和 1500V DC 低压配电系统的电气安全 用于测试、测量或监测保护措施的设备 第 9 部分：IT 系统中绝缘故障定位设备

[中文适用范围]： 本部分 IEC 61557 规定了绝缘故障定位系统 (IFLS) 的要求，该系统用于在不接地 IT 交流系统和不接地 IT 交流系统中定位任何部分的绝缘故障，这些系统具有额定电压高达 1000 V AC 的直流电路，以及在不接地 IT 直流系统中定位电压高达 1500 V DC 的绝缘故障，与测量原理无关。 注1：IT 系统在 IEC 60364-4-41 中有描述。关于绝缘故障定位的更多信息可以在以下国际标准中找到：IEC 60364-4-41:2005, 411.6 和 IEC 60364-4-41:2005/AMD1:2017, 411.6, 以及 IEC 60364-5-53:2019/AMD1:2020, 531.3。 注2：本文件涵盖被动式 IFLS 和主动式 IFLS。主动式 IFLS 可用于断电系统。 注3：本文件不涵盖符合 IEC 61557-8 的 IMD。 [外文原描述]： IEC 61557-9:2023 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 61557-9:2023 edition 4.0 and the previous IEC 61557-9:2014 edition 3.0. Furthermore, comments from IEC TC 85 experts are provided to explain the reasons of the most relevant changes, or to clarify any part of the content. IEC 61557-9:2023 specifies the requirements for the insulation fault location system (IFLS) that localizes insulation faults in any part of the system in unearthed IT AC systems and unearthed IT AC systems with galvanically connected DC circuits having nominal voltages up to 1 000 V AC, as well as in unearthed IT DC systems with voltages up to 1 500 V DC, independent of the measuring principle. IEC 61557-9:2023 cancels and replaces the third edition published in 2014. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) new terms and definitions on maximum admissible locating AC and DC currents and voltages; b) the requirements on locating current and locating voltage have been revised; c) performance requirements have been added; d) the test requirements for locating current and locating voltage have been revised; e) the structure of this document has been adapted to that of IEC 61557-1:2019; f) the limit values under Clause A.2 were adapted to fit the changed test methods in 6.2.3.