A novel higher rotational speed maintaining control for wind power generation systems under unstable wind conditions

Abstract

This study proposes Higher Rotational Speed Maintaining (HRSM) control as a novel control algorithm that is suitable for large wind speed fluctuations. One of the challenges for wind generators is operating with significant wind speed oscillations. A wind generator with a large moment of inertia increases the time constant in rotational speed control and delays the tracking of the optimal operating point. It could reduce generated power by up to 40% or more. There are numerous regions in Japan’s inland areas where average wind speeds exceed 6.5 m/s. However, frequent fluctuations in wind speeds make wind power generation challenging. Therefore, this paper proposes a control algorithm suitable for wind turbines under unstable wind conditions. Higher rotational speeds are required to convert sudden high wind speeds into higher power when wind speed oscillations are large. Hence, the proposed algorithm focuses on maintaining the rotational speed throughout periods of unstable wind conditions for improving generation efficiency. The effectiveness of the proposed control method for wind turbines is verified via numerical simulation results. The novel control algorithm promotes the spread of wind turbines in unstable wind conditions area by overcoming the disadvantages.