A Synchronous Machine Transient Model Based upon an Algebraic Loop Accounting for Nonlinearity and Cross-Magnetization

Figure 22

Equal area criterion used for explaining the transient stability. The continuous bell-shaped curve represents the synchronous torque in p.u. whereas the shaded one is the transient torque in p.u.: (a) 14-cycle sag-linear model ; (b) 14-cycle sag-non-linear model ; (c) 18-cycle sag-linear model for ; (d) 18-cycle sag-non-linear model .

(a)

(b)

(c)

(d)