Modeling and Modern Control of Wind Power

Edited by Qiuwei Wu, PhD, is an Associate Professor at the Technical University of Denmark (DTU). His research areas include wind power integration and wind turbine modeling, the standard modeling of wind power, VSC HVDC connection for offshore wind power integration, coordinated control of wind power and energy storage systems. Yuanzhang Sun, PhD, is a Full Professor at Wuhan University, Hubei Province, China. His research interests are power system stability and control, operational reliability of power systems, smart grid, and renewable energy.

• List of Contributors xiAbout the CompanionWebsite xiii1 Status of Wind Power Technologies 1Haoran Zhao and Qiuwei Wu1.1 Wind Power Development 11.2 Wind Turbine Generator Technology 41.2.1 Type 1 41.2.2 Type 2 51.2.3 Type 3 51.2.4 Type 4 61.2.5 Comparison 71.2.6 Challenges withWind Power Integration 71.3 Conclusion 9References 92 Grid Code Requirements for Wind Power Integration 11Qiuwei Wu2.1 Introduction 112.2 Steady-state Operational Requirements 122.2.1 Reactive Power and Power Factor Requirements 122.2.2 Continuous Voltage Operating Range 172.2.3 Frequency Operating Range and Frequency Response 182.2.4 Power Quality 242.3 Low-voltage Ride Through Requirement 262.3.1 LVRT Requirement in the UK 262.3.2 LVRT Requirement in Ireland 292.3.3 LVRT Requirement in Germany (Tennet TSO GmbH) 302.3.4 LVRT Requirement in Denmark 312.3.5 LVRT Requirement in Spain 312.3.6 LVRT Requirement in Sweden 322.3.7 LVRT Requirement in the USA 332.3.8 LVRT Requirement in Quebec and Alberta 342.4 Conclusion 36References 363 Control of Doubly-fed Induction Generators for Wind Turbines 37Guojie Li and Lijun Hang3.1 Introduction 373.2 Principles of Doubly-fed Induction Generator 373.3 PQ Control of Doubly-fed Induction Generator 403.3.1 Grid-side Converter 413.3.2 Rotor-side converter 433.4 Direct Torque Control of Doubly-fed Induction Generators 463.4.1 Features of Direct Torque Control 473.4.2 Application of Direct Torque Control in DFIGs 493.4.3 Principle of Direct Torque Control in DFIG 503.5 Low-voltage Ride Through of DFIGs 583.6 Conclusions 61References 614 Optimal Control Strategies of Wind Turbines for Load Reduction 63Shuju Hu and Bin Song4.1 Introduction 634.2 The Dynamic Model of aWind Turbine 644.2.1 Wind Conditions Model 644.2.2 Aerodynamic Model 644.2.3 Tower Model 664.2.4 DrivetrainModel 664.2.5 Electrical Control Model 674.2.6 Wind Turbine DynamicModel 674.3 Wind Turbine Individual Pitch Control 674.3.1 Control Implementation 684.3.2 Linearization of theWind Turbine Model 684.3.3 Controller Design 714.3.4 Simulation Analysis 734.4 Drivetrain Torsional Vibration Control 734.4.1 LQG Controller Design 734.4.2 Simulation Analysis 794.5 Conclusion 83References 835 Modeling of Full-scale Converter Wind Turbine Generator 85Yongning Chi, Chao Liu, Xinshou Tian, Lei Shi, and Haiyan Tang5.1 Introduction 855.2 Operating Characteristics of FSC-WTGs 885.3 FSC-WTG Model 895.3.1 Shaft Model 895.3.2 Generator Model 915.3.3 Full-scale Converter Model 945.4 Full Scale Converter Control System 965.4.1 Control System of Generator-side Converter 975.4.2 Grid-side Converter Control System 1015.5 Grid-connected FSC-WTG Stability Control 1075.5.1 Transient Voltage Control of Grid-side Converter 1085.5.2 Additional DC Voltage Coupling Controller 1085.5.3 Simulations 1095.6 Conclusion 114References 1146 Clustering-based Wind Turbine Generator Model Linearization 117Haoran Zhao and Qiuwei Wu6.1 Introduction 1176.2 Operational Regions of Power-controlledWind Turbines 1186.3 SimplifiedWind Turbine Model 1196.3.1 Aerodynamics 1196.3.2 Drivetrain 1206.3.3 Generator 1206.3.4 Tower 1216.3.5 Pitch Actuator 1216.4 Clustering-based IdentificationMethod 1226.5 Discrete-time PWA Modeling ofWind Turbines 1236.5.1 Identification of Aerodynamic Torque Ta 1236.5.2 Identification of Generator Torque Tg 1236.5.3 Identification of Thrust Force Ft 1246.5.4 Identification of Correction Factor Kc 1256.5.5 Formulation of A′ d and B′ d 1266.5.6 Region Construction through Intersection 1266.5.7 PWA Model of aWind