Methods for Identification of Frequency Response Characteristic of Voltage Measurement Systems

The Technical Brochure of WG A3.45 deals with the technology of voltage measurement systems, which are covered by the standard family IEC 61869. First, an overview of all voltage measurement technologies is discussed in detail for conventional voltage transformers and low-power voltage transformers for the rated frequency and based on that, the higher frequency performance is derived. The modern requirements of the grid versus the performance requirements of secondary equipment are the basis for the required performance of the voltage measurement system in the frequency domain, but also in the time domain. Assessment criteria, reasonable accuracy classes and definitions build the base for the measurement performance and also the acceptance criteria. On the other hand, depending on the type of voltage measurement system, various examples show the individual limitations of the frequency response performance. Furthermore, crucial dependencies and influence factors on the frequency response behaviour are listed and discussed. To characterise the intended voltage measurement technology, the brochure provides, on the one hand, detailed mathematical modelling concepts, and on the other hand, necessary measurement methodologies in order to be able to evaluate and select the appropriate test voltage measurement systems. The brochure finally provides a detailed overview, summarised in a table which allows for identifying the correct measurement technology to be used depending on grid requirements in terms of disturbance phenomena and applications, applications, and accuracy requirements. The separation into the conventional VTs and Low-power voltage transformers allows a better orientation.