UHV Power Grid Research Articles

Research on electromagnetic scattering characteristics of high voltage transmission lines considering rough surface

With the continuous construction of the UHV power grid in China, the electromagnetic scattering of electromagnetic waves from random rough surfaces will have a certain impact on the passive interference of high-voltage transmission lines. To solve the problem of solving the propagation law of electromagnetic scattering in the electromagnetic interference of high-voltage transmission lines to radio stations, this paper is based on the approximation method and moment method of electromagnetic scattering, This paper explores the influence of lossless rough surface and lossy rough surface on the passive interference of high-voltage tower line, focusing on the influence of sea level and dielectric constant of seawater on the electromagnetic scattering characteristics of the target under the sea background, and obtains the general law.

Application of double core symmetrical phase shifting transformer in power flow regulation of UHV power grid

With the development of society, the demand for electric energy is growing day by day. However, the energy centers and load centers are geographically distributed in a reverse direction, so the power supply and demand are unbalanced. High voltage transmission lines are characterized by long distance and large capacity, and the power flow problems are increasingly prominent. In order to flexibly adjust the line power flow, improve the comprehensive utilization of grid assets, and improve the transmission capacity of the system, this paper analyzes the principle of double core symmetrical phase-shift transformer (DS-PST) and the application of power flow regulation. Firstly, the basic principle of phase shifting transformer is analyzed in detail, and the equivalent mathematical model of DS-PST and the calculation of main parameters are derived. Impedance coefficient and excitation coefficient are introduced to modify the parameter design of DS-PST. Then, an electromagnetic simulation model is established to verify the effectiveness of the design method. Finally, a system simulation model is built to verify the power flow regulation effect of DS-PST by taking 500 kV UHV power grid and IEEE standard multi-node system as examples. DS-PST can transfer the active power transmitted by the lines with high load rate to the lines with low load rate, which makes the power flow distribution of the system more balanced and effectively improves the transmission capacity of the power system.

Design of Infrastructure for Pumped Storage Power Station and Automatic Monitoring System Using Geographic Information System

The pumped storage power station realizes grid connected power generation through the conversion between the potential energy of surface water and mechanical energy. It has become the strategic resource of UHV power grid with its low valley peak regulation and emergency standby function. The green basic design and design of the pumped storage power station needs systematic research. Based on the collaborative analysis method of production and ecological safety of storage disk, this paper takes Ninghai pumped storage power station as an example to carry out green infrastructure planning and design research. Through the comprehensive evaluation and analysis of construction land based on GIS, from the perspective of adaptability of power station construction to mountain creek pit environment, the function of horizontal layout is constructed in parallel and vertical layout, and a modular and distributed spatial structure of green infrastructure is constructed; Then, based on the continuous recycling of water resources, the monitoring and early warning system of power plant production ecological safety is constructed, which is “one water, two lines and three slopes”. It is hoped that the correlation between the production and the ecological dispatching of the storage tray can be found through the dynamic tracking of multiple factors and quantitative analysis of production cycle, which can provide reliable basis for timely mitigation of damage and formulation of compensation strategies, Scientific control of green infrastructure planning, design and construction.

Influencing factors and countermeasure analysis of a 800kV coupling capacitor dielectric loss test

The coupling capacitor is installed on the AC bus side of the converter station for AC filtering to filter out a large amount of harmonics generated by the converter during the AC/DC conversion process. Therefore, the reliability assessment test of its insulation status is of great importance to the safety and stability of the UHV power grid Meaning. In the UHV field test, the dielectric loss factor of the coupling capacitor is tested at a voltage of 10 kV and below, but the device itself has the Garton effect, and the abnormal data measured at some times cannot truly reflect the insulation state of the device. The thesis analyzes the abnormality of the dielectric loss factor test data of 800kV coupling capacitors in UHV converter stations from the structure, use conditions and test methods of the equipment, and gives a detailed analysis of the causes of the abnormality. Recommendations for operation.

The Electromagnetic Environment Analysis of Transmission Engineering in UHVDC Converter Station Based on Computer

UHVDC conveyance lines and unique advantages play a very special role in the construction of UHV power grid strategy. However, people gradually found that its related electromagnetism condition has become an important factor limiting its future development. At present, the problem of electromagnetic discharge in the living room and the electromagnetic discharge in the living room have aroused the attention of the experts[1]. First, this paper briefly describes the characteristics of UHVDC conveyance technique and the support of main equipment. Then, this paper describes the electromagnetic environment analysis of the UHV DC converter station transmission project based on the computer. Finally, the conclusion is drawn.

