SAS Presentation [Autosaved], DFIG in WECS

Renewable Energy Sources (RES).
Wind Energy Conversion System (WECS).
Induction Generators (IGs).
Energy Storage System (ESS).
These have robust construction and requires less maintenance.
These are relatively cheaper than other generators.
They have very small size per KW of output power i.e. they have high energy density.
These can run in parallel without hunting.
No synchronization to the supply line is required like a Synchronous Generator.

Power Quality Improvement in Renewable Energy Sources in Conjunction with Energy Storage System .
Design & Simulation of Controller for Power Quality Improvement in Wind Energy Conversion System with Energy Storage System.
Rotor
Wind Blades
Gear-Box
Low Speed shaft
High Speed Shaft
Turbine with Generator
Converter Circuit
Sensors
Mechanical Energy Storage System
Electrochemical Energy Storage System
Thermal Energy Storage System
Electrical Energy Storage System
Hydrogen Based Storage System
Power Quality: Electrical Network’s ability to supply a stable power supply.
Poor Power Quality: Sufficient Deviation in the power supply to cause equipment failure.
Good Power Quality: Power supply is sufficient for the equipment to operate satisfactorily.
Power Quality = Voltage Quality, P = VI
Voltage Sag (Dip)
Voltage Spikes
Voltage Swell
Harmonic Distortion
Voltage Fluctuations
Noise
Voltage Imbalance
Filters
Isolation Transformers
Voltage Regulators
Dynamic Voltage Restorer (DVR)
Uninterruptable Power Supply (UPS)
Unified Power Quality Conditioner (UPQC)
Static VAR Compensator (SVC)
Thyristor Based Static Switch (TBSS)
The literature review suggests that the study and design of controllers like Proportional Integral (PI), Proportional Integral Derivative (PID), Artificial Neural Network (ANN) etc. were developed to stabilize both the grid and rotor side current control loops of direct drive SG & IG based WECS.
But the study and design of an FO-PID Controller for BESS system in the DC link capacitor with soft computing techniques needs to be explored to improve the power quality response of DFIG based WECS.
Therefore, the present work will focus on this research gap.
Modelling and Simulation of FO-PID (Fractional Order-PID) Based Controller in DFIG Based WECS by introducing the Battery Energy Storage System (BESS).
Modelling and Simulation of Soft Computing Techniques i.e. ANFIS (Adaptive Neuro-Fuzzy Inference System) & FL (Fuzzy Logic) for BESS Control for Power Quality Improvement.
Investigate the proposed work for different grid conditions through comparative analysis of Soft-Computing Techniques.
The methodology will include following steps for the objectives of this work are as follows:
Modelling of FO-PID (Fractional Order-PID) Based Controller for a 3-phase DFIG driven by a windmill. Modelling & Simulation of Battery Energy Storage System (BESS) in the DC-Link Capacitor. Simulation of the Controller using MATLAB / Simulink for 3-phase DFIG based WECS under different

1. Research Proposal of the Ph.D. T hesis on Modelling and Simulated Performance of Advanced Controller for Power Quality Improvement in DFIG Based Variable Speed Grid Connected WECS Presented by Pradeep Singh Registration No. 42000074 Under the Supervision of Dr. Krishan Arora, Associate Professor Dr. Umesh C. Rathore , Professor and Head, GHEC- Bandla , Bilaspur , HP School of Electronics and Electrical Engineering LOVELY PROFESSIONAL UNIVERSITY Jalandhar - Delhi G.T. Road, Phagwara , Punjab (India) - 144411 1

2. KEY AREAS OF STUDY FOR RESEARCH Renewable Energy Sources (RES). Wind Energy Conversion System (WECS). Induction Generators (IGs). Energy Storage System (ESS). Power Quality Improvement in Renewable Energy Sources in Conjunction with Energy Storage System . Design & Simulation of Controller for Power Quality Improvement in Wind Energy Conversion System with Energy Storage System. 2

