Evaluation and characterisation of test signals in the time and frequency domain for the frequency response analysis of voltage measurement systems

The power grid is undergoing a rapid transition driven by the large-scale integration of renewable energy sources and the adoption of SF6 -free technologies. Converter-interfaced renewable generation, long-distance HVDC transmission, and increasingly frequent switching operations are contributing to elevated levels of high-frequency distortion across modern networks. These non-fundamental voltage components result in complex signal environments that require advanced measurement and monitoring to assess their origin and impact on grid assets. At the same time, new equipment such as vacuum circuit breakers, SF6 -free instrument transformers, and SF6 -free gas-insulated switchgear is being deployed with limited long-term experience, highlighting the need for a deeper understanding of the…