Research on application scheme of UPFC in UHV power grid based on multi-objective evaluation

UPFC can distribute the line transmission power rationally and improve the stability of power grid operation, which is not only the focus of the current attention of the engineering community, but also the hot spot in the academic field. Aiming at the application of UPFC in UHV power grid, this paper first introduces UPFC’s principle and function. Based on the analysis of the problems in UHV power grid planning, this paper proposes the UPFC application scenarios in UPFC power grid. Then using BPA simulation platform, this paper calculates and analyzes the feasibility of each UPFC alternative location in different scenarios. Finally, based on the fuzzy evaluation, the comprehensive evaluation of each scheme in technical level is carried out. The results show that UPFC has strong capability in improving the transmission capability and improving the system voltage, which can solve the problems that UHV Power Grid will face effectively.

Research on the Operation and Inspection System of UHV and Cross-Regional Distribution Network Based on Big Data Technology

With the development of UHV and cross-regional distribution network, the operation and inspection of electric transmission and transformation equipment need to use big data and other new technologies to build a smart grid operation and inspection system, in order to better support the operation and inspection business. This paper analyzes the new development situation of UHV and trans-area power grid and the demand of smart grid operation and inspection service under the new situation. Combining big data analysis technology with production command and management practice, based on data and business requirements, this paper puts forward the data architecture of intelligent operation and inspection system according to big data technology, gives the technical framework and technology selection of intelligent operation and inspection system, then analyzes the application framework of intelligent operation and inspection service. The whole architecture of intelligent operation and inspection system is proposed, which provides better support for the development and application of intelligent operation and inspection system through the key architecture design. It has far-reaching application value and broad application prospect.

GMAW welding process training for high neck flange of thin-walled tube of transmission tower

In order to meet the increasing demand for transmission and improve the transmission and economic performance, the development of UHV power grid is the commanding heights of the global transmission technology competition in the future.[1] with the development of welding manufacturing technology, a steel tower with steel tube and flange as main component has been invested in the transmission line. The welding process performance has become an important part of quality assurance for transmission line. In the manufacturing process, thin walled pipe and neck flange welding, because of reducing the pipe diameter and wall thickness, accordingly put forward some new difficulties for its welding process. According to the welding technology characteristics of thin-walled pipe and neck flange, the corresponding welding training process is worked out, and training for relevant employees is carried out, so as to achieve the purpose of controlling the welding process and improve the qualification rate of products at a time.

Study on the ability of Shanghai UHV AC grid access point voltage regulation

Shanghai as China’s highest load density and largest urban power grid, located in the end position of East China Power Grid, is an important access point of East China UHV AC power grid. Making sure the voltage of UHV power grid placement has enough regulation ability is an important condition for safe operation of the system. The basic measures of system voltage regulation are given and the possible problems of voltage of UHV power grid are analyzed in the actual operation. Using sensitivity analysis method to calculate the ability of Shanghai UHV power grid placement voltage regulation after East China UHV AC target grid operation.

A Review on Research Methods of Disturbance Propagation in Large-Scale Power Grids

Nowadays, our country has entered the era of UHV and large-scale power grid, the scale of power grid is increasing continuously, which has contributed to develop the optimal allocation of resources adequately, meanwhile, the possibilities of the occurrence of large-scale blackouts increased, posing a new challenge for security and stability controlling for power system. Therefore, a growing number of scholars began to focus on the process of disturbance propagation, which can help us gain deeper insight into the performance of power system and offer some valuable suggestion for controlling measurements. Based on the current research status about disturbance propagation, research methods used to reveal the mechanism of disturbance propagation were classified into five types: time-domain simulation methods and their counterparts with transient energy function, linearization analysis, flow analysis algorithms and graph theory analysis methods included. Meanwhile, every existing method was described in detail from four different aspects: concept, present status and hotspots, critical difficulties, future direction. Finally, the future development trend in the field is focused.