3. POWER SCENARIO IN INDIA…… Coal (56 %) Hydro (14 %) Wind (10 %) Solar (8 %) Gas (7 %) Bio-Power (3 %) Nuclear (2 %) 3

4. POWER SCENARIO Coal (32 %) Hydro ( 9 %) Wind ( 17 %) Solar (36 %) Gas (3 %) Bio-Power (1 %) Nuclear (2 %) 4

5. SCHEMATIC DIAGRAM OF WECS 5

6. COMPONENETS OF WECS Rotor Wind Blades Gear-Box Low Speed shaft High Speed Shaft Turbine with Generator Converter Circuit Sensors 6

7. AVERAGE WIND SPEED IN DHARAMSHALA, H.P . Month Wind Speed in mph January 4.3 February 5.0 March 5.6 April 6.0 May 6.3 June 6.0 July 5.3 August 4.8 September 4.6 October 4.8 November 4.3 December 4.1 7

8. ADVANTAGES OF WECS It is available free and is inexhaustible. It is clean and non-polluting. It has low maintenance cost. It has low cost of power generation of about 2.25 Rs ./KWH. 8

9. CLASSIFICATION OF WINDMILLS Sr. No. Diameter Maximum Power Output Typical Hub Heights 1. 24 Meters 100 kW 24.5 to 36 Meters 2. 47 to 54 Meters 1 MW 35 to 76 Meters 3. 70 to 101 Meters 2 to 3 MW 57 to 138 Meters 4. 101+ Meters 2.4 to 7.5 MW 91 to 140 Meters 9

10. BLOCK DIAGRAM OF WECS 10

11. GENERATORS IN RES…… Self-Excited Induction Generator (SEIG) 11

12. ……GENERATORS IN RES Doubly-Fed Induction Generator (DFIG) 12

13. ADVANTAGES OF DFIG These have robust construction and requires less maintenance. These are relatively cheaper than other generators. They have very small size per KW of output power i.e. they have high energy density. These can run in parallel without hunting. No synchronization to the supply line is required like a Synchronous Generator. 13

14. TYPES OF ENERGY STORAGE SYSTEM (ESS) Mechanical Energy Storage System Electrochemical Energy Storage System Thermal Energy Storage System Electrical Energy Storage System Hydrogen Based Storage System 14

15. POWER QUALITY Power Quality : Electrical Network’s ability to supply a stable power supply. Poor Power Quality: Sufficient Deviation in the power supply to cause equipment failure. Good Power Quality: Power supply is sufficient for the equipment to operate satisfactorily. Power Quality = Voltage Quality, P = VI 15

16. POWER QUALITY PROBLEMS Voltage Sag (Dip) Voltage Spikes Voltage Swell Harmonic Distortion Voltage Fluctuations Noise Voltage Imbalance 16

17. Power Quality Solutions Filters Isolation Transformers Voltage Regulators Dynamic Voltage Restorer (DVR) Uninterruptable Power Supply (UPS) Unified Power Quality Conditioner (UPQC) Static VAR Compensator (SVC) Thyristor Based Static Switch (TBSS) 17

18. SUMMARY OF LITERATURE REVIEW Sr. No. Author/Year Journal/Volume No. Findings 1. Grid Connection of Doubly-Fed Induction Generators in Wind Energy Conversion System Ahmed G. Abo-Khalil et. al. (2006) In this paper, the control strategy employed FOC (field oriented control) which allows independent control of electromagnetic torque & stator reactive power. This includes speed control & reduced flickers which is achieved by controlling the VSC. This paper also describes smooth & fast synchronization scheme of the DFIG to the grid as well as independent control of real & reactive power of the generator using the stator flux oriented control at normal operation. The magnitude of stator induced emf or voltage is controlled by adjusting the phase difference between the stator & grid voltage is compensated by PLL algorithm. 2. Islanded Operation of A Doubly-Fed Induction Generator (DFIG) Wind-Power System with Integrated Energy Storage Amimaser Yazdani et . al. (2007) This paper presents the multimode control scheme for a DFIG based wind power/storage system that enables the system to operate in the ( i ) the grid connected mode of operation (ii) the islanded mode of operation. Here in this paper, in islanded mode of operation, the system can effectively maintain the load frequency and voltage in-spite of significant load & wind speed variations. 18

