3. IJMPERD - CONDITION MONITORING OF TURBO GENERATORS …

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www.tjprc.org [email protected] CONDITION MONITORING OF TURBOGENERATORS OF A THERMAL POWER PLANT USING FUZZY LOGIC CH. SAI AMULYA 1 & M. SRINIVASA RAO 2 1 M.Tech Student, Department of Mechanical Engineering, GMRIT, Rajam, Srikakulam, Andhra Pradesh ,India 2 Professor, Department of Mechanical Engineering, GMRIT, Rajam, Srikakulam, Andhra Pradesh, India ABSTRACT Turbogenerator is one of the main components in thermal power plant and its maintenance plays avital role in many applications. Condition monitoring is the process of determining the condition of machinery while in operation which lessens the probability of failure by allowing the maintenance to be scheduled.In this work,vibration monitoring analysis of steam turbo generators is studied. In this study Fuzzy Logic Toolbox in MATLAB is used for analysing the health condition of the turbo generators considering displacement and velocity as parameters.For this purpose, a thermal power plant (TPP) of the Visakhapatnam Steel Plant has been chosen as a case study.This type of analysis is very useful for assessing the condition of complex systems of thermal power plants. KEYWORDS:Condition Monitoring, Vibration Analysis, Thermal Power Plant, Fuzzy Logic, Health Condition Received: Jun 19, 2016; Accepted: Jul 14, 2016; Published: Jul 19, 2016; Paper Id.: IJMPERDAUG20163 INTRODUCTION A condition monitoring program plays an essential role in industries that have plant machinery. It gives the health condition of the components of the power system. There are various types of condition monitoring techniques depending on the industry and application which include vibration analysis, signal processing, analysis, acoustic analysis, etc. Vibration condition monitoring analysis is carried out on Turbogeneratorsin TPP, Visakhapatnam Steel plant. Bently Nevada 3500 series condition monitoring vibration system is used to measure the vibration. Cheng et al.[1] stated that fuzzy distributions were used instead of the classical probability distribution for the components, and calculate the fuzzy numbers to solve the fuzzy system reliability via non-linear programming techniques. He demonstrated that this approach and its computation algorithm are efficient and simple to implement.Shaaban et.al[2] proposed a decision tree method to improve steam turbine generator fault diagnosis. He stated that the method is an effective fault data disposal method for steam turbine generator fault diagnosis. Pavan Kumar et al.[3] stated that vibration-monitoring technique is very powerful tool for assessing the condition of rotary machine and if used with proper precautionary methods it can reduce the breakdowns of power plants. Lun et al.[4] described a reliable condition monitoring system to prevent machinery malfunction and which predicts the useful life of the machine. For this purpose a bearing case from NASA data repository was taken as a case study to validate the feasibility of the proposed method which showed that degradation of bearing can be effectively monitored. Original Article International Journal of Mechanical and Production Engineering Research and Development (IJMPERD) ISSN(P): 2249-6890; ISSN(E): 2249-8001 Vol. 6, Issue 4, Aug 2016, 25-34 © TJPRC Pvt. Ltd

Transcript of 3. IJMPERD - CONDITION MONITORING OF TURBO GENERATORS …

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CONDITION MONITORING OF TURBOGENERATORS OF A

THERMAL POWER PLANT USING FUZZY LOGIC

CH. SAI AMULYA 1 & M. SRINIVASA RAO 2

1M.Tech Student, Department of Mechanical Engineering, GMRIT, Rajam, Srikakulam, Andhra Pradesh ,India 2Professor, Department of Mechanical Engineering, GMRIT, Rajam, Srikakulam, Andhra Pradesh, India

ABSTRACT

Turbogenerator is one of the main components in thermal power plant and its maintenance plays avital role in

many applications. Condition monitoring is the process of determining the condition of machinery while in operation

which lessens the probability of failure by allowing the maintenance to be scheduled.In this work,vibration monitoring

analysis of steam turbo generators is studied. In this study Fuzzy Logic Toolbox in MATLAB is used for analysing the

health condition of the turbo generators considering displacement and velocity as parameters.For this purpose, a

thermal power plant (TPP) of the Visakhapatnam Steel Plant has been chosen as a case study.This type of analysis is

very useful for assessing the condition of complex systems of thermal power plants.

