Control Of DC Microgrids Research Articles

Operation Analysis of Coordinated Droop Control for Stand-alone DC Micro-grid

This paper introduces a coordinated droop control for the stand-alone DC micro-grid., which is composed of photo voltaic generator, wind power generator, engine generator, and battery storage with SOC (state of charge) management system. The operation of stand-alone DC micro-grid with the coordinated droop control was analyzed with computer simulation. Based on simulation results, a hardware simulator was built and tested to analyze the performance of proposed system. The developed simulation model and hardware simulator can be utilized to design the actual stand-alone DC micro-grid and to analyze its performance. The coordinated droop control can improve the reliability and efficiency of the stand-alone DC micro-grid

The Coordinated Power Control of Flexible DC Microgrids in Sustainably Optimized Yacht Marinas

Nowadays, the industrial world is undergoing a disruptive transformation towards more environmentally sustainable solutions. In the blue economy, this new approach is not only expressed in the domain of actual vessels, but also in the development of charging infrastructure, displaying a notable transition towards more eco-friendly solutions. The key focus lies in adopting flexible power systems capable of integrating renewable energy sources and storage technologies. Such systems play a crucial role in enabling a shift towards low-emission maritime transport. The emissions reduction goal extends beyond onboard shipboard distribution systems, encompassing also the design of supplying platforms and marinas. This study explores the implementation of a controlled DC microgrid tailored to efficient management of power flows within a yacht marina. Once having established the interfaces for the vessels at berth, the integration between the vessels, the onshore photovoltaic plant and the battery storage unit is made possible thanks to the coordinated management of multiple power converters. The overarching goal is to curtail reliance on external energy sources. Within this DC microgrid framework, a centralized controller assumes a pivotal role in orchestrating the power sources and loads. This coordinated management is essential to achieve sustainable operations, ultimately leading to the reduction of emissions from both ships and onshore power plants.

Decentralized current sharing in dc microgrids considering normal and disturbed operation modes

The accurate ratio-based current sharing, which is one of the desired features of the droop controlled dc microgrid, might be affected by the system impedance. Several strategies have been presented in the literature to achieve precise current sharing. This paper proposes a new controller reconfiguration algorithm that is capable to achieve enhanced operation during normal conditions and after system disturbances. For this purpose, the proposed algorithm allows the converter to follow the set-points determined by a higher-level controller when there is no disturbance in the system. After a system disturbance, when the necessity for the current sharing arises, the proposed controller enables accurate ratio based current mismatch sharing between the droop controlled converters. The time-domain simulation conducted in Matlab/ Simulink environment demonstrates the effectiveness of the proposed approach.

Intelligent Control of DC Microgrid Involving Multiple Renewables for Fast Charging Control of Electric Vehicles

Electric vehicles (EVs) are now considered to be a cutting-edge form of transportation. However, the electrical grid infrastructure is not sufficiently developed to meet the rising charging demand for electric vehicles. Therefore, it is impossible to rely entirely on grid-generated electricity. This article discusses a control approach for extremely rapid charging of EV batteries driven by a hybrid DC microgrid, consisting of isolated, Photovoltaic (PV), Wind Turbine, Fuel Cell and Energy Storage Systems. An adaptive sliding mode controller is designed to provide the appropriate power for charging and discharging EVs and energy storage units (ESUs) under a variety of power generation and demand scenarios. The proposed adaptive sliding mode controller operates in a decentralized manner to maintain power distribution amongst the microgrid DC-link EVs and the ESUs. In order to validate the effectiveness of the sliding mode controller in battery charging applications, a comprehensive comparison between fuzzy logic and adaptive sliding mode control is conducted. The proposed controller operates exceptionally well in the presence of unpredictable operating point variations such as rapid changes in EV charging load, fluctuations in solar irradiation, unexpected wind conditions, and so on. Finally, the proposed controller is verified by both simulation and experimental studies.

Design and control of utility grid-tied bipolar DC microgrid

Abstract This paper explains in detail the design and control of a utility grid-connected bipolar DC microgrid, which consists of a solar photovoltaic system (SPV), a wind energy conversion system (WECS), a battery energy storage system (BESS) at the DC bus, and a three-level neutral point clamped (NPC) converter to connect the DC microgrid to the utility grid. A three-level bidirectional DC–DC converter at the battery energy storage system (BESS) is controlled with model predictive current control (MPCC), and a three-level NPC converter is controlled with a voltage-oriented control based proportional resonant (VOC-PR) controller. The proposed MPCC scheme for the three-level bidirectional DC–DC converter and the VOC-PR control scheme for the three-level NPC converter coordinate with each other to balance and regulate the voltage at the bipolar DC microgrid, control the power flow to the loads at the DC microgrid and the load at the point of common connection (PCC), and also inject or draw power from the utility grid and BESS based on the availability of Renewable Energy Sources (RES). Simulation and experimental results are presented to demonstrate the effectiveness of the proposed MPCC control scheme.

