Power system analyses(Dynamic modeling)

Using PSS/E for power system analyses- Load flow -

Istanbul, May 2011

PSS/E Program overview

Professional software package PSS/E™(Power System Simulator for Engineering) is developed by PTI (Power Technologies International). PSS/E is comprised of the following calculation modules:

PSS/E Power FlowPSS/E Optimal Power Flow (PSS/E OPF)PSS/E Balanced or Unbalanced Fault AnalysisPSS/E Dynamic Simulation

PSS/E Power Flowmodule is basic PSS/E program module and it is powerful and easy-to-use for basic power flow network analysis. Besides analysis tool this module is also used for Data handling, updating, and manipulation

Graphical interface

1. Main toolbar2. Network tree3. Work window4. Progress

window

2

4

3

1

Over toolbarTools/Customize…

Toolbar customization

Right click on toolbar you can switch on/off toolbars

Program option and settings

Using icon or over toolbar Misc/Change program settings (OPTN)

Program preferences

Building a new modelStart with command File/new

Enter base power and model heading

Working with filesOpening files

Using toolbar icon or over meny File/open

Saving/exporting filesUsing toolbar icon or over meny File/Save or show

Working with filesSaving dynamic data

Using toolbar icon or over menu File/open with DYNAMIC DATA SHEET ACTIVE!!!

101 'GENROU' 1 6.5000 0.60000E-01 0.20000 0.50000E-01

4.0000 0.0000 1.8000 1.7500 0.60000

0.80000 0.30000 0.15000 0.90000E-01 0.38000 /

101 'IEEET1' 1 0.0000 400.00 0.40000E-01 7.3000

-7.3000 1.0000 0.80000 0.30000E-01 1.0000

0.0000 2.4700 0.35000E-01 4.5000 0.47000 /

101 'TGOV1' 1 0.50000E-01 0.50000E-01 1.0500 0.30000

1.0000 1.0000 0.0000 /

Bus data

Bus type/code1 PQ node (load)2 PV node (generation)3 swing bus (must be a plant)

Areas/zones/Owners defined when bus is defined

Filtering and subsystem selectingBus selection filter

Name maskBus numberVoltage rangeType

Bus Subsystem Selector

Bus loads

3 types (or mixed)Constant powerConstant currentConstant admittance

Adding new loadDouble click empty field or just enter bus numberSelect busEnter data

Generator/plant data

Define plant dataScheduled voltageRemote controlled bus

Enter machine data

Branch dataDouble click empty field to select bus (or enter bus number)Enter rest of dataPaste data from excell

Zero impedance linesFor modeling bus ties, jumpers, couplers or breakertreated as the same bus (identical bus voltages but loading is determined)

Bus tie

Line breaker

Two winding transformer data

Select connected busesDefine winding 1 side!!Enter rest of data

SS TEST2 400±1x3%/22 kV;Pcu=840kW;uk=12.57%;PFe=235kW;j0=0.05%SS TEST2 400±1x3%/22 kV;Pcu=840kW;uk=12.57%;PFe=235kW;j0=0.05%

SS TEST3 400±1x5%/231 kV;Pcu=620kW;uk=11.91%;PFe=130kW;j0=0.08%SS TEST3 400/231±2x2.5% kV;Pcu=650kW;uk=10.2%;PFe=120kW;j0=0.08%

Three winding transformer data

SS TEST1 420/15.75/15.75 kV;S=380/190/190 MVA;Pcu=1110/1110/1110kW;uk=11.6/22.3/11.6%PFe=310kW;j0=0.38%

Switched shunt data

Inter area transfers

If you apply transaction to PDES then these figures are added on desired interchange

Double click to select areas or enter area numbers

Deleting buses and elements

Or just select element in table and press DELETE

GOUT/GEXMCalled over icon and then entering bus number (or selecting over select option)or from bus spread sheet by selecting bus and over right click menu

GOUT/GEXM – right click menu

Right click menuAnnontiationEditing network dataSwitching actions

One line diagramsTurn on auto-draw on icon

Click symbol for bus and click into draw window (selection dialog appears)

Drawing by “dragging”With auto-draw option turned one select and drag bus to diagram area

Growing diagram bus by busGrow diagram using selected bus and right-click menu

Drawing multiple busesSelect multiple buses and auto-draw

Shape up the diagram

Calculation parameters

Running Load flow calculations

Using icon or over toolbar Powerflow\Solution\Solve (NSOL/FNSL/FDNS/GSLV/MSLV)

