Harmonics Monitoring for DER

with Optical Voltage Sensing

In a typical monitoring application for a distributed energy resource, the primary sensor is pole-mounted and attached to the line and then connected via optical fiber to the secondary converter. The primary sensor is completely passive and the optical fiber provides isolation between the electronics and the high voltage environment. The low voltage analog (or digital) output is then connected to a power quality meter or data acquisition device.

Here a set of NGVS optical sensors is installed on a distribution feeder near a solar photovoltaic farm. Any slight errors in conversion switching timing can create harmonics which can be difficult to detect with conventional instrument transformers.

Secondary converter electronics are mounted away from the sensors at a convenient point which could even be many spans away from the primary sensor. The output is a low energy analog voltage or digital signal which can be connected to a data acquisition system or power quality meter. Power input is 24 V_dc. Custom powering, cable length, and enclosure options can be specified at the time of order.