Black Start with DFIG-Based Wind Turbines Using Improved Virtual Synchronous Control

While the power system benefits from an increasing amount of grid-integrated wind farms these days, its blackouts have become a more severe problem. In consequence, there is a growing demand of conceiving black start plans to achieve a rapid and reliable restoration. This paper proposes firstly a plan of black start at low voltage level with a doubly-fed induction generator (DFIG)-based wind turbine that uses an improved virtual synchronous control (VSynC) strategy, in which a DC voltage source connecting with the DC link of a DFIG is used for fast self-start of DFIG under the circumstance of blackouts. Secondly, the feasibility of the proposed plan is verified by simulation on the MATLAB/Simulink platform. Comparative study is also accomplished between the improved and traditional virtual synchronous control strategy in this case, which demonstrates the advantages of the former in providing frequency support.