POWER FLOW ANALYSIS USING NR METHOD

Transcription

1 POWER FLOW ANALYSIS USING NR METHOD Adtya Shaa 1, Manyu San 2 and MdIfan Ahed 3 1 UG Student, 2,3 Assstant Pofesso, Electcal Engneeng, Caee Pont Unvesty, Kota, Raasthan, (Inda) ABSTRACT Powe s geneated n geneatng staton, tanstted though tanssson lne and then dstbuted to consues. Powe syste contans of 3 types of buses. They ae geneato bus, load bus and slack bus. Each bus s categozed by fou paaetes. They ae bus voltage, phase angle, actve powe and eactve powe. These buses ae classfed accodng to known paaetes. Unknown paaetes ae found usng Powe flow studes. The powe syste analyss and desgn s geneally done by usng powe flow analyss.ths analyss s caed out at the state of plannng, opeaton, contol and econoc schedulng.they ae useful n detenng the agntude and phase angle of load buses, and actve and eactve powe flows ove tanssson lnes, and actve and eactve powes that ae nected at the buses. Fo ths wok the Newton-Raphson (NR) ethod s used fo nuecal analyss. The obectve of ths poect s to develop a MATLAB poga to calculate voltages, actve and eactve powe and losses at each Bus fo 3 bus systes. Keywods: Newton Raphson (NR), Gauss-Sedel (GS), Optal Powe Flow (OPF) I. INTRODUCTION Powe flow calculatons ae pefoed n powe systes fo plannng, opeatonal plannng, and opeaton/contol. Powe flow equatons, coonly efeed to as powe flow ae the backbone of powe syste analyss and desgn. The powe flow poble conssts of the calculaton of powe flows and voltages of a netwok fo a specfed tenal o bus condtons [1].Load flow studes ae used to ensue that electcal powe tansfe fo geneatos to consues though the gd syste s stable, elable and econoc. Conventonal technques fo solvng the load flow poble ae teatve usng the Newton-Raphson ethods Load flow analyss fos an essental peequste fo powe syste studes. Consdeable eseach has aleady been caed out n the developent of copute pogas fo load flow analyss of lage powe systes [3]. Powe flow analyss s vey potant n plannng stages of new netwoks o addton to exstng ones lke addng new geneato stes, eetng ncease load deand and locatng new tanssson stes.the load flow soluton gves the nodal voltages and phase angles and hence the powe necton at all the buses and powe flows though nteconnectng powe channels [4]. It s helpful n detenng the best locaton as well as optal capacty of poposed geneatng staton, substaton and new lnes. It detenes the voltage of the buses. The voltage level at the cetan buses ust be kept wthn the closed toleances. 218 P a g e

2 1.1 Obectve of the Wok The an a of ths pape s to calculate voltages, actve and eactve powe and losses usng NR Method. II LOAD FLOW ANALYSIS Load flow studes at done unde steady condtons. Load flow solutons ae essental fo desgnng a novel powe syste, and plannng fo the extenson of the exstng one fo nceased load deand. The an nfoaton obtaned fo the load flow studes s the [5] : Magntude of voltage Phase angle Real powe and eactve powe. Accodng to these fou paaetes, the buses of the syste ae classfed as: 1. Load Bus 2. Geneato Bus 3. Slack Bus BUS SPECIFIED QUANTITIES OBTAINING QUANTITIES Load Bus P,Q V, Geneato Bus Slack Bus P, V Q, V, P,Q Table 1 Classfcaton of Buses Accodng to these specfed quanttes at a bus n a syste, these buses ae also naed as:. Load Bus as PQ bus. Geneato Bus as PV bus. Slack bus as efeence bus. PQ bus: The specfed quanttes fo the load bus ae eal and eactve powe and the detenng quanttes ae agntude of voltage and phase angle wth the help of load flow soluton [1]. Voltage at load bus can be allowed to vay wthn a pescbed value 6% PV bus: The specfed quanttes n the geneato bus ae eal powe and the agntude of the voltage and the detenng quanttes ae eactve powe and phase angle.. Refeence bus: The specfed quanttes ae agntude of voltage and the phase angle and the detenng quanttes ae eal and eactve powe. Usually the value of slack bus s taken as 1 0 p.u. n evey bus thee ust be one slack bus thee ust be one slack bus and othes ay be the PQ o PV accodng to the equeent of the syste. 219 P a g e

