drives in power generation - abb group - automation and power

© ABB Group September 3, 2010 | Slide 1

Drives in Power Generation

Franz Frank ABB Switzerland

Mauricio Rotella ABB Chile


Agenda

� Power generation “hot topics”� Energy saving with VSDs

� Power generation segments with VSD applications� VSD applications in thermal power plants

� Pump and fan control with VSDs� VSD applications in gas turbine power plants� VSD applications in pump storage power plants

� References � Energy savings case example


Usefulenergy

50%transport

conversionefficiency line losses

productionprocess

net energy

motor efficiency

Primaryenergy

Electricalenergy

Trans-mission &Distibution

IndustrialPlant

Motors &Drives Buildings

Energyinput

Energy use

Energy Value ChainEnergy Efficiency: Improvement Targets


Power generation “hot topics”

� Global warming and choice of primary energy sources

� Rising fuel costs

� CO2 emissions (trading, capturing, storage?)

� Nuclear power on the rise again

� Profitability

� Minimize costs of production, necessity to raise efficiency

� Growing energy demand

� Ageing of existing plants (� requirement for overhaul, upgrade, expansion)

� Requirement for new plants


Three items to focus on

1. Alternative primary energy sources(wind, solar, biofuel etc.)

2. Capture and storage of CO2

3. Increasing the efficiency of the conversion process for saving energy resources and reducing the CO2 emissions.


Energy saving through variable speed drives Electrical auxiliary consumption in a coal fired power plant

80%

20%Electric motors

Others (heating,lighting etc.)

dedicated to processes driven by electric motors

� 5 - 10% of the produced power is dedicated to electrical auxiliary consumption in the power plant (i.e. “losses”)

� Processes driven by electric motors typically consume 80% of this electricity

� By applying electrical variable speed drives (VSDs), total losses can be reduced by ~20%

� In an 800 MW power plant there exists a reduction potential of >8 MW


variable speed drivesfor

soft startersfor

Applications

Segments

-hydro turbines of pumped

storage power plants(LCI.SO)

HYDROPump Storage

feedwater pumpsgas turbine(LCI.ST)

THERMALGAS Turbine

feedwater pumps,condensate pumps,

FD and ID fans,district heating pumps

-THERMAL(Solid fuelled)

Power generation segments with MV VSD applications


Boiler feed pump2000-20000 kW

Boiler recirc. pump

100-400 kWCooling water pump

300-2300 kW

Condensate pump100-1200 kWFeed water

booster pump

Thermal power plant Pump applications

Aux. consumption of a thermal PP: 5-10%


H2 = 0,64

Q2

= 0,

7

Q2

= 0,

7H2 = 1,27

89.027.1*7.0P =≈

Power demand Throttling control versus VSD control

�

�

H1 = 1Q

1 =

1

45.064.0*7.0P =≈

�

H1 = 1

Q1

= 1

�

Throttling VSD Control

Design Point

Design Point


Energy Efficiency of Pump Control Methods

Pump Control

0

20

40

60

80

100

120

0 30 40 50 60 70 80 90 100

Flow

Po

wer

Dem

and

Bypass Control

Throttling Control

Hydro Coupling

VSD Control

Theoretical PowerDemand

Energy savings potential of VSD Control versus Throttling Control


Thermal power plant Fan applications

Coal pulverizer fan100-400 kW

Gas recirc. fan400-1500 kW

Force draft fan400-4500 kW

Primary air fansecondary air fan

400-4000 kWInduced draft fan

400-9000 kW

Induced draft fan (booster)400-9000 kW

See notes for add’l info

106

106


Performance of a fixed speed fan with damper control

Fan Characteristic Design Point / TB (Test Block condition) various contingency factors considered

Flow Rate

Pre

ssur

e

Fan EfficiencyLevels

Damper Positions

25% Flow ReductionEfficiency drop from

85.3% to 40% �� 45% losses

Operating point / MCR (Maximum Continuous Rating)

“The power demand for the TB rating is significantly larger than for the MCR with the MCR rating being between 60 and 75 percent of the TB rating.”[IEEE Std 958-2003]

System Characteristic


Performance of a variable speed controlled fan

FanCharacteristic

depending on Motor/Fan

Speed

Design Point / TB

Pre

ssur

e

Flow Rate

25% Flow ReductionEfficiency drop from 89% to 87%

�� 2% losses

System Characteristic

Fan EfficiencyLevels


Fan Control

0

20

40

60

80

100

120

0 30 40 50 60 70 80 90 100

Flow

Po

wer

Req

uir

ed

Outlet Damper Control

Inlet Guide Vane Control

Electrical VSD Control

Theoretical PowerDemand

Energy Efficiency of Fan Control Methods

Energy savings potential of VSD Control versus Damper Control



soft startersfor

Applications

Segments



HYDROPump Storage


THERMALGAS Turbine






Combined-cycle power plant applications

(HRSG) Boiler feed pump1100-4500 kW

Boiler recirc. pump

100-400 kW

Cooling water pump100-1500 kW

Condensate pump100-1100 kW

District heating recirc. pump100-1500 kW

Co-Generation(COGEN)

