scholarly journals A Control Scheme with the Variable-Speed Pitch System for Wind Turbines during a Zero-Voltage Ride Through

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3344
Author(s):  
Enyu Cai ◽  
Yunqiang Yan ◽  
Lei Dong ◽  
Xiaozhong Liao
Keyword(s):  
Wind Turbines ◽  
Low Voltage ◽  
System Modeling ◽  
Fault Analysis ◽  
System Level ◽  
Level Control ◽  
Control Logic ◽  
Control Scheme ◽  
Pitch System ◽  
Zero Voltage

Zero-voltage ride through (ZVRT) is the extreme case of low-voltage ride through (LVRT), which represents the optimal grid-connection capability of wind turbines (WTs). Enforcing ZVRT will improve the dynamic performance of WTs and therefore significantly enhance the resiliency of renewable-rich grids. A control scheme that includes a pitch system is an essential control aspect of WTs riding through voltage dips; however, the existing control scheme with a pitch system for LVRT cannot distinguish between a ZVRT status and a power-loss condition, and, consequently, does not meet the ZVRT requirements. A system-level control scheme with a pitch system for ZVRT that includes pitch system modeling, control logic, control circuits, and overspeed protection control (OPC) is proposed in this paper for the first time in ZVRT research. Additionally, the field data are shared, a fault analysis of an overspeed accident caused by a voltage dip that describes the operating status at the WT-collapse moment is presented, and some existing WT design flaws are revealed and corrected by the fault analysis. Finally, the pitching performance during a ZVRT, which significantly affects the ZVRT performance of the WT, is obtained from laboratory and field tests. The results validate the effectiveness of the proposed holistic control scheme.

scholarly journals Multi-Objective Supervisory Control for DC/DC Converters in Advanced Aeronautic Applications

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3216 ◽  
Author(s):  
Alberto Cavallo ◽  
Giacomo Canciello ◽  
Beniamino Guida ◽  
Ponggorn Kulsangcharoen ◽  
Seang Yeoh ◽  
...  
Keyword(s):  
Low Voltage ◽  
Control Strategies ◽  
Gain Control ◽  
High Gain ◽  
Level Control ◽  
Mathematical Arguments ◽  
Control Scheme ◽  
Sliding Manifold ◽  
High Gain Control ◽  
High Level

In this paper, an intelligent control strategy for DC/DC converters is proposed. The converter connects two DC busses, a high-voltage and a low-voltage bus. The control scheme is composed by a two-layer architecture, a low-level control based on the concept of sliding manifold, and high gain control, and a high-level control used to guarantee the achievement of various objectives. The proposed control strategies are based on solid mathematical arguments, with stability proofs for the non-linear case, and decision trees for parameter selection. The paper results are analyzed and discussed by using simulation at different detail levels in MATLAB/Stateflow/PowerSystem, and validated by experimental results, also considering MIL standard performance indices.

Power Quality Measurements of a Horizontal Axial Small Wind Turbine

2017 ◽  
Vol 870 ◽  
pp. 329-334
Author(s):  
Yu Jen Liu ◽  
Yen Chang Chen ◽  
Pei Hsiu Lan ◽  
Tsang Pin Chang
Keyword(s):  
Wind Turbine ◽  
Power Quality ◽  
Wind Turbines ◽  
Distribution System ◽  
Large Scale ◽  
Low Voltage ◽  
System Structure ◽  
System Level ◽  
Small Wind Turbines ◽  
Quality Measurements

As small wind turbines are increasingly used, the assessments of power quality may thus become paramount. Unlike the large-scale wind turbines which are optional required to perform power quality measurements during production certification stage; however the power quality measurements are often neglected in small wind turbines since they are not requested on the certain of national grid codes at low-voltage distribution system level. Considering the high penetrations of small wind turbines may be connected to the future urban electric network, the paper performs the power quality on-site measurements of a horizontal axle small wind turbines. The issues may include the discussion of measurement system structure, the description of measurement method, and the analysis of wind turbine power characteristic, voltage/current trends, harmonics and flicker phenomena. The measured data collected in the study will valuable for the further analysis of power systems connected with the small wind turbines.

scholarly journals LVRT and Stability Enhancement of Grid-Tied Wind Farm Using DFIG-Based Wind Turbine

