Thème de Thèse : Contribution à la Commande Robuste des Systèmes Éoliens Autonomes PhD Topic:

1. Thème de Thèse : Contribution à la Commande Robuste des Systèmes Éoliens Autonomes PhD Topic: Contribution to Robust Control for Autonomous Wind Systems Supervisor: Presented By: Kassa IDJDARENE Soufiane MEDDOURI 03/01/2020 17:45:21

2. Introduzione Outline Conclusioni IEC61131 Hardware di base Architettura OS & Funz. • Introduction • Brief State of The Art / Motivation and Objectives • Studied System and Modeling • Implemented Control Techniques for The Production System • Energy Storage System • Concluding Remarks • Research Activities • Scientific Publication / Attended Courses / Attended Seminars and Summer Schools

3. Introduzione Outline Conclusioni IEC61131 Hardware di base Architettura OS & Funz. • Introduction • Brief State of The Art / Motivation and Objectives • Studied System and Modeling • Implemented Control Techniques for The Production System • Energy Storage System • Concluding Remarks • Research Activities • Scientific Publication / Attended Courses / Attended Seminars and Summer Schools

4. Introduction – Context Description Concluding Remarks Energy storage system Studied system and modeling Implemented Control techniques Introduction • General motivations • Increase interest of using renewable energies to overcome environmental issues ( 392 GW June 2015 / 04%)[WWEA]. • Problem of transmission of electricity over long distances (a great investment for cables, pylons, and loss during transport is relatively important, 7% to 10%). • Absence of an efficient storage system in particular for long term storage systems. • In this context, popular increasing of small autonomous operating units to ensure supply of isolated sites using wind energy. • Different electrical generator can be used to fulfil the electromechanical task. • Squirrel Cage Induction Generator (SCIG) is useful for this kind of applications. • Advantages of SCIG: • Absence of DC supply, Small size, robustness, low maintenance cost… •  Drawbacks of the SCIG: • Absorption of the reactive power for its magnetization. • Inherently poor voltage regulation. 4

5. Introduction – Detailed Description of the work goals Concluding Remarks Energy storage system Studied system and modeling Implemented Control techniques Introduction Introduction • General goals • Design of an innovative control scheme to overcome the inherently poor voltage regulation. • Study and improve the performance of a chain of autonomous wind conversions based on a squirrel cage induction machine. • Study the performance of the systemwith a good accuracy using a saturated induction generator model. • Using a PWM inverter/rectifier structure connected to a single capacitor to provide the isolated IG a reactive power to be excited. • Include a suitablestorage system which can contribute in the ancillary service. 5

6. Introduction – Detailed Description of the work goals Concluding Remarks Energy storage system Studied system and modeling Implemented Control techniques Introduction • Detailed objectives • To design a control scheme for autonomous induction generator system based on robust controller. • To have a constant voltage regardless of rotor speed variation, load and the parameter uncertainties of the generator model. • To improve the weak performances of the control schemes based on traditional controllers previously developed (PI) . • To test the effectiveness of linear MPC controller applied to a non-linear plant, under different conditions. • Improve the electric power using a suitablestorage system. 6

7. Introduzione Outline Conclusioni IEC61131 Hardware di base Architettura OS & Funz. • Introduction • Brief State of The Art / Motivation and Objectives • Studied System and Modeling • Implemented Control Techniques for The Production System • Energy Storage System • Concluding Remarks • Research Activities • Scientific Publication / Attended Courses / Attended Seminars and Summer Schools

8. Studied System and Modeling Studied system and modeling Concluding Remarks Energy storage system Implemented Control techniques Introduction Introduction • Variable wind turbine • Saturated induction generator (IG) • Variable load • Suitable storage system (flywheel) WindTurbine Induction Generator Variable Load Gearbox Storage System (Flywheel)

9. Studied System and Modelling Studied system and modeling Energy storage system Implemented Control techniques Concluding Remarks Introduction Introduction • Detailedsystem description: • The induction generator (IG) driven by variable wind turbine speed • A PWM converter connected to a single capacitor to excite the IG, and a battery in order to start up the system • A diode for decoupling rectifier from the battery as soon as the voltage generated at the output of the rectifier is higher than the battery side • Control algorithm for DC voltage and flux control 9

10. Studied System and Modelling Studied system and modeling Concluding Remarks Energy storage system Implemented Control techniques Concluding Remarks Introduction • The widely used Induction generator model: • The proposed model here takes into account the saturation effect of magnetic circuit by the expression of the magnetizing inductance Lm with respect to the magnetizing current im • To express Lm in function of im, a polynomial approximation of degree 12 is adopted 10

11. Studied System and Modelling Studied system and modeling Concluding Remarks Energy storage system Implemented Control techniques Concluding Remarks Introduction • The evolution of the magnetizing inductance in function of magnetizing current im • Saturated induction generator model: 11

