All JINTU World Get The Most Out Of Imagineering OBJECTIVE: Computer methods in power systems introduce formation sion line, power flow studies by various methods. It also deals with short circuit analysis of power system for steady state and transient stability. GROUP -A (SHORT ANSWER QUESTION: eee | cours No our Taxonomy | (Course Level U Po M NETWORK MATRICES- T [What are the advantages Vbus mattig ver 2Bus Matrix? Understand [1 2] What is the Tormula find. Yous mat wing singular Wansonmation | Understand | method? 3 What area ea Tadesand [1 7 5 nodes, hen what he mamber of | Understand | 1 3 Understand | 1 3 Distr ea Taiesand [1 § “YoWhat isthe dimension bus incidence matrix? Understand [1 tos Understand | 1 State Bus Incidence Matix Analyze i POWER SYSTEM NETWORK MATRICES Define Toad Bas Rralyae z 2 | Define slack bos Analyze 2 37 Define bus impedance mati Analyze 2 4 Write shor notes on PQ bus Undewsund | 2 37] Wirte shor notes on PY us. Tndersand [2 7 Wirte impedance matrix i adding branch To The worenee as Tndersand [2Waite impedance matrix iPadding Iink to the reference bus Understand Tr mnutval coupled elements are removed than what is the impedance matrix? | Analyze UNIT POWER FLOW STUDIES T_| Which quantities are specified at slack bus? Understand z 2_| Which quantities are specified at load bus? ‘Analyze 2 '3 | What are the disadvantages of the Gauss Seidel Load Flow Analysis? ‘Analyze 2 ‘What isthe advantage of using acceleration factor in Gauss-siedel load flow 4 [eee Analyze 5__| Which quantities are specified at voltage controlled bus? Evahate (6 | What are the advantages of conducting power flow studies? ‘Understand 7_| What is the data for power flow studies? ‘Remember 2 ‘S| What is the normal value of acceleration fuctor used in GS method? ‘Remember 2 9)_| Write static load flow equations, Evi 10__| What happens if we select wrong value of acceleration factor? 2 POWER FLOW STUDIES 1 | A 12 bus Power System has three voltage-controlled buses. The dimensi 2 ofthe Jacobean matrix will be? 2 [Ina load flow study, when PV bus is treated as PQ bus? inderstand 2 33 _| Which is the best method for accurate load Flow Caleulati lerstand 2 power system? F_[ List out some advantages of FDLF method with DLF meth ‘Analyze 2 ‘S| What isthe Jacobean matrix? Understand 2 6 _| Compare Newton Rap son method With DLE Understand 2 7 fethod? Understand 2 8 Understand) 2 9 Understand 2 0 Understand 2 ‘ANALYSIS. T ‘Analysis 3 2_[ Why regulating trans ‘Analysis 3 3 _| Explicit the per unit repi ‘Understand 3 4 ‘Understand 3 3 Understand 3 6 | What are ‘Analysis 3 7 _| Discus f finding fault level of a bus? ‘Understand 3 &_| What 2 Evaluate 3 ‘9__| What is mean’ circuit capacity of bus? ‘Analysis 3 10__| Formulate short cireuit MVA calculations? Evaluate 3 SHORT CIRCUIT ANALYSIS is mean by positive sequence components? Understand 3 ‘mean by zero sequence components? Understand: 3 ‘oltage and current positive, negative and zero sequence networks. | Evaluate 3 a Tault occurs most frequently in a power system? ‘Analyze 3 ich fault isthe most severe fault on the power system? ‘Analyze 3 ‘A.15 MVA, 6.9 KV generator, star connected has positive, negative and | Evaluate 3 zero sequence reactance’s of 50%, SO%and 10% respectively, A Tine-to- Tine fault occurs at the terminals of the generator operating on no-load. What is the positive sequence component of the fault current in p.u? 7_[ Write short notes on LG faults? Evaluate 3 '8_| Write short notes on symmetrical component transformation? Understand 3 | For a double fine fault on phase b and e, What is the value of Vb? Understand 3TO] The postive sequence current Ty ‘when power aytem is | Undersund | 3 subjeetto singe line to ground fa UNITIV POWER SYSTEM STEADY STATE STABILITY ANALYSIS 1 [Define sabi Understand [ 2 | Define steady slate abi Understand | 4 3 | Define transient state stably Understand | 4 4 [Define dynamic site stability. Understand | ip ¢ 3 