2021 ◽  
Vol 4 (2) ◽  
pp. 33
Author(s):  
Jannatul Mawa Akanto ◽  
Md. Rifat Hazari ◽  
Mohammad Abdul Mannan
Keyword(s):  
Wind Turbines ◽  
Large Scale ◽  
Wind Farm ◽  
Reactive Power ◽  
Low Voltage ◽  
Wind Farms ◽  
Induction Generators ◽  
Control Scheme ◽  
Wide Range ◽  
Doubly Fed

According to the grid code specifications, low voltage ride-through (LVRT) is one of the key factors for grid-tied wind farms (WFs). Since fixed-speed wind turbines with squirrel cage induction generators (FSWT-SCIGs) require an adequate quantity of reactive power throughout the transient period, conventional WF consisting of SCIG do not typically have LVRT capabilities that may cause instability in the power system. However, variable-speed wind turbines with doubly fed induction generators (VSWT-DFIGs) have an adequate amount of LVRT enhancement competency, and the active and reactive power transmitted to the grid can also be controlled. Moreover, DFIG is quite expensive because of its partial rating (AC/DC/AC) converter than SCIG. Accordingly, combined installation of both WFs could be an effective solution. Hence, this paper illustrated a new rotor-side converter (RSC) control scheme, which played a significant role in ensuring the LVRT aptitude for a wide range of hybrid WF consisting of both FSWT-SCIGs and VSWT-DFIGs. What is more, the proposed RSC controller of DFIG was configured to deliver an ample quantity of reactive power to the SCIG during the fault state to make the overall system stable. Simulation analyses were performed for both proposed and traditional controllers of RSC of the DFIG in the PSCAD/EMTDC environment to observe the proposed controller response. Overall, the presented control scheme could guarantee the LVRT aptitude of large-scale SCIG.

scholarly journals Reactive power control of DFIG-based wind turbines for voltage support during faults

2020 ◽  
Author(s):  
João Paulo Man Kit Sio ◽  
Romeu Reginatto
Keyword(s):  
Power Control ◽  
Wind Turbines ◽  
Reactive Power ◽  
Low Voltage ◽  
Current Injection ◽  
System Level ◽  
Reactive Power Control ◽  
Injection Strategy ◽  
Reactive Current ◽  
Voltage Support

The wind power penetration in the power system has already reached a considerate proportion. An important step in that path was the requirement of wind farms to provide Low Voltage Ride Through (LVRT) capacity, remaining connected to the grid during faults. More recently, grid codes are also requiring wind turbines to inject reactive power during the fault event so as to contribute to grid voltage support. The purpose of this work is to analyze a reactive current injection strategy for DFIG-based wind turbines that acts on the reactive power control loop during faults. The results of the simulations show, the behavior of the voltage, active power, and the total current injected in the system for different connection characteristics. The reactive current injection strategy helps in the voltage level during the fault, and the effectiveness is better for connections to the transmission system level.

scholarly journals Holistic simulation of wind turbines with fully aero-elastic and electrical model

2021 ◽  
Author(s):  
Marcus Wiens ◽  
Sebastian Frahm ◽  
Philipp Thomas ◽  
Shoaib Kahn
Keyword(s):  
Renewable Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Elastic Model ◽  
Electrical Model ◽  
Holistic Model ◽  
Electric System ◽  
Electrical Components

AbstractRequirements for the design of wind turbines advance facing the challenges of a high content of renewable energy sources in the public grid. A high percentage of renewable energy weaken the grid and grid faults become more likely, which add additional loads on the wind turbine. Load calculations with aero-elastic models are standard for the design of wind turbines. Components of the electric system are usually roughly modeled in aero-elastic models and therefore the effect of detailed electrical models on the load calculations is unclear. A holistic wind turbine model is obtained, by combining an aero-elastic model and detailed electrical model into one co-simulation. The holistic model, representing a DFIG turbine is compared to a standard aero-elastic model for load calculations. It is shown that a detailed modelling of the electrical components e.g., generator, converter, and grid, have an influence on the results of load calculations. An analysis of low-voltage-ride-trough events during turbulent wind shows massive increase of loads on the drive train and effects the tower loads. Furthermore, the presented holistic model could be used to investigate different control approaches on the wind turbine dynamics and loads. This approach is applicable to the modelling of a holistic wind park to investigate interaction on the electrical level and simultaneously evaluate the loads on the wind turbine.

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.

Sign in / Sign up

Export Citation Format

Share Document