An Actively Calibrated Capacitively Coupled Electrostatic Device for high voltage measurement

Active control and monitoring of the distribution system is a crucial part to successfully integrating variable generation in the distribution grid. This may require a large deployment of Phasor Measurement Units (PMU´s) on the distribution system, which can be prohibitively expensive due to installation cost. Additionally, devices at medium to high voltage possess a significant risk to system reliability due to line to ground paths in the device. Alternatives to the traditional voltage measurement transformers are non-contact electric field measurements and capacitively coupled electrostatic devices. However these devices are unable to reach the metering quality required due to changes in conductor and ground geometry. Here we present a class of Actively Calibrated Capacitively Coupled Electrostatic Devices as a viable non-contact instrumentation option for deploying large numbers of Phasor Measurement Units onto the medium voltage distribution system. We develop the instrument physics and evaluate the performance in a laboratory setting.