Define nena constant Understand 6 | Why transient stability Fimit is Tower than steady state silty Ti ‘Apply 7__| Menton two methods fo improve transient stability ‘Appl 4 8__| Writ short notes on power angle curve. ‘Apply 4 9 [Define Transfer reactance Tr 4 TO Define nein constant. UNITV POWER SYSTEM TRANSIENT STATE STABILI 1 [Derive te swing equation: 3 2 | Derive te transient stabi by Equal Area Getion Evalue [5 3° [ What are the application of Equal Area Criterion ‘Apply 5 4 [Derive the ertcal clearing angle valuats—[ 3 3 [Explain point By pint solution of swing equation Understand [3 [Write short notes on Auto Reclosing. Understand [3 7 Understand [3 z Understand [3 37 [Explain the pocedae for selection of wer systems, | Understand’ [5 TO | Applications of auto reclosing and ast aes Understand |S 2. GROUP -I1 (LONG ANSWER QU Blooms "| Course S.No Taxonomy] uitcome Level Understand PT Understand | 1 Understand | 1 Analyze 1 uss about augmented loop incidence male Analyze 1 ‘about formation of network malfices by singular Wansfommation, | Analyze 1 ese oud Now solution with P-V bus Evaluate 1 SS Ppbiscus Formation of ¥ bus by using direct inspection method Understand [1 ive branch maltioes from bus mates? Evaluate H Discuss about bus admitance and bus impedance matrik Understand [1 POWER SYSTEM NETWORK MATRICES [Derive te bus impedance matrix iFadding element w the reference bus. | EvaTuate i 2 | Write algorithm for formation ofbus impedance matrix Evaluate 1 3 [Wile about modification ofthe bus impedance mati for network changes | Understand [Derive the partial network Evaluate 7 3 Hoow do you represent transformer in Toad How studios Understand [1© _ | Discuss about algorithm for the modification of Z bus matrix for addition of | Understand T element from a new bus to reference bus. 7_| Discuss about algorithm for the modification of Z bus matrix Tor addition of | Evaluate T clement from a new bus to an old bus. B__| Discuss about algorithm for the modification oF Z bus matrix for addition of | Understand T clement between old bus to reference bus. 9 | Discuss about algorithm for the modification of Z bus matrix for addition of | Understand T clement between two old buses TO | Merit and Demerits of using polar and rectangular coordinates in load flow | Understand studies UNIT POWER FLOW STUDIES. T__| Explain Gauss-Seidal iterative method for power flow analysis of any given | Evaluate 2 power system with a flow chart. 2__| Derive static load flow equations. Ui 3 | Explain with a flow chart the computational procedure for Toad 2 solution using Gauss seidel method F__[ Derive bus voltages if injected active power 2 'S__| Distinguish between D.C load flow and A.C load flow. Evaluate 2 6 | Explain in detail how D.C load flow is performed in power syste alysis 2 77 _| Draw and explain the flow chart for Gauss seidel load flo alate 2 8 | Advantages and Disadvantages of GS and NR methods ‘Analysis 2 load flow problem 9] Classify various types of buses in a power sysjem for Toad flow Studies. | Understand a Justify the classification, TO | What is acceleration factor? Where is used. Understand z PO’ IES: T_] Explain with @ flow chart the Tor Toad flow | Understand 2 solution using Newton raphson, 2 | Discuss about load flow sol FDLF method Understand z '3_| Discuss about load flow sol °V bus by using FDLF method | Understand 2 4 | Comparison between ti thod and FDLF method Understand zi 5__| Comparison between Understand zi 6 | Explain with a ‘Analysis, 2 solution using ‘Analysis, z ‘Analysis, az uss about jacobian matrix Analysis z diseuss about advantages and disadvantages of FDLF and DLF | Understand 2 UNIT-IT SHORT CIRCUIT ANALYSIS Derive the algorithm for symmetrical short cireuit analysis of a multi | Analysis 3 ‘machine power system using Z bus matrix. 