“…ΔX PMSG , A PMSG , B PMSG and Δu PMSG are, respectively, the small-signal model of the state vector (17 × 1 order), the system matrix (17 × 17 order), the input matrix (17 × 5 order) and the input vector (5 × 1 order); subscript '0' represents the value of the steady-state point; ω b is the reference frequency of the system; H 1 , H 2 are the inertia constants of the masses 1 and 2, respectively; D 1 , D 2 are the self-damping coefficients of the masses 1 and 2, Due to the adoption of 'back-to-back' full power converter, there are two PI controllers in the control unit of the rectifier, so the small-signal system still has17 state variables Δθ 2 , Δω 1 , Δω 2 , Δψ ds , Δψ qs , Δx 1 , Δx 2 , ΔU DC , Δx 3 , Δx 4 , Δx 5 , Δx 6 , Δi Lx , Δi Ly , Δu cx , Δu cy…”