Theoretical assessment of energy losses in the inter-array MV interconnecting network of a windfarm and comparison with actual annual operation data

摘要

The current study focuses on the estimation of the expected energy losses in the internal electric network of wind farms. A comprehensive methodology for estimating these energy losses is proposed. Both wind analysis data and technical characteristics of the electrical infrastructure of the wind farm are considered in the calculations. An operating onshore wind farm of total capacity 21MW, is examined as a case-study. The estimated energy losses are compared to actual data taken from the wind farm's SCADA system over a year's period. Based on time-series of wind measurements, the operation profile and the expected load duration curve are derived. The operation profile data are sorted in classes and for each of them a power flow simulation is performed in NEPLAN software package [1]. The energy losses are calculated for each operating scenario and finally are added-up. The losses calculated by the aforementioned method are somewhat higher than the actual losses recorded in the SCADA system of the wind farm. We conclude that the proposed method slightly overestimates the expected energy losses in the MV network of the wind farm, therefore it can be used by investors as the worst case scenario, when drawing up their business plans.