2 | What are per unit quantities? What are its advantages Understand 5] 3__| Write application of series reactors Understand ai 4 [A Three phase fault(inot involving ground) occurs at bus p. explain the | Understand 3 ‘method of finding fault current & fault voltages( voltage at Evaluate faculty bus and at healthy buses) in terms of symmetrical component quantities.3] Determine the Tnerraping current in a circu breaker connected To a] Understand | 3 generator rated at 20MVA, S3KV. Take Xd=25% and Eg=Ip.. T—] Write the thres phase representation of power system for show creat | —Evalmate 3 studies and briefly explain 7 Explain about Per-Unit equivalent reactance network oF three phase Power | Understand | 3 System 8 | Briefly explain fault level of bus justify infinite bus as a constant voltage | Understand 3 9 | write the thse phase representation of power sytem For short eireult studies | Understand and briefly explain TO] Explain the use of automate reclosing cireult breakers in improving eye | Understand stability SHORT CIRCUIT ANALYSIS 1 Give a step by step procedure of analyzing a L-G fault on a power system | Eval by bus impedance matrix method and explain 2] With the usual notation derive the equation oF computation of sequence 3 currents fora line to ground fault onan n bus power system using algorithm. 3] With the usual notation derive the equation of computation Tina 3 ‘currents for a line to ground fault on an n bus power system algorithm. |] Devslop the expressions for analyzing single Tine Yo gro inderstand | 3 power system using 7 Bus matrix 3 [Explain about Line to ground tau Understand | 3 | Explain about LL tl Understand | 3 7 [Derive the LLG fat with and without Ful iy Understand | 3 ¥ | Briefly explain Fault fevel of bus justi constant voliage | Understand | 3 9 —[ Explain the nena constant Evalue 3 10 | Explain the bus-impedance Evaluate 3 fault TATE STABILITY ANALYSIS 1] Disease the various fact f transient stability of a power | Understand | 4 system 2 | Distinguish be sient sate and dynamic stability | Understand | 3 | Whats 7 dsfne stability limit ofthe system Understand | 4 | Derive steady state stability limit using ABCD | Understand | 4 parame [Derive the poweranle equation of single machine connested to Taine bus | Understand [a 6 | Give the ist of nthods improving tansint stability ofthe system Understand [4 TegjpDerive the equaares criterion of stability and explain clearly how you can | Understand | 4 ine the stability imit ofa synchronous motor when there isa sudden inthe mechanical load on the motor plain what you understand stabil. Distinguish between steady | Understand | 4 cand transient stabil 9 jcribe about steady state stability power limit ‘Understand 4 jain the transfer reactance Understand a UNITY POWER SYSTEM TRANSIENT STATE STABILITY ANALYSIS 1] What are the steps between followed for determine mult machine stability? | Understand 5 2 [Write notes onthe state variable formulation of swing equation Understand | 5 3] Give the mathematical model Tor the transient analysis of malty machine | Understand | 3 power system,7 [What yor ndeand by eal clea ime and cea ang angle] Une [5 S Draw a digi to Mstas the application of equal ereon to rudy | Evaluate 5 train aii when there sudden nerease nthe puto generator TY Discuss taint subi Tower thn steady sate sity and The use OF | Evans 7 fulomateeorng cet breakers improve system sbliy | Write noes on concep of mult machine sabiiy Cadena | —s [Explain point by point meod use for saving ving Gaon. Analysis 5 3] Derive te expression or rel eering angle Tor synchronous tacline | Analyse 5 connected to infinite bus system when a 3 phase fault occurs and it is cleared by opening of crit breakers TOP Explain what is “swing Cur” Explain Ws proce significance Tn] Evaluate stability analysis. 