Contactless investigation on kHz to MHz emission levels of high voltage systems

Nowadays electrical power is produced more and more within off-shore wind parks or by photovoltaic instead of conventional power plants with the need of conversion from AC to DC and/or DC to AC for transportation and distribution. Usually this conversion takes place with semiconductor power devices that switch very fast to increase efficiency. These switching events take place in addition to the normal transient events within the power grid like lightning impacts or switching operations of circuit breakers. Measurements on power quality as well as the monitoring of voltage and current flowing on the transmission lines usually is performed by cable bound measurements via voltage dividers or current transformers. These devices are neither designed to measure high frequency disturbances from power converters nor are traceable calibration methods established. This paper proposes a contactless measurement setup to measure high frequency disturbances. Advantages in comparison to measurements with high voltage dividers as well as the most important measurement parameters and their dependencies will be discussed.