Article
Engineering, Electrical & Electronic
Angel Borrell, Manel Velasco, Antonio Camacho, Jaume Miret, Miguel Castilla
Summary: This article presents a novel control scheme for remote negative-sequence voltage fair compensation in a grid-forming inverter-based islanded AC microgrid. The scheme reduces voltage imbalances by adjusting the negative-sequence output voltage of the inverters, achieving two control objectives: voltage reduction at a remote node and fair compensation. The controller features plug-and-play and parallel operation, and requires minimal communication control data.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Aangel Borrell, Manel Velasco, Jaume Miret, Antonio Camacho, Pau Marti, Miguel Castilla
Summary: This article presents a novel control scheme for achieving voltage balance at any node of an ac microgrid, regardless of the impedance value of the power network. The collaborative strategy aims to set a specific sharing of the balancing currents, thus avoiding adverse effects of unbalanced compensation by a single inverter. The control scheme utilizes a complex form of a proportional resonant controller and a communication link, with successful testing in a laboratory microgrid setup.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Haoyang Zheng, Zeng Liu, Ronghui An, Jinjun Liu, Tong Wu, Zhenhuang Lin
Summary: This article proposes an islanding detection method based on impedance measurement for the microgrid comprised of grid-forming inverters with seamless transfer capabilities. The proposed method achieves synchronized injection of small-ac-signal (SACS) current using the SACS current droop control and the virtual impedance. The control scheme is peer-to-peer and enables plug-and-play functionality.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Jeremy D. Watson, Yemi Ojo, Khaled Laib, Ioannis Lestas
Summary: The paper proposes a method for designing microgrid controllers using passivity theory, which can achieve stable operation and improve performance. By satisfying decentralized conditions, plug-and-play operation can be achieved, and performance can be enhanced by incorporating this condition as a constraint in optimization problems.
IEEE TRANSACTIONS ON SMART GRID
(2021)
Article
Engineering, Electrical & Electronic
Ankit Singhal, Thanh Long Vu, Wei Du
Summary: This paper presents an automatic secondary control scheme that fully coordinates grid-following (GFL) and grid-forming (GFM) inverters in a 100% inverter-based microgrid. The proposed coordination achieves frequency/voltage restoration, accurate power sharing, and circulating var mitigation. The study emphasizes the need and benefits of GFL-GFM coordination in microgrids, as the fully-coordinated secondary control outperforms other approaches.
IEEE TRANSACTIONS ON SMART GRID
(2022)
Article
Energy & Fuels
Nathan Baeckeland, D. Venkatramanan, Michael Kleemann, Sairaj Dhople
Summary: This article introduces a nested-loop control architecture for grid-forming inverters and integrates novel current-limiting strategies. The salient features of the proposed control architecture are validated through electromagnetic transient simulations.
IEEE TRANSACTIONS ON ENERGY CONVERSION
(2022)
Article
Automation & Control Systems
Jiadong Lu, Yihua Hu, Yuge Song, Yue Su, Jie Wang, Jinglin Liu
Summary: This article proposes an auxiliary power transfer strategy using inactive motor drives in bipolar DC grids, allowing bidirectional power transfer and voltage balancing without requiring additional hardware support.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Jiajun Yu, Shike Wang, Zeng Liu, Jiarui Li, Jinjun Liu, Jiayu Shang
Summary: This article proposes a small-signal terminal characteristic model for the grid-forming inverter with droop-control in the synchronous reference (dq-) frame. It accurately captures the dynamics of the power controller, voltage and current control loops, and all circuit components. The proposed terminal characteristics are used to characterize the small-signal dynamics introduced by the fundamental frequency-active power droop scheme. Based on these terminal characteristics, the stability of parallel grid-forming inverters can be predicted using the generalized Nyquist criterion. Furthermore, a single-input single-output (SISO) stability analysis approach is proposed to simplify the analysis process and reduce calculation complexity.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Ehsan Dehghanpour, Michel Normandeau, Geza Joos, Yves Brissette
Summary: One of the main challenges in the protection of Inverter-Based Microgrids (IBM) is the detection of faults. This paper introduces two parameters and proposes a protection scheme based on these parameters to protect feeders and Distributed Generators (DGs) in IBMs. The effectiveness of the proposed scheme is verified through simulation and experiment results.
IEEE TRANSACTIONS ON POWER DELIVERY
(2022)
Article
Automation & Control Systems
Yonghui Ling, Yanjun Li, Zhenquan Yang, Ji Xiang
Summary: This article proposes a dispatchable droop control method for multiple distributed generators in islanded ac microgrids, achieving effective power and frequency control.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Dayan B. Rathnayake, Si Phu Me, Reza Razzaghi, Behrooz Bahrani
Summary: This article proposes a second-order discrete-time controller to achieve a well-damped step response for power reference commands and improved virtual inertia provision capability. A control design method based on H-infinity is also proposed, which adjusts the proposed controller based on the frequency response of the system. The proposed control design presents a systematic process to specify desired performance indices through frequency-domain constraints. The performance of the controller is validated analytically, through simulation results, and through experimental results, verifying its superior performance over the virtual synchronous generator controller in terms of tracking performance and virtual inertia provision capability.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2023)
Article
Automation & Control Systems
Mohsen Eskandari, Andrey Savkin
Summary: This article explores the impact of the interaction between droop controllers through the power network on the dynamic stability of a networked microgrid. New models are developed to analyze the effects of power network impedance, droop controllers, and impedance characteristics of voltage source inverters. It is shown that a low X/R ratio amplifies low-frequency oscillations and that the virtual inductance loop improves dynamic performance. However, the resistive-capacitive impedance characteristics of the inverters pose stability risks. A H-infinity robust controller is proposed to stabilize the microgrid.
IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS
(2022)
Article
Engineering, Electrical & Electronic
Manuela Minetti, Alessandro Rosini, Gio Battista Denegri, Andrea Bonfiglio, Renato Procopio
Summary: Inverter based islanded MicroGrids are challenging ways to integrate Distributed Energy Resources into electric networks. An Advanced Droop Control strategy (ADC) is proposed to regulate voltage and share reactive power in islanded MicroGrids. The ADC strategy is presented with its control law, stability analysis, and controller parameter setting procedure. Simulations and comparisons with other control techniques highlight the advantages of the proposed control strategy in combined regulation of voltage and reactive power.
IEEE TRANSACTIONS ON POWER SYSTEMS
(2022)
Article
Engineering, Electrical & Electronic
Mohammad S. Golsorkhi, David J. Hill, Mehdi Baharizadeh
Summary: The paper proposes a new hierarchical control scheme for accurate load sharing and power quality enhancement in networked microgrids with unbalanced load currents. The scheme involves coordination of local DER controllers, MG control units, and Networked MG control center to achieve efficient sharing of power and maintenance of power quality.
IEEE TRANSACTIONS ON SMART GRID
(2021)
Article
Energy & Fuels
Mazaher Karimi, Mohammad Farshad, Qiteng Hong, Hannu Laaksonen, Kimmo Kauhaniemi
Summary: This article proposes a new passive islanding detection technique for inverter-based DG in microgrids, utilizing local synchrophasor measurements to monitor the rate of change of voltages and the VoI index at the DG connection point for accurate and fast detection of utility grid frequency fluctuations or islanding conditions. The simulation studies confirm the proposed scheme is accurate, robust, fast, and simple to implement for inverter-based DGs.
Article
Engineering, Electrical & Electronic
Miguel Castilla, Manel Velasco, Jaume Miret, Angel Borrell, Ramon Guzman
Summary: This article presents a control scheme that solves the problems of negative-sequence voltage compensation and negative-sequence current sharing in grid-connected microgrids. The proposed control scheme improves previous schemes with characteristics such as accurate negative-sequence current sharing and low control-data traffic. Experimental results in a laboratory microgrid validate the characteristics of the proposed control.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Automation & Control Systems
Carlos Alfaro Aragon, Ramon Guzman, Luis Garcia de Vicuna, Jaume Miret, Miguel Castilla
Summary: This article proposes a large-signal model and control method for microgrids. The model does not require direct voltage control and is able to maintain stability under different impedances and loads. Experimental results demonstrate satisfactory performance of the proposed control method in case of load variations and non-linear loads.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Energy & Fuels
Gabriel Nasser Doyle de Doile, Pedro Paulo Balestrassi, Miguel Castilla, Antonio Carlos Zambroni de Souza, Jaume Miret
Summary: This paper proposes a tool for tuning the parameters of the secondary consensus control for inverter-based islanded microgrids, aiming to improve energy conversion efficiency. Using experimental design methodology, microgrid parameters can be adjusted efficiently to reach the optimal setting, reducing the time and cost of the trial-and-error process.
Article
Engineering, Electrical & Electronic
Jaume Miret, Miguel Castilla, Manel Velasco, Ramon Guzman, Luis Garcia de Vicuna
Summary: In islanded microgrids, a closed-loop control is proposed to ensure maximum current injection during any kind of short circuit while maintaining the underlying droop control. By emulating low-voltage ride-through protocols, voltage unbalance can be reduced. The proposed control strategy is validated through experimental results.
IET POWER ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Hossein Khoun Jahan, Mehdi Abapour, Kazem Zare, Seyed Hossein Hosseini, Frede Blaabjerg, Yongheng Yang
Summary: This paper proposes a switched-capacitor (SC)-based cascaded half-bridge multilevel inverter to address the issues of the cascaded H-bridge multilevel inverter (CMI) in photovoltaic (PV) applications. The proposed topology only requires one dc source and achieves the minimum number of switches, spontaneous capacitor charging, voltage boosting, and continuous input current. The feasibility and effectiveness of the proposed topology are validated through simulations and experimental tests.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2023)
Article
Automation & Control Systems
Josue Duarte, Manel Velasco, Pau Marti, Antonio Camacho, Jaume Miret, Carlos Alfaro
Summary: This article presents a distributed control strategy for islanded AC microgrids that achieves accurate power sharing and voltage regulation simultaneously. The strategy uses a single controller at each voltage source inverter (VSI) that combines two control loops for decoupled design of power sharing control and voltage control. The cooperative operation of all VSIs through a communication network ensures control objectives are met independently of impedance mismatches and connection/disconnection of inverters and loads. Experimental results validate the proposed control approach.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Miguel Castilla, Jaume Miret, Luis Garcia de Vicuna, Angel Borrell, Carlos Alfaro
Summary: This paper presents a control scheme for grid-forming inverters in islanded microgrids that limits the current to a safe value during short circuits while providing a lower voltage imbalance. The control scheme reduces the reference voltage amplitude and the instantaneous reference voltage to achieve low voltage imbalance. Theoretical and experimental results confirm the improvement in voltage imbalance. The paper also includes control design guidelines and practical performance comparison based on experimental tests.
IET POWER ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Angel Borrell, Manel Velasco, Antonio Camacho, Jaume Miret, Miguel Castilla
Summary: This article presents a novel control scheme for remote negative-sequence voltage fair compensation in a grid-forming inverter-based islanded AC microgrid. The scheme reduces voltage imbalances by adjusting the negative-sequence output voltage of the inverters, achieving two control objectives: voltage reduction at a remote node and fair compensation. The controller features plug-and-play and parallel operation, and requires minimal communication control data.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2023)
