A New Local Control Method of Interlinking Converters to Improve Global Power Sharing in an Islanded Hybrid AC/DC Microgrid

2020 ◽  
Vol 35 (2) ◽  
pp. 1014-1025 ◽  
Author(s):  
Jae-Won Chang ◽  
Seung-Il Moon ◽  
Gyu-Sub Lee ◽  
Pyeong-Ik Hwang
Keyword(s):  
Local Control ◽  
Control Method ◽  
Power Sharing ◽  
Dc Microgrid ◽  
Global Power

Decentralized Voltage Balancing and Power Sharing in Islanded Bipolar DC Microgrids

2020 ◽  
Author(s):  
Saman Dadjo Tavakoli
Keyword(s):  
Transfer Functions ◽  
Control Method ◽  
Input Voltage ◽  
Voltage Regulation ◽  
Power Sharing ◽  
Dc Microgrid ◽  
Voltage Balancing ◽  
Dc Microgrids ◽  
Converter Topology ◽  
Unbalanced Loads

<div>This paper presents a decentralized control scheme for voltage balancing and power sharing in bipolar dc</div><div>microgrids. This relies on utilizing a converter topology which offers three levels of output voltage availability with the key features of boosting the input voltage and balancing the output voltages. This converter makes it possible to further improve the structure of bipolar dc microgrids as it does not require a central voltage balancer. Small-signal analysis is done and system transfer functions are derived. Based on the RGA concept the highly coupled input-output pairs are found which helps with replacing the MIMO control system of the converter by two SISO systems. The appropriate voltage and current controllers are designed based on SISO principles. Moreover, a double droop control method is proposed which fulfills the simultaneous power sharing and voltage regulation of DG units in the host microgrid. The effectiveness of the proposed control strategy is demonstrated through simulation studies conducted on an</div><div>islanded bipolar dc microgrid involving unbalanced loads, while the voltage balancing of the bipolar dc microgrid and the power sharing accuracy are evaluated.</div>

scholarly journals Decentralized Voltage Balancing and Power Sharing in Islanded Bipolar DC Microgrids

2020 ◽  
Author(s):  
Saman Dadjo Tavakoli
Keyword(s):  
Transfer Functions ◽  
Control Method ◽  
Input Voltage ◽  
Voltage Regulation ◽  
Power Sharing ◽  
Dc Microgrid ◽  
Voltage Balancing ◽  
Dc Microgrids ◽  
Converter Topology ◽  
Unbalanced Loads

<div>This paper presents a decentralized control scheme for voltage balancing and power sharing in bipolar dc</div><div>microgrids. This relies on utilizing a converter topology which offers three levels of output voltage availability with the key features of boosting the input voltage and balancing the output voltages. This converter makes it possible to further improve the structure of bipolar dc microgrids as it does not require a central voltage balancer. Small-signal analysis is done and system transfer functions are derived. Based on the RGA concept the highly coupled input-output pairs are found which helps with replacing the MIMO control system of the converter by two SISO systems. The appropriate voltage and current controllers are designed based on SISO principles. Moreover, a double droop control method is proposed which fulfills the simultaneous power sharing and voltage regulation of DG units in the host microgrid. The effectiveness of the proposed control strategy is demonstrated through simulation studies conducted on an</div><div>islanded bipolar dc microgrid involving unbalanced loads, while the voltage balancing of the bipolar dc microgrid and the power sharing accuracy are evaluated.</div>

scholarly journals A Centralized Shifted Voltage Control Method for Accurate Power Sharing in DC Islanded Microgrids

2021 ◽  
Vol 19 ◽  
pp. 155-159
Author(s):  
Minh-Duc Pham ◽  
◽  
Hong-Hee Lee
Keyword(s):  
Output Voltage ◽  
Control Method ◽  
Voltage Drop ◽  
Renewable Energy Sources ◽  
Control Variable ◽  
Voltage Control ◽  
Power Sharing ◽  
System Stability ◽  
Small Scale ◽  
Dc Microgrid

Due to line impedance mismatch among renewable energy sources (RESs), it is hard to realize accurate power sharing in the DC microgrid system. To solve this issue, a distributed power sharing strategy for adjusting the RES output voltage is developed by adding shifted output voltage into each local controller. Thanks to the shifted voltage, the influence of voltage drop caused by the droop controller is effectively mitigated, so that the DC bus voltage is constantly balanced regardless of the load changes. The proposed method is realized with a centralized approach, and all the required control variable to determine the reference voltage is transmitted through low-bandwidth communication. The controller design and system stability are analyzed in detail with a simplified microgrid model. Small-scale DC microgrid is simulated to verify the effectiveness of the centralized shifted voltage control method.

scholarly journals Matlab based simulation model of standalone DC Microgrid for Remote Area Power Applications

2018 ◽  
Vol 7 (1.8) ◽  
pp. 153 ◽  
Author(s):  
G Srinivasa Rao ◽  
K Harinadha Reddy ◽  
B Ravi Teja ◽  
B Devasahayam ◽  
Shaik Khaleel
Keyword(s):  
Control Method ◽  
High Reliability ◽  
Voltage Regulation ◽  
Remote Area ◽  
Operating Conditions ◽  
Power Sharing ◽  
Renewable Energy Resources ◽  
Grid Data ◽  
Energy Management Strategy ◽  
Dc Microgrid

DC microgrids are playing an important role in remote area power applications like power supply to off-grid tele communication towers, off-grid data centres, rural electrification etc. and moreover these are extensively used, as these appear as solutions for integrating two or more renewable energy resources. In this paper, photovoltaic (PV) and wind energy systems have been integrated along with batteries and a load to form an autonomous DC microgrid with high reliability and stability.  The primary aspects which are to be taken into consideration in a standalone DC microgrid are voltage regulation, load sharing and battery management. In this paper, an energy management strategy is proposed which includes maximum power point tracking (MPPT) algorithms and voltage droop control method. This strategy ensures optimal power sharing among the sources and increases reliability and stability profile of the microgrid. The operation of the microgrid in different modes and the behaviour of the system at different operating conditions is studied by varying the solar irradiance and wind speed for specific time periods. The simulation is done in Matlab Simulink software and the results are obtained. 

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.

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