Solar PV and Battery Storage Integration Using a New Configuration
Configuration of power conversion systems for flow battery ...
Transcript of Configuration of power conversion systems for flow battery ...
Customised Technology for Customer Success
THE ENERGY STORAGE COMPANY
Configuration of power conversion systemsfor flow battery applications
E. A. Lewis 16th June 2010
This document contains confidential and proprietary information of Converteam and must not be used forany purpose other than that for which it is supplied by Converteam. Its contents must not be disclosed to
any other person nor copied in whole or in part without the prior written consent of Converteam
FOR CUSTOMER SUCCESS Slide 2
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 2 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
Introduction
Converteam and Prudent Energy are collaborating on the design of a range ofVanadium Redox flow cell energy storage systems.
This presentation describes the evolution of the initial flow cell energy storagesystem rated at 200 kWatts.
The initial design is complete and four systems are under manufacture.
The four systems will be installed on an AC grid in China during 2010.
FOR CUSTOMER SUCCESS Slide 3
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 3 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
Converteam
Converteam is a company with more than 100 years experiencein power conversion, with the knowledge of GEC, AEG, CGEAlsthom and Westinghouse. Converteam is now owned byBarclays bank 1/3 rd, LBO bank 1/3 rd and managers 1/3 rd.
Converteam is an engineering companyproviding customised designs, solutionsand systems for converting electricalenergy into productive performance.
Powergeneration
Power transmission& distribution
Converteammotors andconverters
M
FOR CUSTOMER SUCCESS Slide 4
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 4 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
Converteam Energy Storage Technology
Converteam can supply the optimum energy storage solution for any project :
Lithium ion energy storage.
Super-capacitor energy storage.
Rotary energy storage in flywheels.
Flow cell energy storage.
FOR CUSTOMER SUCCESS Slide 5
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 5 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
Prudent Energy
One of few companies in the world having capabilities of deliveringcommercial MW-class energy storage solutions.
Provides proprietary VRB energy storagesolutions for grid and renewable energystorage applications.
Founded in 2006 with headquarters in Beijing.
Branches in Vancouver, Canada.
Employees are 19 in R&D, 8 in sales, 27 inmanufacturing and 26 in engineering.
Manufacturing Facilities in China with presentcapacity of 3MW per shift.
Expansion to 10MW in 2010 and 25MW in 2011.
Controls all substantial patents including 24issued patents and 38 pending patentapplications in 34 countries
Recognized as the only commercialized VRBsolution provider by China State Grid.
Company Overview Low Cost Manufacturing
Global Footprint
FOR CUSTOMER SUCCESS Slide 6
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 6 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
The Vanadium Flow Cell Energy Storage Technology
AC gridElectrochemical energy storagesystem at ambient temperature.Same unique element Vanadiumused in both reaction half cells, sono cross contamination problems.The electrolyte never wears out, sovery low maintenance.Unlimited deep cycles for 10 yearswith very fast charge and discharge.Most unique features are :
MW rating setsreaction cell size.MWh rating setstank size.Vanadium is easilyavailable.Works by proton &electron transfer.DC volts low at 150to 250 volts DC.
FOR CUSTOMER SUCCESS Slide 7
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 7 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
Flow Cell Module
Modules are now on test
FOR CUSTOMER SUCCESS Slide 8
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 8 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
The Diode Bridge Converter For Flow Cells
AC grid
Diode bridgeDC bus
Flow cell DC output voltage
“ VDC “
AC supply voltage“ VAC “
Diode
AC volts100 5000 150 200 250
00 50
100
150
250
200
300350
DC volts
With a diode bridge the DC output voltage isdirectly set by the AC supply voltage.VDC = Peak of the VAC.So VDC = √ 2 x VAC, see the red line.The flow cells requires a voltage of 150 to 250volts DC depending on current flow and charge.For VDC = 150 volts, then VAC = 106 volts AC.No output voltage control is possible.This circuit can not be used with flow cells.
Transformer
FOR CUSTOMER SUCCESS Slide 9
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 9 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
The Thyristor Bridge Converter For Flow Cells
AC grid
Thyristor bridgeDC bus
Flow cell DC output voltage
“ VDC “
AC supply voltage“ VAC “
Thyristor
AC volts100 5000 150 200 250
00 50
100
150
250
200
300350
DC volts
Transformer
With thyristors the DC output voltage can bereduced down to zero by the control signalsent to the thyristors.With thyristors VDC maximum = √ 2 x VAC.For an AC supply voltage = 180 volts outputvoltage control is possible within the blue area.This circuit is ideal for flow cells.Unfortunately the thyristor circuit can not meetthe AC grid code requirements.
