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—This article shows a method to optimize the reliability of an electric power system by the introduction of distributed generation. The reliability index of the system is determined as the failure probability of the system. A hybrid method that uses a binary shuffled frog-leaping algorithm and probabilistic load flow is proposed to search a large number of combinations for location and size of biomass power plants and photovoltaic units. The combination with the best performance minimizes the reliability index (probability of failure) of the system.

This article presents a developed method to improve the representation of a voltage-controlled bus in the current injection load flow method. This improvement is based on a hybrid current and power mismatches formulation, where the load bus equations are represented by current mismatches and voltage-controlled buses bus equations are based on power mismatches. In this method, the advantages of the Newton–Raphson method and current injection mismatches method are collected. The total number of equations is reduced, where only one equation is required for each voltage-controlled bus. This article also describes direct modeling of voltage/power control devices in the developed load flow method. The static synchronous compensator can be represented as a voltage-controlled bus node in terms of power mismatch. The static series synchronous compensator and unified power flow controller are modeled by series impedance and two current injections at the corresponding nodes. In the case of unified power flo...

This article shows that technical constraints must be considered in radial distribution networks, where voltage regulation is one of the primary problems in distributed generation photovoltaic systems. Loads and distributed generation production are modeled as random variables. Results prove that the proposed method can be applied for keeping voltages within desired limits at all load buses of a photovoltaic grid-connected system. To evaluate the performance of a photovoltaic system, this article has developed a probabilistic model that takes into account the random nature of solar irradiance and load. This work introduces a new method utilizing discrete particle swarm optimization and probabilistic radial load flow. Computer simulation reduction demonstrates better performance of the new probabilistic load flow in comparison to the Monte Carlo simulation. Acceptable solutions are reached in a smaller number of iterations. Therefore, convergence is rapidly attained, and computational cost is low ...