KEYWORDS:Condition Monitoring, Vibration Analysis, Thermal Power Plant, Fuzzy Logic, Health Condition

Received: Jun 19, 2016; Accepted: Jul 14, 2016; Published: Jul 19, 2016; Paper Id.: IJMPERDAUG20163

INTRODUCTION

A condition monitoring program plays an essential role in industries that have plant machinery. It gives

the health condition of the components of the power system. There are various types of condition monitoring

techniques depending on the industry and application which include vibration analysis, signal processing,

analysis, acoustic analysis, etc. Vibration condition monitoring analysis is carried out on Turbogeneratorsin TPP,

Visakhapatnam Steel plant. Bently Nevada 3500 series condition monitoring vibration system is used to measure

the vibration.

Cheng et al.[1] stated that fuzzy distributions were used instead of the classical probability distribution

for the components, and calculate the fuzzy numbers to solve the fuzzy system reliability via non-linear

programming techniques. He demonstrated that this approach and its computation algorithm are efficient and

simple to implement.Shaaban et.al[2] proposed a decision tree method to improve steam turbine generator fault

diagnosis. He stated that the method is an effective fault data disposal method for steam turbine generator fault

diagnosis.

Pavan Kumar et al.[3] stated that vibration-monitoring technique is very powerful tool for assessing the

condition of rotary machine and if used with proper precautionary methods it can reduce the breakdowns of

power plants. Lun et al.[4] described a reliable condition monitoring system to prevent machinery malfunction

and which predicts the useful life of the machine. For this purpose a bearing case from NASA data repository was

taken as a case study to validate the feasibility of the proposed method which showed that degradation of bearing

can be effectively monitored.

Original A

rticle International Journal of Mechanical and Production Engineering Research and Development (IJMPERD) ISSN(P): 2249-6890; ISSN(E): 2249-8001 Vol. 6, Issue 4, Aug 2016, 25-34 © TJPRC Pvt. Ltd

26 Ch.Sai Amulya & M. Srinivasa Rao

Impact Factor (JCC): 5.7294 NAAS Rating: 2.45

Ariavie et al.[5] developed a Fuzzy Inference System for predicting the performance of steam turbine based on analyzing

the generated data for different inlet and outlet conditions. The result of efficiency for different types of membership

functions and defuzzification method was obtained. He stated that Fuzzy logic can be used to effectively predict the

performance of a steam turbine.Ignatio et al. [6]described how online remote condition monitoring increases the

maintenance system. His findings specified the several aspects of online remote condition monitoring system which

thermal power plants can consider to improve on plant safety.Shen et al.[7] developed a diagnostic model algorithm based

on the Fuzzy logic modeling method that estimated engine health condition analysis for prediction of engine operation

behavior. The resulted models were nonlinear in nature and could predict the performance and could be examined for

abnormality.

Yang et al.[8] proposed integrated fuzzy multiple criteria decision making (MCDM) method for vendor selection

problem that included triangular fuzzy numbers,interpretive structural modeling, the fuzzy analytical hierarchy process,

non-additive fuzzy integral to determine the best vendor based on fuzzy weights with fuzzy synthetic utilities.Rui

Francisco et al.[9] described a detection method for rotating machine failures based on a change in vibration pattern. He

stated that a Fuzzy System was adjusted to detect and analyze the evolution of severity and decision making about

maintenance of rotating machines.Malay et al. [10] explained that a Fuzzy base maintenance system (FBMS) has been

considered for his study taking frequency and downtime asinput parameters because fuzzy logic technique is best suited for

adapting multi variable parameters. His study aimed at reducing the causes of breakdowns and this model can be used to

analyze maintenance practice cost and maintenance time.

From the above literature survey, it was observed that as the time passes the health condition of the machine,

occurrence frequency of failures and its effect vary. Hence to mitigate these limitations, vibration analysis technique has

performed in this work for condition monitoring of turbo generators in thermal power plant of the Visakhapatnam Steel

plant. After that the results obtained from the vibration analysis have been further analysed by using Fuzzy logic tool in

MATLAB to evaluate the health condition of turbo generators.In this work Visakhapatnam Steel Plant has been taken as a

case study for the analysis.

CONDITION MONITORING OF TURBOGENERATORS USING VIBRA TION ANALYSIS

Panel In this work the displacement and velocity of five turbo generators are collected from maintenance log

books of the thermal power plant. The health condition of five turbo generators is analysed and modelled by using Fuzzy

tool box in MATLAB as described below.

