modelling grid tied re sources

Fractional Order Modeling & Control Strategies Fractional Order Modeling & Control Strategies for Grid-Connectedfor Grid-Connected Renewable Energy Renewable Energy

SourcesSources

Major Professor : Dr. ChenMajor Professor : Dr. Chen

Committee members: Dr. Cripps, Dr. Spencer, Committee members: Dr. Cripps, Dr. Spencer, Dr. Wu and Dr. BanDr. Wu and Dr. Ban

Presenter: Hadi MalekPresenter: Hadi Malek

Ph.D. StudentPh.D. StudentElectrical & Computer Engineering DepartmentElectrical & Computer Engineering Department

Utah State UniversityUtah State University

04/27/2012

Email: hadi.malek@ieee.org1

Outline

New trends in power electronics for applying fractional order calculus (FOC) in grid-connected renewable energy systems.

Advantages of using FOC.

Review of the current system and recent researchers regarding applying FOC.

2

Introduction

Increasing number of renewable energy resources and distributed generators

New strategies for the operation and management of the electricity grid

Improve the power-supply reliability and quality

3

Power-electronics technology

Plays an important role in distributed generation

Integration of renewable energy sources into the electrical grid

Fast evolution, due to:a. development of fast semiconductor switchesb. introduction of real-time controllers

4

– Variable-speed technology – 5% increased efficiency

– Easy control of active and reactive power flows– Rotor acts as a flywheel (storing energy)– No flicker problems– Higher cost

New technologies - wind turbines

5

Wind turbine technology

Wind-turbine market has been growing at over 30% a year

Important role in electricity generation Germany and Spain

6

Rectifier and chopper

step-up chopper is used to adapt therectifier voltage to the dc-link voltage of the inverter.

driver controlling the torque generator, using a vector controlstrategy

Energy Transfer Control of the active and reactive powers total-harmonic-distortion control

7

PV Photovoltaic Technology

PV systems as an alternative energy resource

Complementary Energy-resource in hybrid systems

Solar-electric-energy growth consistently 20%–25% per annum over the past 20 years

1) an increasing efficiency of solar cells1) an increasing efficiency of solar cells2) manufacturing-technology improvements2) manufacturing-technology improvements3) economies3) economies of scale of scale8

PV growth

2001, 350 MW of solar equipment was sold 2003, 574 MW of PV was installed.

In 2004 increased to 927 MW Significant financial incentives in Spain,

Germany, Italy and France triggered a huge growth in demand

http://www.erec.org9

Perspectives

World solar photovoltaic (PV) installations were 2.826 GW peak (GWp) in 2007, and 5.95 GW in 2008

The three leading countries (US, Germany, & Japan) represent nearly 89% of the total worldwide PV installed capacity.

In 2012, 12.3GW- 18.8GW (expected!)10http://www.renewableenergyworld.com

Efficiency

Market leader in solar panel efficiency (measured by energy conversion ratio) is SunPower, (San Jose USA) - 23.4%

market average of 12-18%. (http://www.sroeco.com)

Efficiency of 42% achieved at the University of Delaware in conjunction with DuPont (concentration) in 2007.

The highest efficiency achieved without concentration is by Sharp Corporation at 35.8% using a proprietary triple-junction manufacturing technology in 2009.

11 G. Pilawjian , “Analysis of Photovoltaic Concentrating Solar Energy Systems”, ARPN Journal of Systems and Software VOL. 2, NO. 3, March 2012.

ON Grid – OFF Grid

12

Power-Quality Requirements for Grid-Connected RES

Flicker + interharmonicsinterharmonics Anti-Islanding Voltage Fault Ride Through Capability Standards (IEEE, NEC, IEC, …)

13

Requirements

K. Fujii1, N. Kanao, T. Yamada1, Y. Okuma, “Fault Ride Through Capability for Solar Inverters”, Power Electronics and Applications (EPE 2011), Proceedings of the 2011-14th European Conference on , vol., no., pp.1-9, Aug. 30 2011-Sept. 1 2011

14

Islanding

Islanding is the continued operation of the inverter when the grid has been removed on purpose, by accident, or by damage

Detection schemes - active and passive. 1. The passive methods -monitor grid

parameters.2. The active schemes introduce a disturbance

into the grid and monitor the effect.

15

Islanding

PV Generator Converter AC-DC Local Loads Grid16

Standards

1. Flicker analysis2. Switching operations. Voltage and current

transients3. Harmonic analysis (FFT) - rectangular

windows of eight cycles of fundamental frequency. THD up to 50th harmonic

17

TThe standards he standards EN61000-3-2, IEEE1547, U.S. National Electrical Code (NEC) 690 IEC61727

power quality, detection of islanding operation, grounding

structure and the features of the present and future PV modules.

18

Standards

19

Maximum Power Point Tracker

EX.: ripple voltage should be below 8.5% of the MPP voltage in order to reach a utilization ratio of 98%

S.B. Kjaer, Member, J. K. Pedersen, F. Blaabjerg, “A Review of Single-Phase Grid-Connected Inverters for Photovoltaic Modules”, IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. 41, NO. 5, OCT 200520

High efficiency

Wide range of input voltage and input power Very wide ranges as functions of solar irradiation and ambient temperature.

21

Fractional Order Calculus

Definitions Why Fractional Order Calculus? What have been done? What’s the plan?

22

Fractional Order Calculus

Reimann-Liouville Definition:

Caputo Definition:

23

Laplace Transform

Fractional Order Calculus

24

Fractional Order Calculus

I. Podlubny, “Geometric and physical interpretation of fractional integration and fractional differentiation”, Fractional Calculus and Applied Analysis, vol. 5, no. 4, pp. 367– 386, 2002.

