Study of Frequency Regulation by a Wind Farm Using Time-Varying Inertia and Droop Controls

• Main Authors: YANG,WU-HAN, 楊武翰
• Other Authors: WU,YUAN-KANG
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/62973035779885027633

碩士 === 國立中正大學 === 電機工程研究所 === 105 === With the rising of renewable energy, frequency stability problem has caused a particular concern for the transmission system operators (TSOs) especially in a small power system. Traditional wind generation system does not provide the appropriate capability of frequency regulation because of the decoupling from the power grid. Therefore, as conventional thermal generators are replaced partly by wind generators, the issue of wind generation system about frequency regulation has become more and more important. Several literatures have studied on the inertia control and droop control of wind generators to support frequency regulation capability in the power grid. To develop the functionality of frequency regulation capability, it is necessary to add control loops with inertia and droop variables to determine the power reference that is an input signal for rotor side converter (RSC) of DFIG. The inertia variable represents the transient frequency response and the droop variable affects the steady state frequency response. This study proposes a new control strategy for the inertia and droop variables to implement coordinate control in different wind speeds and time based on the current frequency regulation model in recent literatures. The new control strategy integrates the inertia control, rotor speed control and pitch angle control to accomplish the complete frequency regulation mechanism. Compared to the frequency regulation framework of the past, the new proposed method is verified in a two-bus test power system and an island power system. Consequently, it superiorly improves the performance of frequency regulation in the power grid.