  For high wind power-penetrated power systems, the multiple renewable energy
station short-circuit ratio (MRSCR) is often insufficient due to weak grid
structures. Additionally, transient voltage sag/overvoltage issues may cause
trip faults of wind turbines (WTs). Due to the time delay in WTs' controllers,
it is difficult for WTs alone to meet the reactive power demands in different
stages of the transient process. Some synchronous machines (SMs) must be
retained through unit commitment (UC) scheduling to improve MRSCR and prevent
trip faults of WTs. The MRSCR and short-term voltage security constrained-UC
model is a mixed integer nonlinear programming (MINLP) problem with
differential algebraic equations (DAEs) and symbolic matrix inversion, which is
intractable to solve. Based on the dynamic characteristics of different
devices, the original model is simplified as a general MINLP model without
DAEs. Then, generalized Benders decomposition is applied to improve the
solution efficiency. The relaxed MRSCR constraints are formulated in the master
problem to improve the convergence, and the precise MRSCR constraints are
formulated in the subproblems to consider the impact of voltage profiles. Case
studies based on several benchmark systems and a provincial power grid verify
the validity and efficiency of the proposed method
