Bedeutende Energieeinsparungen und Reduktion der Emissionen

© ABB Group May 3, 2023 | Slide 1

Significant energy savings and reduced emissions in power plants through variable speed drives

Franz Frank (ABB Switzerland Ltd) – PowerGen Europe 2010


Agenda

Savings potential by using variable speed drives What is a Variable Speed Drive (VSD) system ?

Variable speed drive applications in power stations Comparison of process control methods with respect to efficiency

References Payback calculation – case example

ABB medium voltage drives portfolio


Savings potential by using variable speed drivesElectrical aux. consumption in a coal fired power plant

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

Processes driven by electric motors 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 (mounting up to 8 – 12 MEUR capital costs)

Auxiliary consumption

Electric Motors

Others (HVAC, lighting, etc.)


What is a Variable Speed Drive (VSD) System ?

Consisting of input transformer, frequency converter (also called ‘drive’) and motor

Controlling motor speed, torque and power On process level control of flow, pressure, level, etc.

always with best possible efficiency !

Usual scope of a VSD system

Input Frequency MotorTransformer Converter


Main components of a VSD systemInput transformer

Main purpose

Voltage matching

Galvanic isolation of the VSD system from the medium voltage mains supply

Possible designs

Dry type transformers

Oil immersed transformers

Efficiencies >99 % possible today,e.g. using ABB EcoDry99plus design


Main components of a VSD system Frequency converter

Main purpose

Continuous adjustment of output voltage and frequency

Benefits Permanent operation of the motor at

its optimum duty point best possible efficiency

Heavy duty start without overcurrent no more network dips

Increased system lifetime due to reduced mechanical and thermal stress of the driven equipment

Types of design

Air cooled (up to ~7 MVA)

Water cooled (from ~2 MVA on)

Efficiency typically >98 %


M

3 ~

Types of design Air and water cooled Forced or self ventilated

Induction motors Power range: up to ~22 MW Efficiencies of >97 % possible today

Synchronous motors Power range: >100 MW Efficiencies >98 % possible

Efficiency optimization Minimized air gap Low loss bearings High quality material Optimized air flow

increased lifetime expectancy

Main components of a VSD system Medium voltage motor


Agenda






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


H2 = 0,64

Q2 =

0,7

Q2 =

0,7

H2 = 1,27

89.027.1*7.0P

Power demand Throttling control versus VSD control

H

Q

H1 = 1Q

1 =

1

45.064.0*7.0P

Q

H1 = 1

Q1 =

1

HThrottling 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

Pow

er D

eman

d

Bypass Control

Throttling Control

Hydro Coupling

VSD Control

Theoretical PowerDemand

Energy savings potential of VSD Control versus Throttling Control


Agenda






Case example Grosskraftwerke Mannheim, Germany

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 6 kV motors

Benefits 20 – 25 percent energy savings:

around 12’000 MWh / year

Reduction of CO2 emissions:10’000 t / year

Container Solution


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 EUR

based 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


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


Agenda






Product portfolioABB Medium voltage drives

Motor [MW] 100

50

20

10

5

2

1

0.3151.8 2.3 3.3 4.0 4.16 6.0 6.9 10.0 Motor [kV]

LCI

6.6

ACS 1000

ACS 5000

AC

S 60

00

ACS 2000

LCI

ACS 2000


ACS 1000, ACS 1000i

3-Level Voltage Source Inverter (VSI) Air and water cooling Power range: 315 kW – 5 MW Output voltage range: 2.3 – 4.16 kV ACS 1000-Air optionally with integrated

input transformer and feeding contactor

Portfolio

ACS 1000i

ACS 1000Water cooled


ACS 5000

5-Level Voltage Source Inverter (VSI) Air and water cooled Power range: 2 MW – 22 MW

(up to 30 MW on request) Output voltage range: 6.0 – 6.9 kV ACS 5000-Air optionally with integrated

input transformer

Portfolio

ACS 5000Air cooled

ACS 5000Water cooled


ACS 2000ABB’s new member of the ACS family

5-level VSI with Active Front End Available for operation with or without

input transformer Air cooled Power range: 400 kVA – 1 MVA

(higher power to follow) Motor voltage range: 6.0 – 6.9 kV

Portfolio

ACS 2000


ACS 2000 converter topology Line supply connection flexibility

Direct to Line Configuration Lower investment costs Less space required Quick installation and commissioning

Connection to external transformer For matching supply line to VSD

voltage Galvanic isolation from supply line

PortfolioMotor friendly Output


Documents

Bedeutende Energieeinsparungen und Reduktion der Emissionen