Article
Energy & Fuels
Zuliang Huang, Yan Li, Xin Cheng, Mingjun Ke
Summary: This paper proposes a distributed secondary control strategy for parallel battery energy units (BEUs) in a DC microgrid. The strategy consists of two layers: a primary control layer with droop control and a secondary control layer that generates a voltage-shifting term using an information state factor. A sigmoid function with a balancing adjustment factor is adopted to improve SOC balancing accuracy and speed. The proposed method reduces communication burden, avoids unnecessary cyclic charge or discharge, and achieves accurate current sharing and consistent output voltage.
JOURNAL OF ENERGY STORAGE
(2023)
Article
Engineering, Electrical & Electronic
Fanghong Guo, Zhen Huang, Lei Wang, Yu Wang
Summary: This paper proposes a distributed voltage restoration and power allocation control scheme for the DC microgrid system, which utilizes discrete and aperiodic event-triggered communication. The approach breaks the hierarchy of secondary control and tertiary optimization and solves the power regulation and voltage restoration problems simultaneously in the secondary layer. The proposed method allows for significant communication cost savings compared to existing methods.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2023)
Article
Energy & Fuels
Mrutunjaya Panda, Devara Vijaya Bhaskar, Tanmoy Maity
Summary: This paper proposes a coordinated power management strategy for a dc microgrid, utilizing secondary controllers for voltage restoration, SoC balancing, and distributed power sharing. The strategy re-establishes distributed power sharing through low bandwidth communication, optimizes battery performance, and utilizes PV generation through a state transition strategy.
JOURNAL OF ENERGY STORAGE
(2022)
Article
Energy & Fuels
Shi Chen, Qingwu Gong, Xiaoqing Lu, Jingang Lai
Summary: This paper presents a distributed cooperative control strategy for a DC islanded microgrid with vanadium redox batteries, aiming to alleviate voltage fluctuations, achieve economic dispatch, and maintain SOC balance. The proposed method includes a consensus term for incremental cost convergence and an additional term for power balance, with real-time equilibrium considerations and SOC constraints. Numerical simulations are conducted to validate the effectiveness of the algorithm in a microgrid with six DERs.
SUSTAINABLE ENERGY GRIDS & NETWORKS
(2021)
Article
Engineering, Electrical & Electronic
Yang Mi, Jiahang Guo, Yang Fu, Chenshan Wang, Peng Wang
Summary: An adaptive droop coefficient control method based on virtual power rating is proposed for isolated island DC microgrid connected with multidistributed energy storage. The method is able to quickly equalize the state of charge of energy storage and eliminate the influence of mismatched line impedance. The proposed strategy uses the virtual power rating to construct the compensation term, which can automatically eliminate the output power deviation based on the line impedance difference of the distributed energy storage unit.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Waner Wodson A. G. Silva, Thiago R. Oliveira, Pedro F. Donoso-Garcia
Summary: This article proposes a distributed secondary control strategy for DC microgrids that achieves accurate power sharing and voltage restoration based on voltage shifting. The simple integrator as the secondary level controller and shared lambda factor information state among converters help achieve the objectives. The control technique simplifies the control structure and reduces the number of converter variables needed.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Automation & Control Systems
Boxi Li, Chang Yu, Xiaoqing Lu, Fanrong Wang
Summary: This article proposes a SoC balancing strategy for battery energy storage systems in DC microgrids. By using an integral feedforward sliding mode controller to improve the voltage response speed of the converter, and an adaptive droop control strategy to achieve cooperation and SoC balance among multiple batteries. Simulation results show that the proposed strategy can improve the transient performance and robustness of BESSs against PV output power volatility.
Article
Engineering, Electrical & Electronic
Renan F. Bastos, Cassius R. Aguiar, Attila Balogh, Zoltan Suto, Ricardo Q. Machado
Summary: This paper proposes a new decentralized control and power-sharing strategy for managing powerflow among energy sources, energy storage systems, and the common dc-link. The proposed technique eliminates communication among energy storage systems to reduce complexity and increase reliability while maintaining dc-link voltage restoration. The technique achieves power imbalance sharing among batteries proportional to their state-of-charge and energy capacity, and promotes voltage restoration for ultracapacitors.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2022)
Article
Automation & Control Systems
Jinghang Lu, Haiyang Jiang, Xiaochao Hou, Peng Wang
Summary: This article proposes a distributed edge-based event-triggered control strategy for dc bus voltage recovery and proper current sharing under denial of service (DoS) attacks. By designing a new sampling and triggered mechanism, the proposed technique eliminates dc bus voltage deviation and achieves proper current sharing under DoS attacks. The stability of the system is proven using Lyapunov theory, demonstrating that the edge-based event detector guarantees the asymptotic stability of the dc microgrid under DoS attacks. Experimental case studies are presented to verify the feasibility of the proposed control method.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Energy & Fuels
Bonan Huang, Shun Zheng, Rui Wang, Huan Wang, Jianfang Xiao, Peng Wang
Summary: This paper proposes an improved dual-quadrant SoC weighted control strategy and a distributed optimization control method to address the issues of SoC imbalance and bus voltage deviation in autonomous DC microgrids. By coupling injected/released power with current SoC and observed average SoC value, accurate power-sharing and bus voltage recovery are ensured. The proposed method optimizes the average bus voltage and achieves accurate power-sharing through constructing correlated variables and voltage independent intermediate variables.
