Lu Jiayu

Design of the UHVDC corona cage of China

The function, shape, structure and the parameters of the UHVDC corona cage of China are presented in this paper. The corona loss measurement system, radio interference measuring system and the audible noise measuring system are also detailed, including the measurement theory, connection with the cage, the parameters and the designing basis.

A electromagnetic effect calculation method for engineering design on oil/gas pipelines due to 1000kV AC transmission line in single-phase ground fault

In order to improve the efficiency of path planning and design for 1000kV AC transmission line, a simple and effective method is required to evaluate the electromagnetic effect on petroleum/gas pipelines from 1000kV AC transmission lines and to determine the safe distance. An easily handled fitting formula is inversed based on multiple calculation results, which are the maximum potential differences on the pipeline anticorrosive coating produced by 1000kV AC transmission lines under different conditions, and obtained after the computation for multiple simulation models. The formula can be used to calculate the maximum pipeline coating stress, when single-phase ground fault occur on AC transmission lines. The verification of formula shows that, the calculation results obtained from fitting formula matches with that from models, and the fitting formula is applicable to engineering calculation. This research could be applied to evaluate the electromagnetic effect of 1000kV AC transmission line on nearby pipelines, as well as to determine the safe distance and the maximum parallel length.

Study on simulating test of total electric field of double-circuit DC transmission line

Double-circuit DC transmission lines will been built in China to increase transmission capacity of corridor. There is no practical precedent of double-circuit DC transmission lines in the world, so electromagnetic environment of the line needs to be studied to provide technical foundation of engineering design. Simulating test of total electric field and corona current of double-circuit DC transmission Line are carryed out by using simulating line. The characteristics of lateral distribution of the total electric field at ground, the relative magnitude relationship of the electric field and corona current in various scenarios of pole conductor arrangement are obtained. Priority order of pole conductor arrangement scenarios to reduce total electric field at ground , high electric field area, corridor width and corona loss, are given.

Numerical analysis of the influence of the surrounding buildings on the performance of a grounding grid

By the use of numerical method, the influence of the surrounding buildings on the performance of a real small testing grounding grid is researched. Experiments have been done to verify the numerical method. The performance of the grid considering the surrounding buildings is compared with that not considering the surrounding buildings. From the experiments and the calculation, it can be seen that the influence of the surrounding buildings is very small. Both the method and the results are useful for designing the grounding grids of the substations in city.