Effect of HFTID Controller on the Stability of Thermal Power Generator Anhuman Sehgal, Japreet Kaur, Parveen Lehana 2 Department of Electrical Engineering, Baba Banda Singh Bahadur Engineering College, PUNJAB, INDIA 2 Department of Phyic and Electronic, Univerity of Jammu, Jammu, J&K, INDIA # Email addre: anhumanehgal.ehgal@gmail.com Abtract In power ytem the active and reactive power demand are never teady and they are continually changing with the riing or falling trend of load demand. Steam input to turbo-generator (or water input to hydro-generator) mut be regulated continuouly to match the active power demand in cae of falling or riing trend of load demand failing which reult in conequent change in frequency which i highly undeirable (maximum permiible change in frequency i - 0.5 Hz).We may note that the frequency i affected mainly due to the change in real power while the reactive power i le enitive due to the change in frequency and depend only on voltage magnitude. Thu, real and reactive power i controlled eparately. The load frequency control (LFC) loop which we had taken for our dicuion control the real power and frequency only. Thi Paper preent, the effect of HFTID on the tability of thermal Power generator. In thi tudy hybrid fuzzy-pid i ued which i uually called in general Hybrid Fuzzy Tilt Integral Derivative Controller thi enhance the robutne and performance of the. Two performance parameter were ued for the comparion. Firt one being the ettling time and other i the overhoot of the frequency deviation were compared. Keyword - Area control error; fuzzy control; load frequency control; HFTID I. INTRODUCTION Energy play a vital role in any country economy. Day by day the energy conumption i increaing very rapidly. The tandard of living of a given country can be directly related to per capita energy conumption. In the preent cenario, every country meet it energy need from different ource available. Some major ource of energy are dicued below:- Solar energy can be a major ource of power becaue Sun energy can be utilized a thermal and photovoltaic. When we talk about olar photovoltaic (SPV) application thi energy can be ued in SPV lighting Sytem, olar powered drive (Solar water pumping ytem, olar vehicle), building integrated photovoltaic (BIPV). But o far it could not be developed on a large cale due to certain limitation a it i expenive and intallation cot i more, efficiency i very leer, weather dependent and only available in day time. Wind energy can be economically ued for the generation of electrical energy. Wind energy can be utilized to run a wind mill, which in turn drive a generator to produce electricity. Wind energy had certain merit a dicued: due to the availability of wind everywhere in the world, the greatet advantage of electricity generation from wind i that it i renewable and not depleted with the ue like foil fuel; village in remote area particularly in INDIA are till in dark. But due to thi technology electricity cab ne provided in any remote area. But it ha certain demerit alo a dicued: thi ource of power i non-teady and unreliable a there are wide variation in peed and direction of wind, favorable wind are available only in few geographical location. Hydro energy can alo be a major ource of power becaue water i available in abundant on earth. The kinetic energy of the moving tream while falling from the top end of the dam can be ued to run a turbine, which in turn drive a generator to produce electricity. Hydro energy had certain merit a dicued: Water Power i quite cheap where water i available in abundance and the operating cot of hydroelectric power plant are quite low.but it ha certain demerit alo a dicued: capital cot of hydro hydroelectric power plant i higher and it take coniderable long time for the erection of uch plant. Energy from foil fuel can alo be utilized to generate electricity like in thermal, nuclear and dieel power plant. In thermal power plant coal i burned to produce heat which in turn evaporate the water then through nozzle team produced while coming out of the nozzle hit the turbine a the reult turbine rotate which in turn drive the generator to generate electricity. Thermal power plant had certain merit a dicued: Overall capital cot i leer than that for hydro plant, occupy le pace compared to hydro and can be located very conveniently near the load centre. But it ha certain demerit alo a dicued: Maintenance and operating cot are high and the preence of environmental hazard due to dut and hot temp in the plant were alo enormou. Power ytem operation conidered o far wa under the condition of teady load. But in actual both active and reactive power demand are never teady they continually change with riing or falling trend of load demand. So, input to the generator (team input to turbo-generator or water input to hydrogenerator) mut be continuouly upplied to match the real power demand, if not a a reult the machine peed will vary with conequent change in frequency which i highly undeirable(max. permiible change in frequency i - 0.5 Hz). A manual regulation i not feaible, o automatic generation control a dicued in Section III for ingle area ytem and voltage regulation equipment mut be intalled on each generator, in order to reduce the problem of tabilization in power ytem which further improve the voltage and 7 Anhuman Sehgal, Japreet Kaur, and Parveen Lehana, Effect of HFTID on the tability of thermal power generator,, Volume 2, Iue 3, pp. 7-2, 206.
