IEC 61558-2-16:20 21涉及开关模式电源单元和开关模式电源单元变压器的安全性。 本第二版取消并取代了2009年出版的第一版和修正案1:20 13。本版构成技术修订版。 与上一版相比，此版本包括以下重大技术变更: 根据IEC 61558-1:20 17调整结构和参考文献； 不同电压特性的定义； 部分排放和移至IEC 61558-1:20 17的结构描述； 确定间隙尺寸的替代方法； 取消了对均匀现场条件的要求。 根据IEC指南104，它具有团体安全出版物的地位。 本国际标准将与IEC 61558-1:20 17结合使用。

IEC 61558-2-16:2021 deals with the safety of switch mode power supply units and transformers for switch mode power supply units.
This second edition cancels and replaces the first edition published in 2009 and amendment 1:2013. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:

1. adjustment of structure and references in accordance with IEC 61558-1:2017;
2. definitions of different voltage characteristics;
3. partial discharge and description of constructions moved to IEC 61558-1:2017;
4. alternative method for dimensioning of clearances;
5. removal of requirements for homogeneous field conditions.

It has the status of a group safety publication in accordance with IEC Guide 104.
This International Standard is to be used in conjunction with IEC 61558-1:2017.