An Active Power Sharing Method among Distributed Energy Sources in an Islanded Series Micro-Grid

Abstract

Active power-sharing among distributed energy sources (DESs) is not only an important way to realize optimal operation of micro-grids, but also the key to maintaining stability for islanded operation. Due to the unique configuration of series micro-grids (SMGs), the power-sharing method adopted in an ordinary AC, DC, and hybrid AC/DC system cannot be directly applied into SMGs. Power-sharing in one SMG with multiple DESs involves two aspects. On the one hand, capacitor voltage stability based on an energy storage system (ESS) in the DC link must be complemented. Actually, this is a problem of power allocation between the generating unit and the ESS in the DES; an extensively researched, similar problem has been grid-off distributed power generation, for which there are good solutions. On the other hand, power-sharing among DESs should be considered to optimize the operation of a series micro-grid. In this paper, a novel method combining master control with auxiliary control is proposed. Master action of a quasi-proportional resonant controller is responsible for stability of the islanded SMG; auxiliary action based on state of charge (SOC) realizes coordinated allocation of load power among the source. At the same time, it is important to ensure that the auxiliary control does not influence the master action.

Analyzing the Effects of Micro‐Source Disconnection on Interactive Stability of Grid and Micro‐Grid with Series Inverters

“…A new structure of the micro-grid has been recently proposed [1][2][3] in which distributed generation units are connected to the respective inverters and the output terminals of the inverters are cascaded. A distributed generation unit of this micro-grid is called a micro-source (MS) here.…”

Optimization and Analysis of a Hybrid Energy Storage System in a Small-Scale Standalone Microgrid for Remote Area Power Supply (RAPS)

“…Although LB and SC have different technical characteristics, they are both energy storage technologies which can be charged and discharged as required through corresponding PCS. A general mathematical model available for LB-ESS and SC-ESS is presented in [24][25][26][27][28][29][30]. As shown in Equations (6)- (8), this model includes the computation of power output limits and state of charge (SOC) for ESSs.…”