frequency of upply within the permiible limit. So for automatic generation control we need different which tabilize the ytem repone due to diturbance in a hort period of time. Different technique of tabilization have been dicued in Section-II. II. TECHNIQUES OF STABILIZATION Different had been ued now day for automatic generation control and voltage regulation for generator. Some of them are a follow:-. PI Controller: - Conventional Proportional plu Integral (PI) make the ytem repone to be teady tate in the farm of frequency deviation, but it exhibit poor dynamic performance (uch a no. of ocillation and more ettling time) a dicued in equation () t u( t) K e( t) k e( ) d p i () 0 2. PID Controller: - A Proportional Integral Derivative (PID Controller) i a control cloed loop feedback mechanim ytem a dicued in (equation 2). It i widely ued in indutrial control Sytem a hown in Fig.. It exhibit good dynamic performance (uch a no. of ocillation and etting time) and i better a compared to PI Controller. t de u( t) K pe( t) ki e( ) d Kd (2) 0 P Proportional Gain I S Input Integral Gain Integrator Output SUM D N - Derivative Filter Co-efficient Gain S Filter Fig.. Simulation model of PID. 3. Fuzzy Logic Controller: - In the preent cenario Fuzzy Logic Control ytem application become very ueful. The Fuzzy logic a hown in Fig. 2. i framed by the combination of different interface named a fuzzification interface, the inference rule deign interface and defuzzification interface. It exhibit very good dynamic performance and i better a compared to PI and PID. 4. HFTID Controller: - A Hybrid Fuzzy-TID (Tilt-Integral- Derivative) Controller i a new approach to get the better reult a compare to the PI, PID and Fuzzy Controller. In a PID Type Compenator, where the proportional compenating unit i replaced by a compenator deigned to have a tranfer function denoted by /S (/n). Thi i called Tilt Compenator. So the entire compenator act a a Tilt- Integral-Derivative (TID) Compenator a hown in Fig. 3. It exhibit very good dynamic performance a compared to PI, PID and Fuzzy Controller a hown in Fig. 4. Input du Derivative Integrator Fuzzy Logic Controller -k- -kki (u())^ (/n) Fcn Integrator Fig. 3. Simulation model of HFTID. TID db TD PID PID Fig. 4. Graphical repreentation of PID and TID. III. THEORY OF AGC 30 20 0 Degree Output To increae the reliable and uninterrupted power upply, there i a neceity to maintain the certain parameter of the power ytem. In thi tudy the main attention i given to the frequency deviation, peak overhoot and ettling time of a thermal power ytem. Normally, thermal ytem conume bae load and hydro ytem for peak load, due to eaine in control. The fluctuation of load in thee ytem i very common, which can either reduce their efficiency or may indulge the ytem to behave in an abnormal manner or may damage it, but thee iue can be prevented by the ue of different in order to make the ytem repone to different in order to make the ytem repone to be teady tate. The which are commonly ued now day are conventional PI and fuzzy logic Automatic generation control (AGC) i defined a the controlling of the regulation of controllable generator within a certain controllable limit with reference to the change in ytem frequency o a to maintain the teady tate ytem frequency. To maintain the ytem frequency to be teady tate AGC play an very important role and alo cheduled the ytem parameter value during normal period. The ynchronization of different ytem to interconnected ytem In du Derivative Fuzzy Logic Controller Fig. 2. Simulation model of FLC. Out 8 Anhuman Sehgal, Parveen Lehana and Japreet kaur, Effect of HFTID on the tability of thermal power generator,, Volume 2, Iue 3, pp. 7-2, 206.