IEEE TRANSACTIONS ON ENERGY CONVERSION
(2022)
Article
Engineering, Electrical & Electronic
Mohammad Eydi, Reza Ghazi
Summary: In the field of DC microgrids, challenges such as DC bus voltage restoration, proportional current-sharing, and SOC balancing are addressed. The drawbacks of using communication links and a central controller in microgrid control systems are discussed, leading to the proposal of a novel communication-less control method. This method utilizes droop control for voltage regulation, fuzzy controllers for SOC balancing and current sharing, and AC signal injection for DC bus voltage regulation, showing promising performance in both single-bus and multi-bus microgrids.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2022)
Article
Green & Sustainable Science & Technology
Lantao Xing, Fanghong Guo, Xiaokang Liu, Changyun Wen, Yateendra Mishra, Yu-Chu Tian
Summary: DC microgrid secondary control is essential for current sharing and DC bus voltage restoration, but existing methods only cover fixed current sharing ratios. This paper introduces a new distributed secondary control strategy that ensures adjustable current sharing ratios among DC converters, improving control performance in DC microgrids.
IEEE TRANSACTIONS ON SUSTAINABLE ENERGY
(2021)
Article
Engineering, Electrical & Electronic
Sifat Chowdhury, Mohammad Noor Bin Shaheed, Yilmaz Sozer
Summary: An adaptive control algorithm is proposed for achieving state-of-charge balancing and stability control in a battery system without the need for communication among batteries. The effectiveness of the control algorithm is validated through simulation and experimental tests, showing higher reliability, flexibility, and scalability compared to conventional centralized control methods.
IEEE TRANSACTIONS ON TRANSPORTATION ELECTRIFICATION
(2021)
Article
Engineering, Electrical & Electronic
Qinjin Zhang, Yuji Zeng, Yancheng Liu, Xuzhou Zhuang, Hanwen Zhang, Wangbao Hu, Haohao Guo
Summary: This article proposes an improved distributed cooperative control strategy for the energy storage system in an islanded dc microgrid. A hierarchical control structure is established to achieve state of charge balance, accurate current sharing, and voltage regulation. The proposed strategy shows excellent plug-and-play performance and can achieve SoC balance and accurate load current sharing under various complex operating conditions.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2022)
Article
Energy & Fuels
Noushin Poursafar, M. J. Hossain, Seyedfoad Taghizadeh
Summary: This paper presents an enhanced distributed DC-bus signaling control strategy for converters of photovoltaic systems (PVs) to make the islanded DCMG less dependent on the backup energy storage system (BESS). The proposed control method maintains DC-bus voltage via intelligently managing output powers of the PVs and switches between MPPT and voltage regulating control operations. It effectively protects the DCMG from shutdowns during the absence of the BESS and reduces oscillations on the DC-bus voltage during the presence of the BESS.
CSEE JOURNAL OF POWER AND ENERGY SYSTEMS
(2022)
Article
Engineering, Electrical & Electronic
Minh-Duc Pham, Hong-Hee Lee
Summary: Inaccurate reactive power sharing and voltage distortion in parallel inverter systems can be improved through an enhanced inverter control scheme with output impedance adjustment. This adjustment considers fundamental and harmonic frequencies to achieve accurate power sharing and improved PCC voltage quality. The compensation scheme is easily applied in multiple parallel inverters without prior knowledge of the feeder impedance, and experimental results validate its feasibility.
JOURNAL OF POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Khanh Duc Hoang, Hong-Hee Lee
Summary: This paper proposes a new method for achieving state of charge balancing and accurate power sharing among distributed batteries in a DC microgrid by injecting an AC signal instead of using a communication network for control. This method not only reduces system cost, but also ensures system reliability under fault conditions.
JOURNAL OF POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Minh-Duc Pham, Van-Tuan Hoang, Hong-Hee Lee
Summary: This paper proposes a cost-effective synchronization strategy for distributed generators to connect with islanded microgrid systems without the need for additional voltage sensors, and the feasibility and effectiveness of this strategy are validated through experiments with a scaled-down islanded microgrid.
