电缆.额定电流的计算.第1-1部分:额定电流方程（100%负载系数）和损耗的计算.总则

[中文适用范围]： 本部分IEC 60287适用于所有交流电压和高达5kV直流电压的电缆在稳态运行条件下的情况，包括直接埋地、管道、槽道或钢管中的电缆，无论土壤是否部分干燥，以及空气中的电缆。术语“稳态”指的是足以渐进产生最大导体温度的连续恒定电流（100%负载系数），假设周围环境条件恒定。 本文件提供了额定电流和损耗的计算公式。 给出的公式基本上是字面上的，并有意留出某些重要参数的选择。这些参数可以分为三组： - 与电缆构造相关的参数（例如绝缘材料的热阻率），基于已发表的工作选择了代表性值； - 与周围条件相关的参数，这些参数可能变化很大，其选择取决于电缆使用或将要使用的国家； - 由制造商和用户之间协议确定的参数，这些参数涉及服务安全性的余量（例如最大导体温度）。 [外文原描述]： IEC 60287-1-1:2023 CMV contains both the official standard and its commented version. The commented version provides you with a quick and easy way to compare all the changes between IEC 60287-1-1:2023 edition 3.0 and the previous IEC 60287-1-1:2006+ AMD1:2014 edition 2.1. Furthermore, comments from IEC TC 20 experts are provided to explain the reasons of the most relevant changes, or to clarify any part of the content. IEC 60287-1-1:2023 is applicable to the conditions of steady-state operation of cables at all alternating voltages, and direct voltages up to 5 kV, buried directly in the ground, in ducts, troughs or in steel pipes, both with and without partial drying-out of the soil, as well as cables in air. The term "steady state" is intended to mean a continuous constant current (100 % load factor) just sufficient to produce asymptotically the maximum conductor temperature, the surrounding ambient conditions being assumed constant. This document provides formulae for current ratings and losses. The formulae given are essentially literal and designedly leave open the selection of certain important parameters. These can be divided into three groups: - parameters related to construction of a cable (for example, thermal resistivity of insulating material) for which representative values have been selected based on published work; - parameters related to the surrounding conditions, which can vary widely, the selection of which depends on the country in which the cables are used or will be used; - parameters which result from an agreement between manufacturer and user and which involve a margin for security of service (for example, maximum conductor temperature).