Transient stability analysis of power system in the presence of asynchronous generators using potential energy boundary surface PEBS

Nowadays, in the power industry, the reduction of power outage and stability of the system due to disturbances is one of the important issues for network operators. Operation of power system depends on the nature of all elements in network. One of the factors that help maintain synchronism during fault is inertia of synchronous generators. This inertia will prevent the acceleration and loss of synchronization. Nowadays penetration of wind farms is increasing and asynchronous generators have lower inertia compared with synchronous generators, so the transient stability decreases in the network. This paper reviews the effect of system inertia reduction on transient stability in the presence of asynchronous generators in the power grid using the energy function. As a simulation, the asynchronous generator is modeled as an equivalent conventional synchronous generator with negligible inertia. The evaluation is done on a sample network for calculating critical energy and critical clearing time (CCT) using three methods which are called the closest unstable equilibrium point (UEP), controlling unstable equilibrium point, and the potential energy boundary surface (PEBS). Reduction of line reactance is proposed by using FACTS devices to compensate the inertia reduction of the system in the presence of an asynchronous generator and the compensation amount in the transmission lines will be calculated.