High-gain-high-power (HGHP) DC-DC converter for DC microgrid applications: Design and testing

Summary In this paper, a new extendable high step‐up multi‐input‐single‐output dc‐dc converter is presented. The proposed converter is composed based on the conventional boost converter and conventional buck‐boost converter. The benefits of the proposed converter consist of the simple control of each duty cycle and low‐voltage stress across the semiconductors. Therefore, conduction losses can be reduced by using the switch with lower resistance rDS(on). The presented converter is flexible to obtain the high power level with the proper selection of duty cycle values. Therefore, the presented converter is controllable in different power levels of input sides. In fact, the proposed converter supports the operation of multiple input sources without any changes in the structure of the topology. The dynamic modeling and efficient multivariable controller design with dynamic responses for the proposed converter are analyzed completely. To confirm the performance of the presented converter, mathematical analysis and simulation results are presented. In addition, the comparison between the presented converter and some other topologies is provided. In order to illustrate the efficient operation of the presented converter, a laboratory prototype for a 425 V/300 W with 40‐ and 45‐V input voltages and 95.62% efficiency is implemented.

Section: Introductionmentioning

confidence: 99%

A multi‐input‐single‐output high step‐up DC‐DC converter with low‐voltage stress across semiconductors

Mohseni

Hosseini

Sabahi

et al. 2019

“…In DC microgrids, the concepts of reactive power, grid synchronization, and grid frequency regulation does not exist, and thus in comparison with AC microgrids, DC microgrids have simple control structure, lower transmission loss, and higher efficiency . Therefore, operation, planning, and implementation of DC microgrids seem to be simpler and less expensive …”

Section: Introductionmentioning

confidence: 99%

“…[16][17][18][19][20] Therefore, operation, planning, and implementation of DC microgrids seem to be simpler and less expensive. 21 Usually in a DC microgrid, renewable and distributed energy sources are connected in parallel to a main DC bus through interface converters and transmission lines. [22][23][24] The interface converters of generation sources in a DC microgrid are usually controlled based on a popular decentralized approach known as conventional droop control method.…”

mentioning

confidence: 99%

A generalized droop‐based compensator for addressing the issues raised in a DC microgrid comprising hybrid wind‐battery‐back up generation sources

Rahimi

Ghadiriyan

2019

Summary This paper deals with the improvement of stability margin, dynamic behavior, and steady state performance of a direct current (DC) microgrid system consisting of wind energy sources, battery energy storage, and back up generation source. The DC microgrid control system should set the DC bus voltage at the allowable range and provide proper load sharing among generation sources. Accurate load sharing, proper voltage regulation, and dynamic stability of the system at presence of constant power loads (CPLs) are the main problems that may be raised in operation of DC microgrid systems. In order to address these issues, this paper proposes a generalized droop‐based compensator that not only stabilizes the DC microgrid dynamics at high penetration of CPLs, but also addresses the issues such as inaccurate load sharing and improper voltage regulation. The proposed generalized droop‐based compensator comprises three parts: the first part enhances the DC microgrid stability even at high penetration of CPL, the second part compensates the transmission lines voltage drops and improves the function of voltage regulation, and the third part performs proper load sharing among different generation sources. At the end, capability of the proposed compensator is examined by frequency response analysis and time domain simulations.

“…1,2 Nanogrid is a power system architecture, where power generated through renewable sources are connected to the grid locally through power electronic converters. [3][4][5][6][7] Schematic of DC nanogrid where power is supplied primarily by PV panels is shown in Figure 1. It comprises of PV panel, battery bank, and various DC and AC loads.…”

Section: Introductionmentioning

confidence: 99%

Multicell multi‐output converter to counter unbalanced input sources in nanogrid applications

Pilli

Khan

Kumar

et al. 2019

Summary Nanogrid is an apt solution to encourage renewable power generation and counter the problem of global warming. It comprises of mostly the PV sources feeding both AC and DC loads. To meet out this scenario, a converter that can convert DC to both DC and AC is required. This paper proposes a hybrid converter providing both AC and DC output for DC input. The proposed converter is a derived form of Split‐Pi converter, known as hybrid Split‐Pi. It works in both boost and buck mode. Inherent shoot through problem of bridge circuit present in a Split‐Pi converter is eliminated as the shoot‐through period is utilized to charge the boost inductor of the proposed converter. Hence, enhanced output is obtained because of the absence of dead time operation. A hardware prototype is developed to validate the proposed converter. Proposed converter is tested for both buck and boost mode. Variation of AC and DC gain with change in duty ratio is observed. The output AC RMS and its THD is studied for different modulation index. Peak of output AC voltage is limited by the input DC voltage. To overcome this issue, the single cell proposed converter is extended to a multicell arrangement. Multicell arrangement integrates multiple input DC voltage sources having different voltage levels. It is simulated for different cases and outputs are discussed.