3. GROUP - IIL (ANALYTICAL QUESTIONS) S.No QUESTION my | course lad Outcome UNIT-1 POWER SYSTEM NETWO! T] Find e YBUS by deat inspection met forthe network so only T OBO 2OLO [Forde ower arien remot agli we iynee Bu, Detce | Apply T A twe and eostee. Wile the incidence matrix and tse io obs ‘YBUS? Stet aria i PORT i ow Tiare WH aC ae Tm pA? | — Apply T 7-2For the system shown below obtain J) primi ‘matrix Select ground as referenee. Line mum Bus code Admittance in pu 14 14 12 16 23 24 34 20 24 Ls. 7 admittance matrix it) bus incidence Apply (a) What are the advantages of ZBUS building algorithm? {(b)Z. bus matrix elements are given by ZI1= 0.2, Z22= 0.6, Z12-0 find the modified ‘ZBUS if a branch having an impedance 0.4 p.u. is added from the reference bus (Bus - 1) to new bus? Also find the modified ZBUS if a branch having an impedance 0.4 p.u. is added from existing bus (other than reference bus) to new bus? Apply Form ZBUS by building algorithm for the power system network, data given in the table below. Bus Code | SelfImpedance(pu.) | Bus Code | Mutual Impedance a) he at 23) 0.65 34 035 a1 0.75 24 0.25 Appl ') Explain the branch path incidence matrix (K) with an example. }b) Find the Yaus by direct inspection method for the network shown in Dee @ a2 Lec +10 oe Apply ‘What are the properties of node to Understand Form Zyosby building algorithm r system network, data given in the table below. Bus Code] Self Impedan Bi Mutual Impedance (pu) 12 Ol 23, 06, 34 a1 24 3 ‘on Apply 10 jveen the two elements of a power system network is 26, nal elements ofthe Zyus matrix? How do you decide the and V; Apply ‘of NR-method over GS-method? Explain, tage at bus-1 is adjusted to 1.05 p.u voltage magnitude at bus- is taken from bus- Apply ‘oupled and Fast decoupled methods of power flow analysis mathematical ds? What are the assumptions for reducing the NR-method to DLE and FDLE ls? Analyze (a) Formulate the power flow problem and show how it can be solved by Decoupled method, (b) Explain how the voltage controlled buses are treated in the above method. Understand, 0 (a) What are the disadvantages of NR-method over GS-method? (b) What are the advantages and disadvantages of polar and Rectangular form of NR- method? UnderstandUNIT SHORT CIRCUIT ANALYSIS ‘The equivalent impedance of a 10 KVA, 2200 V/220 V, 60 Hz Transformer is 10.4 + {JB1.3 S when referred to the high-voltage side. The transformer core losses are 120 W. Determine (a.) the per-unit equivalent circuit (b.) the voltage regulation when the transformer delivers 75% of full load at a power factor of 0.6 lagging, and ( c.) the transformer efficiency given the transformer load of part (b ‘Apply (@) A generator operating at S0Hz delivers I p.u. power to an infinite bus through a transmission circuit in which resistance is ignored. A fault takes place reducing the maximum power transferable to 0.5 p.u, whereas before the fault this power was 2.0, pau. and after the clearance of the fault it is 1.5 p.u. By the use of equal area criterion determine the eritical clearing angle (b) Derive the formula used in the above problem. Apply ‘A single phase 9.6 kVA, 500 V7 1.5 kV transformers has an Impedance of 1.302 0 with respect to primary side, Find its per-unit impedance with respect to primary and, secondary sides. Apply ‘A single phase 20 EVA, 480/120, 60 Fiz single-phase transformer has an impedance of Zeq2 = 0.0525p78.130 S referred to the LV winding. Determingythe per-unit transformer impedance referred to the LV winding and the HV winding A three phase 500 MVA, 22 KV generator has winding reactance of 1.065 ohms find its per unit reactance, Apply ‘A200 MVA II KV 50 Hz 4 pole turbo generator has an inertia Constant Of 6 MIT MYA. (a) Find the stored energy in the rotor at synchronous seed. (b) The machine is operating at a load of 120 MW. Whefithe load suddenly increases to 160 MW, find the rotor retardation, Neglect losses. (c) The retardation calculated above is mainfaitted for S eyeles; find the change in power angle and rotor speed in rpm at the end of thiiperiod. Apply ‘A 120 MVA, 19.5 KV generator hasiXs = 0.15 perourit and is connected wo a transmission line by a transformer rated 150 MVA, 230 ¥/I8A kV with X = 0.1 per