The doubly fed induction generator (DFIG) is a mainstream technology for wind power generation. How to fully exploit its potential to suppress voltage imbalance without exceeding rotor-side current/voltage stress constraints is crucial for enhancing the grid-integration capacity of wind power systems. Owing to the transient decaying component of the DFIG air-gap flux linkage during fault

improper coordination between demagnetization and voltage support can lead to rotor-side overcurrent and overvoltage

potentially triggering wind turbine disconnection from the grid. To address this

this paper proposes a double-layer optimization model: the upper layer minimizes demagnetization time

while the lower layer minimizes the voltage unbalance factor (VUF). By using boundary contraction with geometric analysis

the nonlinear multi-variable non-convex problem is simplified into a single-variable optimization for current command design in multi-sequence domains. Compared with existing methods

this approach can further reduce the VUF and mitigate rotor-side stress risks. Experimental results validate the effectiveness of the proposed strategy.