One Solution for Simulation of Steam Turbine Power

350MW350MW

Idea About Simulator

The global industry trend is to reduce all costs regardless of their origin. In electrical industry, one part of solutions for reducing the number of plant dropouts is system optimization and good personnel trainingpersonnel training.

• Simulators and training systems represent a modern method of training staff that operates in various sectors of a power plant (production, maintenance etc.) An inadequate training often leads to non-professional reactions in critical situations.

• Some of the advantages of such training systems are the possibility of a thorough analysis of a recorded event, the possibility to set the simulator to a state preceding a turbine trip or anotherrecorded event, the possibility to set the simulator to a state preceding a turbine trip or another critical situation and the analysis of various influences on the plants stability.

• The price of the insurance policy significantly diminishes if the personnel have been trained on a certified training system.

Simulator Usage

The turbine simulator consists of several hardware and software components and it is used for testing ofturbine governor and turbine protection:

• in the phase of installation

• during design and optimization of the algorithm

• for factory acceptance test

• during testing and putting into operation a complete integrated system on facility

• training of staff with the new system of regulation before the first turbine startup

Steam Turbine

Turbine parameters:Nominal power 350MWRated speed 3000rpmSteam pressure in front of turbine 180barIntermediate pressure 42.4barPressure behind LP chamber 6bar

Condensate steam turbine of 350MW, type 18-K-348, manufacturer ZAMECH (Elblag,Poland) is considered for the modeling approach. This turbine installed at Unit B2 of TPP“Kostolac B”, Drmno, Serbia.

Generator

Generator (nominal voltage 410kV, nominal power P = 410MW, cosφ=0.85) overgenerator breaker unit transformer (nominal power 410MW incoming voltage 410kVgenerator breaker, unit transformer (nominal power 410MW, incoming voltage 410kV,outgoing voltage 22kV) and main circuit breaker is connected with network. Auxiliary unittransformer is connected at generator voltage.

Turbine ModelTurbine model is designed so that it can fully complete simulation of important real process parameters. Overall model contains:

Boiler model,

HP, LP and start-up bypass station model,

Electro-hydraulic servo drive,

Model of control valves,

Reheter model,

Turbine mechanical power modelTurbine mechanical power model,

Generator model

Turbine Model

Structure of turbine-generator model

Turbine Model – steam flow characteristic

80

90

100 high-pressure flow characteristicintermediate-pressure flow characteristic

Nonlinear functions define

60

70

80 Nonlinear functions define

the flow of steam through HP valves depending on the HP valve position.

40

50[%]

Similarly, flow of steam through IPvalves is showed also These nonlinearfunction are the most important part ofmodel since it defines steam flow

20

30

model, since it defines steam flowlinearization through turbine. Values ofthese functions are obtained frommeasurements of steam flow and valve

i i k d i diff bi

0 10 20 30 40 50 60 70 80 90 1000

10

HP/IP l iti [%]

position, taken during different turbineoperating conditions.

HP/IP valves position [%]

Results – model VS real plant (verification)

2000

2500

3000 The comparison of the obtained parameters by the simulation showed satisfactory matching with real data.

1000

1500

2000

- max absolute error 1.8687%- mean absolute error 0 37665%

turbine speed SIMturbine speed ARH

g

0 1000 2000 3000 4000 5000 6000 7000 8000 90000

500

mean absolute error 0.37665%

Increasing turbine speed from a cold state with position of HP valves, IP

40

50 valves and LP bypass station

20

30

posi

tion

[%]

0 1000 2000 3000 4000 5000 6000 7000 8000 90000

10

time [s]

HP valve positionIP valve positionLP bypass position

Results – model VS real plant (verification)

160

180

200

120

140

160

MW

]

Increasing turbine power after sinhronization to power grid 80

100

120

ctric

pow

er [M

40

60

ele

electric power SIMelectric power ARH

0.9 0.95 1 1.05 1.1 1.15 1.2 1.25 1.3 1.35 1.40

20

x 104time [s]

Results – model VS real plant (verification)

3000

turbine speed SIMturbine speed ARH

2000

2500

m] - max absolute error 1.9185%

Comparative analysis of simulated and real turbine speed during turbine droopout

1000

1500

spee

d [rp

m

- mean absolute error 0.56801%

and speed reducing

500

1000

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

x 104

0

time [s]

Hardware – for real-time simulationsTo operate the model in real time it is used National Instruments PXI-1044 platform which consists of:• Embedded controller PXI-8105, that satisfies demands for real-time work. The used operating system is

LabView® 2009 Real Time v.9.0.• Multi-function acquisition card M-Series, type PXI-6289 has four 16-bit analog outputs, 16 differential analog inputs, 48 digital bidirectional channels and two pulse outputs with maximum output frequency of 80MHz.• Multi-function acquisition card M-Series, type PXI-6723 has 32 analogue outputs, 8 digital bidirectional channels and two pulse outputs with maximum output frequency of 20MHz.

Simulator user interface is situated on the computer, PC with MS Windows® operating system, which is separated from the real-time controller and it communicates with the real-time controller through a local area network.

Turbine governor & Simulator

Turbine

Simulator

governor

ConnectionConnection

Operation Panel for SimulationThe operation panel is used to:The operation panel is used to:

• start or stop the real-time simulation• set some digital or analog input variables• turn on certain system parts (bypass stations, generator breaker,...)

it i i l t t t i l h l t i t ti d f th t bi t• monitoring simulator output signals such as electric power, rotation speed of the turbine or steamturbine pressure

Conclusion• Complete training system realistically reflects the behavior of the real system in all operating modes,

• Simulator enables training and testing of the plant personnel without any risk to the actual turbineequipment and it is possible to simulate certain incidental states that rarely occurequipment and it is possible to simulate certain incidental states that rarely occur,

• More convenient to train staff how to behave in critical situations in the simulator than on real plant,

• This model can be integrated into other simulator tools,

• Further development of the described simulator will be reflected in the modeling of mechanicalmeasurements on the turbine (vibrations and shifts) and the temperature of the material in some parts ofturbine.

Contacts

Institute Mihajlo Pupinj pIMP Automation & Control Systems Ltd.

Process Automation Department

Volgina 15, Belgrade, Serbiag , g ,tel: +381 (11) 67 71 017fax: +381 (11) 67 82 885

е-mail: аutomatika@pupin.rsp pweb: www.pupin.rs