19. Sr. No. Author/Year Journal/Volume No. Findings 3. Large Offshore DFIG-Based Wind Farm With Line - commutated HVDC Connection to the Main Grid: Engineering Studies Serihy Bozhko et. al (2008) This paper presents a large wind farm with a LCC (Line Commutated Converter) HVDC connection to maintain onshore network. Here a STATCOM (Static Compensator) was used that can typically provide much faster control than a synchronous compensator & also with lower losses. 4. Multimode Control of a DFIG-Based Wind-Power Unit for Remote Applications Faruk A. Bhuiyan et. al. (2009) This paper presents the development of effective control strategies that enables the wind power systems to operate in the islanded mode as well as in the grid connected mode. It uses unified controller for all the modes of operation . 5. Reinforced Control and Operation of DFIG-Based Wind Power Generation System Under Unbalanced Grid Voltage Conditions Jiabing Hu et. al. (2009) This paper presents an enhanced control & operation of DFIG system under unbalanced grid voltage conditions by coordinating the control of the RSC (rotor side control) & GSC (grid side control). This paper shows behavior & operation of Doubly Fed Induction Generators RSC & GSC during voltage imbalances. Co-ordinated control & current control schemes are also proposed using controllers. 19

20. Sr. No. Author/Year Journal/Volume No. Findings 6. Modeling and control of isolated hybrid system using wind driven DFIG and hydro driven SCIG Puneet K. Goel et. al. (2010) This paper presents design and control of a new isolated wind-hydro hybrid generation system by using a DFIG which is driven by a variable wind speed turbine & a constant speed SCIG (Squirrel Cage Induction Generator) driven by a constant power hydro turbine feeding local loads. The performance is observed here under different electrical & mechanical dynamic conditions. 7. Understanding the Doubly Fed Induction Generator During Voltage Dips G. D. Marques et. al. (2012) This paper presents a comprehensive study of the DFIG during voltage dips. Here a closed loop model of the system & the design of the rotor PI current controller according to the integral of the time multiplied by the absolute error (ITAE). 8. Grid Power Leveling using Ultra Capacitor, Battery and an Optimal Control Strategy for Reactive Power in DFIG based WECS Diptoshi Roy et. al. (2014) This paper presents about the BESS system. The Bess system is the one which is used for reduction of power fluctuations on the grid caused due to varying & unpredictable nature of the wind. This paper presents the comparative study between BESS & ultra-capacitor & the combination of both in a DFIG based WECS to reduce the power fluctuations on the grid. In this, the main focus is on DFIG based WECS with ultra-capacitor in the dc link has been proposed & demonstrates for different speeds (Sub-Synchronous, Synchronous & Super-Synchronous). Here, the reactive power control is also implemented in the proposed system. 20

21. Sr. No. Author/Year Journal/Volume No. Findings 9. Speed - Sensorless Voltage & Frequency Control in Autonomous DFIG based Wind Energy Systems Rishabh Dev Shukla et. al. (2014) In this paper, here the hysteresis current control technique is used for RSC to control the output voltage & frequency of a DFIG based WECS system has been implemented & simulated. The performance is observed for both the transient as well as in steady state & which is observed is quite satisfactory. 10. Single-Phase Power Generation Employing VFC for Stand-Alone Three-Phase Doubly Wound Asynchronous Generator Shailendra Kumar Sharma et. al. (2015) Here in this paper, the PWM controlled back-to-back connected Voltage Source Converter are used. This is used to provide functions of load leveler, a current balancer & a harmonics eliminator. This system here is developed for feeding stand-alone consumers. 11. Sliding Mode Power Control of a DFIG based Variable Speed Wind Energy Conversion System Santosh Sharma et. al. (2015) In this paper, the sliding mode control (SMC) based vector control is applied to a grid connected DFIG based variable WECS to improve the dynamic performance while controlling the independently generated active and reactive powers over traditional PI controller under different wind speed patterns. 21