JOURNAL OF POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Minh-Duc Pham, Hong-Hee Lee
Summary: The paper introduces an enhanced compensation strategy for distributed generation systems to achieve accurate power sharing and harmonics compensation at the point of common coupling. The strategy involves modifying output impedance, adjusting load harmonic currents, and regulating DG equivalent impedance adaptively. Additionally, a distributed communication network is used to improve reliability and stability. Experimentally validated effectiveness and reliability are shown in a prototype microgrid system.
JOURNAL OF POWER ELECTRONICS
(2021)
Article
Automation & Control Systems
Minh-Duc Pham, Hong-Hee Lee
Summary: The article proposes a coordinated virtual impedance control strategy to compensate for mismatched line impedance among DGs by adjusting both virtual resistance and virtual inductance, enhancing microgrid system stability. The adaptive regulation of virtual impedance ensures good power-sharing performance even with communication interruptions or sudden load changes.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Minh-Duc Pham, Hong-Hee Lee
Summary: A consensus-based distributed power-sharing scheme is proposed to improve microgrid voltage quality and share distortion powers, along with PCC harmonics mitigation. This method tunes the controllable parts of output impedance at fundamental and harmonic frequencies separately by simple integral controllers without relying on feeder impedance parameters, ensuring high voltage quality despite sudden changes in load power. Experimentation with a scaled-down microgrid system validates the effectiveness of this less complicated control scheme.
IET GENERATION TRANSMISSION & DISTRIBUTION
(2021)
Article
Engineering, Electrical & Electronic
Tuan Hoang, Hong-Hee Lee
Summary: This article proposes an enhanced DG VIC control method to achieve accurate harmonic power sharing and voltage harmonic compensation in islanded microgrids. The controller is developed based on simple integral controllers and the feasibility and effectiveness of the method are validated through theoretical analysis and simulation experiments.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Huu-Cong Vu, Hong-Hee Lee
Summary: This paper proposes a simplified model-predictive current control strategy to eliminate common mode voltage and reduce current harmonics. By evaluating virtual voltage vectors and choosing the best one in a new control set, the computational burden is significantly reduced.
JOURNAL OF POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Huu-Cong Vu, Hong-Hee Lee
Summary: This article presents a simple model-predictive current control scheme aimed at reducing the common-mode voltage and current harmonics for a two-level seven-phase voltage-source inverter. By utilizing 14 virtual voltage vectors as input control set, the proposed scheme aims to achieve optimal output current performance without the need for a cost function. Simulation and experimental results demonstrate the effectiveness of this approach in reducing computational burden compared to conventional methods.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Huu-Cong Vu, Hong-Hee Lee
Summary: This article introduces a simple model-predictive current control (MPCC) strategy for a three-level sparse five-phase voltage source inverter to suppress current harmonics and balance the neutral-point voltage. Simulation and experimental results are provided to verify the validity of the proposed strategy.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Van-Tien Le, Hong-Hee Lee
Summary: This paper proposes a robust finite-control-set model predictive control method for a two-level voltage source inverter against LC-filter parameter mismatch and variation. The predictive schemes for inductor current and capacitor voltage are treated separately to avoid filter-inductance dependency, and the capacitance is accurately identified by means of least-squares minimization. Experimental results demonstrate the robustness and high control performance of the proposed method compared to conventional approaches.
JOURNAL OF POWER ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Van-Tien Le, Hong-Hee Lee
Summary: An enhanced model-free predictive control method is proposed in this study to improve prediction accuracy by eliminating stagnant current variation update for PWM rectifiers. By estimating only four variables, the proposed method effectively removes the need for identifying voltage vector combinations and lookup tables, resulting in the elimination of active power spikes and grid current notches. Both simulation and experiment confirm the effectiveness of the proposed MFPC.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Duy-Long Nguyen, Hong-Hee Lee
Summary: In this article, an enhanced consensus-based control scheme is proposed to achieve accurate power sharing and voltage restoration in islanded microgrids. By developing average microgrid voltage and per unit power estimators, the adverse impact of heterogeneous communication time delays is eliminated. The effectiveness and feasibility of the control scheme are validated through theoretical analysis, simulations, and experiments.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Van-Tien Le, Hong-Hee Lee
Summary: This article investigates the performance of model-free predictive current control (MFPCC) under different sampling frequencies and measurement-noise conditions. An enhanced MFPCC method is proposed to overcome the sensitivity to measurement noise and remove the stagnant current variation update. The effectiveness and robustness of the proposed method are verified through simulation and experiment results.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Duy-Long Nguyen, Hong-Hee Lee
Summary: An anti-heterogeneous time delay estimator is proposed to achieve accurate power sharing in a DC microgrid. The proposed method uses scattering transformation and a PI consensus algorithm to modify transmitted/received signals and estimate average consensus. It enables proportional power sharing and voltage compensation despite heterogeneous delays, mismatched line resistances, and load variation.
JOURNAL OF POWER ELECTRONICS
(2023)