12. Introduzione Outline Conclusioni IEC61131 Hardware di base Architettura OS & Funz. • Introduction • Brief State of The Art / Motivation and Objectives • Studied System and Modeling • Implemented Control Techniquesfor The Production System ( Fuzzy Logic Control) • Energy Storage System • Concluding Remarks • Research Activities • Scientific Publication / Attended Courses / Attended Seminars and Summer Schools

13. Implemented Control Techniques –Vector Control Principal Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Concluding Remarks Introduction Rotor flux oriented control principle has been used in the proposed control scheme (rd =rand rq=0). • The operating of the machine can be then considered practically linear (Lm=M=constant) 13

14. Implemented Control Techniques – Fuzzy Vector Control Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Concluding Remarks Introduction • The detailed control schemeapplied • The estimated rotor flux and stator pulsation are given as follow:

15. Implemented Control Techniques – Fuzzy Vector Control Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Concluding Remarks Introduction E e Ke U’ U_PI FZ- PI RULE BASE 1/s K1 e’ K’ e Kd U_PID U_PD U FZ- PD RULE BASE K2 • General fuzzy-PI/PDrule base • Input output membershipfunction

16. Results Analysis Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Introduction • The following simulations have been performed: • Impact of rotor speed changes (rotorspeed varied by 20% WRT the synchronous speed) with variable reference rotor flux value • Impact of rotor speed changes with fixed reference rotor flux value • Impact of load changes (load varied by ≈ 43%) 16

17. Implemented Control Techniques – Fuzzy Vector Control Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Concluding Remarks Introduction • 20% upper and lower variation of the synchronous speed ( = 750 tr / mn = 78.5398 rad / s) • The rotor flux reference is changing inversely proportional to the variable speed Undershoot 47 V ≈ 10%

18. Implemented Control Techniques – Fuzzy Vector Control Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Concluding Remarks Introduction

19. Implemented Control Techniques – Fuzzy Vector Control Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Concluding Remarks Introduction • Rotor speed changes: 20% upper and lower variation of the synchronous speed (( = 750 tr / mn = 78.5398 rad/s) • The rotor flux reference ref=0.7 (Wb) 47 V ≈ 10%

20. Implemented Control Techniques – Fuzzy Vector Control Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Concluding Remarks Introduction • Load changes (≈ 43%) 66 V ≈ 15%

21. Implemented Control Techniques – Fuzzy Vector Control Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Concluding Remarks Introduction • Load changes

22. Introduzione Outline Conclusioni IEC61131 Hardware di base Architettura OS & Funz. • Introduction • Brief State of The Art / Motivation and Objectives • Studied System and Modeling • Implemented Control Techniques for The Production System (Model Predictive Control MPC) • Energy Storage System • Concluding Remarks • Research Activities • Scientific Publication / Attended Courses / Attended Seminars and Summer Schools

23. Implemented Control Techniques – MPC control Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Concluding Remarks Introduction MPC controller: control action is obtained by solving finite horizon optimal control problem at each time instant. 23

24. Implemented Control Techniques – MPC control Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Concluding Remarks Introduction MPC controller: control action is obtained by solving finite horizon optimal control problem at each time instant. 24

25. Implemented Control Techniques – MPC – Model Identification Concluding Remarks Energy storage system Studied system and modeling Implemented control techniques Concluding Remarks Introduction • The estimated model is numerically constructed by a step response identification method around specified equilibrium point. change of rotor speed 25

26. Implemented Control Techniques – MPC Formulation Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Introduction • The obtained transfer functions of the MIMO system are as follows: • The transfer functions are subsequently transformed into a discrete state space model : 26

27. Implemented Control Techniques – MPC Formulation Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Introduction • According to Dynamic Matrix Control, the outputs’ prediction is formulated taking into account also last outputs’ measurement error: the vector of future outputs prediction (ΔΦ and ΔVdc) vector of future control actions increments the latest actual control actions i.e., Δisd, Δisq estimated value of state variables vector of predicted mechanical pulsation measurement error 27

28. Implemented Control Techniques – MPC Formulation Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Concluding Remarks Introduction • Cost function • Smoothing isd • Smoothing isq DC voltage tracking Flux tracking 28

29. Implemented Control Techniques – MPC – Reference trajectory Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Introduction A reference trajectory is proposed and implemented as a gradual transition to the desired set-point inside the MPC formulation. 29

30. Implemented Control Techniques – Switched and adaptive MPC Implemented control techniques Concluding Remarks Concluding Remarks Concluding Remarks Energy storage system Studied system and modeling Introduction • Introducing switched and adaptive MPC • A single linear system model is rarely a good enough. • Innovative control schemes (a switched and an adaptive MPC) are proposed. • Employment of a set of models estimated around different operational points of the system. • Introducing switched and adaptive MPC Modelsswitching M1 M2 Predicted output Mn

