Fuzzy  Based Representative Quality Power Factor for Unbalanced Three  Phase Sy
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Fuzzy  Based Representative Quality Power Factor for Unbalanced Three  Phase Systems Presented By VIVEK RAVEENDRAN S7 Electrical and Electronics College Of Engineering, Trivandrum 200711 batch Fuzzy  Based Representative Quality Power Factor for Unbalanced Three  Phase Systems.pptx (Size: 633.95 KB / Downloads: 95) Hi guys, If you like this presentation, say hi to vivek: vivekr1212@gmail.com Contents Introduction Existing systems FPSPF TEPF OSCPF Power factor definitions Fuzzy logic – Introduction Fuzzy based RQPF module Application and simulation results Conclusions References Introduction Under ideal sinusoidal operating conditions, the definition of power factor for single phase and balanced threephase systems is unique and meaningful In non sinusoidal situations and unbalanced threephase system operation, different power factors have been proposed Three recommended power factors 1) Fundamental positivesequence power factor (FPSPF); 2) Transmission efficiency power factor (TEPF) 3) Oscillation power factor (OSCPF) A new fuzzybased representative quality power factor (RQPF) is introduced to represent three recommended power factors. The RQPF is applied to different cases: balanced, unbalanced, linear, nonlinear, sinusoidal, and non sinusoidal. Existing systems The FPSPF indicates how much active power is being transmitted out of the maximum power when considering the fundamental frequency component only The TEPF indicates how much active power, including the fundamental plus the non fundamental components, is being transmitted from the source to the load. The OSCPF is an indication of how much oscillation is being superimposed on the transmitted power Why existing sytems are inadequate? Power factor definitions For a sinusoidal singlephase system, there is a unique definition for the power factor that is given by the ratio Where P is the transmitted active power and is the S maximum active power or the apparent power The FPSPF is defined PF as the ratio where are the fundamental positivesequence active power and apparent power respectively, such that The TEPF is defined as the ratio The oscillation power factor will be the ratio where For singlephase system, the maximum value of the OSCPF is 0.816 while for threephase system, the maximum value is 1 Fuzzy Inference Systems (FIS) Fuzzification: Transforms any crisp value to the corresponding (fuzzy value) Knowledge base: Contains membership functions definitions and the necessary IFTHEN rules. Inference engine: Simulates the human decisionmaking process. Defuzzification: Transforms the fuzzy output into a crisp numerical value. FUZZYBASED RQPF MODULE The value of the RQPF represents an amalgamation of the existing power factors—FPSPF, TEPF, and OSCPF Fuzzy IFTHEN Rules:Examples 1) If (FPSPF is L) and (TEPF is L) and (OSCPF is L), then (RQPF is L). 2) If (FPSPF is L) and (TEPF is L) and (OSCPF is M), then (RQPF is ML). 3) If (FPSPF is L) and (TEPF is L) and (OSCPF is H), then (RQPF is SL). Contnd… low (L), moderately low (ML), somewhat low (SL), medium (M), somewhat high (SH), moderately high (MH), and high (H). Application and simulation results RQPF module is applied to different test cases with different situations: linear, nonlinear, balanced, unbalanced, sinusoidal, and nonsinusoidal Linear Load Supplied From the Balanced Sinusoidal Source Linear Load Supplied From Unbalanced Sinusoidal Source In all cases, the OSCPF is less than one which indicates more oscillations in the transmitted power in this situation. In all cases, the RQPFs have values less than that for the balanced sinusoidal source which indicates that the RQPF is very expressive and sensitive in all situations to any change in the OSCPF Linear Load Supplied From the Balanced Nonsinusoidal Source For case 1, the FPSPF and the TEPF have the same value of one while they have different values in the other cases which indicate that the transmitted power is not only due to the fundamental positivesequence component. In almost all cases, the FPSPF is greater than or equal to the TEPF which indicates that there is some amount of power that is not transferred as active power to the load. Nonlinear Load Supplied From the Balanced Sinusoidal Source For all cases, the FPSPF and TEPF have different values since for the nonlinear load, the current may contain some harmonics. For the balanced cases 1, 2, and 3, the OSCPF values are close but not equal to one. For cases 4, 5, and 6 unbalanced cases, the OSCPF values are less than one since the load imbalance contributes to the oscillation Nonlinear Load Supplied From the Nonsinusoidal Source Contnd… In cases 1, 3, 4, and 5, the OSCPF has been reduced than in sinusoidal condition, which means more oscillation in the transmitted power. The RQPF tracks the increase and decrease of the OSCPF in this situation and takes into account the deviations between the FPSPF and the TEPF. Conclusion The RQPF represents an amalgamation of the three recommended power factors by representing them with a single value. In order to test its validity, accuracy, and sensitivity, it has been applied to different cases and simulation results are analysed. RQPF developed is very expressive, accurately represents the three recommended power factor values, and is very sensitive to any changes in them. Contnd… The use of fuzzy logic for developing that module has many advantages, such as being simple, easy to apply, altered, adjusted, and self contained. RQPF can be useful in many applications, such as customer billing, setting up tariffs, evaluating the power quality especially in unbalanced non sinusoidal situations. References [1]Walid G. Morsi and M. E. ElHawary,” A new fuzzybased representative quality power factor for unbalanced threephase systems with nonsinusoidal situations,” IEEE Trans. Power Del., vol.23, no. 4, pp.24262438, Jul.2008. [2]P. S. Filipski, “Polyphase apparent power and power factor under distorted waveform conditions,” IEEE Trans. Power Del., vol. 6, no. 3, pp.1161–1165, Jul. 1991. [3] Y. Jin, Advanced Fuzzy Systems Design and Applications. New York: PhysicaVerlag Heidelberg, 2003. S. A. Farghal, M. S. Kandil, and A. Elmitwally, “Quantifying electric power quality via fuzzy modeling and analytic hierarchy processing,” Proc. Inst. Elect. Eng., Gen. Transm. Distrib., vol. 149, no. 1, pp. 44–49, Jan. 2002. Use Search at http://topicideas.net/search.php wisely To Get Information About Project Topic and Seminar ideas with report/source code along pdf and ppt presenaion