Research of Comprehensive Compensation of Harmonics, Reactive current and DC Bias in UHV Power Grid

A comprehensive compensation device with paralleled decoupling for suppressing harmonics current, reactive power, and DC Bias of power transformer is proposed. Harmonics current and reactive current are detected by instantaneous reactive power theory. In this way, the fundamental active power is converted to be compensated reactive power and harmonics by controlling the converter. Compared to the ASVG with IGBT, the capacity and withstanding voltage level of ASVG with GTO are improved. The voltage across the devices of APF with multi-level inverter is reduced because of the paralleled decoupling connection. The harmonics compensation with multi-stage inverter can also reduce the voltage across the devices effectively. The reactive power compensator can work as a controllable rectifier and output controllable current by changing control algorithm. This current injects neutral point of transformer and suppresses its DC Bias, which has obvious effect on a power transformer. As a part of intelligent power grid, this compensator plays an important role for the development of smart grid automation.

Calculation of geomagnetically induced currents reactive power loss disturbance in China’s UHV power grid considering the influence of 500 kV power grid

Geomagnetically induced currents (GIC) in power systems which are generated during magnetic storms, increased reactive power consumption in transformers, it is necessary for geomagnetic storms disaster prevention in power system to calculate GIC-Q increment and recognize voltage changes of substation nodes under simultaneity and proruption of massive GIC-Q loss disturbance in whole power grid. A method combines U - I curve and transformers’ reactive loss coefficient parameter K is proposed to calculate transformers’ GIC-Q increment, based on the GIC data of 1000 kV UHV power network in China, and considering the influence of 500 kV transformers’ GIC-Q loss on 1000 kV power grid, we used the Newton method to calculate voltage fluctuation of 1000 and 500 kV power grid under GIC-Q disturbance. At last, the impact of the simultaneity of massive GIC-Q loss on the 1000 and 500 kV grid is analyzed, we investigated the mutual influence between these two power grids under all circumstances. The results show that 1000 kV Fuzhou substation has a maximum voltage fluctuation that drops by 74.48 kV, whose voltage deviation compared with normal shows a decrease of 7.13%, which beyonds the regulation that the operating voltage deviation should not exceed ±5%. And whether the suddenly voltage drop of 74.48 kV can lead to the reduction of SVC devices reactive power output, and the simultaneity of massive GIC-Q loss as well as the suddenly reduction effect of SVC reactive power output need to be further researched.

Component Analysis and Calculation for Social Benefits of UHV Assessment

With the rapid development of the UHV power grid, evaluation of the economic and social benefits of the UHV power grid is conducive to guiding the planning and construction of UHV power grid. At present economic benefit evaluation system of the UHV power grid is driving to maturity stage on the whole at home and abroad, but it invariably tends to regard social benefits as part of economic benefits, without evaluating social benefit separately. The social benefit evaluation model of UHV power grid is built in case of sufficient investigation. The differentials between social benefit and social cost are calculated respectively by three kinds of solutions according to the constructed social cost evaluation index system and social benefits evaluation index system, conclusion that UHV power grid transmission has better social benefits can be reached by contrastively analyzing the social three kinds of solutions corresponding to benefits. At last, the evaluation model and method are verified and analyzed through the analysis of engineering projects.

Analysis of Limiting Measures of Three-phase Short-circuit Current of 500kV Intensive Receiving-end Power Grid in the Early Stage of UHV Construction

This paper took the intensive receiving-end power grid as the research object and analysed the problems of three-phase short-circuit current over-limited of 500kV intensive power grid in the early stage of UHV construction. Firstly, this paper analysed the influence factors of the short-circuit current based on self-impedance analysis model of two-port network theory and the equivalent model of UHV power grid. Then, the applicable current-limiting measures were put forward. Finally, this paper proposed one scheme to solve the problems of three-phase short-circuit current over-limited of 500kV buses in one practical receiving-end power grid and verified the feasibility of this scheme from three different aspects. Aiming at the over-limited influential factors, the applicable current-limiting measures can be taken as follows: separating the 500kV bus at UHV substation, lapping the lines outside the substation and decentralizing the power supplies. The proposed measures can effectively solve the problems of short-circuit current over-limited in the early stage of UHV construction and provide reference for other power grid.

