Performance Comparison of Peak Shaving and Adaptive Envelope Protection System Algorithms

This study compares, for the first time in the literature, the performance of Peak Shaving (PS) and Adaptive Envelope Protection System (AEPS) algorithms, which are both designed to protect wind turbines from excessive thrust forces. The AEPS algorithm is realized within the National Laboratory of the Rockies (NLR) Reference Open-Source Controller (ROSCO). The International Energy Agency (IEA) 15 MW floating offshore reference wind turbine is simulated using the Wind Turbine Control test bench (WTCBench) tool together with the OpenFAST simulation tool for cases: no protection (AEPS and PS off), PS only and AEPS only. Simulation results are presented under a normal turbulent wind (Design Load Case-DLC 1.1) around the rated wind speed from both controller and turbine perspectives. Turbine side performance metrics, including thrust force, tower base fore-aft moment and power output are analyzed in terms of percent reductions with respect to the no protection case. Test results show that PS and AEPS algorithms achieve comparable reductions in the maximum thrust force, with AEPS offering a slightly greater reduction, 0.46%. AEPS achieves a 1.29% further reduction in the maximum tower base fore-aft moment compared to PS algorithm. AEPS performs slightly better in reducing peak loads, whereas PS provides a 3.61% larger reduction in mean thrust and a 4.70% greater reduction in mean tower base fore-aft moment. Compared to PS algorithm, AEPS provides a 2.41% higher mean power output and further decreases the fluctuations in these metrics by up to almost 1%.