The proposed scheme can observe the initial value of the virtual line-flux-linkage precisely. As a result, the virtual line-flux-linkage vector can serve as the oriented vector in the vector control of the converter and the linevoltage sensor will be eliminated. The simulation and experimental results prove the validity of the proposed control scheme.
The contribution of crowd effect of load on voltagecollapse margin is analyzed by Continual Power Flow (CPF) simulation. Furthermore,the contributions of main physical and economic features of market participators tovoltage collapse margin are analyzed by dynamic simulation. A WAMS based on-linevoltage collapse index to generator reactive power reserve (VCIG)and transmissionline transfer capacity is proposed.