Butterfly optimizer-assisted optimal integration of REDG units in hybrid AC/DC distribution micro-grids based on minimum operational area

Satish Kumar Injeti

doi:10.1186/s43067-021-00035-w

Abstract

This paper presents the impact of optimal location and sizing of renewable and non-renewable-based distributed generators in the AC/DC micro-grid system using the latest optimizer called butterfly optimization algorithm with an aim to minimize power loss. Generally, hybrid AC/DC micro-grids systems are modeled by separating AC and DC feeders with the help of high-power converters (HPC).AC grids sustained by substation and DC grids are maintained by their individual DG units. While planning of DGs in the hybrid AC/DC systems, the power loss incurred by HPCs is not considered avoiding complexity by many authors. In this paper, the sizing of DGs is determined by the operational area required by the type of DG technology as one variable and all possible candidate buses in the respective zones of AC/DC micro-grid system are another variable with due consideration of HPC losses in AC/DC micro-grid system. A hybrid AC/DC MG system is developed by classifying the existing benchmark 33-bus and 69-bus radial distribution systems into various AC/DC zones. To evaluate the proposed approach, it is implemented on aforementioned micro-grid systems and the obtained results are verified with other existing approaches in the literature. The results proved that the proposed approach is better than the other approaches in technical aspects.

Highlights

The mass accessibility of sustainable power sources is successfully used in giving uninterruptable power supply to islanded zones
A distribution system consists of both AC and DC loads and to serve the DC loads connected to the system they must have interfaced through high power converters (AC/ DC) which intern contributes harmonic content and conversion losses to the system
This paper presents a methodology to determine optimal allocation of REDGs in AC/DC micro-grid system with an objective of power loss minimization which includes high-power converters (HPC) conversion losses by considering area required by REDGs to compute the size of REDG and locations for the integrating REDGs simultaneously as variables using efficient and novel optimizer called butterfly optimizer (BO) to satisfy the AC/DC loads under various system constraints

Summary

Introduction

The mass accessibility of sustainable power sources is successfully used in giving uninterruptable power supply to islanded zones. A micro-grid is an assembly of interconnected dispersed energy sources and loads within clearly defined electrical boundaries that can be operated in a coordinated and controlled way either while connected to the central grid or while island mode [1]. The problems associated with AC micro-grids such as reactive power flow, current harmonics, failure of transformers and protection equipment and unbalanced loading of phases create a way to encourage DC micro-grids with DC loads served by dedicated DC sources like. DC micro-grid systems are designed and integrated as a part of the AC micro-grid system with the help of HPCs (high-power converter) which can act as an individual grid system and supports the AC grid system in the case of substation failure to meet the load demand [3]

Methods

Results

Conclusion