Condition monitoring of turbogenerators in Visakahapatnam steel plant is carried out by Bently Neveda 3500

series vibration monitoring system (BNVMS) as shown Figure 1.The vibration probes are connected to the turbogenerator

bearings at four positions i.e., at turbine front, turbine rear, geneator front and generator rear. Voltage from BNVMS is sent

to all probes and the vibration is taken in vertical, horizontal and axialdirections at all four positions which is sent to the

Distributed Control System (DCS). The DCS connected to Human Machine Interface takes the vibration trends at each

position of the system at every interval of time and the technical data of the system is also displayed.

Condition Monitoring of Turbogenerators of a Thermal Power Plant Using Fuzzy Logic 27

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Figure 1: Bently Neveda Vibration Monitoring System in TPP, Vizag Steel Plant

By using the Bently NevedaVibration Monitoring System, the vibration data of turbo generators were collected

from the maintenance log books. Velocity and displacements of turbo generators are taken in three directions i.e., axial,

vertical and horizontal directions along turbine front,turbine rear, generator front and generator rear positions. The sample

data of TG 1 is shown in Table 1.

Table 1: Displacements and Velocities at Different Positions on TG 1

TG 1 Position Displacement Velocity

Vertical

TF 22 1.7

TR 18 1.5

GF 24 2.1

GF 23 2.1

Horizontal

TF 15 2.3

TR 41 4.6

GF 35 3.9

GF 16 1

Axial

TF 21 1.5

TR 31 3.6

GF 42 4.9

GF 27 3.3 CONDITION MONITORING OF TURBO GENERATORS USING FUZZ Y LOGIC

In this work, the data obtained from Bently NevedaVibration Monitoring System the displacement and velocity of

turbo generators are further analysed using fuzzy logic technique.The displacement and velocity of five turbo generators

are taken as the input parameters and health condition is taken as the output parameter in the fuzzy logic. In fuzzification,

each input parameter has sub divded into five triangular membership functions and the output parameter has sub divided

into trapezoidal membership functions. Fuzzy rules have been developed for each parameter and finally, after the

defuzzifcation process the health condition of each turbo generator has evaluated.

THE FUZZY SYSTEM

The fuzzy inference system contains following five steps : (i) Fuzzification (ii) Rule base (iii) Fuzzy inference

system (iv) data base and (v) Defuzzification. The fuzzy inference system is shown in Figure 1.

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The function of each block is mentioned briefly as below

A fuzzification interface which converts the crisp

consisting a number of fuzzy if-then rules

inputs (features in the case of fuzzy classification) to outputs

fuzzy sets used in the fuzzy rules.A defuzzification interface which converts the fuzzy results of the inference into a crisp

output.

FUZZIFICATION OF INPUT AND OUTPUT

The application of fuzzy logic is to identify the variation in ranges of input and output variables. Then the range of

each process variable is divided into group of fuzzy subsets. Each fuzzy sub set is given a proper name and assigned a

member ship function. The membership function is assigned without depending on the results of the experiments. In

general membership functions are classified into trapezoidal, triangular etc. The Mamdani type of Fuzzy Inference System

was chosen for this work. The displacement and velocity of the each turbogenerator are taken as the input parameters while

the health condition is taken as the output of the Fuzzy Inference System (FIS) for vibration monitoring of turbo

generators. The fuzzification process of a fuzz

Displacementrange of TG 1:The maximum to and fro motion of the vibrating part when force is applied;

measured in “Microns”. The displacement is in the range of {0 50} from dat

membership functions as Very high, High, Medium

{25 50}, {37.5 62.5}.

Ch.Sai Amulya

The function of each block is mentioned briefly as below :

A fuzzification interface which converts the crisp inputs into degrees of match with linguistic values

then rules.A fuzzy inference system (FIS) is a system that uses fuzzy set theory to map

in the case of fuzzy classification) to outputs. Database which defines the membership functions of the

A defuzzification interface which converts the fuzzy results of the inference into a crisp

Figure 2: Fuzzy Inference System

FUZZIFICATION OF INPUT AND OUTPUT PARAMETERS

The application of fuzzy logic is to identify the variation in ranges of input and output variables. Then the range of

each process variable is divided into group of fuzzy subsets. Each fuzzy sub set is given a proper name and assigned a

ship function. The membership function is assigned without depending on the results of the experiments. In

general membership functions are classified into trapezoidal, triangular etc. The Mamdani type of Fuzzy Inference System

e displacement and velocity of the each turbogenerator are taken as the input parameters while

the health condition is taken as the output of the Fuzzy Inference System (FIS) for vibration monitoring of turbo

generators. The fuzzification process of a fuzzy logic system shown below in Figure 3

