Power system voltage stability analysis using Modified Differential Evolution

The problem of voltage stability is one of the main concerns in the operation of power systems. Many approaches have been used to estimate the voltage stability limit. One of the approaches is determining the maximum loading point of the system. In this approach, the margin from the current operating point to the maximum loading point of the system is determined. Finding this maximum loading point can be formulated as an optimization problem. Differential Evolution (DE) algorithm has the main advantages of faster convergence, simple with regard to application and modification and requires a few control parameters. But DE requires higher population size for faster convergence and sometimes settles in local optima. Modified Differential Evolution (MDE) eliminates the disadvantages of DE. This paper utilizes Modified Differential Evolution for determining the maximum loadability limit of power systems. Details of the implementation of the proposed method to two test systems, sample six bus and IEEE 30 bus, are presented. The results are compared to those obtained by the widely used Conventional Power Flow (CPF). Good agreement has been obtained proving the validity and applicability of the proposed method.