3 Methods used fo load flow studes ae: 1. Gauss sedal ethod 2. Newton Rapshan ethod 3. Decoupled Load Flow ethod 4. Fast Decoupled Load Flow ethod III. COMPARISON OF GAUSS-SEIDEL AND NEWTON-RAPHSON METHOD PROPERTIES GS METHOD NR METHOD Accuacy Lesse Hghe Convegence ate Slow Fast Nube of poves wth Reans fxed teatons the sze of powe syste Type of Lnea Quadatc convegence Stablty Fo sall powe Fo lage powe syste syste Effect of slack bus Moe dependent Less dependent selecton Guaantee of Not guaanteed Guaanteed convegence Acceleaton Extenal Intenal Te fo each Less Moe teaton Table 2 Copason of GS and NR Method IV. PROBLEM FORMULATION 4.1 NEWTON-RAPHSON METHOD NR ethod s used fo solvng the nonlnea algebac equatons. It povdes fast esponse and sue convegence as copaed to Gauss Sedel ethod. Powe flow equatons [2] : P (Real Powe) = V ( V cos( 1 Y Q (Reactve Powe)= - V ( V Y Sn( 1 Whee, V = voltage at th bus 220 P a g e

4 V = voltage at th bus Y = adttance of th and th bus = angle of the adttance = phase angle of the th bus I = phase angle of the th bus J s the acoban atx whch s used fo solvng the NR ethod. Y bus atx 4.2 Iteaton Algoth J= Y bus = dp d dq d Y11... Y Step 1: Consde one bus s slack bus n a syste whose voltage and phase angle ae 1 0 and assue the all othe buses as PQ and PV buses. Step 2: In the th teaton, Let, P Q V V 1 1 dp V dp V Y... Y ( V Y cos( ( V Y sn( e V cos And f V sn G B Y Y Then Calculate, cos sn P =P (scheduled) - Q =Q (scheduled) - P fo PV and PQ buses Q fo PQ buses Hee f all the values of P and Q ae less than the toleance, teatons ae stopped, calculate P1 and Q1 and the soluton s obtaned. Step 3: If the convegence ctea s not obtaned, calculate the Jacoban atx eleents. Step 4: coecton of voltage agntude and phase angles. Step 5: Next update the voltage agntude and phase angles. V ( 1) V V 221 P a g e

5 ( 1) Agan go to step 2 and contnue the pocess unless the convegence s obtaned. 4.3 Flow Chat fo NR Method Fgue 1. Flow chat of NR Method V. RESULTS In ths pape, the 3 bus syste s analyzed by usng NR ethod. The an wok of ths pape s to develop a MATLAB poga to calculate voltages, actve and eactve powe and losses at each bus fo 3 bus systes. In fst stage detene the actve and eactve powe at each unt and n the next stage Lne Losses s detened. Ths ethod s tested on 3 unt syste. The coplete esult s shown n Table 5.1 Table 3 Load flow analyss esult usng NR ethod n 3 unt syste 222 P a g e

6 VI. CONCLUSIONS The an wok of ths pape s to develop a MATLAB poga to calculate voltages, actve and eactve powe and losses at each bus fo 3 bus systes. In fst stage detene the actve and eactve powe at each unt and n the next stage Lne Losses s detened. Ths ethod s tested on 3 unt syste. REFERENCES [1] P. Skanth, O. Raenda, A. Yesua, M. Tlak, and K.Raa (2013) Load Flow Analyss of Ieee14 Bus Syste Usng MATLAB Vol- 2 Issue. 5 Page Intenatonal Jounal of Engneeng Reseach & Technology [2] Sunl Joseph P., and C.DneshBala (2013) Tanssson Loss Mnzaton Usng Optzaton Technque Based On Pso Vol- 6 Issue-1 Page IOSR Jounal of Electcal and Electoncs Engneeng [3] L.Raesh, S.P.Chowdhuy, S.Chowdhuy, A.A.Nataaan, and C.T.Gaunt (2009) Mnzaton of Powe Loss n Dstbuton Netwoks by Dffeent Technques Vol-3 Page Intenatonal Jounal of Electcal and Electoncs Engneeng [4] Hassan Kubba (2014) Assessent and Copaatve Study of Dffeent Enhanced Atfcal Neual Netwoks Based Powe Flow Solutons Vol- 03 Issue-03 Page Intenatonal Jounal of Engneeng Reseach & Technology [5] DaleetKau, D. S. K. Bath and Dashan Sngh Sdhu (2014) Open Ccut Fault Analyss of Electcal Powe Syste Usng MATLAB Vol- 03 Issue-03 Page Intenatonal Jounal of Engneeng Reseach & Technology 223 P a g e