scholarly journals A Novel Bidirectional DC-DC Converter for Dynamic Performance Enhancement of Hybrid AC/DC Microgrid

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1653 ◽  
Author(s):  
Morteza Daviran Keshavarzi ◽  
Mohd Hasan Ali
Keyword(s):  
Power Flow ◽  
Performance Enhancement ◽  
Dynamic Performance ◽  
Poor Performance ◽  
Dc Microgrid ◽  
Voltage Level ◽  
Grid Voltage ◽  
Step Down ◽  
Battery Energy ◽  
Bidirectional Power Flow

The conventional bidirectional DC-DC converter (BDC), which employs a half-bridge configuration, has some major disadvantages, including a controller designed for one direction with poor performance in the other direction, a bidirectional operation which does not have symmetrical voltage gain resulting in asymmetrical operation, and step-up and step-down switches that are simultaneously modulated, thereby increasing switching losses. To overcome these drawbacks, this paper proposes a new, nonisolated, DC-DC converter for the bidirectional power flow of battery energy storage applications in DC and hybrid microgrids (HMGs). The proposed converter uses two back-to-back Boost converters with two battery voltage levels, which eliminates step-down operation to obtain symmetric gains and dynamics in both directions. In discharge mode, two battery sections are in parallel connection at a voltage level lower than the grid voltage. In charge mode, two battery sections are in series connection at a voltage level higher than the grid voltage. Simulations demonstrate the efficacy of the proposed converter in the MATALB\Simulink environment. The results show that the proposed converter has promising performance compared to that of the conventional type. Moreover, the novel converter adds no complexity to the control system and does not incur considerable power loss or capital cost.

scholarly journals Economic Load Dispatch of a Grid-Tied DC Microgrid Using the Interior Search Algorithm

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 634 ◽  
Author(s):  
Kamil Khan ◽  
Ahmad Kamal ◽  
Abdul Basit ◽  
Tanvir Ahmad ◽  
Haider Ali ◽  
...  
Keyword(s):  
Energy Storage ◽  
Power Flow ◽  
Search Algorithm ◽  
Operating Cost ◽  
Daily Cost ◽  
Dc Microgrid ◽  
Battery Energy Storage ◽  
Power Scheduling ◽  
Battery Energy ◽  
Bidirectional Power Flow

This paper presents the effectiveness of the interior search algorithm in economic power scheduling of a grid-tied DC microgrid with renewable generation (wind and photovoltaic) and battery energy storage. The study presents the modelling and simulation of various DC/DC converters for tracking maximum power from wind and photovoltaic sources and the bidirectional power flow of battery energy storage. The DC microgrid and its controllers were modelled and simulated in MATLAB/Simulink. The generating units were dispatched economically using the interior search algorithm with the objective to minimize the operating cost of the microgrid. The simulated results verify the effectiveness of the interior search algorithm as the daily cost of microgrid operation was reduced by 11.25%.

scholarly journals Bidirectional Power Sharing for DC Microgrid Enabled by Dual Active Bridge DC-DC Converter

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 404
Author(s):  
Sara J. Ríos ◽  
Daniel J. Pagano ◽  
Kevin E. Lucas
Keyword(s):  
Power Management ◽  
Distribution Systems ◽  
Control Method ◽  
Dynamic Performance ◽  
Management Control ◽  
Photovoltaic System ◽  
Dc Microgrid ◽  
Dual Active Bridge ◽  
Control Scheme ◽  
Bidirectional Power Flow

Currently, high-performance power conversion requirements are of increasing interest in microgrid applications. In fact, isolated bidirectional dc-dc converters are widely used in modern dc distribution systems. The dual active bridge (DAB) dc-dc converter is identified as one of the most promising converter topology for the mentioned applications, due to its benefits of high power density, electrical isolation, bidirectional power flow, zero-voltage switching, and symmetrical structure. This study presents a power management control scheme in order to ensure the power balance of a dc microgrid in stand-alone operation, where the renewable energy source (RES) and the battery energy storage (BES) unit are interfaced by DAB converters. The power management algorithm, as introduced in this work, selects the proper operation of the RES system and BES system, based on load/generation power and state-of-charge of the battery conditions. Moreover, a nonlinear robust control strategy is proposed when the DAB converters are in voltage-mode-control in order to enhance the dynamic performance and robustness of the common dc-bus voltage, in addition to overcoming the instability problems that are caused by constant power loads and the dynamic interactions of power electronic converters. The simulation platform is developed in MATLAB/Simulink, where a photovoltaic system and battery system are selected as the typical RES and BES, respectively. Assessments on the performance of the proposed control scheme are conducted. Comparisons with the other control method are also provided.

