Ancillary services from wind turbines: AGC from a single Type 4 turbine

Abstract. Wind turbines possess the technical ability to provide various ancillary services to the electrical grid. Several regions have set ambitious targets of providing an increasing share of annual electrical energy from wind and other renewable sources of generation. Despite this, renewable generators such as wind and solar have traditionally not been allowed to provide significant amounts of ancillary services, in part due to the variable and uncertain nature of their electricity generation. Increasing levels of renewable generation, however, continue to displace existing synchronous generation and thus necessitate new sources of ancillary or system services. This work is part of an ongoing project that seeks to provide empirical evidence of how ancillary services can be provided from wind turbines. We focus specifically on providing secondary frequency response (AGC) and demonstrate that wind turbines have the technical capability to provide this service. The algorithms used are intentionally simple so as to evaluate the capabilities and limitations of the turbine technology. This work presents results from a single, 800 kW, IEC Type 4 wind turbine. 10 % of rated power is offered on the regulation market. We do not separate up- and down-regulation into individual services. Up-regulation is offered through a 5 % constant power curtailment. The AGC update interval is 4 s, to mimic real-world conditions. We use performance scoring methods from the Pennsylvania-Jersey-Maryland (PJM) operator and the National Research Council (NRC) of Canada to quantify the wind turbine's response. We use the calculated performance scores, annual site wind data and 2017 PJM market price data to estimate income from providing secondary frequency regulation. In all cases presented, income from the regulation market is greater than the energy income lost due to curtailment.