25

Fractional Order Calculus(Why?)

Stability

Is BIBO stable if:

Ivo Petras, “STABILITY OF FRACTIONAL-ORDER SYSTEMS WITH RATIONAL ORDERS: A SURVEY”, Fractional Calculus & Applied Analysis, Vol 12, No. 3, 2009

26

Fractional Order Calculus(Why?)

Robustness

27 Y.Q. Chen, H.S. Ahn and I. Podlubny, “Robust Stability Check of Fractional Order Linear Time Invariant Systems With Interval Uncertainties”, Proceedings of the IEEE International Conference on Mechatronics & Automation Niagara Falls, Canada • July 2005

Fractional Order Calculus

More Degree of Freedom Better Time Domain Specification

28

Fractional Order Calculus(Why?)

Nature of Input

Z. J. Ye X., Xia X. and Y.Q. Chen, “Fractional analysis and synthesis of the variability of irradiance and pv power time series,” in FDA, (China), May 2012.

29

Fractional Order Calculus(Why?)

Nature of the System

30

Fractional Order Calculus(Why?)

Nature of the System

31

Fractional Order Calculus(Done!)

Wind TurbineR. Melício, V.M.F. Mendes, J.P.S. Catalão, Fractional-order control and simulation of wind energy systems with PMSG/full-power converter topology, Energy Conversion and Management, Volume 51, Issue 6, June 2010, Pages 1250-1258.

32

Fractional Order Calculus(Done!)

FO Controller for Three Level MNP Inverter

K. Arab-Tehrani, T. Capitaine, Ludovic Barrandon , M. Hamzaoui, S.M.R.Rafiei and A. Lebrun, “Current Control Design with a Fractional-Order PID for a Three-Level Inverter” FDA2012.

33

Fractional Order Calculus(Done!)

FO Controller for Three Level MNP Inverter

34

Fractional Order Calculus(Done!)

FO Controller for DC-DC Buck Converter

A.J. Calder´on, B. V. Vinagre, and V. Feliu. Fractional Order Control of a Power Electronics Buck Converter. In Proceeding of the 5th Portuguese Conference on Automatic Control 2002 (Controlo 2002) , pages 365–370, September 5th Portuguese Conference on Automatic Control.

35

Fractional Order Calculus (Feasibility!)

Analoge Implementation

Gary W. Bohannan, “Analog Realization of a Fractional Control Element”, October 27, 200236

Fractional Order Calculus (Feasibility!)

Digital Implementation

37

Research Plan

Grid-Connected PV System

38

Research Plan

Irradiation

http://www.mavericksolar.net/39

Research Plan

FO MPPT

40

Research Plan

FO MPPT

http://www.mpoweruk.com41

Research Plan

FO MPPT (Extremum Seeking Control)

M. Krstic & H.H. Wang, Automatica, 36, 2000.42

Research Plan

FO MPPT (Extremum Seeking Control)

Ref: S.L. Brunton, C.W. Rowley, R.K. Sanjeev, C. Clarkson, IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 25, NO. 10, OCTOBER 2010

43

Research Plan

Traditional Control Strategy

Zhang, Jianzhong; Cheng, Ming; , "DC link voltage control strategy of grid-connected wind power generation system," Power Electronics for Distributed Generation Systems (PEDG), 2010 2nd IEEE International Symposium on , vol., no., pp.970-975, 16-18 June 2010

44

Research Plan

FO DC Link Voltage Control

45

Research Plan

FO Current Control Loop

Romero-Cadaval, E.; Milanes-Montero, M.I.; Gonzalez-Romera, E.; Barrero-Gonzalez, F.; , "Power Injection System for Grid-Connected Photovoltaic Generation Systems Based on Two Collaborative Voltage Source Inverters," Industrial Electronics, IEEE Transactions on , vol.56, no.11, pp.4389-4398, Nov. 2009

46

Research Plan

FO Current Control Loop

47

Research Plan

FO Filtering

K. Fujii1, N. Kanao, T. Yamada1, Y. Okuma, “Fault Ride Through Capability for Solar Inverters”, Power Electronics and Applications (EPE 2011), Proceedings of the 2011-14th European Conference on , vol., no., pp.1-9, Aug. 30 2011-Sept. 1 2011 48

Research Plan

FO Filtering

G. Shen, D. Xu, L. Cao, and X. ZhuAn, “Improved Control Strategy for Grid-Connected Voltage Source Inverters With an LCL Filter”, IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 23, NO. 4, JULY 2008.

49

50

Plan

Developing better fractional order models of inputs and converter devices such as DC/DC converters, Voltage Source Inverter (VSI) or Current Source Inverter (ISI) and storage devices.

Developing better control techniques based on these newly developed models

Dialyzing and comparing several modeling topologies and control strategies.

51

Timeline

Irradiation Modeling 1. Review current estimation methods.

2. Applying FO estimation to experimental data and comparison with other methods

2 month

Boost Converter 1. Design and Implementation of FO MPPT (Simulation)

2. Analyses (Stability, …) & tuning

3. Performance Evaluation4. Comparison the efficiency

4 month

Inverter 1. Review current control strategies

2. Applying and tuning FO controllers to VSC and ISC & analyzing the results (Simulation)

3. Comparison with traditional strategies.

4 month

52

Timeline

Filtering 1. Apply & tuning FO filters to the system

2. Analysis (Stability, time domain specification, freq. domain specification, …)

2 month

Overall 1. Design and Implementation of overall system with FO controllers and filters

2. Analyses (Stability, Robustness, …) & tuning

3. Performance Evaluation4. Calculate and comparison

the efficiency

2 month

53

Thank You!

Questions?

54