31. Implemented Control Techniques – Switched and adaptive MPC Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Concluding Remarks Introduction • Introducing switched and adaptive MPC • Introducing adaptive MPC Linear interpolation for the load changes Quadratic interpolation for the rotor speed changes 31

32. Implemented Control Techniques – Switched and adaptive MPC Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Introduction • Nonlinearity of the system 32

33. Results Analysis Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Introduction • The following simulations have been performed: • Impact of rotor speed changes (rotorspeedvaried by 20% WRT the synchronous speed) • Impact of load changes (load varied by 100 %) • Impact of introducing the switched for large changes • Impact of introducing the adaptive MPC for small changes 33

34. Results Analysis – load change Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Introduction • Impact of load variation using Single MPC: • Small load variations, while V*dc and * r are constants 66 V reduction ≈ 100 % of improvement comparing to FLC 34

35. Results Analysis – load change Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Introduction • Impact of load variation using Single MPC and Switched MPC: • Large load variations of about 100% while V*dc and * r are constants using Single MPC and Switched 20 V reduction ≈ 76 % of improvement 35

36. Results Analysis – load change Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Introduction • Impact of load variation: • Large load variations of about 100% while V*dc and * r are constants using Single MPC and Switched 36

37. Results Analysis – load change Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Introduction • Impact of load variation using Adaptive MPC: • Small load variations, while V*dc and * r are constants 2 V reduction ≈ 33 % of improvement comparing to Single MPC 37

38. Results Analysis - rotor speed changes Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Introduction • Impact of rotor speed changes caused by wind speed variation: • Rotor speed varies 20% below and above the synchronous speed ( = 750 rpm = 78.5398 rad/s), as a step • Desired DC voltage reference and load are kept constant (V*dc =465V, R=70) • Rotor flux reference is inversely proportional to the speed to make IG work at lower saturation level in case of high speeds 38

39. Results Analysis - rotor speed changes Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Introduction • Comparison between MPC and FLC • Controlled DC voltage at the output of the rectifier using FLC and MPC controllers 10 V reduction ≈ 22 % of improvement comparing to FLC 39

40. Results Analysis - rotor speed changes Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Introduction • Controlled rotor flux using FLC and MPC controllers FLC Single MPC 40

41. Results Analysis - rotor speed changes Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Introduction • Stator currents Isd and Isq using Single MPC strategy 41

42. Results Analysis - rotor speed changes Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Introduction • Switched MPC strategy • Controlled DC voltage at the output of the rectifier using Switched MPC ≈ 3 V reduction Comparing to Single MPC 42

43. Results Analysis - rotor speed changes Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Introduction • Adaptive and Single MPC strategy • Controlled DC voltage at the output of the rectifier using Adaptive and Single MPC for small changes in rotor speed Single MPC Adaptive MPC 43

44. Results Analysis – robustness analysis Implemented control techniques Concluding Remarks Energy storage system Studied system and modeling Introduction • Robustness analysis on magnetizing inductance and stator resistance • Adding white Gaussian noise N(0, 0.0001) that accounts for approximately adding 10% error of inductance values. • + 100% and –100% of stator resistance varaiton in a ramp manner 44

45. Introduzione Outline Conclusioni IEC61131 Hardware di base Architettura OS & Funz. • Introduction • Brief State of The Art / Motivation and Objectives • Studied System and Modeling • Implemented Control Techniques for The Production System • Energy Storage System • Concluding Remarks • Research Activities • Scientific Publication / Attended Courses / Attended Seminars and Summer Schools

46. Energy Storage System Energy storage system Concluding Remarks Studied system and modeling Implemented control techniques Introduction • Energy Storage Technologies Classification • Increasein renewable energies => increase the storage problem. • Energystorageis one of the components od sustainable energy. • The electricity cannot be stored easily, it requires a transformation process to another energy 46

47. Energy Storage System Energy storage system Concluding Remarks Studied system and modeling Implemented control techniques Introduction • Energy storage solution based on Flywheel. 47

48. Energy Storage System Energy storage system Concluding Remarks Studied system and modeling Implemented control techniques Introduction • Studied system including the mechanical part and storage system using flywheel: 48

49. Energy Storage System Energy storage system Concluding Remarks Studied system and modeling Implemented control techniques Introduction • Studied system including the mechanical part and storage system using flywheel: • The aerodynamic torque of the turbine • The reference of electromagnetic torque The active power exchanged between FESS and DC-link circuit and the reference energy for FESS • The reference energy for FESS • The reference speed • The reference flux 49

50. Energy Storage System Energy storage system Concluding Remarks Studied system and modeling Implemented control techniques Introduction