Inverters have different techno-economic specifications which contribute to the changes in system sizing. Therefore, it is essential to know which inverter is more beneficial for certain considerations. In this research, the optimal designs for a DG-PV and DG-PV-battery off-grid/ island system using the central, string, multistring, and AC module types of inverters were compared to determine the recommended inverter configuration. The problem was solved as a multi-objective optimization considering both cost and reliability. The results were matched in terms of cost, reliability, renewable energy penetration, renewable energy curtailment, and changes in battery cost. The results showed that the central inverter can be a good choice when a balance between cost and reliability is considered. The string inverter is best recommended for the least cost but is highly affected by the decrease in battery cost. The multistring can be recommended for higher renewable energy penetration. Meanwhile, the AC module can be the choice for high reliability and low curtailment. Furthermore, the Partitioned Step Particle Swarm optimization was proven effective not only in solving the sizing problem but as well as constrained and unconstrained benchmark functions compared with other algorithms.

Inverters have different techno-economic specifications which contribute to the changes in system sizing. Therefore, it is essential to know which inverter is more beneficial for certain considerations. In this research, the optimal designs for a DG-PV and DG-PV-battery off-grid/ island system using the central, string, multistring, and AC module types of inverters were compared to determine the recommended inverter configuration. The problem was solved as a multi-objective optimization considering both cost and reliability. The results were matched in terms of cost, reliability, renewable energy penetration, renewable energy curtailment, and changes in battery cost. The results showed that the central inverter can be a good choice when a balance between cost and reliability is considered. The string inverter is best recommended for the least cost but is highly affected by the decrease in battery cost. The multistring can be recommended for higher renewable energy penetration. Meanwhile, the AC module can be the choice for high reliability and low curtailment. Furthermore, the Partitioned Step Particle Swarm optimization was proven effective not only in solving the sizing problem but as well as constrained and unconstrained benchmark functions compared with other algorithms.

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