Interactions between regulating equipments in voltage instability environment

Control equipment interactions pose a cumbersome and difficult-to-solve problem in a voltage-unstable environment. The authors present a simple and qualitative criterion concerning the oscillatory/nonoscillatory behavior of two OLTC units with time delays. The correspondence between the multiple-load-flow solutions and a set of stable and unstable equilibrium points is made clear. The extension and applicability of the proposed method are discussed