电磁兼容性(EMC).第3-13部分:限值.不平衡装置对MV、HV和EHV动力系统的连接用排放限值的评估

[中文适用范围]： IEC 61000 的这一部分提供了原则指导，可用作确定不平衡装置（即导致电压不平衡的三相装置）与中压、高压和超高压公共电力系统（涵盖低压装置）连接要求的基础。其他 IEC 文件中）。就本报告而言，不平衡装置是指在系统上产生电压不平衡的三相装置（可能是负载或发电机）。单相装置的连接没有具体说明，因为此类装置的连接是在系统操作员或所有者的控制之下。然而，当考虑单相装置的连接时，可以调整一般原则。主要目标是为系统运营商或所有者提供工程实践指导，这将有助于为所有互联客户提供足够的服务质量。在解决安装问题时，本文件无意取代排放限制的设备标准。该报告讨论了系统吸收干扰能力的分配。它没有解决如何减轻干扰，也没有解决如何增加系统的容量。由于本报告中概述的指南必然基于某些简化假设，因此无法保证此方法始终为所有不平衡负载情况提供最佳解决方案。就工程而言，在全部或部分应用给定的评估程序时，应灵活地使用推荐的方法和判断力。系统运营商或所有者负责指定可能导致系统不平衡的装置连接要求。干扰安装应理解为完整的客户安装（即包括平衡和不平衡部件）。与不平衡相关的问题分为两个基本类别。 • 不平衡装置会吸收负序电流，从而在供电系统上产生负序电压。此类装置的示例包括电弧炉和牵引负载（通常在高压处连接到公共网络），以及各个负载不平衡的三相装置（通常在中压和低压处连接）。叠加到旋转电机端电压上的负序电压会产生额外的热损失。负序电压还会导致电源转换器产生非特征谐波（通常是正序三次谐波）。 • 线与中性点连接的不平衡装置也会产生零序电流，根据耦合变压器的连接类型，零序电流是否可以转移到供电系统中。中性点接地系统中的零序电流流动会导致零序不平衡，从而影响线电压。这通常不是通过设置排放限值来控制的，而是通过系统设计和维护来控制。然而，中性线不接地系统和相间连接装置不受这种电压不平衡的影响。 [外文原描述]： This part of IEC 61000 provides guidance on principles which can be used as the basis for determining the requirements for the connection of unbalanced installations (i.e. three-phase installations causing voltage unbalance) to MV, HV and EHV public power systems (LV installations are covered in other IEC documents). For the purposes of this report, an unbalanced installation means a three-phase installation (which may be a load or a generator) that produces voltage unbalance on the system. The connection of single-phase installations is not specifically addressed, as the connection of such installations is under the control of the system operator or owner. The general principles however may be adapted when considering the connection of single-phase installations. The primary objective is to provide guidance to system operators or owners on engineering practices, which will facilitate the provision of adequate service quality for all connected customers. In addressing installations, this document is not intended to replace equipment standards for emission limits. The report addresses the allocation of the capacity of the system to absorb disturbances. It does not address how to mitigate disturbances, nor does it address how the capacity of the system can be increased. Since the guidelines outlined in this report are necessarily based on certain simplifying assumptions, there is no guarantee that this approach will always provide the optimum solution for all unbalanced load situations. The recommended approach should be used with flexibility and judgment as far as engineering is concerned, when applying the given assessment procedures in full or in part. The system operator or owner is responsible for specifying requirements for the connection of installations which may cause unbalance on the system. The disturbing installation is to be understood as the complete customer's installation (i.e. including balanced and unbalanced parts). Problems related to unbalance fall into two basic categories. - Unbalanced installations that draw negative-sequence currents which produce negative-sequence voltages on the supply system. Examples of such installations include arc furnaces and traction loads (typically connected to the public network at HV), and three phase installations where the individual loads are not balanced (typically connected at MV and LV). Negative-sequence voltage superimposed onto the terminal voltage of rotating machines can produce additional heat losses. Negative-sequence voltage can also cause non-characteristic harmonics (typically positive-sequence 3rd harmonic) to be produced by power converters. - Unbalanced installations connected line-to-neutral can also draw zero-sequence currents which can be transferred or not into the supply system depending on the type of connection of the coupling transformer. The flow of zero-sequence currents in a grounded neutral system causes zero-sequence unbalance affecting line-to-neutral voltages. This is not normally controlled by setting emission limits, but rather by system design and maintenance. Ungrounded-neutral systems and phase-to-phase connected installations are not, however, affected by this kind of voltage unbalance. This report gives guidance only for the coordination of the negative-sequence type of voltage unbalance between different voltage levels in order to meet the compatibility levels at the point of utilisation. No compatibility levels are defined for zero-sequence type of voltage unbalance as this is often considered as being less relevant to the coordination of unbalance levels compared to the first type of voltage unbalance. However, for situations where a non-zero impedance exists between neutral and earth with the system still being effectively grounded (i.e., where the ratio between zero-sequence, X0 and positive sequence reactance X1 is 0 < X0/X1 = 3), this type of voltage unbalance can be of concern especially when the type of connection of the coupling transformer allows zero-sequence path to flow from MV to LV and vice-versa. This Technical Report has the status of a basic EMC publication in accordance with IEC Guide 107. The contents of the corrigendum of April 2010 have been included in this copy.