A Voltage Transducer for Electrical Grid Disturbance Monitoring over a Wide Frequency Range

As the power electronics advance and renewable sources proliferate on power grids, conducted disturbances increasingly pollute electrical networks and they grow in amplitude and frequency. The trends of international standards about compatibility levels in industrial plants for conducted disturbances is to extend the upper corner of the bandwidth of disturbances to be measured. Therefore new measuring instrumentation is needed to monitor quality of energy over an increasing frequency range. The first part of a power quality measurement chain are voltage and current transducers, which must have a large bandwidth. In this paper a low cost electronic voltage transducer for disturbance monitoring over a wide frequency range is presented. It obtains galvanic insulation by means of an optical insulation stage. Its design and simulation are presented. Experimental characterization has shown that it has an accuracy of 0.1 % until 20 kHz, better than that of recommendations in the international standards.