Determination and evaluation of frequency in power supply networks

For robust control and fault detection in electrical networks, the grid frequency is an important parameter. However, in rapidly changing (transient) network states, the grid frequency is generally not clearly defined, and a compromise must be found between very accurate and very fast measurement. This VDE FNN note describes the relationship between measurement duration and measurement accuracy according to the current state of knowledge and provides an overview of various measurement methods and their applications. The focus is primarily on grid protection, and the note is therefore aimed at grid operators, manufacturers, and users.

It replaces version 1.0 of the VDE FNN note "Determination and Assessment of Grid Frequency – Effects of Network-Side Interference" from 2017. The chapters have been restructured according to functions and areas of application and have been expanded thematically. This VDE FNN note was revised by the VDE FNN expert network on grid protection on behalf of the VDE FNN steering committee for grid technology and operation. It has been coordinated with the VSE (Association of Swiss Electricity Companies) and the "Protection Technology" working group of OESTERREICHS ENERGIE and is published jointly.

The VDE FNN notes are not part of the official VDE regulations.