Control Stability Evaluation of Multiple Distribution Static Compensators based on Optimal Coefficients using Salp Swarm Algorithm

In order to solve the problem of voltage drop and voltage imbalance in the distribution systems, the injection of reactive power by multiple static compensators is used. The distributed generation such as photovoltaic systems could play a role of the static compensators by producing reactive power. In this paper, the integral to droop line algorithm is used to control the reactive power in busbars. The droop coefficient and integral gain are important parameters in this algorithm. The determination process of these coefficients is modeled as a nonlinear and multi-objective optimization problem. The objective function in this problem is defined to establish a tradeoff between the voltage deviation and voltage unbalanced factor considering stability condition, in which the salp swarm optimization algorithm is used to solve the problem. The above problem is solved by three other optimization algorithms, which the salp algorithm has a better performance than the three algorithms. Applying the obtained optimal gain coefficients to the compensators, not only the voltage profile is improved but also the voltage unbalanced factor is reduced. The proposed method is simulated on the IEEE-34 Node test feeder. To evaluate the stability of the system, the eigenvalue analysis is used. The results show the validity of the proposed method on the system stability.