22. Sr. No. Author/Year Journal/Volume No. Findings 12. Experimental Implementation of a Doubly Fed Induction Generator Used for Voltage Regulation at a Remote Location N. K. Swami Naidu et. al. (2016) This paper presents the variable speed DFIG based WECS for regulating the terminal voltage at the remote locations in addition to the power generation. This methodology has been verified for steady state and dynamic changes in wind speed through test results. 13. Modelling and Analysis of a DVR for a Grid Connected DFIG Based Wind Energy System V. Kranthi et. al. (2016) This paper focuses on the fault ride through operation of DFIG wind turbine or system during voltage sag. The DVR (Dynamic Voltage Restorer) is proven effective device for enhancing the voltage stability of the system. It supplies the requires amount of reactive power to the system so as to maintain the parameters within the limit which are required to satisfy the grid. 14. Controller Design of DFIG Based Wind Turbine by Using Evolutionary Soft Computational Techniques OM Prakash Bharti et. al. (2017) In this paper, a PSO (Particle Swarm Optimization) based and BFO (Bacterial Foraging Optimization) based techniques are employed to design the controller to improve the system response & to reduce the percentage overshoot to zero for DFIG based WECS. 22

23. Sr. No. Author/Year Journal/Volume No. Findings 15. Maximum Active and Reactive Power Capability of a Matrix Converter-Fed DFIG-Based Wind Energy Conversion System Suman Mondal et. al. (2017) This paper presents the optimum stator reactive power reference that maximizes the net active power injected to the grid by an MC-fed DFIG (Matrix Converter fed Doubly fed Induction Generator) based WECS at a given speed & grid power factor & within the design limits of the system components. 16. Analysis on Application of a Current-source Based DFIG Wind Generator Model Jin Ma et. al. (2018) This paper presents, current source based generator model represent a large group of DFIG models for power system stability analysis. The model validates under the symmetrical & unsymmetrical operation scenarios During the most severe faults i.e. three phase short circuit are often used for power system stability analysis, the current source based DFIG is the best candidate due to symmetrical nature of these types of faults. 17. A Synchronization Control Technique For Soft Connection of Doubly Fed Induction Generator Based Wind Turbines to the Power Grids Abilash Thakallapelli et. al. (2019) In this paper, a direct voltage control based synchronization based method is used which will cause low or no transient effect during synchronization of DFIG to the grid. The controller is deigned on the basis of multichannel identification technology which is used here for reduction in wings in voltage or frequency when grid is reconnected. 23

24. Sr. No. Author/Year Journal/Volume No. Findings 18. Power Quality Improvement of Grid Connected Wind Energy System Using DSTATCOM - BESS Jawad Hussain et. al. (2019) This paper introduces Power Quality improvement technique for grid connected wind power plant using DSTATCOM (Distribution Static Compensator) with BESS. DSTATCOM used here for reactive power compensation. DSTATCOM does not properly control the active power. So, a BESS is used for better control of active power. It can effectively use to improve the power quality of wind power distribution network. 19. A coordinated control strategy using Super -capacitor energy storage and series dynamic resistor for enhancement of fault ride-through of doubly fed induction generator Subhendu Sekhar Sahoo et. al. (2019) Power fluctuation & fault related complication are the two major issues for DFIG based WECS. Here a Super-capacitor energy storage system (SCESS) with passive series dynamic resistor (SDR) is used for power fluctuation & fault related complications. SCESS is used in the DC link which reduces the power fluctuations & SDR is placed in the rotor circuit which will reduce the overcurrent possibility. 20. Power smoothing method of PMSG based grid integrated wind Energy conversion system using BESS / DSTATCOM Jayalakshmi S. N. et. al. (2019) In this paper, a PMSG (Permanent Magnet Synchronous Generator) based WECS is incorporated using DSTATCOM with BESS for smoothening the power produced from wind generator system. Here a VSC based DSTATCOM is used & a battery current is controlled to smooth the net power injected to the utility grid from wind power generation system. It has the power quality enhancement ability but it also has the capability to supply required amount of power to the utility with the help of battery bank. 24

