Coordinated power quality mitigation strategy in an increasingly weak power electronics based electricity network

To achieve net zero in the electricity industry, conventional generation are displaced by renewable energy resources (wind, PV, energy storage etc.) which are connected to the electricity grid through power-electronic interfaces. Additionally, matured HVDC technologies are an integral part of network design solutions for integrating renewable generation sources. Utilities in many countries (e.g. U.K., Ireland) already have periods of demand throughout the day being fully met by renewable energy. The significant use of power electronic based equipment for both renewables and network design has posed difficult challenges in ensuring voltage waveform distortions are within acceptable quality – as set out in recommendations and/or standards adopted by different utilities. To date, normal approach used to deal with connections is based on a queue; and whilst this has worked in the past for a traditional power system, meeting harmonic compliance and designing mitigation measures are becoming difficult challenges. In recognition of this challenge, some utilities have previously investigated and proposed harmonic mitigation solutions to speed up uptake of batches of onshore connected wind farms and directly transmission connected offshore wind farms. As, the electricity system accelerates towards net zero operability, a pro-active approach would be required to identify issues and propose solutions which will need to be prioritised. This paper will present (1) background to approaches previously investigated for harmonic solutions, (2) present the challenges in an actual power electronic dominated future grid and (3) propose and implement a coordinated harmonic mitigation strategy on an actual net zero grid.