FOR CUSTOMER SUCCESS Slide 10
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 10 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
The IGBT Bridge Converter For Flow Cells
AC grid
IGBT bridgeDC bus
Flow cell DC output voltage
“ VDC “
AC supply voltage“ VAC “
IGBTDC volts
AC volts100 5000 150 200 250
00 50
100
150
250
200
300350
Transformer
With insulated gate bipolar transistors IGBTs “the diodes are essential as the AC current isconstantly switching between an IGBT and theadjacent diode.Due to the diodes VDC minimum = √ 2 x VAC.For an AC supply voltage = 106 volts outputvoltage control is possible within the blue area.This circuit can be used for flow cells but the ACsupply voltage has to be very low.The circuits meets the AC grid code requirements.For optimal cost a more complex circuit is needed.
DiodeHarmonicfilter
FOR CUSTOMER SUCCESS Slide 11
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 11 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
The Origin Of The Power Converter Technology
The most common power system for high power wind turbines uses two fully ratedPWM inverters to change variable frequency generated AC power, to DC power at aconstant DC voltage and then in to fixed frequency AC Grid power.This is the heart of the flow cell converter system.
690 V
PWM Filter
PWM voltage
AC supply inverter
Clean current PWM current
ACGrid
Generator inverter
Direct coupledAC generator
FOR CUSTOMER SUCCESS Slide 12
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 12 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
The Available Inverter Modules
A complete range available to over 30 MW .
2 & 3 level inverters.Flat pack IGBTs.Glycol watercooling system.
3 level inverters.Ceramic IGBTs.Deionised watercooling system.
MW
Volts
51 30
6600
0
2 level inverters.Flat pack IGBTs.Air cooled.
3300
440
15
690
900
0
3 Level
2 Level
For a typical 200 kW flow cell design the optimum Converteam inverter is theDelta module rated at up to 690 volts and 1000 amps AC. The Delta invertermodule is very cost effective as it produced in high volumes for wind turbines.
FOR CUSTOMER SUCCESS Slide 13
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 13 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
The Inverter Module Used
Converteam Delta module ratings :
MVDL643 = 643 amps AC at 690 volts AC.MVDL800 = 800 amps AC at 690 volts AC.MVDL1000 = 1000 amps AC and 690 volts AC.
Two overload ratings110 % overload at rated output.150 % overload at reduced rated output.
Coolant is water with added ethylene glycol.
More than 10 per day produced.
More than 4 GW supplied.
FOR CUSTOMER SUCCESS Slide 14
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 14 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
Circuit For The Prudent Flow Cell Order
Harmonicfilter DC bus
ACgrid
DC to DCIGBT inverter
Flow cell
AC to DCIGBT inverter
If a single stage input inverter was used for a typical 200 kW design :For an AC voltage tolerance of +/- 20% the AC supply = 106 x 0.8 = 85 volts AC.This would need an AC current of ( 2 x 105 ) / (√ 3 x 85 ) = 1360 amps AC.This would use two Delta inverter modules in parallel and would have high losses.
The selected design uses two Delta inverter modules in series :The AC to DC input inverter operates at 440 volts AC with an 800 volt DC bus.This needs an AC current of ( 2 x 105 ) / (√ 3 x 440 ) = 260 amps AC.The DC to DC output inverter can control the flow cell voltage from 0 to 250 volts DC.This is ideal as it also provides the initial charging action of the flow cell.This dual combination uses the same number of delta modules as the single stagedesign and the lower currents give lower losses than the single stage design.
FOR CUSTOMER SUCCESS Slide 15
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 15 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
Power flow Power flowPower flow Power flowPower flow Power flowPower flow Power flow
Operating Mode 1 Storing And Delivering Power
Harmonicfilter DC bus
ACgrid
DC to DCIGBT inverter
Flow cell
AC to DCIGBT inverter
The system is either importing, exporting or storing AC power.The AC power is controlled by an external control signal.Can change from importing to exporting power in one AC mains cycle.No limit on the number or depth of the charge and discharge cycles.Can also supply AC reactive power at the same rating as the power rating.The AC reactive power is controlled by a separate external control signal.The system is thus able to operate with an AC power factor of +/- 0.7per unit.Meets all grid code performance specifications.Can also complete the initial flow cell charging from zero volts DC.
FOR CUSTOMER SUCCESS Slide 16
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 16 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
Operating Mode 2 For Grid Fault Conditions
The system operates to deliver the MVArs specified by the relevant Grid code.For a partial grid loss can deliver MWatts and MVArs.For a complete grid loss can only deliver MVArs.A Grid loss either recovers within a few seconds or is a longer time Grid loss.For the initial grid loss a small UPS keeps the micro processors operational but theauxiliary systems can shutdown for a few seconds.If the Grid loss persists will go to either the Self Sufficient Waiting Mode 3 or the IslandMode 4.