Study on Effect of UHV Power Grid Construction Schemes on Short Circuit Current

The commissioning of Southern Hami-Zhengzhou ±800 kV UHVDC transmission project has important significance to heighten operation reliability, transfer capability and supply electric ability of Henan power grid. However, short circuit currents of 500 kV buses in the Center of Henan are almost close to the operation upper limitation. In order to decrease the short circuit currents effectively, it’s necessary to strengthen the network structure of Center of Henan power grid and calculate short circuit currents. Two schemes of strengthening the network structure of Center of Henan power grid are studied. The calculated values of short circuit currents of some important 500 kV buses in the two schemes are still bigger than excepted. According to the latest Plan of State Grid, Yubei UHV substation and Zhumadian UHV substation located in Henan power grid. The calculated values of short circuit currents of some important 500 kV buses with the commissioning of Yubei UHV and Zhumadian UHV are qualified. So, reasonable network structure with UHV is suitable to heighten transfer capability and supply electric ability of Henan power grid.

Research on UHV Grid Construction and Development in China

State Grid Company put forward for the first time the building schedule of the 8 ultra-high voltage (HUV) lines included in Atmospheric Pollution Prevention Plan in mid-2014 work conference, which will start construction before the first half of next year. UHV grid in China is in full speed construction phase. This paper analyzed the internal contradiction between energy distribution and social development, and pointed out the center position of electric power in energy development, finally gave a detailed analysis of the necessity of the construction of UHV power grid.

Risk Analysis about Operation of UHV Power Grid Operation and Maintenance Based on Security Benchmarks

For high risk issues of UHV power grid construction and operation in considering the economic premise, based on the requirements of grid construction security baseline. The various factors affecting the risk is scoring by strict rules. Various factors characteristic index value can be drawn and create a collection of various factors affecting the risk. Then referring to safety baseline of grid construction, the risks that exist in construction and operation of the power grid is determine. According to a number of factors, the risk values is divided into the corresponding level of risk. The different level of risk should take appropriate measures to achieve as much as possible to reduce risk and protect the power grid construction and operation security. Finally, the method is proved to be operability in the context of economic in practice.

Research of “Foreign Electricity to Enter Jiangxi” Ensure Electricity Supply

In this article, it describes the energy supply and demand situation in Jiangxi Province. To forecast the electricity demand in Jiangxi Province, in-depth analysis the significance of implements the strategy of “Foreign electricity to enter Jiangxi”. In accordance with the national UHV power grid development plan, Combined with characteristics of Jiangxi 500 kV main grid architecture, formulate overall objectives and specific programs of “Foreign electricity to enter Jiangxi”, put forward “Foreign electricity to enter Jiangxi” strategy safeguards.

Analysis of UHV Power Grid Operation and Maintenance System Construction and Optimization Strategy - Taking Shan-Xi UHV Grid as an Example

Compared with the traditional power grid, UHV power grid has the character of stronger system function, higher control requirement, and also set a higher request to the daily maintenance management. The operation and maintenance experience of Shan-xi province electric power company on the UHV power grid proved the importance of establishing the new mode of management, strengthening the application of automation technology, and guarenteeing the technology and resources . In order to improve the efficience and quality of UHV power grid operation and maintenance, we should speed up the formulation of operation guidelines for UHV live working and strengthen personnel training and reserve technical talents.

Architecture and Key Technologies of Intelligent Dispatching Based on Situational Awareness

With the construction of UHV power grid, integration of large-scale renewable clean energy, and large-scale energy base putting into operation, the power grid dispatching faced with more and more complex challenges. On the basis of existing research results, architecture of intelligent dispatching based on situation awareness is proposed, so as to accurately achieve prevention and control of the power system. The shortcomings of traditional dispatching mode are analyzed firstly, and the concepts and characterization approaches of grid situational awareness and operation state trajectory of power grid are then introduced. The overall objective of intelligent dispatching is presented, including data processing and integrated knowledge mining, predictive perception of grid operation, risk analysis and comprehensive early warning, so as to achieve "automatic cruise under normal operating conditions, automatic navigation under abnormal operating conditions ". The functional framework of intelligent dispatching is also proposed in details, including four major aspects of the perception and forecasts, risk analysis, decision-making support, and automatic control, as well as three supporting functions such as post-assessment of dispatching, trajectory index calculation, and human-computer interaction (HCI).Technical innovations to support automatic intelligent dispatching are discussed and organised in three levels, i.e. perception, comprehension and projection. The breakthroughs are: construction of index system, trajectory recognition based on massive information and knowledge mining, trajectory projection taking into accounts the uncertainties, online risk assessment and early warning, power grid intelligent decision-making support, automatic coordination of grid operation control, online assessment, natural human-computer interaction mode, and etc... These are the future research areas of automatic intelligent dispatching.