Automated energy storage and curtailment system to mitigate distribution transformer aging due to high renewable energy penetration

Abstract

The increase of distributed generation units in low voltage distribution grids, stimulated by different mechanisms (mostly economic), like the Energy Performance of Buildings Directive in Europe and the associated nearly-Zero Energy Building concept, stresses in-depth research on the possible impacts that such generation may impose on fundamental grid equipment such as distribution transformers. Taking this into consideration, this paper has two main objectives: i) to analyze the impacts of distributed generation on a non-residential building supplied by a dedicated distribution transformer when this building is converted to a nearly-Zero Energy Building; and ii) to develop a Transformer Anti-Aging Protection System (TAAPS) that mitigates existing negative impacts in order to reduce transformer aging. The present study is based on 1-year, 1-min resolution, real electricity demand and weather data and uses the standard IEC 60076-7 (Loading Guide For Oil-immersed Power Transformers) to model the transformer aging. The collected results show that the introduction of distributed generation increases transformer aging and that the proposed protection system (TAAPS) fulfills its objectives preventing the excessive aging. An economic analysis, related with the proposed system, is also provided in this paper.