Emulated Inertial Response From Wind Turbines: Gain Scheduling and Resource Coordination

With increasing wind penetration levels on power systems worldwide, conventional thermal plant, along with the ancillary services they provide are being displaced. To address this issue, modern variable speed wind turbines can offer a short-term controlled response to temporary power imbalances, by harnessing their stored rotational energy, a so called emulated, or synthetic, inertial response. However, unlike conventional frequency response services, the emulated inertial response is dependent on the wind turbine operating condition and provides a response which is distinct to that from synchronously connected plant. While much research has investigated the harnessing of such a response from wind turbines and its effect on system frequency, this paper investigates potential issues associated with the system-wide integration of the technology at scale. The ability for wind generation to provide frequency support through emulated inertia is assessed, as well as the potential for tuning such a distributed response resource to ensure timely and effective frequency recovery under different system conditions. It is shown that the frequency response capability of future systems and the operating protocols for system participants, including wind generation, will require development if emulated inertia technology is adopted at scale.