depend upon () voltage magnitude (2) frequency and (3) phae equence. It i to be noted that the wide variation of the ytem parameter like frequency voltage will lead the ytem to become uncontrollable or totally collaped. A frequency deviation generally take place due to the change in load at demand ide a a reult there i alo a correponding change in tie line power ignal alo which are then combined and feed to the in the farm of a control ignal. The combined ignal which i feed to the i known a area control error (ACE). ACE i generally ued to indicate when total generation mut be lowered or raied in a particular control area which can be. Maintaining the ytem frequency at teady tate i very important for the generating equipment a well a for the equipment to be ued at the conumer end. Hence we can ay that due to the riing energy need of any nation AGC become very ueful for the interconnection of different ytem to meet the increaed energy need a well a to maintain the ytem repone to be teady tate with the change in load. In an independent power ytem, the main iue i not to maintain the interchange power tranfer. Therefore the function of AGC i to retore frequency to the pecified nominal value. With the primary LFC loop a hown in Fig. 5. the ytem frequency deviation due to change in load were maintained to be teady tate, which mainly depend on the regulation of governor peed. In order to reduce the frequency deviation to zero, we mut need an reet action that can be achieved with the help of integral which change the peed rotation etting of the turbine with reference to load perturbation. The integral increae the ytem by type which force the final frequency deviation to zero and their methodology i dicued in Section-IV. The LFC loop of a ingle area i hown below in Fig. 5. IV. METHODOLOGY While performing Simulation on Thermal ytem with and without the parameter to be ued in Fig. 7 and Fig. 8 are a follow while their reult and comparion are eparately dicued in Section V. Nominal ytem frequency (F) =60Hz, Governor peed regulation parameter (R i) =2.4 Hz/per unit MW, Steam governor time contant (T g) =0.08ec, Reheat time contant (T r) =0.0ec, Reheat contant ( K r) =0.5ec, Inertia Contant (H i) =5ec, Area rated power(pri) =2000MW, Steam turbine time contant (T t) =0.3ec, D i =8.33*0-3 p.u. MW/Hz, T Pi= 20ec, K pi = 20Hz.p.u./MW where T pi= 2H i/ f * D i, Di = P Di/ f i K pi = /D i, ACE= Area Control Error, B i=frequency bia factor, K d, K p, K i = Electric governor derivative, proportional and integral gain, repectively, i = Subcript referred to area. Fig. 5. Block diagram repreentation of iolated power ytem load frequency control. The fuzzy logic block i deigned by the combination of area control error ACEi and by the rate of change of area control error ACE i. It mainly conit of three interface block which mainly conit of two-input and one output. Each memberhip function conit of two trapezoidal memberhip and five triangular memberhip a hown in Fig. 6. The mechanim i realized by 49(7 7) rule for the fuzzy block. The following memberhip function ued for the deigning the fuzzy are hown in Table I. TABLE I. Fuzzy logic rule for HFTID. ACE/ ACE LN MN SN Z SP MP LP LN LP LP LP MP MP SP Z MN LP MP MP MP SP Z SN SN LP MP SP SP Z SN MN Z MP MP SP Z SN MN MN SP MP SP Z SN SN MN LN MP SP Z SN MN MN MN LN LP Z SN MN MN LN LN LN * LN: Large Negative; MN: Medium Negative; SN: Small Negative; Z: Zero; SP: Small Poitive; MP: Medium Poitive; LP: Large Poitive Fig. 6. Repreent the I/P and O/P of the fuzzy logic. 9 Anhuman Sehgal, Parveen Lehana and Japreet kaur, Effect of HFTID on the tability of thermal power generator,, Volume 2, Iue 3, pp. 7-2, 206.
Fig. 7. Single area thermal ytem without any. Fig. 8. Single area thermal ytem with HFTID. V. RESULTS DISCUSSIONS AND TABLES Comparion of ytem performance with and Without HFTID Controller on Single area Thermal Power Sytem at.5 Step Change in Load. Simulation tudie are performed to invetigate the performance of the ingle area thermal ytem. A tep load diturbance of.5 of the nominal loading i conidered in the ingle area. The parameter of the power ytem are given in appendix. Fig. 9 and Fig. 0 depict the dynamic repone of the thermal ytem in the farm of frequency deviation and area control error with.5 tep change in load without uing any. Fig and Fig 2 depict the dynamic repone of the thermal ytem in the farm of frequency deviation and area Fig. 0. ACE repone of thermal ytem without uing any. Fig. 9. Frequency repone of thermal ytem without uing any. Fig.. Frequency repone of thermal ytem with HFTID. 20 Anhuman Sehgal, Parveen Lehana and Japreet kaur, Effect of HFTID on the tability of thermal power generator,, Volume 2, Iue 3, pp. 7-2, 206.
