عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Reactive power limit of power system generators have significant affect on the static voltage stability margin such as maximum loadability point and dynamic voltage stability margin such as HB, LIB and SNB. However, as the load increases, reactive power demand increases as well and thus reactive power limit of generators or other voltage-regulating devices such as Static Var Compensators (SVCs) may reach. Therefore, voltage stability margin is decreased and or voltage collapse is occurred. Hence, different techniques such as reactive power redispatch or change of terminal voltage of generators, use of reactive power compensation devices and optimization method to determine optimum sizing and sitting of this device is proposed to improvement and increasing reactive power capacity. In this paper, based on a combination method include of time domain simulation, modal analysis and bifurcation theory effect of regulation of terminal voltage of critical generators on the reactive power limit of generators and dynamic voltage stability status of power system based on the HB and LIB is evaluated. The obtained results give good information for network operators to optimum planning and operating of power system. The proposed dynamic method is examined on the New England 39-bus, IEEE 68-bus test systems.