Turbine 1266.6 Case Study 1276.6.1 LowWind Speed Case 1286.6.2 HighWind Speed Case 1296.7 Conclusion 131References 1317 Adaptive Control of Wind Turbines for Maximum Power Point Tracking 133Haoran Zhao and Qiuwei Wu7.1 Introduction 1337.1.1 Hill-climbing Search Control 1347.1.2 Power Signal Feedback Control 1357.1.3 Tip-speed Ratio Control 1357.2 Generator Control System forWECSs 1357.2.1 Speed Reference Calculation 1367.2.2 Generator Torque Control 1387.2.3 Speed Control 1397.3 Design of óD1 Adaptive Controller 1407.3.1 Problem Formulation 1407.3.2 Architecture of the óD1 Adaptive Controller 1407.3.3 Closed-loop Reference System 1427.3.4 Design of óD1 Adaptive Controller Parameters 1427.4 Case Study 1447.4.1 Wind Speed Estimation 1447.4.2 MPPT Performance 1447.5 Conclusion 147References 1488 Distributed Model Predictive Active Power Control of Wind Farms 151Haoran Zhao and Qiuwei Wu8.1 Introduction 1518.2 Wind Farm without Energy Storage 1528.2.1 Wind Farm Control Structure 1528.2.2 Load Evaluation of theWind Turbine 1548.2.3 MPC Problem Formulation 1548.2.4 Standard QP Problem 1568.2.5 Parallel Generalized Fast Dual Gradient Method 1588.3 Wind Farm Equipped with Energy Storage 1608.3.1 Wind Farm Control Structure 1608.3.2 Modelling of ESS Unit 1618.3.3 MPC Problem Formulation 1628.4 Case Study 1638.4.1 Wind Farm Control based on D-MPC without ESS 1638.4.2 Wind Farm Control based on D-MPC with ESS 1668.5 Conclusion 171References 1729 Model Predictive Voltage Control ofWind Power Plants 175Haoran Zhao and Qiuwei Wu9.1 Introduction 1759.2 MPC-basedWFVC 1769.3 Sensitivity Coefficient Calculation 1789.3.1 Voltage Sensitivity to Reactive Power 1789.3.2 Voltage Sensitivity to Tap Position 1799.4 Modeling ofWTGs and SVCs/SVGs 1809.4.1 WTG Modeling 1809.4.2 SVC/SVG Modeling 1819.4.3 General Composite Model 1829.5 Coordination with OLTC 1839.6 Formulation of MPC Problem forWFVC 1849.6.1 Corrective Voltage Control Mode 1849.6.2 Preventive Voltage Control Mode 1869.7 Case Study 1869.7.1 Scenario 1: Normal Operation 1879.7.2 Scenario 2: Operation with Disturbances 1879.8 Conclusion 190References 19110 Control of Wind Farm Clusters 193Yan Li, Ningbo Wang, Linjun Wei, and Qiang Zhou10.1 Introduction 19310.2 Active Power and Frequency Control of Wind Farm Clusters 19410.2.1 Active Power Control Mode of Wind Farms 19410.2.2 Active Power Control Strategy of Wind Farm Cluster 19810.2.3 AGC of Wind Farm Cluster 20010.3 Reactive Power and Voltage Control of Wind Farms 20010.3.1 Impact of Wind Farm on Reactive Power Margin of the System 20010.3.2 Reactive Voltage Control Measures for Wind Farms 20210.3.3 Reactive Voltage Control Strategy of Wind Farm Cluster 20810.3.4 Wind Farm AVC Design Scheme 21010.4 Conclusion 213References 21311 Fault Ride Through Enhancement of VSC-HVDC Connected Offshore Wind Power Plants 215Ranjan Sharma, Qiuwei Wu, Kim Høj Jensen, Tony Wederberg Rasmussen, and Jacob Østergaard11.1 Introduction 21511.2 Modeling and Control of VSC-HVDC-connected Offshore WPPs 21611.2.1 Modeling of VSC-HVDC-connected WPP with External Grid 21711.2.2 Modeling of VSC-HVDC-connected WPP 21711.2.3 Control of WPP-side VSC 22011.3 Feedforward DC Voltage Control based FRT Technique for VSC-HVDC-connected WPP 22211.4 Time-domain Simulation of FRT for VSC-HVDC-connected WPPs 22311.4.1 Test System for Case Studies 22411.4.2 Case Study 22411.5 Conclusions 229References 23012 Power Oscillation Damping from VSC-HVDC-connected Offshore Wind Power Plants 233Lorenzo Zeni12.1 Introduction 23312.1.1 HVDC Connection of Offshore WPPs 23312.1.2 Power Oscillation Damping from Power Electronic Sources 23412.2 Modelling for Simulation 23512.2.1 HVDC System 23512.2.2 Wind Power Plant 23712.2.3 Power System 23812.3 POD from Power Electronic Sources 23812.3.1 Study Case 23812.3.2 POD Controller 24112.3.3 Practical Considerations for Parameter Tuning 24112.4 Implementation on VSC-HVDC-connected WPPs 24512.4.1 Realization of POD Control 24512.4.2 Demonstration on Study Case 24612.4.3 Practical Considerations on Limiting Factors 24812.5 Conclusion 254Acknowledgement 254References 254Index 257