and climate play a leading role in determination of icing type and severity.

输电线路智能监测系统通信技术应用研究

本文从输电线路智能监测系统通信网络架构、通信需求分析出发，研究智能在线监测系统的四种通信组网模式和传输通道要求，提出输电线路智能监测系统通信解决方案。在输电线路智能监测系统应用中，通过“EPON + 宽带无线MESH”、“工业交换机 + 宽带无线MESH”、“光纤 + 分布式无线宽带系统”、无线公网等多种方式的介绍和方案优缺点分析，因地制宜的选择合适的通信模式，实现电力输电线路及杆塔运行状态实时监控，可有效提高输电线路安全性。 On the basis of the intelligent monitoring system communication network architecture and communication needs analysis, we have researched the requirements of the intelligent online monitoring system of four kinds of communication modes and the transmission channel, and discussed the solution of the transmission line communication intelligent monitoring system. In the application of intelligent monitoring system for transmission line, through the “EPON + broadband wireless MESH”, “industrial switches + broadband wireless MESH”, “fiber + distributed wireless broadband system”, the wireless public network and other means of introduction and scheme analysis of advantages and disadvantages, we chose an appropriate communication mode to suit one’s demand to local conditions, to achieve real-time monitoring of power transmission lines and tower operation state, which can effectively improve the security of transmission line.

Optimal Allocation of FACTS Devices in Distribution Networks Using Imperialist Competitive Algorithm

FACTS devices are used for controlling the voltage, stability, power flow and security of transmission lines. Imperialist Competitive is a recently developed optimization technique, used widely in power systems. This paper presents an approach to finding the optimal location and size of FACTS devices in a distribution network using the Imperialist Competitive technique. IEEE 30-bus system is used as a case study. The results show the advantages of the Imperialist Competitive technique over the conventional approaches.

Safety Risk Analysis of the Transmission Line Project Affected by Dangerous Slope Rock

The unstable slope rock is one of the geological disasters of mountains along the transmission lines, which includes the falling style and the slumping type, and the former is very dangerous, and threat to the security of transmission line. By means of a typical example study about the falling dangerous rock mass along the 10kV transmission lines, this paper analyzes qualitatively the basic characteristics, failure mechanism, influencing factors of the dangerous rock, et al., and calculated quantitatively the maximum depth affected by the impact of the dangerous rock to the transmission lines. The paper proposes the response measures of dangerous rocks risk, which is of a certain reference in other similar projects.

Power Line Measurement Method Based on Vertical Baseline Stereo Camera

Conducting regular inspections and measurements of power lines is an important way to ensure the stability and security of transmission line. For the problem of being poor reliability, poor flexibility and high cost, a power line measurement method based on vertical baseline photography is proposed and studied: Line patrol officers use portable vertical baseline stereo camera shooting in the outdoor field, and measure accurately in the stereo image taken in or after patrol. This paper describes the system design and technical methods, and analyzes the key technologies in the system calibration and measurement, and uses several sets of experiments to prove the accuracy and feasibility of this method.

Security Constrained Stochastic Multi-objective Optimal Power Dispatch

A stochastic multi-objective line security constrained problem is formulated to minimize non-commensurable objectives viz. operating cost, polluting gaseous emission and variance of active power generation and reactive power generation, with explicit recognition of statistical uncertainties in the thermal power generation cost coefficients, gaseous emission coefficients, power demands and hence power generations and bus voltages, which are considered random variables. Specific technique is put forth to convert the stochastic models into their respective deterministic equivalents. Fuzzy set theory has been exploited to evaluate the different objectives that are quantified by defining their membership functions. Security of transmission lines with respect to expected active power flow is considered in the form of fuzzy objective function. The solution set of such formulated problems is non-inferior due to contradictions among the objectives undertaken. The weighting method is used to simulate the trade-off relationship between the conflicting objectives in the non-inferior domain. Generally, the weights are either simulated or searched in the non-inferior domain. In the paper Evolutionary search technique is implemented to search the ‘preferred’ weightage pattern in the non-inferior domain, which corresponds to the ‘best’ compromised solution. Among the non-inferior solutions, the system operator selects the ‘preferred’ optimal operating point that provides maximum satisfaction level of the most under achieved objective in terms of membership function and is termed as fitness function. The validity of the proposed method has been demonstrated on an IEEE system comprising of 11-nodes, 17-lines and 5-generators.

A Simulated Annealing-Based Goal-Attainment Method for Economic Emission Load Dispatch with Nonsmooth Fuel Cost and Emission Level Functions

A novel multiobjective optimization method for economic emission load dispatch (EELD) with nonsmooth fuel cost and emission level functions in power system operation andscheduling phases is presented. In this paper, the problem treats economy, emission, and transmission line security as competing objectives. The load constraints and operating constraints are taken into account. Assuming that the decision maker (DM) has goals for each of the objective functions, the multiobjective problem is converted into a single-objective optimization by the goal-attainment method, which is then handled by the simulated annealing (SA) technique. The solution methodology can offer a global or near-global noninferior (best compromising) solution in a sense close to the DM's requirements. Results for a sample test system have been presented to demonstrate the applicability and validity of the proposed method.