Energy management of distributed renewable energy sources for residential DC microgrid applications

Abstract

This paper proposes a low voltage (400 Vdc) distributed renewable energy fed DC microgrid structure for a residential system, which uses DC voltage for the electronic appliances. The distributed energy sources—solar photovoltaic (PV) and wind energy are considered as input sources. The output power from these sources is stochastic in nature. An efficient energy management and switching circuit is designed to control the power flow from the sources with a high gain DC‐DC converter as the main component. The output power regulation is achieved by means of controlling duty ratios of the switches in the proposed high gain converter through PI controller. The control algorithm effectively converts the unregulated DC power from the solar PV and wind into regulated DC for driving a DC load connected in DC‐microgrid. The energy management and switching circuits account for seamless operation of the DC microgrid under various modes when one or all the sources and loads are connected directly at the DC grid link. The designed energy management and switching circuit also ensures the power balancing in the proposed system. The proposed DC microgrid structure is simulated using MATLAB Simulink. The performance of the proposed high gain converter for the DC grid link voltage regulation is analyzed under source power variation and dynamic changes in load for various operating conditions. The proposed DC microgrid structure is validated using simulation results.

Analysis and control of a single switch wider step‐down gain DC–DC converter for low‐voltage applications

“…Equation 3 represents a duty ratio function, having D as a linear gain of TBC, which is multiplied by a term 1/(2 − D) 2 that contributes in wider nonlinear variation. To understand the high step-down conversion feature properly, CLSDC's ideal voltage gain variation with duty ratio is pitted against existent TBC, QBC, new QBC (NQBC), and stacked buck converter (SBC) configurations in Figure 3B.…”

“…The recent shift in paradigm toward low‐power electronic systems has evolved several variants of DC–DC step‐down converter to be incorporated in advanced point‐of‐load (PoL) applications 1,2 . Battery chargers, data servers, automotive drivetrains, photovoltaic (PV) energy systems, and LED ballasts are some typical PoL examples 1–3 powered from unregulated 36/42/48 V DC bus or battery packs as shown in Figure 1 to operate within 1.2 – 12 V range, drawing high currents up to 20 A. Because a traditional buck converter (TBC) offers simple dynamics and low‐cost advantages, it has predominantly governed the power supply market.…”

Amultimicrogridenergy management model implementing an evolutionary game‐theoretic approach

“…Electricity production is affected by weather variability, and therefore an energy management system (EMS) is necessary. An EMS is efficiently designed among a single MG 1 controlling power flow through DC‐DC power converters using a PI controller. In addition, an EMS is presented for multiple MGs (MMGs) 2 as per the load at each building, and the electricity demand oscillates accordingly.…”

Dynamic control of grid‐connected microgrids for tie‐line smoothing

“…Tie‐line fluctuation in grid‐connected MGs can cause severe stability and quality issues in a distribution network. Previous research has addressed this problem by controlling the power of MG resources, such as non‐renewable generation control, demand side control, ESS control or coordinate control through an energy management system (EMS) of the MG 7‐16 …”