scholarly journals Robust Power Sharing and Voltage Stabilization Control Structure via Sliding-Mode Technique in Islanded Micro-Grid

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 883 ◽  
Author(s):  
Quan-Quan Zhang ◽  
Rong-Jong Wai
Keyword(s):  
Dynamic Response ◽  
Sliding Mode ◽  
Active Power ◽  
Power Sharing ◽  
System Stability ◽  
Droop Control ◽  
Voltage Amplitude ◽  
Voltage Deviation ◽  
Micro Grid ◽  
Control Relation

With a focus on the problems of active power sharing and voltage deviation of parallel-connected inverters in an islanded micro-grid (MG), in this study, the power-voltage droop controller and the inner voltage regulator are redesigned based on a total sliding-mode control (TSMC) technique. As for the power-voltage droop control loop, a droop control relation error between the active power and the point-of-common-coupling (PCC) voltage amplitude is defined. Then, the TSMC scheme is adopted to reach the new droop control relation, where the active power sharing and voltage amplitude recovery can be achieved simultaneously. Owing to the faster dynamic response and strong robustness provided by the TSMC framework, high-precision active power sharing during transient state also can be ensured without the influence of line impedances. The power allocation error can be improved by more than 81.2% and 50% than the conventional and proportional-integral (PI)-based droop control methods, respectively, and the voltage deviation rate can be reduced to 0.16%. Moreover, a small-signal model of the TSMC-based droop-controlled system is established, and the influences of control parameters on the system stability and the dynamic response are also investigated. The effectiveness of the proposed control method is verified by numerical simulations and experimental results.

scholarly journals Distributed Finite-Time Secondary Frequency and Voltage Restoration Control Scheme of an Islanded AC Microgrid

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6266
Author(s):  
Junjie Ma ◽  
Xudong Wang ◽  
Siyan Zhang ◽  
Hanying Gao
Keyword(s):  
Power Distribution ◽  
Finite Time ◽  
Voltage Drop ◽  
Impedance Control ◽  
Reference Value ◽  
Voltage Regulation ◽  
Active Power ◽  
Power Sharing ◽  
Control Scheme ◽  
Voltage Deviation

To solve the problems of frequency and voltage deviation caused by the droop control while meeting the requirements of rapid response, a distributed finite-time secondary control scheme is presented. Unlike the traditional cooperative controllers, this scheme is fully distributed; each unit only needs to communicate with its immediate neighbors. A control protocol for frequency restoration and active power sharing is proposed to synchronize the frequency of each unit to the reference value, and achieve accurate active power distribution in a finite-time manner as well. The mismatch of the line impedance is considered, and a consensus-based adaptive virtual impedance control is proposed. The associated voltage drop is considered to be the compensator for the voltage regulation. Then, a distributed finite-time protocol for voltage restoration is designed. The finite-time convergence property and the upper bound of convergence times are guaranteed with rigorous Lyapunov proofs. Case studies in MATLAB are carried out, and the results demonstrate the effectiveness, the robustness to load changes, plug-and play capacity, and better convergence performance of the proposed control scheme.

scholarly journals Adaptive Droop Control for DC Voltage Deviation and Power Sharing in Multi-terminal DC(MTDC) Grids

2019 ◽  
Vol 486 ◽  
pp. 012041
Author(s):  
H D Teng ◽  
L H Ning ◽  
Y J Yin ◽  
L Gao ◽  
N M Liu ◽  
...  
Keyword(s):  
Power Sharing ◽  
Droop Control ◽  
Dc Voltage ◽  
Voltage Deviation

Analysis and Modeling of Droop Control in Micro-Source for Islanded Micro-Grid

2014 ◽  
Vol 960-961 ◽  
pp. 1151-1155 ◽  
Author(s):  
Wei Lin Zhang ◽  
Jing Xiong ◽  
Yu Jiong Gu ◽  
Ping Zhu
Keyword(s):  
Distributed Generation ◽  
Control Method ◽  
Controller Design ◽  
Power Sharing ◽  
Droop Control ◽  
Simulation Data ◽  
Storage Devices ◽  
Load Power ◽  
Micro Grid ◽  
System Frequency

