Study Of Midium And Low Voltage Cables’s Economic Current Density

In recent years, with the worldwide economic fluctuations, the deepening ofdomestic reforms, many aspects such as the national electricity policy, marketenergy sources prices, the country’s financial policy, the tariff system, are beingconstantly adjusted. At the same time, copper conductors and XLPE insulatedpower cables are selected more and more popular and widely used. At the same time,since the Eleventh Five-Year, energy saving is the long-term goal of China’snational economic and social development, the power industry, especially thethermal power companies shoulder more pressures for energy saving.Therefore, re-propose modification on the economic current density curve ofthe conductor in the existing standard, will be of great significance for conductorselection by economic current density method in the current economic conditions.Meanwhile, the economic current selection used in the thermal power plant cablesystem design, it will be of great significance for electric power companies not onlyfor energy saving but also for improving economic efficiency.Firstly, this paper analyzes the parameters of current electric power system,and compares the main parameters in researching the economic current density inthe existing standard”Design technical rule for selecting conductor and electricalequipment”. And this paper also analyzes existing problem in current standard, andfinalizes the values of each parameter. Tariff fluctuations method is proposed in thispaper. And the necessity of modifying the economic current density is proved.Secondly, this paper draws the latest economic current density curve, anddraws the economic current range of all types of MV and LV cables, according tosingle part tariff and two parts tariff by using tariff fluctuation method. And newand old curves are compared and analyzed.Finally, this paper analyzes the feasibility by using the economic cross-sectionfor HV and LV loads in power plants, and gives recommendations of selection ofmedium and low voltage cables basing on auxiliary power systems design ofHuaneng the Jiutai Power Plant2×660MW coal-fuels units.This paper studies the economic current density of cables, and achieves certainresults. By using tariff fluctuation method, according to the actual tariff system, andaccording to the latest economic data, economic current density curve of cables isdrawn. Through analysis, the necessity and gist is put forward for revising theeconomic current density curve of cable in existing standard. This paper also givessuggestion and attestation for MV and LV cable sizing in power plant design, and ithas important significance for both economic value and social value.