Irregular Wind Power Plant Dynamics Induced by Power Factor Command Truncation

This paper examines an unusual dynamic phenomenon observed at a wind power plant connected to Dominion Energy’s transmission system. The phenomenon is characterized by irregular non-sinusoidal reactive power output without a fixed frequency, which differs from conventional oscillatory responses. Although initially identified as an oscillation by monitoring tools, detailed analysis using synchrophasor data revealed that the anomaly originates from the plant’s control logic rather than controller-to-grid interaction dynamics. Specifically, the root cause is the truncation of power factor setpoints to three decimal places when converting reactive power commands from the Power Plant Controller into turbine-level instructions, creating a quantization-like effect that limits the control signal to a discrete set of values. This constraint leads to abrupt reactive power changes during voltage regulation, producing step-like patterns and erratic behavior. The paper presents field observations, explains the mechanism behind this response, and demonstrates its impact through a proof-of-concept illustration focused on explaining the controller observed behavior. These findings highlight the need for improved communication protocols, accurate control modeling, and improved measurement-based validation to prevent control-induced anomalies as inverter-based resources continue to reshape the dynamics of power systems.

Abstract reproduced from Bikal Pudasaini, Luigi Vanfretti, Chetan Mishra, Jaime De La Ree Jr., Kevin D. Jones, “Irregular Wind Power Plant Dynamics Induced by Power Factor Command Truncation,” 2026 IEEE Green Technologies Conference (GreenTech), 2026. doi.org/10.1109/greentech68285.2026.11471549 ↗