Figure 3 Fuzzification Process of TG 1

Displacementrange of TG 1:The maximum to and fro motion of the vibrating part when force is applied;

measured in “Microns”. The displacement is in the range of {0 50} from data table 1 and is classified into

membership functions as Very high, High, Medium, Low and Very Low with ranges {-12.5 12.5},

Ch.Sai Amulya & M. Srinivasa Rao

NAAS Rating: 2.45

inputs into degrees of match with linguistic values. Rule base

A fuzzy inference system (FIS) is a system that uses fuzzy set theory to map

se which defines the membership functions of the

A defuzzification interface which converts the fuzzy results of the inference into a crisp

The application of fuzzy logic is to identify the variation in ranges of input and output variables. Then the range of

each process variable is divided into group of fuzzy subsets. Each fuzzy sub set is given a proper name and assigned a

ship function. The membership function is assigned without depending on the results of the experiments. In

general membership functions are classified into trapezoidal, triangular etc. The Mamdani type of Fuzzy Inference System

e displacement and velocity of the each turbogenerator are taken as the input parameters while

the health condition is taken as the output of the Fuzzy Inference System (FIS) for vibration monitoring of turbo

Displacementrange of TG 1:The maximum to and fro motion of the vibrating part when force is applied;

and is classified into five triangular

12.5 12.5}, {0 25}, {12.5 37.5},

Condition Monitoring of Turbogenerators of a Thermal Power Plant Using

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Figure 4:

Velocity range of TG 1:The maximum speed at which the motion takes place in a vibrating part;

“mm/sec”. The velocity parameter is in the range of {0 20} from data table 1 and

membership functions as Very high, High, Medium,

25}.

Figure

Health condition of TG 1: The range of health condition is considered between {0 10} and

trapezoidal membership functions as Very good, good, fair, rough and Very rough.with ranges {

7.2}, {5.3 9.7}, {7.8 12.2}.

Condition Monitoring of Turbogenerators of a Thermal Power Plant Using Fuzzy Logic

4: Membership Functions of Displacement of TG 1

of TG 1:The maximum speed at which the motion takes place in a vibrating part;

“mm/sec”. The velocity parameter is in the range of {0 20} from data table 1 and is classified into

membership functions as Very high, High, Medium, Low and Very Low with ranges {-5 5}, {0 10}, {5 15},

Figure 5: Membership Functions of Velocity of TG 1

Health condition of TG 1: The range of health condition is considered between {0 10} and

membership functions as Very good, good, fair, rough and Very rough.with ranges {

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of TG 1:The maximum speed at which the motion takes place in a vibrating part; measured in

is classified into five triangular

5 5}, {0 10}, {5 15}, {10 20}, {15

Health condition of TG 1: The range of health condition is considered between {0 10} and is classified into five

membership functions as Very good, good, fair, rough and Very rough.with ranges {-2.2 2.2}, {0.3 4.7}, {2.8

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Impact Factor (JCC): 5.7294

Figure 6: Membership

RULE EVALUATION

The relationship between input and the out

fuzzy rules. If all the fuzzy rules are saved in a data base, a fuzzy rule base will be established. The number of fuzzy rule

in fuzzy system is related to the number of fuzzy set for ea

7. In this paper two input parameters are taken

based on if-then statement to describe this model.

Figure

DEFUZZIFICATION

The final step is the defuzzification process. It is a process of converting fuzzification value to an equivalent crisp

value of actual use. This process is based on the idea of deriving a crisp value

the collection of membership function values to a single scalar quantity.From the defuzzification process the health

condition of TG 1 at displacement, velocity

of TG 1 is said to befairas shown in Figure 8.

Ch.Sai Amulya

Membership Functions of Health Condition of TG

The relationship between input and the output in fuzzy system is given by a set of statements which are called

fuzzy rules. If all the fuzzy rules are saved in a data base, a fuzzy rule base will be established. The number of fuzzy rule

in fuzzy system is related to the number of fuzzy set for each input variable. The fuzzy rules for TG 1 are shown in Figure

7. In this paper two input parameters are taken each has five subdivisions and one hundred twenty five rules rules are taken

then statement to describe this model.