unit. Ifthe base to be used in the glewlationlis 100 MV.A, 230 kV for the transmission Tine, find the per unit values tobe used for the transformer and the generator reactance’s Apply ‘A300 MVA, 20 KV three-phase @eferators has a sub transient reactance of 20%. The generator supplies agfiumbs® @f)synchronous motors over 64-km transmission line having transformers at both ends, as shown in Fig. 1.11. The motors, al rated 13.2 kV, are representedyByajust tWo Equivalent motors. Rated inputs to the motors are 200 MVA and 100 MVAbfor MU and,M2, respectively. For both motors X” = 20%. The three phase transformenT 1 is rated 350 MVA, 230/20 kV with leakage reactance of 10%. Transformer T2 is)vomposed of three single-phase transformers each rated 127/132 KV, 100 MYA with leakage reactance of 10%. Series reactance of the tdansmission line is@5-Q/km. Draw the impedance diagram, with all impedances matkedhin per-unit, Select the generator rating as base inthe generator circuit WO* Apply ‘transformer rated 200 MVA, 34S 720.58 RV connected atthe receiving end of @ twansmission line feeds a balanced load rated 180 MVA, 22.5 kV, 0.8 power factor. Determine (a) The rating of each of three single-phase transformers which when properly connected will be equivalent to the above three-phase transformer and (b) ‘The complex impedance of the load in per-unit, ifthe base in the transmission line is 100 MVA, 345 kV, ‘Apply10 Explain the use of automatic reclosing eivcult breakers in Improving system stability. Understand ‘SHORT CIRCUIT ANALYSIS 4) Explain the analysis ofa short circuit on a loaded three phase synchronous machine. ) A synchronous generator and a synchronous motor each rated 25 MVA, 11 KV having 15% sub transient reactance are connected through transformers and a transmission line, The transformers are rated 25 MVA, 11/66 kV and and 66/11 kV with leakage reactance of 10% on a base of 25 MVA, 66KV. The motor is drawing 15 MW at 0.8 power factor leading and a terminal voltage of 10,6kV when a symmetrical three fault occurs at the motor terminals. Find the sub transient current in the generator, motor and the fault. “Apply ‘A Three phase fault(not involving ground) occurs at bus p. explain the method of finding fault current & fault voltages(voltage at faculty bus and at healthy buses) in terms of symmetrical eomponent quantities. Understand) ‘An IIKy, 25MVA synchronous generator has positive, negative and zero sequence reactance of 0.12, 0.12 and 0.08 per unit respectively. The generator neutral is ‘grounded through a reactance of 0.03 pu. A single line to ground fault occurs at the generator terminals. Determine the faull current and line to line voltages. Asstime that the generator was unloaded before the fault Apply ‘A synchronous generator and motor are rated 30,000KVA, 13.2KV andjboth have sub transient reactance’s of 20%. The line connecting them has a reactange of 10% i the base of machine ratings. The motor draws 20,000KW @ 0.8 power factor leading and a terminal voltage of 12.8KV. When a symmetrical three phdge fault ogeurs at the ‘motor terminals, Find the sub transient current in the generator and moto Apply ‘A synchronous generator is rated 1OMVA T3.8K.V. It has positive, negative and 7270 sequence reactance of 0.15, 0.15 and 0.05 pu respeetively. A single line to ground fault occurs when the altemator is working on w@ lod at a terminal voltage of 13.2K.V. Determine the value of fault current in amperes where the neutral is grounded through i, a reactance of 0.7 Tia resistance of 0.7. Apply Draw and explain the wave form of Je symmetrical shor elrcult armature current in synchronous machine Understand The expressions for fault Current'at the Buses and lines, Voltages at the faulted bus ‘and at other buses when a single? ino-to-groundifault occurs at a bus on conventional phase ‘a’, using fault impedance atk Bus impedance matrices, in sequenice component form. Analyze Explain vollage and Clement