25. Sr. No. Author/Year Journal/Volume No. Findings 21. Comparative analysis of fractional order PI and integer order PI based controller for hybrid standalone wind energy conversion system Anjana Jain et. al. ( 2019) This article presents comprehensive analysis of fractional order proportional integral (FOPI) and integer order proportional integral (IOPI) controllers for voltage and frequency control of a variable speed hybrid standalone WECS connected to PMSG–BESS has been presented. , FOPI is able to achieve the desired response with reduced overshoot and settling time. Robustness of the controllers is tested with 25% and 50% disturbance. Results show that IOPI fails the stability criterion at 50% disturbance. The results show that, FOPI based controller is able to maintain the terminal voltage and frequency constant with improved transient response in comparison to IOPI. 22. Moving Average Filter-PLL-Based Voltage and Frequency Control of Standalone WECS Anjana Jain et . al. ( 2020) In this paper, moving average filter (MAF)-based PLL is proposed to solve this issue for permanent magnet synchronous generator (PMSG)-based WECS. MAF allows suitable measurement of frequency and eliminates dc offset, harmonics, and unbalance in voltage. Also scheme is able to perform harmonics reduction. The proposed controller is able to keep steady terminal voltage and frequency during varying working environments like variable wind velocity and variable load. It is found that MAF shows better response than other PLLs. 23. Intelligent Proportional Integral Terminal Sliding Mode Control for variable speed standalone wind energy conversion system Anjana Jain et. al. (2020) This study investigates the design of robust nonlinear controller for control of voltage and frequency of variable-speed standalone Wind Energy Conversion System (WECS). The variation in wind-speed and load raise the oscillation in terminal-voltage and frequency. To overcome this issue, an Intelligent Proportional Integral Terminal Sliding Mode Controller ( iPI -TSMC) is proposed. From the test results, it is inferred that controller offers a stable terminal voltage with minimum settling time, which shows the robustness of the controller. 25

26. Sr. No. Author/Year Journal/Volume No. Findings 24. Mitigating Power Fluctuations for Energy Storage in Wind Energy Conversion System Using Super-capacitors Irfan Hussain Panhwar et. al. (2020) This paper presents the application of a super-capacitor in WECS to increase the life of the lead-acid battery which also eliminates power fluctuations caused by variable wind speed & instantaneous load switching. The result indicates improvement in DC link terminal voltage & reactive power. The integration of a super-capacitor provides a smooth charging and extended discharging of the battery & keeps the power electronics circuit safe from current spikes during charging cycle of the battery. 25. Testing the Performance of Battery Energy Storage in a Wind Energy Conversion System Adnan Sattar et. al. (2020) Here, in this paper, dynamic and transient performances of a BESS connected system with the output of a WECS to smoothen the short-term fluctuations in the output power. The system is modelled with PMSG. Three factors are considered here namely the BESS rated voltage, the ease of commissioning & the losses. 26. TSBC Converter with BESS for DFIG-Based Wind Energy Conversion System Arindam Das et. al. (2020) This paper proposes the integration of a BESS in a DFIG based WECS. Here a TSBC (Triple Star Bridge Cell) converter is proposed for the control of DFIG & BESS. A control strategy is proposed to mitigate fluctuations within the rating of the BESS thereby reducing the fluctuations of the power fed to the grid. 26

27. Sr. No. Author/Year Journal/Volume No. Findings 27. Unified Power Quality Conditioner with Advanced Dual Control for Performance Improvement of DFIG-Based Wind Farm Ruo Huan Yang et. al. (2021) This article proposes a cost effective energy storage device based Unified Power Quality Conditioner (ESD-UPQC) to improve the LRT (Low Voltage Ride Through) capability of the DFIG to suppress voltage oscillations under unbalanced faults & regulate DFIG output during fluctuated wind speed conditions. The SSC (Series Side Converter) of UPQC precisely compensate the output or required voltage & the PSC (Parallel Side Converter) can accurately maintain the constant output power during wind power fluctuations. It helps in mitigate the oscillations in grid side current, grid side active & reactive power. 28. Fuzzy Distribution Static Compensator based control strategy to enhance low voltage ride through capability of hybrid renewable energy system Ashwani Kumar et. al. (2021) In this paper, to increase the fast response of compensation & good transient performance of hybrid renewable energy system (HRES), FACS devices such as DSTATCOM are employed. This paper proposes a strategy through a BESS embedded with fuzzy based DSTATCOM. The proposed system used of the improvement of DC Link voltage, Voltage at the PCC (Point of Common Coupling), Reactive Power (Q) & Active Power (P). 27

