Control of storage elements in an islanded microgrid with voltage-based control of DG units and loads

Abstract

Because of their small scale and large share of intermittent power sources, islanded microgrids require additional means of flexibility, such as dedicated storage. For controlling the loads and distributed generation (DG) units in an islanded microgrid, the voltage-based droop (VBD) control has been developed. This controller determines the switching actions of these units' power electronic interfaces in order to ensure a stable islanded microgrid operation. In this paper, the VBD control is extended for storage applications, taking into account the state of charge. As the VBD control automatically fixes the priority of power changes of the microgrid elements, the storage elements are included in this priority list without inter-unit communication, benefiting the coordinated integration of DG units in the system. Simulation examples are included illustrating the transient and dynamic response of the VBD control of all grid assets. The paper also provides an experimental validation of the VBD control for both the DG units and the storage elements in an islanded microgrid.

Optimisation of droop coefficients of multiple distributed generators in a micro‐grid

“…The DERs and energy storage systems (battery energy storage system, compressed air energy storage systems, thermal energy storage, pumped hydro etc.) generally feed the micro-grid at distribution voltage level [18]. Power electronic interfaces (DC/AC, AC/DC, DC/DC, or AC/DC/AC) are introduced between DERs and micro-grid.…”

H‐Infinity versus model predictive control methods for seamless transition between islanded‐ and grid‐connected modes of microgrids

“…It improves the system reliability, consumer confidence, and system power quality [1]. Nowadays, MGs have become the main trend in distribution systems as they reduce the transmission losses, gas emissions, total cost, and hence increase the system efficiency [2]. MGs have the ability to operate in conjunction with the utility grid (on-grid) or in islanded mode (off-grid) [3].…”

A multistage H‐infinity–based controller for adjusting voltage and frequency and improving power quality in islanded microgrids

“…1 MGs are used for improving system power quality, reducing both CO 2 emission and energy losses, decreasing transmission lines loading and offering an efficient way of integrating renewable energy systems. 2,3 There are two operating modes for MGs: islanded and grid-connected modes. In the case of grid-connected, the MG transfers power to/from the main grid based on the generating power and load demand and hence its voltage and frequency are adjusted according to the utility grid references.…”

“…A microgrids (MG) is a combination of different distributed energy pesources (DERs) and various loads defined as electrical boundaries acting as single controllable devices with respect to the utility 1 . MGs are used for improving system power quality, reducing both CO 2 emission and energy losses, decreasing transmission lines loading and offering an efficient way of integrating renewable energy systems 2,3 …”