Novel Black Start Control Strategy With Power Boundary Analysis for PMSG-Based Wind Turbines

A novel power boundary analysis-based black start control (PBBC) strategy of PMSG-based wind turbines (WTs) is proposed in this paper to reduce the outage time of WTs and improve the reliability of wind power supply. The active power-rotor speed maximum boundary is quantified to estimate the kinetic energy (KE) reserve limit and the power response capability of the WTs during the black start period. In the power boundary analysis, the power response capability will collapse as the rotor speed increases to maximum. To achieve the trade-off between high KE reserve and power response capability, an overloaded power response control method during the black start period is developed, which can fully utilize the reserved KE. Moreover, the dc-bus capacitor charging model of WTs with initial KE is constructed, which can accurately represent the required KE of the WTs black start. The WTs are coordinated to achieve black start with the minimum backup power supply for the safety devices and auxiliary load according to the capacitor charging model. The proposed PBBC strategy can maximize the KE reserve of the WT and improve the power response capability, as well as reduce the backup power cost during the black start period.