Fully Actuated System-Based Modeling and Control of DC Microgrids With Inductive Tie Lines: A Predictive Strategy

Fully Actuated System-Based Modeling and Control of DC Microgrids With Inductive Tie Lines: A Predictive Strategy

HPPD-Type Fuzzy State-FDI Estimation and Resilient Control of Cyber-Physical DC Microgrids with Hybrid Attacks

HPPD-Type Fuzzy State-FDI Estimation and Resilient Control of Cyber-Physical DC Microgrids with Hybrid Attacks

Robust Model Predictive Control of Uncertain DC Microgrids Based on Improved Adaptive Consensus Algorithm

Robust Model Predictive Control of Uncertain DC Microgrids Based on Improved Adaptive Consensus Algorithm

An Adaptive Fixed-Time Cascaded Distributed Control for Bipolar-Type DC Microgrids Considering Time Delays

An Adaptive Fixed-Time Cascaded Distributed Control for Bipolar-Type DC Microgrids Considering Time Delays

Distributed Control of Islanded DC Microgrids: A Passivity-Based Game Theoretical Approach

Distributed Control of Islanded DC Microgrids: A Passivity-Based Game Theoretical Approach

Fixed-Time Distributed Control for Parallel DC Microgrids With Scaled Power Sharing

Fixed-Time Distributed Control for Parallel DC Microgrids With Scaled Power Sharing

Coordinated Control for Islanded DC Microgrid Based on Derivative of Bus Voltage

The unbalanced power generated by unintentional islanding is a tremendous challenge to the stable operation of the DC microgrid. When dealing with this challenge, the existing communication-free voltage-threshold-based coordinated control lags far behind the actual power variation, which exacerbates the risk of voltage violations in the microgrid. To address the drawback of the existing control, this paper proposes a new method based on the derivative of bus voltage. Firstly, based on the mathematical correlation between unbalanced power and the derivative of bus voltage, a coordination control strategy and its switching criterion before the battery energy storage system (BESS) exits operation is proposed. Meanwhile, we propose a communication-free approach to sense the operation state of the BESS based on the dynamic process of the derivative of bus voltage. Thus the information obtained under complicated circumstances could be further enriched. Subsequently, a new control strategy after BESS operates operation is established to coordinate different sources among the microgrid. Compared with the existing coordinated control methods, the proposed one can better utilize the information contained in the dynamic process of the bus voltage. Numerical results validate the effectiveness and advantages of the proposed method.

Discrete-Time distributed secondary control of DC microgrids with communication delays

Discrete-Time distributed secondary control of DC microgrids with communication delays

Event-Triggered Distributed Sliding Mode Control for DC Microgrids With Imperfect Sources

Event-Triggered Distributed Sliding Mode Control for DC Microgrids With Imperfect Sources

Resilence Control of DC Microgrid Integrated with Multi-Nanogrids Considering Connected-Islanded States

Resilence Control of DC Microgrid Integrated with Multi-Nanogrids Considering Connected-Islanded States

Decentralized Control of DC Microgrids Using Interconnection and Damping Assignment Passivity-Based Control Technique: Experimental Verification

Decentralized Control of DC Microgrids Using Interconnection and Damping Assignment Passivity-Based Control Technique: Experimental Verification

Coordinated Predictive Secondary Control for DC Microgrids Based on High-Order Fully Actuated System Approaches

The problem of voltage recovery and current balancing has been a hot research topic in the field of DC microgrids. How to build a model that reflects the circuit and component-level control (e.g., inner control loops) characteristics and design a secondary controller based on it to accomplish the above output regulations is the concern of this paper. Accordingly, in this paper, based on the large-signal model of microgrids, the corresponding high-order fully actuated model is developed for DC microgrids, which is not only simple in form but also able to capture the details of the actual power system, such as the relationship between voltage and current. Further, a distributed predictive fully actuated secondary control strategy is proposed based on the developed model to achieve voltage recovery and accurate current sharing. Allowing one to design the secondary controller free from the constraints of physical coupling in the microgrid is one feature of this control strategy, while the other is the arbitrarily assignable closed-loop poles. An analytical model of the closed-loop DC microgrid system with predictive fully actuated secondary control is developed, and the analysis of stability and output current consensus is presented therewith. Extensive tests on a hardware system of a DC microgrid with solar panels and an MPPT controller are performed to validate the performance of the designed controller.

Dynamic Tube Control for DC Microgrids

Dynamic Tube Control for DC Microgrids

Bus voltage stability control of DC microgrid considering voltage constraints

Bus voltage stability control of DC microgrid considering voltage constraints

Distributed Hybrid Model Predictive Secondary Control of DC Microgrids with Random Communication Disorders

Distributed Hybrid Model Predictive Secondary Control of DC Microgrids with Random Communication Disorders