短路电流.效果推算.第1部分:定义和计算方法

[中文适用范围]： 本部分IEC 60865适用于短路电流的机械和热效应。它包含计算以下内容的程序：刚性导体和柔性导体上的电磁效应，以及裸导体上的热效应。对于电缆和绝缘导体，参考IEC 60949和IEC 60986。对于发电厂和变电站直流辅助设施中的电磁和热效应，参考IEC 61660-2。本标准仅涉及交流系统。应注意以下各点：a) 短路电流的计算应基于IEC 60909。为确定最大可能的短路电流，可参考其他IEC标准的额外信息，例如关于计算底层电路的详细信息或关于限流装置的详细信息，如果这导致机械应力降低。b) 本标准中使用的短路持续时间取决于保护概念，并应以此为依据考虑。c) 这些标准化过程已根据实际要求进行调整，并包含保守的简化。可使用测试或更详细的计算方法，或两者兼用。d) 在本标准的第5章中，仅计算刚性导体排列中由短路电流引起的应力。此外，还可能存在其他应力，例如由死负载、风、冰、操作力或地震引起的应力。将这些负载与短路负载的组合应是协议的一部分，或由标准（如施工规范）规定。柔性导体排列中的拉力包括死负载的影响。关于其他负载的组合，上述考虑是有效的。e) 计算的负载是设计负载，应作为异常负载使用，无需根据IEC 61936-1 [1]等的安装规范添加任何额外的部分安全系数。 [外文原描述]： IEC 60865-1:2011 is applicable to the mechanical and thermal effects of short-circuit currents. It contains procedures for the calculation of: the electromagnetic effect on rigid conductors and flexible conductors, the thermal effect on bare conductors. For cables and insulated conductors, reference is made, for example, to IEC 60949 and IEC 60986. For the electromagnetic and thermal effects in d.c. auxiliary installations of power plants and substations reference is made to IEC 61660-2. Only a.c. systems are dealt with in this standard. This third edition cancels and replaces the second edition published in 1993 and constitutes a technical revision. The main changes with respect to the previous edition are: - The determinations for automatic reclosure together with rigid conductors have been revised. - The influence of mid-span droppers to the span has been included. For vertical cable-connection the displacement and the tensile force onto the lower fixing point may now be calculated. Additional recommendations for foundation loads due to tensile forces have been added. The subclause for determination of the thermal equivalent short-circuits current has been deleted (it is now part of IEC 60909-0). The regulations for thermal effects of electrical equipment have been deleted. The standard has been reorganized and some of the symbols have been changed to follow the conceptual characteristic of international standards.