Considering decentralization of the micro-source units and loads in the micro-grid and concentrating on generation types and models of the storage devices,droop controlstrategy is used in controller design for the distributed generation units. The generation units adopting droop control method based on the droop characteristics can facilitate load power sharing when the powers of loads vary, and can also maintain the system frequency when a unit fault occurs and the micro-grid islands. Then, the operation variations of the micro-grid are analyzed when it runs with load changes in islanding mode and runs with the load power of micro-source varied suddenly. The corresponding rules of the active power, voltage and current for each micro-source and the frequency for the micro-grid are obtained. The simulation data results show the correctness and validity of the droop control strategy.

scholarly journals An Enhanced Dual Droop Control Scheme for Resilient Active Power Sharing Among Paralleled Two-Stage Converters

2017 ◽  
Vol 32 (8) ◽  
pp. 6091-6104 ◽  
Author(s):  
Hongpeng Liu ◽  
Yongheng Yang ◽  
Xiongfei Wang ◽  
Poh Chiang Loh ◽  
Frede Blaabjerg ◽  
...  
Keyword(s):  
Active Power ◽  
Power Sharing ◽  
Droop Control ◽  
Two Stage ◽  
Control Scheme

scholarly journals A New Adaptive Control Strategy of active and reactive power sharing in Islanded Microgrids

2016 ◽  
Vol 19 (4) ◽  
pp. 14-34
Author(s):  
Phuong Minh Le ◽  
Duy Vo Duc Hoang ◽  
Hoa Thi Xuan Pham ◽  
Huy Minh Nguyen ◽  
Dieu Ngoc Vo
Keyword(s):  
Transmission Line ◽  
Distributed Generation ◽  
Reactive Power ◽  
Active Power ◽  
Power Sharing ◽  
Droop Control ◽  
Active And Reactive Power ◽  
Three Phase ◽  
Islanded Microgrid ◽  
Adaptive Control Strategy

This paper proposes a new control sharing method for parallel three-phase inverters in an islanded microgrid. The proposed technique uses adaptive PIDs combined with the communication among the parallel inverters to accurately share active power and reactive power among the inverters via adjusting the desired voltage if there is a distinct difference between line impedance and the load change in the microgrid. Moreover, the paper also presents the response ability of the inverters to maintain the error within the allowed limits as the transmission line is interrupted. The proposed technique has been verified in a microgrid with three parallel distributed generation-inverter units using Matlab/Simulink. In the simulation, as the droop control using the communication information among the inverters, the sharing errors for active power and reactive power are around 0.2% and 0.6%, respectively. As the connection between the microgrid and transmission line is interrupted, the sharing errors for active power and reactive power increase to 0.4% and 2%, respectively. The simulation results have indicated that the proposed technique is superior to the traditional droop control in terms of the accuracy and stability. Therefore, the new proposed technique can be a favor alternative model for active power and reactive power sharing control of parallel inverters in an islanded microgrid.

scholarly journals Improved Droop Control with Washout Filter

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2415 ◽  
Author(s):  
Yalong Hu ◽  
Wei Wei
Keyword(s):  
Dynamic Performance ◽  
Singular System ◽  
Active Power ◽  
Power Sharing ◽  
Droop Control ◽  
Hardware In The Loop ◽  
Signal Model ◽  
Modeling Technology ◽  
Small Signal Model ◽  
Washout Filter

In this paper, a droop washout filter controller (DWC), composed of a conventional droop controller and a washout filter controller, is proposed. The droop controller is used to ensure the “plug-and-play” capability, and the droop gain is set small. The washout filter is introduced to compensate the active power dynamic performance (APDP). Compared to the droop controller, the DWC can achieve accurate active power sharing and smaller frequency difference without losing the APDP. Additionally, a novel modeling technology is proposed, using which a small-signal model for an island microgrid (MG) is constructed as a singular system. The system’s stability is analyzed and the DWC is verified using real-time (RT-LAB) simulation with hardware in the loop (HIL).

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