problems and applications of power converters for … and applications of power converters for smart...

Problems and Applications of Problems and Applications of Power Converters for Smart Grid

and Energy Efficiencyand Energy Efficiency

Prof. Frede Blaabjerg

Fellow IEEE DL IASFellow IEEE, DL-IASInstitute of Energy TechnologyAalborg University, Denmarkg y,

[email protected]

Energy and Power ChallengeEnergy and Power Challenge

Main challenges in energy :

• Sustainable energy production (backbone, weather based)gy p ( , )• Energy efficiency• Mobility• Infrastructure

Different initiatives :

- EU Set-plan (20-20-20) and beyond- Danish Climate Commision- Many other countries- Globally many initiatives (Smat grid etc)

Content

∙ Electric Power System ArchitectureElectric Power System Architecture• Renewable Grid-Interactive Control• Smart Grid• System Topologies of Distributed Energy Resources• A Real World Example in Denmark• Energy Saving• Future Research Areas

Electric Power System Architecture

Electric Power System ArchitectureElectric Power System Architecture

Traditional Power System Architecture

• Centralized energy production

• Unidirectional power flow

• Vertical operation and control


Challenges in Traditional Power System

Lolland Fuel Cell Micro CHP

Horns Rev offshore wind farm

• Grid integration of large-scale renewable energy systems

• Proliferation of distributed energy resources

• Several blackouts over the last years

• Increased energy demandsIncreased energy demands

• Redesign the entire power system architecture?


Electric Power System in Denmark

Key figures for Electricity Generation in 2008

Composition of renewable electricity generated in 2008

Western Denmark Eastern Denmark Source: Energinet.dk


Development of Danish Electric Power System


Development of the Power Balance in Western Denmark

Very high coverage of distributed generation.

Renewable Grid-Interactive Control


Horns Rev - Vestas V80–2.0 MWHorns Rev 160 MW

Renewable Grid Interactive Controlog

ies

Horns Rev 160 MW

tech

nolo

-sho

re t

Off-

Rotor Diameter 80 mHub Height 70 mWeight 245 tonsS d /

• 80 x 2MW (Vestas V80, pitched, variable speed DFIG with Start Wind 4 m/s

Nominel Wind 13 m/sMax Wind 25 m/sPlatform for helicopter hoist

variable-speed, DFIG with gearbox)

• In operation for more than 3 years Platform for helicopter hoist

Improved Power ControlImproved Corrosion ProtectionImproved HSE Facilities

y


Nysted wind farm 158.4 MW

Renewable Grid Interactive Controlog

ies

All turbines in operation

tech

nolo Sept 12, 2003

-sho

re t

Off-

O&MO&MService once a year• Automated greasing• extended SCADA• Access by boat

Renewable Grid-Interactive ControlRenewable Grid Interactive Control

DFIG control level: Control for DFIG:

Wind turbine control level: pitch control

Targets for control: maximum power point operation

Control for DFIG: active& reactive power

Control of grid side converter DC-link voltage it f t

power limitation control

maximum power point operation power limitations for high wind speeds reactive power control

unity power factor

Renewable Grid-Interactive ControlRenewable Grid Interactive Controlrb

ines

Win

d Tu

trol

of W

Con

t

PMSG control level: Maximum power point Control of grid side converter



Control of grid side converter DC-link voltage unity power factor

p power limitation control

maximum power point operation power limitations for high wind speeds reactive power control

Renewable Grid-Interactive ControlRenewable Grid Interactive Controlrb

ines

Win

d Tu

trol

of W

Con

t

SCIG control level: Maximum power point Control of grid side converter



Control of grid side converter DC-link voltage reactive power

power limitation control

power limitations for high wind speeds reactive power control

Renewable Grid-Interactive Controls

Grid Interfacing DemandsRenewable Grid Interactive Control

rem

ents

on R

equi

onne

ctio

Grid

Co

Renewable Grid-Interactive Controls

Grid Codes

Renewable Grid Interactive Controlre

men

tson

Req

uion

nect

io

Danish Grid Code for Distribution Networks

Danish Grid Code for Transmission Networks

Grid

Co Distribution Networks

German Grid Code for Transmission Networks

1


Power production regulation at Wind Farm LevelGrid Code for Transmission Networks

Renewable Grid Interactive Control

Priority 1 Priority 5

Priority 3 Priority 6

P i it 4Priority 4Priority 7

Renewable Grid-Interactive ControlLVRT


x= 300-500 ms

Successive & non-symmetrical faults

E-On Grid Code

Grid support by 100% reactive current injection


Uniform dynamic performance of WT


Integration of energy storage elements in each WT

The system structure of a variable speed wind turbine integrating with a battery storage system

