On site trial of the new SuperTAPP N+ AVC relay — A step towards an active network

This paper reports on field trials of the SuperTAPP n+ (an advanced voltage control relay (VCR) for online tap changers on transformers). This project is a collaboration between EDF Energy, Central Networks, CE Electric UK, ScottishPower, EA Technology and Fundamentals Limited. The SuperTAPP n+ relay estimates embedded generator output and total network load based on local substation measurements. These estimates are used to optimize the voltage set point at the primary substation in order to maximize voltage headroom and accommodate extra generation capacity. Four trials will be established. The initial results from the first trial demonstrate that the SuperTAPP n+ estimation algorithm is accurate and can be used to optimize voltage to an extent that a conventional VCR could not achieve. The remaining three trials will explore the relay's capabilities on different network designs and with different mixes of distributed generation.