Harmonicfilter DC bus
ACgrid
DC to DCIGBT inverter
Flow cell
AC to DCIGBT inverter
Power flow Power flow
FOR CUSTOMER SUCCESS Slide 17
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 17 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
Operating Mode 3 In Self Sufficient Waiting Mode
ACgrid
AC to DCIGBT inverter
Harmonicfilter DC bus
DC to DCIGBT inverter
Flow cell
If the AC grid power is lost for more than a few seconds it is necessary to restartthe flow cell controls and pumps, to bring the flow cell system to the optimumconditions for long term energy storage.The way that this is achieved is not shown as it is Converteam IPR and subject to apatent application.
Power flow toauxiliary systems
AC contactor
FOR CUSTOMER SUCCESS Slide 18
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 18 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
Operating Mode 4 In Island Generating Mode
AC to DCIGBT inverter
If required the system can act as an island generator.The AC to DC inverter then generates the required AC voltage and frequency for theAC grid.This can continue as long as the flow cell has sufficient energy.
Harmonicfilter DC bus
ACgrid
DC to DCIGBT inverter
Flow cell
Power flow Power flow
FOR CUSTOMER SUCCESS Slide 19
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 19 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
The Standard Power Converter System
PWM filter cubiclePWM filter cubicle PWM inverter cubiclePWM inverter cubicle
FOR CUSTOMER SUCCESS Slide 20
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 20 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
Energy Storage Fills The Gap
Grid powerReserve Grid power stations
123
Operating Grid power stations
123
Renewable Grid generation
12345
Grid frequency
Dynamic energy store12345
An integrated energy storage policy can meet all the requirement of Grid Coderegulations and enable wind power to be fully integrated.Can increase the revenue of wind farms and supply synthetic inertia power to the grid.
Reduced gridinertiaenergyStore
FOR CUSTOMER SUCCESS Slide 21
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 21 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
One Reason Why National Grids Need Energy StorageG
rid fr
eque
ncy
in H
z
Time in hours & minutes11.30 11.35 11.40 11.45 11.50 11.55
Total generation loss = 1.993 GW
48.8
48.6
49.2
49.4
49.0
12.00
4
1 = Loss of 345 MW main generation.2 = Loss of 1237 MW main generation.3 = Loss of 132 MW other generation.4 = Loss of 279 MW other generation.5 = Disconnections started
Data supplied courtesy of William Hung of National Grid
5
50.4
50.2
50.0
49.8
49.6
1
3
2
This happened in the UK during 2008 and the grid was shutting downand needed forced disconnections to survive.
FOR CUSTOMER SUCCESS Slide 22
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 22 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
Medium Voltage Flow Cell Design
Shows a typical 10 MW medium voltage inverter system.
3 level inverter
ACgrid
NP
LV DC toMV DC
DC link
Isolated reversingLV DC to MV DC converter
FlowcellOnly needs 3 modules
To many extraisolated flow cells
FOR CUSTOMER SUCCESS Slide 23
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 23 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
ProEVAr Is The Integrated Solution
This is a cost effective way to implement.Power converter already needed for grid code to supply MVArs.Power converter can also be used to also supply dynamic grid power by adding flow cells.
Flowcell
Flowcell
Flowcell
Flowcell
Onshore to offshorecable
OffshorePFC Offshore generators
AC supplycable
ACsupply
DCDC
DCDC
DCDC
DCDC
Flow cell array
FOR CUSTOMER SUCCESS Slide 24
CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS E Lewis Flow Cell Issue A Slide 24 © 2010 Converteam UK Ltd. All rights reservedCOMMERCIAL IN CONFIDENCE
Conclusions
The Converteam’s energy storage system’s abilities include :Absorbing and delivering energy.
Fast response times below 0.1 seconds.
Has same grid code performance as wind turbines.
Can supply MWs and MVArs.
Can operate in an island mode
Can supply synthetic inertia to simplify turbine designs.
Can smooth power flow.
Can store energy to permit confident pool price bidding based on forecast wind .
Can store energy to sell latter at a high pool price.
Can provide the 20 % df/dt margin required by National grid.
Can maximize energy delivered to maximize revenue.
Can enable simpler wind turbines to be produced with smaller inverters.
Available with different storage methods to be optimal for any given application.
Useable in any application both on land and at sea.
Customised Technology for Customer Success
THE ENERGY STORAGE COMPANY
Thank you
This document contains confidential and proprietary information of Converteam and must not be used forany purpose other than that for which it is supplied by Converteam. Its contents must not be disclosed to
any other person nor copied in whole or in part without the prior written consent of Converteam