Secondary Switched Control With no Communications for Islanded Microgrids

Flexibility and reliability of ac microgrids are enhanced by reducing the dependence on communications in multilayer hierarchical control. In this sense, this paper presents a secondary control with no communications for islanded microgrids. It is based on a control scheme that switches between two configurations according to a time-dependent protocol. With this proposal, an excellent performance in terms of transient response and frequency restoration in steady state is achieved. This paper also presents design considerations for the control parameters. In addition, the theoretical predictions are validated by experimental results from a laboratory microgrid.

I. Introduction

Microgrids have recently emerged as a potential solution for electrical supply due to their advantages as environmental impacts reduction, reliability, and flexible operability [1], [2]. Basically, a microgrid is a cluster of distributed generators (DGs), loads, and energy-storage systems which can operate in two possible modes: grid-connected or islanded [3].