Figure 7: Rules For Membership Functions of TG 1

The final step is the defuzzification process. It is a process of converting fuzzification value to an equivalent crisp

value of actual use. This process is based on the idea of deriving a crisp value for a fuzzy function. Defuzzification reduces

the collection of membership function values to a single scalar quantity.From the defuzzification process the health

condition of TG 1 at displacement, velocity range of {25 10} is {5}. From the defuzzification

Figure 8.

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NAAS Rating: 2.45

TG 1

put in fuzzy system is given by a set of statements which are called

fuzzy rules. If all the fuzzy rules are saved in a data base, a fuzzy rule base will be established. The number of fuzzy rules

ch input variable. The fuzzy rules for TG 1 are shown in Figure

twenty five rules rules are taken

The final step is the defuzzification process. It is a process of converting fuzzification value to an equivalent crisp

for a fuzzy function. Defuzzification reduces

the collection of membership function values to a single scalar quantity.From the defuzzification process the health

range of {25 10} is {5}. From the defuzzification process the health condition

Condition Monitoring of Turbogenerators of a Thermal Power Plant Using

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Turbo Generator 1

RESULTS & DISCUSSIONS

The defuzzification process as performed in the previous section has been performed

and the obtained results are incorporated

Turbo Generator 2

From the defuzzification process the health condition of TG 2 at displacement, velocity

From the defuzzification process the health condition of TG 2 is said to be fair.

Turbo Generator 3

Condition Monitoring of Turbogenerators of a Thermal Power Plant Using Fuzzy Logic

Figure 8: Defuzzified Valuesof TG 1

defuzzification process as performed in the previous section has been performed

results are incorporated from Figure 9 to Figure 12.

Figure 9: Defuzzified Valuesof TG 2

From the defuzzification process the health condition of TG 2 at displacement, velocity

the defuzzification process the health condition of TG 2 is said to be fair.

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defuzzification process as performed in the previous section has been performed for other turbo generators

From the defuzzification process the health condition of TG 2 at displacement, velocity range of {75 10} is {5}.

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Impact Factor (JCC): 5.7294

From the defuzzification process the health condition of TG 3 at displacement, velocitydefuzzification process the health condition of TG 3 is said to be fair.

Turbo Generator 4

From the defuzzification process the health condition of

From the defuzzification process the health condition of TG 4 is said to be fair.

Turbo Generator 5

From the defuzzification process the health condition of TG 5 at displacement, velocity

From the defuzzification process the health condition of TG 5 is said to be fair.

Ch.Sai Amulya

Figure 10: Defuzzified valuesof TG 3

From the defuzzification process the health condition of TG 3 at displacement, velocity range of {50 10} is {5}. From the defuzzification process the health condition of TG 3 is said to be fair.

Figure 11: Defuzzified Valuesof TG 4

From the defuzzification process the health condition of TG 4 at displacement, velocity

defuzzification process the health condition of TG 4 is said to be fair.

Figure12: Defuzzified Valuesof TG 5

From the defuzzification process the health condition of TG 5 at displacement, velocity

defuzzification process the health condition of TG 5 is said to be fair.

Ch.Sai Amulya & M. Srinivasa Rao

NAAS Rating: 2.45

range of {50 10} is {5}. From the

TG 4 at displacement, velocity range of {125 10} is {5}.

From the defuzzification process the health condition of TG 5 at displacement, velocity range of {25 10} is {5}.

Condition Monitoring of Turbogenerators of a Thermal Power Plant Using Fuzzy Logic 33

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CONCLUSIONS

Vibration Monitoring and Analysis using Fuzzy tool box is the easiest way to analyse the complex systems.In this

work turbogenerators of thermal power plant are taken as a case study and a brief description of how to fuzzy the vague

condition monitoring data to get the health condition of the system easily than manual technique has been performed. In

this work, vibration monitoring analysis of steam turbo generators is studied. In this study Fuzzy Logic Toolbox in

MATLAB is used for analysing the health condition of the turbo generators considering displacement and velocity as

parameters. For this purpose, a thermal power plant (TPP) of the Visakhapatnam Steel Plant has been chosen as a case

study.by using fuzzy logic, the vibration analysis data has been further analysed. The obtained results shows that exact

condition monitoring of turbo generators with less effort than the conventional vibration analysis. This type of analysis is

very useful for assessing the condition of complex systems of thermal power plants.

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