Renewable Grid-Interactive ControlA 3.15MWp Large PV Plant in Spain

Renewable Grid Interactive Controlr

Pow

erS

ola

r

(photo: http://www.solarig.com)

• Large-scale, PV grid-connected systems (generally feed into the medium voltage grid)

• Power rating from 200 kWp to many MWp (e.g. 10MWp or more)o e a g o 00 p o a y p (e g 0 p o o e)• The amount of the generated electricity depends on both the

meteorological conditions and the instantaneous grid load: energy rejections 22


Large scale PV


Large scale PV

r P

ower

So

lar

L PV Pl t ( 200 kW ) l it (%)Large PV Plants (> 200 kWp): annual power capacity (%)as market share of total PV power capacity annually installed (MWp) [2]

[2] http://www.pv-power-plants.com

1 23


Large scale PV


Pow

erS

ola

r

C l ti iti

Large PV Plants (> 200 kWp):cumulative power capacity byregion in 2008 [2]

Cumulative power capacitiesin selected European countries in 2008 [2]

[2] http://www.pv-power-plants.com

24


Large scale PV


Pow

erS

ola

r

One line diagram of a Large (1MW ) PV Plant [4]: 4704 polycrystalline PV One-line diagram of a Large (1MWp) PV Plant [4]: 4704 polycrystalline PV modules in 4 PV substructures, 4 PV inverters, the PV system extends over 20000 m2

25

Smart GRID

Smart GRID

How do we control this – Smart GRID ?

Smart GRID

Small scaleLarge scale

Smart GRID

Future Power System

Smart GRID

Three conceptual models for the architecture of future power system

Active Networks ‘Internet’ model ‘Internet’ model

Microgrids

Internet model

c og ds

Source: European Commission “New Era for Electricity in Europe. Distributed Generation: key issues, challenges and proposed solutions.”

Smart GRID

Active Networks

Smart GRID

Possible evolution of passive distribution pnetworks.

Enabling technologies: (1) Power electronics(1) Power electronics(2) New ICT

Smart GRID

Microgrid C di t d d t ll d l t i l b t ith

Smart GRID

Coordinated and controlled electrical subsystem with• Multiple distributed energy resource units

• Multiple consumersp

• Interconnections at distribution voltage level

• Capable of grid independent and grid dispatchable interactive operations

Source: RISØ SYSLAB

Smart GRID

Microgrid Classifications

Smart GRID

c og d C ass cat o s

Single Facility (<2MW) − Smaller individual facilities with multiple loads e g hospitals schoolsloads, e. g. hospitals, schools.

Multi-Facility (2-5MW) − Small to larger traditional CHP facilities plus a few neighboring loads exclusively C&I.

Feeder (5-20MW) − Small to larger traditional CHP facilities plus many or large neighboring loads, typically C&I.

Substation (>20MW) − Traditional CHP plus many neighboring loads Substation (>20MW) Traditional CHP plus many neighboring loads. Will include C&I plus residential.

Rural Electrification − Rural villages of many emerging markets of India, China Brazil etc as well as rural settlementsChina, Brazil etc., as well as rural settlements found in Europe and North America.

Smart GRID

Microgrid Challenges

Smart GRID

c og d C a e ges

Distribution system protection and control practice is largely incompatible with the Microgrid concept.

Bi directional power flows• Bi-directional power flows

• Unit level voltage and VAR support

Non-conventional generation will require new unit control and protection strategies for successful Microgrid operation.g g p

• Variability of renewable energy sources

• Low overload, short circuit ratings

• Power rate limits

• Potential for active load control (e.g., water and hydrogen production)

Supervisory controls will be needed to achieve the full operating potential.• Total energy optimization (electrical and thermal)

• Load management

• Unit commitment

• Aggregation and system performance

• Data acquisition• Data acquisition

Business, regulatory, and tariff structures are presently incompatible with multiparty Microgrids.

Smart GRID

Microgrid Demo Projects

Smart GRID

The Bornholm Island Multi Microgrid in Denmark

Source: EU More Microgrid

System Topologies of Distributed Energy RessourcesEnergy Ressources

System Topologies of Distributed Energy ResourcesSystem Topologies of Distributed Energy Resources

General System Structure for a DER Unit

Conventional rotary DER units • Energy inertia• Fixed speed, low efficiency

Electronically-coupled DER units• Inertialess• Adjustable speed, high efficiencyp , y

• Limited control of power flowdjustab e speed, g e c e cy

• Flexible control of power flow


Conventional rotary DER units Conventional rotary DER units

Elect onicall co pled DER nits

The system structure of a fixed speed wind turbine

Electronically-coupled DER units

The system structure of a variable speed wind turbineThe system structure of a variable speed wind turbine