positive, negative and zero sequence networks Understand 'a) Explain the analysis OP@ Short circuit on a loaded three phase synchronous machine, ) A synchronéus Qenerator aind a synchronous motor each rated 25 MVA, 1] KV having 15% sub frasient reagtance are connected through transformers and a transmission line. The transformers are rated 25 MVA, 11/66 kV and and 66/11 kV with leakage reactance of 10% on a base of 25 MVA, 66KV. The motor is drawing 15 MW at 0.8 power factoeleading and a terminal voltage of 10.6kV when a symmetrical itte@fault occurs At the motor terminals. Find the sub transient current in the generator, motor and the fault. Apply ‘Develop the, expressions for the following matrices which are used for shunt fault analysis for a)F.ine-to-Line fault occurring on conventional phases. (a) Fault admittance matrix in phase and sequence component form Understand UNIT IV POWER SYSTEM STEADY STATE STABILITY ANALYSIS ‘¥50 Hz, Tour pole generators rated 100 MVA, 11 kV has an inertia constant of 8 MI/MVA. ') Find the stored energy in the rotor at synchronous speed, ii) If the mechanical input is suddenly raised t© 80 MW for an electrical load of SO MW, find rotor acceleration, iii) Ifthe acceleration calculated in (i) is maintained for 10 eycles, find the change in torque angle and rotor speed in rpm at the end of this period, Apply1h) Another generator 200 MVA, 3000 rpm, having H- MIIMVA is put in parallel ‘with above generator, Find the inertia constant for the equivalent generator on a base of 100mva Differentiate betwoon steady Stale stability and Wansiont state stability of power systems. Diseuss the factors that effect. Explain the Dynamic and transient stabilities. ‘What are the methods of improving steady state stability Timits Write short notes a) Transfer reactance bb) Synchronizing power co-efficient Explain the power angle curve and determination of steady state stabil Derive the maximum steady state power Write short notes on elementary concepts of steady state stability dynamic stability and Transient stability Derive an expression for steady stato stability limit if the resistance and shunt ‘capacitance of the transmission line are considered 10 Differentiate between steady state stability and tansient state stability systems. Discuss the factors that effect. UNIT V POWER SYSTEM TRANSIENT STATE STA\ 200 MVA TI KV 50 Hz 4 pole turbo generator has an ine MYA. (a) Find the stored energy in the rotor at synchronous spec (b) The machine is operating at a load of 120 MW. When the increases to 160 MW, find the rotor retardation, ‘The retardation calculated above is maintained for angle and rotor speed in rpm at the end of this period lenly Derive the transient stability by Equal A\ Equal Area Criterion Evaluate Derive the critical clearing angle Understand ‘What is the critical fault clearing a ‘expression for the same, What a rs that affect the transient stability? Explain in detail Understand ‘) Write short notes on fast 'b) A.20 MVA, SOHz generato bus. The generator has £2.52 MJIMVA at rated speed. The generator transient reactance i mnsmission circuit has RO and a reactance ‘of .2pu on a 20MVA 11pu and infinite bus voltage V~ 1.0 at an angle O°. At cuit occurs at the midpoint of one the transmission lines. Plots cleated by simultaneous opening of breakers oat b Apply Evaluate Apply critical clearing angle ‘Analyze ils of assumptions made ia the study of steady Slate and transient Stability Analyze ‘4.50 liz, four pole generators rated 100 MVA, IT KV has an inertia constant of 8 MI/MVA. i) Find the stored energy in the rotor at synchronous speed. ii) Ifthe mechanical input is suddenly raised tn 80 MW for an electrical load of 30 MW, find rotar acceleration, ili) If the acceleration calculated in (i) is maintained for 10 cycles, find the change in torque angle and rotor speed in rpm at the end of this period. IV) Another generator 200 MVA, 3000 xpm, having H=6 MJ/MVA is put Apply