The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The aim of this paper is to calculate the current flowing process of HVDC grounding in single stage-earth operation mode. This paper uses finite element model (FEM) to solve the problem. We derived the finite element equation with taking into account temperature effect of soil parameters by setting the electrical and thermal parameters of soil element as the functions of temperature and taking the...
Underground cables are an essential part of the urban electricity grid. However, a disadvantage is that once they reach or even exceed their rated capacity the excessive temperature can considerably shorten the life of their insulation. The ultimate temperature reached is dependent on both the ground temperature and the thermal resistivity of surrounding soil. Modelling the temperature of the core...
When the HVDC system operates in the monopole ground return mode in a long duration, a continuous current with high magnitude travels into the earth through the grounding electrode, leading to temperature rise to the neighbouring soil. In the extreme condition, the soil agglomerates and the grounding resistance increases consequently, threatening the operation safety of the power system. In the current...
In this paper, the principle of a measuring device on thermal response test is introduced and a three-dimensional numerical model is developed. What's more, the effect of testing time, starting time point, ending time point and volumetric specific heat on the calculation results of the thermal response test by two variable parameter fitting method and three-dimensional numerical model are also discussed...
The three-dimension coupled thermal conduction and groundwater advection unsteady state heat transfer model in this paper is developed according to the heat-transfer process between the vertical U tube underground and its ambient soil. The feasibility of this model is verified by intermittent experiment of ground source heat pump in winter. In the model, boundary layer is replaced by velocity equation...
This scientific paper presents a survey of soil resistivity and how its value varies due to geological and meteorological factors. Soil resistivity is not only a useful measurement that reflects subsurface structure, but also a basic parameter of the design of effective grounding and lightening prevention/protection systems. The most significant variations occur from such parameters of soil resistivity...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.