Autonomous control and operation of an interconnected AC/DC microgrid with T-Z-source interlinking converter

Abstract

This paper presents autonomous operation and control of an interconnected AC/DC microgrid with bidirectional T-Z-Source inverter as interlinking converter. The r-Z-source inverter is capable of providing high voltage gain whilst does not have the drawbacks of the conventional inverters. In this paper, an interconnected AC/DC microgrid is considered in which AC load and sources are connected to AC subgrid and DC load and sources are connected to DC subgrid, therefore power conversion stages are reduced in each subgrid resulting in less volume and cost of power converters and higher efficiency and reliability. In addition, in the DC subgrid, a multiport power electronic interface is employed for interfacing DC distributed generations which are photovoltaic power generation along with a battery unit. The r-Z-source inverter is used as interlinking converter for the AC and DC subgrids and its control scheme is described with respect to the autonomous operation of the hybrid microgrid. Moreover, droop control is used for power sharing management of the microgrid as a decentralized control strategy. The performance of the proposed interlinking converter and control strategy of the autonomous microgrid is evaluated by time domain simulations in MATLAB/Simulink.