New Requirements from Microgrid Operations

CERTS microgrid operations − Uniform dynamic performance of DG Units

Integration of energy storage elements in each DG unit in the CERTS microgridIntegration of energy storage elements in each DG unit in the CERTS microgrid

The system structure of a variable speed wind turbine integrating with a battery storage system


System Topologies of Power Electronics Interfaces

Single-stage power conversion system• Simplest configuration• Bulky and expensive low frequency transformerBulky and expensive low frequency transformer• Z-source and NPC multilevel converter are more attractive

Commonly used two-stage power conversion system• One stage controls the primary energy source (MPPT), the other performs grid requirements • Decoupled control of power flow between the energy source side and the grid side converter

System Topologies of Distributed Energy Resources

Operating Conditions and Functions of DER Units

System Topologies of Distributed Energy Resources

• Voltage and frequency controlGrid • Voltage and frequency control• Load sharing

Grid Forming

•Power dispatchGrid •Voltage and frequency supportFeeding

•Maximum active power output• Reactive power support

Grid Supporting Reactive power supportSupporting

A Real World Project in Denmark

A Real World Project in DenmarkA Real World Project in Denmark

The power system in western Denmark production capacity per voltage level

The Cell ProjectThe power system in western Denmark production capacity per voltage level

A Real World Project in DenmarkA Real World Project in Denmark

The Cell Project

Energy Saving

Energy SavingEnergy Saving

• Energy Consumption (dependent on global location) Energy Consumption (dependent on global location)

• 1/3 electricity1/3 electricity• 1/3 heat• 1/3 transport/ p

I f i t• Issues of importance

• Buildings (isolation, behaviour)• New demands (etc. Cooling)• Globalisation (production etc.)

Energy Saving

REFRIGERATORREFRIGERATOR

Energy Saving

SOLAR CELLS TELEVISION

LIGHTSOLAR

DCAC

SOLAR CELLS TELEVISION

LIGHTSOLAR

DCAC

POWER STATION

MOTOR

PUMP

LIGHT

TRANSFORMER

TRANSFORMER

FACTS

SOLARENERGY

3 3 3 1 -3

POWER STATION

MOTOR

PUMP

LIGHT

TRANSFORMER

TRANSFORMER

FACTS

SOLARENERGY

3 3 3 1 -3

ROBOTICS

TRANSFORMER

INDUSTRY

COMPEN -SATOR

FUELCELLS

TRANSFORMER

INDUSTRY

COMPEN -SATOR

FUELCELLS

DCDC

WIND TURBINE=

POWER SUPPLY

ac dc

CELLS

FUEL

COMMUNICATION

3

~WIND TURBINE=

POWER SUPPLY

ac dc

CELLS

FUEL

COMMUNICATION

3

~

ACAC

COMBUSTIONENGINE

TRANSPORT

COMBUSTIONENGINE

TRANSPORT

Energy SavingEnergy Saving

In the modern world 60% of all

electricity is consumed

by electrical motorsby electrical motors

Energy Saving

Total annual energy consumption by motors: 765 x 10^9 kWh

Energy Saving

gy p y(US 1995) ~ 765 TWh

Power plant in Denmark produces: ~ 300 MW ~2 6 TWh/year2.6 TWh/year

CasePower savings by reductions of1% 7 65 TWh 3 power plants1% ~ 7.65 TWh ~ 3 power plants5% ~ 38.25 TWh ~ 15 power plants10% ~ 76.5 TWh ~ 30 power plants

Energy Saving

Problems / Demands

Energy Saving

DEMANDS FOR ASD

3

FLi i t f Sh ft f

Problems / Demands

Single/Three phase Harmonic Standards Regeneration EMI/RFI Line transients U b l

Speed range Torque-speed characteristic Dynamic response Sensor/sensorless Braking (flux)

Grid 3ASM

Frequency

Converter

Field Bus

Line interface Shaft performance

Unbalance Ride-through

Control Methods Self-commisioning Application software Overload control

Bus-structure Auto-configuration Panel setup C

g ( ) Flying start

Control/Monitoring Interface

Overload control Efficiency optimized Fault-detection Fault-handling

Communication Status-information

Performance can vary a lot

Energy Saving

General trends

Energy Saving

• Price pr. kW decreasesp• Weight pr. kW decreases• More intelligence in drives (internet etc.)• Global interconnection (90 V – 380 V)( )• Converter and motor build together• Other motors are becoming an alternative• Power Electronics in general the key for successg y