TABLE II. Change in frequency of thermal ytem. without with HFTID maximum overhoot 0 0.7 minimum overhoot -4.6-3.6 ettling time (in ec) 33 26 Fig. 2. ACE repone of thermal ytem with HFTID. Fig. 3. Comparion of frequency repone of thermal ytem with and without HFTID. Fig. 4. Comparion of ACE repone of thermal ytem with and without HFTID. control error with.5 tep change in load by uing HFTID. Fig 3. and Fig. 4 how the comparion of dynamic repone of the thermal ytem in the hape of frequency deviation and area control error with.5 tep change in load. Table II how the comparion of frequency repone of the thermal ytem with and without in the farm of peak overhoot and ettling time with.5 tep change in load. Table III how the comparion of area control error of the thermal ytem with and without in the farm of peak overhoot and ettling time with.5 tep change in load. Table IV how the bet value for integrator and derivative after performing many imulation with.5 tep change in load. TABLE III. Change in area control error of thermal ytem. without with HFTID maximum overhoot.96.5 minimum overhoot 0.9-0.36 ettling time (in ec) 34 25 VI. CONCLUSION In thi paper, hybrid Fuzzy -tilt integral derivative (HFTID) i applied to power ytem. Thi application i an alternative and ucceful control for LFC. Simulation tudie have been carried out uing MATLAB platform to tudy the tranient behaviour of the ytem due to load perturbation. It i een from the imulation that, the propoed caue le peak overhoot a well a le ettling time for the ytem. Simulation reult etablih the uefulne of the propoed for LFC. TABLE IV. Adjuting the value for integrator and derivative gain. S. No /N Integrator Gain Derivative Gain Ki Kd Kd2 Repone 2.9 0 3 Very bad 2 2.8 5 0.9 0.8 Bad 3 2.7 0. 0.3 Fine 4 2.6 0.5 0.09 0.29 Good 5 2.5 0.2 0.00 0.009 Very Good 6 2.4 0. 0.009 0.00 Excellent REFERENCES [] H. Saadat, Power Sytem Analyi, New Delhi, Mc Graw-Hill, 2002. [2] M. Tuhir and S. Srivatava, Application of a hybrid in load frequency control of hydro-thermal power ytem, IEEE Conference, vol. 5, pp. -5, 202. [3] A. Kumar and R. Dahiya, Load frequency control of three area hydro thermal power ytem with HFTID, IEEE 6 th India International Conference on Power Electronic (IICPE), pp. -6, 204. [4] P. Kundur, Power Sytem Stability and Control, Prentice-Hall, N.Y, U.S.A, 994. [5] A. Mangla and J. Nanda, Automatic generation control of an interconnected hydro-thermal ytem uing conventional integral and fuzzy logic, International Conference on Electrical Utility, Deregulation, Detructuring, and Power Technologie, pp. 372-377, April 2004. [6] G. Karthikeyan and S. Chandraekar, Load frequency control for three area ytem with time delay uing Fuzzy Logic Controller, IJESAT Journal, vol. 2, pp. 62-68, 202. [7] K. S. S. Ramakrihna, P. Sharma, and T. S. Bhatti, Automatic generation control of interconnected power ytem with divere ource of power generation, International Journal of Engineering, Science and Technology, vol. 2, no. 5, pp. 5-65, 200. [8] A. J. Wood and B. F. Wollenberg, Power Generation, Operation and Control, John Wiley & Son, 984. [9] G. D. Rai, Non-Conventional Energy Source, New Delhi, Khanna publication, 988. [0] S. H. Saeed and D. K. Sharma, Non- Conventional Energy Reource, New Delhi, S. K. Kataria and Son publication, 204. 2 Anhuman Sehgal, Parveen Lehana and Japreet kaur, Effect of HFTID on the tability of thermal power generator,, Volume 2, Iue 3, pp. 7-2, 206.