28. BASIC MATLAB MODEL FOR A WINDMILL 28

29. WAVEFORMS OF BASIC MODEL FOR WECS…… Output Power with the change in wind speed Rotor Current 29

30. ……WAVEFORMS OF BASIC MODEL FOR WECS Rotor Speed with the change in wind speed Grid Voltage due to Voltage Dips 30

31. ……WAVEFORMS OF BASIC MODEL FOR WECS Grid Voltage due to Voltage Dips Bus Voltage due to Voltage Dips 31

32. ……WAVEFORMS OF BASIC MODEL FOR WECS Torque Variation with the change in wind speed 32

33. RESEARCH GAP…….. The literature review suggests that the study and design of controllers like Proportional Integral (PI), Proportional Integral Derivative (PID), Artificial Neural Network ( ANN ) etc . were developed to stabilize both the grid and rotor side current control loops of direct drive SG & IG based WECS . 33

34. …….. RESEARCH GAP But the study and design of an FO-PID C ontroller for BESS system in the DC link capacitor with soft computing techniques needs to be explored to improve the power quality response of DFIG based WECS. Therefore , the present work will focus on this research gap. 34

35. RESEARCH OBJECTIVES Modelling and Simulation of FO-PID (Fractional Order-PID) Based Controller in DFIG Based WECS by introducing the Battery Energy Storage System (BESS ). Modelling and Simulation of Soft Computing Techniques i.e. ANFIS (Adaptive Neuro-Fuzzy Inference System) & FL (Fuzzy Logic) for BESS Control for Power Quality Improvement . Investigate the proposed work for different grid conditions through comparative analysis of Soft-Computing Techniques. 35

36. RESEARCH METHODOLOGY…… The methodology will include following steps for the objectives of this work are as follows: Modelling of FO-PID (Fractional Order-PID) Based Controller for a 3-phase DFIG driven by a windmill. Modelling & Simulation of Battery Energy Storage System (BESS) in the DC-Link Capacitor. Simulation of the Controller using MATLAB / Simulink for 3-phase DFIG based WECS under different wind & grid conditions. 36

37. ……RESEARCH METHODOLOGY Modelling and Simulation of various soft computing techniques i.e ANFIS (Adaptive Neuro Fuzzy Inference System ) & FL (Fuzzy Logic) in BESS for Improvement of Power Quality using MATLAB/Simulink. Comparative analysis of various soft computing techniques under different wind & loading conditions. 37

38. CONTROL CIRCUIT OF DFIG 38

39. WORK DONE TILL DATE SINCE AUGUST 2020 (Course Work Already Completed in December 2020)…… Course Code Course Title Credits Status GEN 740 Foundations of Research and Publication Ethics 3 Passed GEN 741 Research Methodology 4 Passed GEN 742 Research Writing and Presentation 1 Passed 39

40. ……WORK DONE TILL DATE SINCE AUGUST 2020 More than 280 (200 IEEE, 80 Non-IEEE Journals & Conference) Research Papers used for Literature Survey/Review. Simulation Model for DFIG based WECS was prepared using MATLAB/Simulink. DFIG Characteristics analysed under different wind loading and operating conditions. 40

41. BASE PAPER Title : Intelligent Proportional Integral Terminal Sliding Mode Control for variable speed standalone wind energy conversion system by Anjana Jain & Rajendran Saravanakumar in 2020. The objective of this research paper is to During variations in load or wind-velocity, voltage, and frequency are not consistent. A suitable controller is required to solve this issue and to provide satisfactory response during different operating conditions. The main objective of proposed iPI -TSMC controller is to modulate the terminal voltage and frequency under different operating conditions. Estimation of frequency is carried out using DSOGI-PLL. 41

