Abstract
This study presents a comprehensive and innovative approach to optimizing the performance of smart inverters in photovoltaic (PV) systems and battery energy storage systems (BESSs) within integrated distribution networks. With the increasing penetration of distributed energy resources (DERs) in power systems, ensuring voltage stability and maximizing the PV hosting capacity (PVHC) of distribution networks has become critical. The core objective of this research is to enhance the PVHC while minimizing voltage deviations and maintaining an equitable distribution of power curtailment across PV units, particularly in networks with high DER penetration. The optimization problem is framed as a multi-objective mixed-integer nonlinear optimization problem, simultaneously addressing the maximization of PVHC and the minimization of voltage deviation and power curtailment disparities. To achieve these goals, the study utilizes the Water Cycle Algorithm (WCA), a nature-inspired metaheuristic optimization technique known for its efficiency in solving complex optimization problems. This approach is particularly relevant as it enables the fine-tuning of reactive power control (Volt/VAr) settings of smart inverters and the optimal placement and sizing of PV systems and BESSs within the network. Additionally, the study extends its focus to refining Volt-Watt control parameters, which are essential for curtailing real power output in response to voltage increases, a common issue in PV-rich distribution networks. Extensive simulations were conducted on standard IEEE 69-bus and 33-bus distribution networks to validate the proposed method. The results demonstrate the superiority of the WCA optimization method over conventional metaheuristic approaches. Specifically, the proposed method significantly enhances the PVHC, allowing for higher integration of renewable energy sources into the distribution network without violating operational constraints. Moreover, it effectively mitigates voltage rise issues caused by high DER penetration and ensures a fair distribution of power curtailment among PV units, thus addressing the financial disadvantages that customers located further from the distribution transformer might otherwise face. One of the key findings of this research is the ability of the proposed method to achieve a balanced optimization that not only maximizes the power injected by PV units but also maintains voltage levels within acceptable limits. This balance is crucial for the practical application of smart inverters in real-world distribution networks, where the challenges of over-voltage and under-voltage conditions are prevalent. The study's focus on the strategic placement and operational dispatch of PV systems and BESSs further underscores its practical relevance, providing a robust framework for future advancements in smart inverter technology and DER integration. This study offers a significant contribution to the field of power systems by providing a novel and effective
optimization method for enhancing the performance of smart inverters in PV and BESS-integrated distribution networks.