Protection Scheme for DC Microgrid Distribution System

2012 ◽  
Vol 614-615 ◽  
pp. 1661-1665
Author(s):  
Ling Hui Deng ◽  
Zhi Xin Wang ◽  
Jian Min Duan
Keyword(s):  
Distribution System ◽  
Cost Efficiency ◽  
Power Flow ◽  
Low Voltage ◽  
Dc Microgrid ◽  
Protection Scheme ◽  
High Level ◽  
Bidirectional Power Flow ◽  
Efficiency And Reliability ◽  
Laboratory Prototype

The low voltage DC (LVDC) distribution system is a new concept and a promising technology to be used in the future smart distribution system having high level cost-efficiency and reliability. In this paper, a low-voltage (LV) DC microgrid protection system design is proposed. Usually, an LVDC microgrid must be connected to an ac grid through converters with bidirectional power flow and, therefore, a different protection scheme is needed. This paper describes practical protection solutions for the LVDC network and an LVDC system laboratory prototype is being experimentally tested by MATLAB/SIMULINK. The results show that it is possible to use available devices to protect such a system. But other problems may arise which needs further study.

scholarly journals Bidirectional Power Flow Control in AC/DC Hybrid System under AC and DC Fault Conditions

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
Wai Wai Hnin
Keyword(s):  
Power Flow ◽  
Storage System ◽  
Control Technique ◽  
Diesel Generator ◽  
Dc Microgrid ◽  
Photovoltaic Array ◽  
Hybrid Microgrid ◽  
Dc Bus ◽  
Bidirectional Power Flow ◽  
Ac Microgrid

This paper presents a hybrid AC-DC microgrid to reduce the process of multiple conversions in an individual AC microgrid or DC microgrid. The proposed hybrid microgrid compose of both AC microgrid and DC microgrid connected together by bidirectional interlink converter (BIC). Utility grid, 150kVA diesel generator (DG) and 100kW AC load are connected in AC microgrid. DC microgrid is composed of 100 kW photovoltaic array (PV), 20kW battery energy storage system (BESS) and 20kW DC load. The droop control technique is applied to control the system for power sharing within the sources in AC/DC hybrid microgrid in proportion to the power rating. When the faults occur at AC bus, protection signal applied to breaker for isolating the healthy and faults system. DC faults occur at DC bus, DC breaker isolate the AC and DC bus. The system performance for power flow sharing on hybrid AC-DC microgrid is demonstrated by using MATLAB/SIMULINK.

A New Interleaved Bidirectional Zero Voltage Switching DC/DC Converter with High Conversion Ratio

2017 ◽  
Vol 26 (06) ◽  
pp. 1750105 ◽  
Author(s):  
Ebrahim Babaei ◽  
Zahra Saadatizadeh ◽  
Behnam Mohammadi Ivatloo
Keyword(s):  
Power Flow ◽  
Low Voltage ◽  
Zero Voltage Switching ◽  
Bidirectional Converters ◽  
Comprehensive Comparison ◽  
Step Down ◽  
High Conversion Ratio ◽  
Bidirectional Power Flow ◽  
Zero Voltage ◽  
Voltage Switching

In this paper, a new interleaved nonisolated bidirectional zero voltage switching (ZVS) dc–dc converter by using one three-windings coupled inductor is proposed. The proposed topology can provide high step-up and high step-down conversion ratios for boost and buck operations, respectively. Moreover, because of interleaving, the proposed converter has low input current ripple at low voltage side in both buck and boost operations. The proposed converter uses lower number of switches to have bidirectional power flow in comparison with other interleaved bidirectional converters. All used switches in the proposed converter are turned on under ZVS. The advantages of the proposed converter in comparison with the conventional interleaved converters are included in the capability of bidirectional power flow, ZVS operation for all switches and high step-up and high step-down voltage gain for boost and buck operations. In this paper, the proposed converter is analyzed completely and all equations of components are extracted as well as the ZVS conditions of all switches. Moreover, a comprehensive comparison between the proposed converter and conventional topologies is presented. To verify the accuracy performance of the proposed converter, the experimental results are given.

Sign in / Sign up

Export Citation Format

Share Document