42. TIMELINES OF THE PROPOSED STUDY   Item Year 2021 Year 2022 Year 2023 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Introduction                         Literature Review                         Objectives and Hypothesis Finalization                         Methodology                         Study of the required Software                         Data Collection                         Tabulation and analysis of data                         Results writing                         Conclusion and suggestion                         Report/ thesis preparation and submission                         42

43. RESEARCH OUTCOMES The main aim of the proposed work is to design a simple, low cost controller which can easily be used to regulate the performance parameters of Induction Generators. Application of the proposed work will be helpful in large scale use of Induction Generators in harnessing the wind energy potential in India, in the districts of Himachal Pradesh and in Himalayan Regions. 43

44. REFERENCES…… Ahmed G. Abo Khalil, Dong- Choon Lee, Se-Hyun Lee “Grid Connection of Double-Fed Induction Generators in Wind Energy Conversion System” CES/IEEE 5th International Power Electronics and Motion Control Conference , 2006, 1-5 . Amirnaesar Yazdani , “Islanded Operation of a Doubly-Fed Induction Generator (DFIG) Wind-Power System with Integrated Energy Storage” IEEE Canada Electrical Power Conference, 2007, 153-159 . Serhiy Bozhko , Greg Asher, Risheng Li, Jon Clare, Liangzhong Lao, “Large Offshore DFIG based Wind Farm with Line-Commutated HVDC Connection to the Main Grid: Engineering Studies” IEEE Transactions on Energy Conversion, VOL. 23, NO. 1, MARCH 2008 . Faruk A. Bhuiyan , Amirnaser Yazdani , “Multimode Control of a DFIG-Based Wind-Power Unit for Remote Applications” IEEE Transactions of Power Delivery, VOL. 24, NO. 4, December 2009 . Jibang Hu, Yikang He, “Reinforced Control and Operation of DFIG-Based Wind-Power Generation System Under Unbalanced Grid Voltage Conditions” IEEE Transactions on Energy Conversion, VOL. 24, NO. 4, December 2009 . Puneet K. Goel , Bhim Singh, S.S. Murthy and Navin Kishore, “Modelling and Control of isolated hybrid system using wind driven DFIG and hydro driven SCIG” (2010) European Transactions on Electrical Power Vol. No. 22, 121-139 .   G . D. Marques, Duarte M. Sousa, “Understanding the Doubly Fed Induction Generator During Voltage Dips” IEEE Transactions on Energy Conversion, VOL. 27, NO. 2, June 2012 . Diptoshi Roy, Chandasree Das, “Grid Power Levelling Using Ultra Capacitor, Battery and an Optimal Control Strategy for Reactive Power in DFIG based WECS” International Journal of Innovative Technology and Exploring Engineering (IJITEE), Volume-4, Issue-4, September 2014 . Rishabh Dev Shukla, Dr. Ramesh Kumar Tripathi , “Speed –sensor less Voltage & Frequency control in Autonomous DFIG based Wind Energy Systems” Australian Universities Power Engineering Conference, AUPEC-2014, Curtin University, Perth, Australia, 28 September – 1 October 2014 . Shailendra Kumar Sharma, Bhim Singh, Ambrish Chandra, Kamal Al-Haddad, “Single-Phase Power Generation Employing VFC for Stand-Alone Three-Phase Doubly Wound Asynchronous Generator” IEEE Transactions on Industry Applications, VOL. 51, NO. 6, November/December 2015. 44

