8/14/2019 Helsingin RevA

http://slidepdf.com/reader/full/helsingin-reva 1/2

Highlights

• Improvedpowerplant

efciency

• Reducedmaintenance

costs

Helsinki EnergyHelsinki Energy is one of theleading experts in the world inthe field of Combined Heat and 

Power (CHP) technology and oneo the biggest energy companiesproducing and distributing electricity  and district heat in Finland. Theenergy is mainly generated in thecompany’s own CHP power plants where a remarkable share o thefuel’s energy is used for districtheating, instead o condensing itby sea water.In 1990 Helsinki Energy was granted the UN International Environmental 

 Award for its pioneering and

determined work in developing CHPtechnology and the consequentimprovement o the city’s air quality.

Combined Heat & PowerThe basic indicator or eciency and environmental impact o powergeneration is the total efficiency 

achieved. The more eectively theplant is able to convert the uel’sthermal energy - either to electricity or to heat - the higher is theeciency o the plant. Combinedheat and power provides low costenergy and produces much lesscarbon dioxide than other powerplants.

Challenge As the loading o a power plantcan vary rom minimum load atnight time to peak load duringdaylight working hours, the plant’sprocesses have to be adjustedaccordingly. The processes, in theorm o liquid or gas low, aretypically driven by large electric

 A feedwater pump drive train: the

 gearbox in front, main pump to the 

 right, booster pump behind the

 2-shat induction motor.

Two o the our ACS 1000 splittable

cabinets installed in the switchboard 

 room.

Helsinki Energy, Hanasaari B power  

 plant, located by the seaside in the city 

o Helsinki. Its capacity is 220 MW or 

electricity and 445 MW for district heating

The power plant’s efciency is 85%.

 ACS 1000 variable speed drives improve efciency o CHP

power plant

Case Study 

Power generationHelsinki Energy, Finland

 Application: Boiler eed-water pump, 4500 kW (6030 hp)

8/14/2019 Helsingin RevA

http://slidepdf.com/reader/full/helsingin-reva 2/2

motors with the power demand ollowinganity laws. There are three main principlesto control the fow: either throttling it (1), oradjusting the pump speed by mechanical orelectrical slip (2) or directly with a requency converter (3).Driving the pumps with xed speed motorsand controlling them at partial loads either by throttling or mechanically by fuid couplingdecreases the power plant’s efficiency tremendously.

Originally, the Hanasaari power plant’sequipment was selected among the best avail-able technologies at the time o constructionto ulll the requirements o high availability and eiciency. However, since the time o construction, variable speed drive technology had taken a big leap orward. Even thoughthe old ASEA and Strömberg wound-rotormotors with slip recovery control systems operated very well, Helsinki Energy decided toupgrade them in order to reduce maintenance work and to urther improve the plant’seciency.

 Additionally suppliers were challenged by thelimitations o the existing building.

SolutionGiven the eciency problem o boiler eed- water pumps driven by xed speed motors atpartial loads, the most economic control isachieved with a variable speed drive system.

In the spring o 1999, Helsinki Energy orderedrom ABB our water-cooled ACS 1000 drivesystems with AMB 560 motors and oil-im-mersed 3-winding supply transormers.

The Hanasaari B power plant’s automationupgrade project was executed together with Helsinki Energy’s HelenEngineering thatspecializes in the design o energy productionand distribution equipment as well as in therelated project management. The aim o thesedesign and construction services is to supportthe protability o business operations

throughout the lie cycle o theequipment.

 As it was not possible to haul thecomplete requency convertercabinet with a total length o only 4.7m into the building withoutmajor destruction, ABB designedand delivered the ACS 1000 drives with splittable cabinets that ft into  the elevator.

Benefts

Powerplantefciency

Boiler eed-water pumps are oneo the biggest energy consumersin a power plant. Operating eed- water pumps with variable speeddrives can signicantly increasethe eciency o a power plant.

Outside the boiler eed-water

pump’s nominal range, thecapacity needs to be sucient tohandle rare but possible abnormalsituations in a boiler that operatesunder very high pressure.Depending on the local authorities’requirements, the pump - and thesupplying drive - have to becapable o delivering 10-25 %over pressure or overfow. As aconsequence, the drive operatespractically all the time underpartial load, a situation where

a variable speed drive oersthe best available eciency.

ReducedmaintenanceUsing ACS 1000 variable speeddrives as level control deviceo eed-water drums can reducemaintenance o the eed-waterthrottling valves. These haven’tnecessarily been designed or theull pressure dierential resultingrom throttling the fow with xedspeed motors.

FurthersavingsFurther savings can be achievedby designing a new generatingunit’s electricity distribution network or eed-water pumpsoperated by requency converters. As main loads, their across-the-line starting behavior typically impacts on - depending onimpedance o the plant transormer- capital cost, either througha more expensive transormer,through higher ault currents, ora more expensive switchboard. Variable speed drives as suchact as sot starters and causeno starting current peaks.

The ACS 1000 can be connected via the most common eldbusesto become an integral part o theplant’s control system.

 ABB Switzerland LtdMedium Voltage DrivesCH-5300 Turgi / Switzerland  Tel +41 58 589 27 95Fax +41 58 589 29 84Email mvdrives@ch.abb.com

www.abb.com/drives    3   B

   H   T   4   9   0   4   1   3   R   0   0   0   1 ,   R  e  v .   A

   ©    C

  o  p  y  r   i  g   h   t   2   0   0   8   A   B   B .   A   l   l  r   i  g   h   t  s  r  e  s  e  r  v  e   d .

   S  p  e  c   i   f  c  a   t   i  o  n  s  s  u   b   j   e  c   t   t  o  c   h  a  n  g  e  w   i   t   h  o  u   t  n  o   t   i  c  e .

ACS 1000 key data

• Inverter type:

Three-level Voltage Source

Inverter (VSI)

• Power range:

 Air cooling: 315 kW – 2 MW 

Water cooling: 1.8 – 5 MW 

• Output voltage:

2.3, 3.3, 4.0, 4.16 kV 

(optional: 6.0 – 6.6 kV 

 with step-up transormer)

• Maximum output requency:

66 Hz (optional: 82.5 Hz)

• Converter eciency:

typically >98%

• Type o motor: induction

motor

Helsinki EnergyHelenEngineeringFIN-00090 Helsinki / Finland  Tel +358 9 - 617 24 30Fax +358 9 - 617 24 42Email mikko.laakkonen@helsinginenergia.f

www.helsinginenergia.f