Synergistic Frequency Regulation Control Mechanism for DFIG Wind Turbines With Optimal Pitch Dynamics
Rashmi Prasad, Narayana Prasad Padhy
Abstract
Conjoint participation of wind generation with conventional power plant, necessitate wind-farms to participate in automatic generation control (AGC) for frequency regulation. This implicates wind farms operator to monitor commands, received from the transmission system operator (TSO). Consequently, advanced control techniques are deployed, which assuredly helps in power tracking, but increases pitch angle controller dynamics. This has resulted in mechanical stress on equipment involved. In order to improve wind-farms response, a synergistic frequency regulation control mechanism (SFRCM) is proposed by the authors. The scheme considers the response time and reserve availability depending on forecasted wind data and also examine load curve pattern to obtain the reference signal for the wind-farm controllers. The work provides a distinct solution to address the following: 1) Optimal pitch dynamics regulated operating point tracking with revised-pitch angle control (R-PAC), 2) Maximization of rotational kinetic energy viz attuned-rotor speed control (A-RSC), to increase stored kinetic energy in the rotor. Case studies at constant and variable wind speed are presented to show the effectiveness of proposed algorithm. To test robustness of the technique, transient operation is conducted as well as forecasted data prediction error is also invoked in the study. The simulations, performed in the real time environment, depict the fulfillment of the above objective in an efficient manner compared with other conventional approaches.