Fuel-gas booster compressor

1100-4000 kW

Aux. consumption of a CCPP: 3-4%


LCI.ST

Gas turbine starterStarting Frequency Converter (SFC)

� Megadrive LCI.ST

� Load Commutated Inverter topology, using thyristor semiconductors

� Proven technology

� > 750 units delivered

� Air cooled design

� Sequential starting of several generators possible with one single LCI.ST


� Start-up sequence� Break away and ramp-up to about

30% speed

� GT (and HRSG) purging

� Continue ramping up and GT ignition

� Continue ramping up in field weakening, GT gradually taking over

� Turn-off SFC

� Turn on main excitation

� Synchronize to grid

How does a Start-up work?



soft startersfor

Applications

Segments



HYDROPump Storage


THERMALGAS Turbine






� In a pumped storage the water is flowing through the turbine and the machine is generating when demand is high.

� When demand is low and electricity is cheap the generator (running as motor) drives the turbine, pumping water back into the reservoir

� Starting frequency converter needed to start-up the generator/motor

Pumped storage power plant


Application: LCI soft starter for 4 generators/motors


Agenda




� References � Energy savings case example


Case exampleHelsinki Energy, Finland

� Retrofit of fixed-speed motors withACS 1000 VSDs, operating four boilerfeedwater pumps (FWPs), each 4500 kW

Benefits:

� Improved power plant efficiency(as FWPs are one of the biggestenergy consumers in a power plant)

� Reduced maintenance costs


� An US university power plant installed a 1,000 hp ACS 1000 MV drive for its scrubber booster fan

� Energy efficiency improved by 25% against that of inlet vanes

� Energy saving: about 1’460’000 kWh/year

� Reduction of CO2 emissions: 730’000 kg/year

� Other benefits� Better process controllability� Less maintenance by soft starting� No more start-up problems

Case exampleUniversity of Illinois power plant, USA


� Refurbishment of the 280 MW boiler at block 6 of the GKM power plant

� Retrofitting 2 of 3 boiler feedwater pumps with ACS 1000 VSDs, by replacing the old hydraulic couplings (with poor efficiency)

� ABB scope of supply:

� 2 x water cooled ACS 1000 VSD incl. dry type transformers, 4000 kW

� General overhaul and star-delta reconnection of the 6kV motors

Benefits:

� 20 – 25 percent energy savings:around 12’000 MWh/year

� Reduction of CO2 emissions:10’000 t/year

Case example Grosskraftwerke Mannheim, Germany

Fully containerized solution


New 900 MW coal fired power station(Block 9) in the city of Mannheim

� Customer‘s goal: all major motors to be VSD controlled in order to optimize plant efficiency

� ABB scope of supply:

� 2 x 70% feedwater pumpsACS 5000W, rated for 21.5MW induction machines

� 12 x ACS 1000 in the power range of 800kW to 3000kW for- condensate pumps- cooling water pumps- district heating pumps- coal pulverizer fans

New reference Grosskraftwerke Mannheim, Germany


New reference ESKOM – Medupi Power Plant

New 4800 MW coal fired power plant, consisting of 6 blocks

� Variable speed driven condensate extractionpumps (each consiting of 6 blocks)

� 6 x air cooled ACS 5000 with integratedtransformer, each 1800 kW

Medupi construction progress April 2009 (source: www.eskom.co.za)

Medupi construction progress Dec. 2009 (source: www.eskom.co.za)


New reference ESKOM – Majuba, Kendal, Matimba Power Plant

LCI refurbishment project for 3 coal fired4000 MW power plants, each consitingof 6 blocks

� 6 x 3 feedwater pumps (12MW @ 6000rpm) per power plant

� 22 x LCI drives order

� ABB high speed machines, WMT 630


New referenceMühleberg Switzerland / Nuclear Power Plant

Refurbishment project, replacing two LCI feed water pump drives, 3.4 MW / 3000 rpm, delivered in 1987/88

• 2 x LCI feedwater pump drives, 3.4 MW

• 1 x ACS 5000 additional pump drive, 3.4 MW

• 2 x ACS 1000 reactor circulation pumpdrives, 1.1 MW


Agenda




� References� Energy savings case example


Payback of applying electrical variable speed drivesCase example

� Feedwater pump, average operating time / year = 8’000 h

� Average electrical power consumption = 4’000kW

� Resulting electrical energy demand = 32’000 MWh

� Energy savings due to applying VSD = 20%

� Resulting energy savings per year = 6’400 MWh

� Energy cost savings = 320’000 EURbased on el. energy costs of 5 ct/kWh

� resulting in a payback time of only two years

� total savings over 20 years lifetime = 5’760’000 EUR

� Additionally !

� Reduction of CO2 emissions of ~5’000 t/year


92%

6%2%

Lifetime costs of a VSD system

� Total investment costs < 6 % of the total lifetime costs

� Customer benefit:Big savings on energy consumption, not on investment costs

Energy costsInvestment costsMaintenance and overhaul costs

20 years total lifetime costs


Power GenerationEnergy Efficient Design of Auxiliary Systems in Fossil Fuel Power Plants

drives in power generation - abb group - automation and power

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