R&D Needs in Energy Technology

R&D needs in Energy TechnologyR&D needs in Energy Technology

• Basic research (material, chemistry, etc)• Energy storage• CO2 reduction in power production incl. more efficient power plants• Behaviour change• More efficient cars/airplanes/ships• Create alternatives to fossil fuel (e.g. biofuel)From Vaste to Value• From Vaste to Value

• More reliable and predictable power/energy systems• The energy and power market place• Better interplay between energy sourcesBetter interplay between energy sources• Develope a 1-2 kW society

R&D needs in Energy TechnologyR&D needs in Energy Technology

More Electric Society

Energy Saving

Automation

Communication

Distributed power/ Renewable energy

Power Quality

Transportation

Aviation and Space

Appliance Applications

Power Transmission

Computers

2007

R&D needs in Energy Technology

More electric society

R&D needs in Energy Technology

y

- New (improved) devices- Power conversion technologies- Smart and CHEAP Integration (converter, system)- New applications (eg. LCD’s, wireless, RES..)- Virtual power prototyping (simulation etc)- Multi-disciplinary design (Electrical Thermal Mechanical EMI)Multi disciplinary design (Electrical, Thermal, Mechanical, EMI)- Reliability- Unity efficiency ASD’s (large energy consumers)- Intelligent Load management – combined with power production

High Compact Energy Storage devices (and cheap)- High Compact Energy Storage devices (and cheap)- New concepts for transportation- Smart light technologies- Rare-earth material substitution- Smart grid – micro grid- Etc.

A. Luna, P. Rodriguez, R. Teodorescu, F. Blaabjerg, "Low voltage ride through strategies for SCIG ind t bines in dist ib ted po e gene ation s stems " Po e Elect onics Specialists

Some published papers in the fieldwind turbines in distributed power generation systems," Power Electronics Specialists Conference, 2008. PESC 2008. IEEE , vol., no., pp.2333-2339, 15-19 June 2008

P. Rodriguez, A. Timbus, R. Teodorescu, M. Liserre, F. Blaabjerg, "Flexible Active Power Control of Distributed Power Generation Systems During Grid Faults," Industrial Electronics, IEEE Transactions on , vol.54, no.5, pp.2583-2592, Oct. 2007

P R d i A Ti b R T d M Li F Bl bj "R ti P C t l f P. Rodriguez, A. Timbus , R. Teodorescu, M. Liserre, F. Blaabjerg , "Reactive Power Control for Improving Wind Turbine System Behavior Under Grid Faults," Power Electronics, IEEE Transactions on , vol.24, no.7, pp.1798-1801, July 2009

F. Blaabjerg, R. Teodorescu, M. Liserre, A.V. Timbus,“Overview of Control and Grid Synchronization for Distributed Power Generation Systems, IEEE Trans. on Industrial Electronics, Vol. 53, No. 5, 2006 398 092006, pp. 1398 – 1409.

S. B. Kjaer, J.K. Pedersen, F. Blaabjerg, "A review of single-phase grid-connected inverters for photovoltaic modules," Industry Applications, IEEE Transactions on , vol.41, no.5, pp. 1292-1306, Sept.-Oct. 2005

T. Kerekes, R. Teodorescu, C. Klumpner, M. Sumner, D. Floricau, P. Rodriguez, "Evaluation of three-h t f l h t lt i i t t l i " P El t i d A li tiphase transformerless photovoltaic inverter topologies," Power Electronics and Applications,

2007 European Conference on , vol., no., pp.1-10, 2-5 Sept. 2007F. Blaabjerg , Z. Chen and S. B. Kjaer "Power electronics as efficient interface in dispersed power

generation systems", IEEE Trans. Power Electron., vol. 19, pp. 2004, pp. 1184-1194.M. P. Kazmierkowski , R. Krishnan and F. Blaabjerg Control in Power Electronics—Selected

Problems,Book,2002;AcademicPress, , ;Z. Chen, J.M. Guerrero, F. Blaabjerg, “A Review of the State of the Art of Power Electronics for Wind

Turbines” IEEE Transactions on Power Electronics, Vol. 24, No. 8, pp. 1859-1875A. Timbus, M. Liserre, R. Teodorescu, P. Rodriguez, F. Blaabjerg, “Evaluation of Current

Controllers for Systems”, IEEE Transactions on Power Electronics, Vol. 24, No. 3, 2009, pp. 654-664.654 664.

F. BLAABJERG, R. Teodorescu, M. Liserre, A.V. TIMBUS,”Overview of Control and Grid Synchronization for Distributed Power Generation Systems”, IEEE Trans. on Industrial Electronics, Vol. 53 , No. 5, 2006, pp.1398 - 1409

Th k f tt ti !Thank you for your attention!

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