45. ……REFERENCES…… Santosh Sharma, Dr. J. P. Mishra, Mr. Subir Datta , “Sliding Mode Power Control of a DFIG based Variable Speed Wind Energy Conversion System” Annual IEEE India Conference (INDICON), 17-20December 2015, 1-6. N . K. Swami Naidu, Bhim Singh, “IEEE Transactions on Industry Applications, VOL. 52, NO. 6, November/December 2016 .  [13] V. Kranthi , B. N. Prasad, “Modelling and Analysis of a DVR for a Grid Connected DFIG Based Wind Energy System” International Journal of Research in Electrical Engineering” Volume. 3, Issue. 3, 2016, pp. 56-60 .   Om Prakash Bharti, R. K. Saket , S. K. Nagar, “Controller Design of DFIG Based Wind Turbine by Using Evolutionary Soft Computational Techniques” Journal of Engineering, Technology & Applied Science Research, Vol. 7, No. 3, 2017, 1732-1736 . Suman Mondal , Debaprasad Kastha , “Maximum Active and Reactive Power Capability of a Matrix Converter-Fed DFIG-Based Wind Energy Conversion System” IEEE Jornal and Emerging and Selected Topics in Power Electronics, VOL. 5, NO. 3, September 2017 .   Jin Ma, Dawei Jhao , Liangzhong Yao, Minhui QianYamashita , Lingzhi Zhu, “Analysis on Application of a Current-source Based DFIG Wind Generator Model” CSEE Journal of Power and Energy Systems, VOL. 4, NO. 3, September 2018 . Abilash Thakallapelli , Sukumar Kamalasadan , Kashem M. Muttaqi , Mehrdad T. Hagh , “A Synchronization Control Technique for Soft Connection of Doubly Fed Induction Generator Based Wind Turbines to the Power Grids” IEEE Transactions on Industrial Applications, VOL. 55, NO. 5, September/October 2019 .   Jawad Hussain, Mujahid Hussain, Safdar Raza, Muhammad Siddique, “Power Quality Improvement of Grid Connected Wind Energy System Using DSTATCOM-BESS, International Journal of Renewable Energy Research, Vol. 9, No. 3, September 2019 .   Subhendu Sekhar Sahoo , Kalyan Chatterjee, P. M. Tripathi , “A Coordinated Control Strategy Using Super-capacitor Energy Storage and Series Dynamic Resistor for Enhancement of Fault-Ride Through of Doubly Fed Induction Generator” International Journal of Green Energy, Volume. 16, Issue. 8, 2019 .   Jayalakshmi N. S., D. N. Gaonkar , Sanchit Kumar Jain, “Power Smoothening Method of PMSG Based Grid integrated Wind Energy Conversion System Using BESS/STATCOM”, International Journal of Power Electronics and Drive Systems (IJPEDS), VOL. 10, NO. 4, 2019. 45

46. ……REFERENCES Irfan Hussain Panhwar , Kafeel Ahmed, Mehdi Seyedmahmoudian , Alex Stojecvski , Ben Horan, Saad Mekhilef , Asim Aslam, Maryam Asghar , “Mitigating Power Fluctuations for Energy Storage in Wind Energy Conversion System Using Super-capacitors”, Special Section on Evolving Technologies in Energy Storage Systems for Energy System Applications, VOL. 8, 2020, 189747-189760 . Adnan Sattar , A. Al-Durra, C. Caruana , S. M. Muyeen , “Testing the Performance of Battery Energy Storage in a Wind Energy Conversion System”, IEEE Industry Applications Society Annual Meeting (IAS), 23-27 September 2018 .   Arindam Das, Amit Kumar Kar , Mayur , Ujwal Kumar, Apurva Verma , Souradeep Pal, Aby Joseph, Bikram Das, Prabir Ranjan Kasari , Abanishwar Chakrabarti , Subhadeep Bhattacharjee , “TSBC Converter with BESS for DFIG-Based Wind Energy Conversion System”, IEEE Transactions on Industry Applications, VOL. 56, NO. 6, November/December 2020 .   Ruo Huan Yang, Jian Xun Jin , “Unified Power Quality Conditioner with Advanced Dual Control for Performance Improvement of DFIG-Based Wind Farm”, IEEE Transactions on Sustainable Energy, VOL. 12, Issue. 1, January 2021 .   Ashwani Kumar, Vishnu Mohan Mishra, Rakesh Ranjan , “Fuzzy Distribution Static Compensator Based Control Strategy to Enhance Low Voltage Ride Through Capability of Hybrid Renewable Energy System”, Journal of Energy Sources, Part A: Recovery, Utilization and Environmental Effects, May 2021, pp. 1-18. 46