An Effective Economical Hierarchical Control Scheme for Low-Voltage AC Microgrids

2019 ◽  
Author(s):  
Mohammad Mahdavyfakhr ◽  
Seyyedmilad Ebrahimi ◽  
Hanqing Lin ◽  
Juri Jatskevich
Keyword(s):  
Low Voltage ◽  
Hierarchical Control ◽  
Control Scheme

scholarly journals Decentralized Fast Delayed Signal Cancelation Secondary Control for Low Voltage Ride-Through Application in Grid Supporting Grid Feeding Microgrid

2021 ◽  
Vol 9 ◽  
Author(s):  
Elutunji Buraimoh ◽  
Innocent E. Davidson ◽  
Fernando Martinez-Rodrigo
Keyword(s):  
Low Voltage ◽  
Hierarchical Control ◽  
Voltage Regulation ◽  
Power Sharing ◽  
Primary Control ◽  
Distributed Energy ◽  
Secondary Control ◽  
Low Voltage Ride Through ◽  
Control Scheme ◽  
Real Time Digital Simulator

In this study, a distributed secondary control is proposed alongside the conventional primary control to form a hierarchical control scheme for the Low Voltage Ride-Through (LVRT) control and applications in the inverter-based microgrid. The secondary control utilizes a fast Delayed Signal Cancelation (DSC) algorithm for the secondary control loop to control the reactive and active power reference by controlling the sequences generated. The microgrid consists of four Distributed Energy Resources (DER) sources interfaced to the grid through interfacing inverters coordinated by droop for effective power-sharing according to capacities. The droop also allows for grid supporting application for microgrid’s participation in frequency and voltage regulation in the main grid. The proposed decentralized fast DSC performance is evaluated with centralized secondary and traditional primary control using OPAL-RT Lab computation and MATLAB/SIMULINK graphical user interface for offline simulations and real-time digital simulator verification. This study presents and discusses the results.

scholarly journals The LVRT Control Scheme for PMSG-Based Wind Turbine Generator Based on the Coordinated Control of Rotor Overspeed and Supercapacitor Energy Storage

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 518
Author(s):  
Xiangwu Yan ◽  
Linlin Yang ◽  
Tiecheng Li
Keyword(s):  
Energy Storage ◽  
Wind Turbine ◽  
Low Voltage ◽  
Specific Capacity ◽  
Coordinated Control ◽  
Input Power ◽  
Voltage Sags ◽  
Rotor Speed ◽  
Control Scheme ◽  
Supercapacitor Energy Storage

With the increasing penetration level of wind turbine generators (WTGs) integrated into the power system, the WTGs are enforced to aid network and fulfill the low voltage ride through (LVRT) requirements during faults. To enhance LVRT capability of permanent magnet synchronous generator (PMSG)-based WTG connected to the grid, this paper presents a novel coordinated control scheme named overspeed-while-storing control for PMSG-based WTG. The proposed control scheme purely regulates the rotor speed to reduce the input power of the machine-side converter (MSC) during slight voltage sags. Contrarily, when the severe voltage sag occurs, the coordinated control scheme sets the rotor speed at the upper-limit to decrease the input power of the MSC at the greatest extent, while the surplus power is absorbed by the supercapacitor energy storage (SCES) so as to reduce its maximum capacity. Moreover, the specific capacity configuration scheme of SCES is detailed in this paper. The effectiveness of the overspeed-while-storing control in enhancing the LVRT capability is validated under different levels of voltage sags and different fault types in MATLAB/Simulink.

scholarly journals A Novel Hierarchical Control Strategy for Low-Voltage Islanded Microgrids Based on the Concept of Cyber Physical System

Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1835 ◽  
Author(s):  
Qiuxia Yang ◽  
Dongmei Yuan ◽  
Xiaoqiang Guo ◽  
Bo Zhang ◽  
Cheng Zhi
Keyword(s):  
Control Strategy ◽  
Physical System ◽  
Reactive Power ◽  
Low Voltage ◽  
Hierarchical Control ◽  
Physical Layer ◽  
Cyber Physical System ◽  
Droop Control ◽  
Control Effect ◽  
Consensus Control

Based on the concept of cyber physical system (CPS), a novel hierarchical control strategy for islanded microgrids is proposed in this paper. The control structure consists of physical and cyber layers. It’s used to improve the control effect on the output voltages and frequency by droop control of distributed energy resources (DERs), share the reactive power among DERs more reasonably and solve the problem of circumfluence in microgrids. The specific designs are as follows: to improve the control effect on voltages and frequency of DERs, an event-trigger mechanism is designed in the physical layer. When the trigger conditions in the mechanism aren’t met, only the droop control (i.e., primary control) is used in the controlled system. Otherwise, a virtual leader-following consensus control method is used in the cyber layer to accomplish the secondary control on DERs; to share the reactive power reasonably, a method of double virtual impedance is designed in the physical layer to adjust the output reactive power of DERs; to suppress circumfluence, a method combined with consensus control without leader and sliding mode control (SMC) is used in the cyber layer. Finally, the effectiveness of the proposed hierarchical control strategy is confirmed by simulation results.

scholarly journals A Hierarchical Control Scheme for Biped Robots

1983 ◽  
Vol 1 (3) ◽  
pp. 167-175 ◽  
Author(s):  
Suguru ARIMOTO ◽  
Fumio MIYAZAKI
Keyword(s):  
Hierarchical Control ◽  
Biped Robots ◽  
Control Scheme

scholarly journals Coordinated Frequency Control Strategy with the Virtual Battery Model of Inverter Air Conditionings

2019 ◽  
Vol 9 (15) ◽  
pp. 3052
Author(s):  
Jiafu Yin ◽  
Dongmei Zhao
Keyword(s):  
Control Strategy ◽  
Frequency Control ◽  
Hierarchical Control ◽  
Frequency Regulation ◽  
Consensus Protocol ◽  
Consensus Control ◽  
Response Characteristics ◽  
Battery Model ◽  
Control Framework ◽  
Control Scheme

Due to the potential of thermal storage being similar to that of the conventional battery, air conditioning (AC) has gained great popularity for its potential to provide ancillary services and emergency reserves. In order to integrate numerous inverter ACs into secondary frequency control, a hierarchical distributed control framework which incorporates a virtual battery model of inverter AC is developed. A comprehensive derivation of a second-order virtual battery model has been strictly posed to formulate the frequency response characteristics of inverter AC. In the hierarchical control scheme, a modified control performance index is utilized to evaluate the available capacity of traditional regulation generators. A coordinated frequency control strategy is derived to exploit the complementary and advantageous characteristics of regulation generators and aggregated AC. A distributed consensus control strategy is developed to guarantee the fair participation of heterogeneous AC in frequency regulation. The finite-time consensus protocol is introduced to ensure the fast convergence of power tracking and the state-of-charge (SOC) consistency of numerous ACs. The effectiveness of the proposed control strategy is validated by a variety of illustrative examples.

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