It is important for the safety of transmission system to accurately calculate single-phase earth fault current distribution.Features of double sided elimination method were illustrated.Quantitative calculation of sing...It is important for the safety of transmission system to accurately calculate single-phase earth fault current distribution.Features of double sided elimination method were illustrated.Quantitative calculation of single-phase earth fault current distribution and case verification were accomplished by using the loop method.Influences of some factors,such as single-phase earth fault location and ground resistance of poles,on short-circuit current distribution were discussed.Results show that:1) results of the loop method conform to those of double sided elimination method;2) the fault location hardly influences macro-distribution of short-circuit current.However,current near fault location is evidently influenced;and 3) the short-circuit current distribution is not so sensitive to the ground resistance of poles.展开更多
The goal of this work is creation of optimal grounding model at the substation 10/0.4 kV of the urban power distribution network. The electric current can pose a major threat to the man’s life and health. In addition...The goal of this work is creation of optimal grounding model at the substation 10/0.4 kV of the urban power distribution network. The electric current can pose a major threat to the man’s life and health. In addition to pose a threat for health, the rise of the short circuit, as a consequence of insulation faults, poses a threat to retirement of electric systems and fire risks. The reliable grounding system design has significant implications for protection of human being as well as for electrical facility protection. The set objective was performed on the base of analytical and software-based methods. Analytical method gives a qualitative indication at each step in analysis. It also allows evaluating the values effect on the result, but the method is not susceptible of tolerable accuracy, that is why analytical method serves as initial approximation in differentiating. Specified estimation can be performed in such software package as MATLAB or ETAP. Software-based estimation is based on the finite element method (FEM), the main advantage of which is the ability to create different forms of grounding and allows obtaining distribution graphs of the step potential on the earth’s surface and touch potential. The calculation results in comparison of analytical and software-based methods taking into account the grounding optimization. There are conclusions on the most effective ground network.展开更多
研究3.0百万吨每年(Million Tonnes Per Annum,MTPA)浮式液化天然气生产储卸装置(Floating Liquefied Natural Gas Production,Storage and Unloading Device,FLNG)配电系统。根据3.0 MTPA FLNG的典型工况,分析其电力负荷和发电机组配置...研究3.0百万吨每年(Million Tonnes Per Annum,MTPA)浮式液化天然气生产储卸装置(Floating Liquefied Natural Gas Production,Storage and Unloading Device,FLNG)配电系统。根据3.0 MTPA FLNG的典型工况,分析其电力负荷和发电机组配置,并从经济性和可靠性等方面对比不同电压等级配电系统型式,包括馈线式配电网和环式配电网。对较大容量配电系统设计中的关键点进行研究,包括中压配电系统保护、单相接地故障电容电流、中性点接地方式选择和功率管理系统。展开更多
文摘It is important for the safety of transmission system to accurately calculate single-phase earth fault current distribution.Features of double sided elimination method were illustrated.Quantitative calculation of single-phase earth fault current distribution and case verification were accomplished by using the loop method.Influences of some factors,such as single-phase earth fault location and ground resistance of poles,on short-circuit current distribution were discussed.Results show that:1) results of the loop method conform to those of double sided elimination method;2) the fault location hardly influences macro-distribution of short-circuit current.However,current near fault location is evidently influenced;and 3) the short-circuit current distribution is not so sensitive to the ground resistance of poles.
文摘The goal of this work is creation of optimal grounding model at the substation 10/0.4 kV of the urban power distribution network. The electric current can pose a major threat to the man’s life and health. In addition to pose a threat for health, the rise of the short circuit, as a consequence of insulation faults, poses a threat to retirement of electric systems and fire risks. The reliable grounding system design has significant implications for protection of human being as well as for electrical facility protection. The set objective was performed on the base of analytical and software-based methods. Analytical method gives a qualitative indication at each step in analysis. It also allows evaluating the values effect on the result, but the method is not susceptible of tolerable accuracy, that is why analytical method serves as initial approximation in differentiating. Specified estimation can be performed in such software package as MATLAB or ETAP. Software-based estimation is based on the finite element method (FEM), the main advantage of which is the ability to create different forms of grounding and allows obtaining distribution graphs of the step potential on the earth’s surface and touch potential. The calculation results in comparison of analytical and software-based methods taking into account the grounding optimization. There are conclusions on the most effective ground network.
文摘研究3.0百万吨每年(Million Tonnes Per Annum,MTPA)浮式液化天然气生产储卸装置(Floating Liquefied Natural Gas Production,Storage and Unloading Device,FLNG)配电系统。根据3.0 MTPA FLNG的典型工况,分析其电力负荷和发电机组配置,并从经济性和可靠性等方面对比不同电压等级配电系统型式,包括馈线式配电网和环式配电网。对较大容量配电系统设计中的关键点进行研究,包括中压配电系统保护、单相接地故障电容电流、中性点接地方式选择和功率管理系统。