Limit checking reports

PTI INTERACTIVE POWER SYSTEM SIMULATOR--PSS/E WED, MAR 17 2004 9:35 WINTER 2005 + UCTE WITH TURKEY

BRANCH LOADINGS ABOVE 100.0 % OF RATING SET A:

X-------FROM BUS-------X X--------TO BUS--------X CURRENT(MVA) NAME BSKV BUS# AREA NAME BSKV BUS# AREA CKT LOADING RATING PERCENT AFIER 2 220 10013* 10 AFIER15 110 10036 10 2 93.8 90.0 104.2 AFIERZ2 220 10004 10 AFIERZ5 110 10065* 10 1 31.8 30.0 106.1 AFIERZ2 220 10004 10 AFIERZ5 110 10065* 10 2 31.8 30.0 106.1 ATIRA15 110 10023 10 AUTR115 110 10026* 10 1 69.4 68.0 102.0 JBGD105 110 34310* 90 JBGD225 110 34365 90 1 106.2 89.6 118.6 JEMARK5 110 34464* 90 JTMORA5 110 34775 90 1 89.9 89.6 100.4 JNSAD151 110 34620* 90 JNSAD351 110 34625 90 1 90.1 89.6 100.6

Necessities for dynamicsModel should be converted!!!

Generators convertedLoads converted

Xd” of generators (dynamic data)=Xsource(load flow data)!!!no generator should be loaded beyond permissible limits (equipment rating)!!!

Machine loaded within Pmin<Pgen<PmaxMachine loaded within Qmin<Qgen<Qmax

Dynamics tab and window

Load *.dyr file!!!Dynamics toolbar and tab

Dynamics adding model

Select dynamic model and right button menu add/replace model

Dynamics editing parameters

Select dynamic model and right button menu edit model

Block diagrams are in PSSE manual

Generation

Type of power plant dictates technical parameters (construction)

hydrothermal

Diesel and heavy fuelsGasCoal

nuclearrenewable sources

sunwindbiomassgeothermaltidal

Generator models - standard

GENSAL and GENSAESuitable for hydro machines – salient pole machines

Generator models - standard

GENROU and GENRAE and GENDCOSuitable for thermal machines – round rotor

Generator models - standard

Necessary parameters for modeling

Generator models - advices

Avoid using simplified models because lack of dataUse typical (and verified) parameters rather then “bad” dataDouble check time constants and integration step (PSSE sensitive and might crash if data not correct)

Integration step < smallest time constant

Generator data sheetData Type Abbreviation Unit � Value Example

Nominal apparent power Sn MVA 850 Nominal active power Pn MW 720 Nominal voltage UGn kV 21 Rated power factor cos・・n 0.85 Basis speed n U/min 3000 Nominal frequency fn Hz 50 Inertia constant (Time constant)* (generator+turbine) TA (based on Sn) sec 10 Flywheel effect (generator+turbine) GD² Mp m² (t m2) 345 Moment of inertia (generator+turbine) J (I) t m² 86 Stator resistance (warm) ra p.u. 0.002 Aperiodic time constant TG sec 0.5 Stator leakage reactance xas p.u. 0.22 Original data corresponding to the equivalent diagram d-axis: Excitation winding resistance rfd p.u. 0.00097 Excitation winding leakage reactance xfd p.u. 0.149 Damping winding resistance rDd p.u. 0.0202 Damping winding leakage reactance xDd p.u. 0.105 Magnetising reactance xhd p.u. 2.38 Excitation/damper winding coupling reactance xfDd p.u. 0 q-axis: Excitation winding resistance rfq p.u. 0.00470 Excitation winding leakage reactance xfq p.u. 0.924 Damping winding resistance rDq p.u. 0.0107 Damping winding leakage reactance xDq p.u. 0.104 Magnetising reactance xhq p.u. 2.31 Excitation/damper winding coupling reactance xfDq p.u.

Generator data sheetData Type Abbreviation Unit � Value Example

Data derived from equivalent diagram (as alternative to original data) d-axis: Subtransient short circuit time constant Td" sec 0.03 Subtransient reactance unsaturated (saturated) xd" (xd"s) p.u. ( ) 0.28 (0.24) Transient short circuit time constant Td' sec 1.15 Transient reactance unsaturated (saturated) xd' (xd's) p.u. ( ) 0.36 (0.32) Synchronous reactance xd p.u. 2.6 q-axis: Subtransient short circuit time constant Tq" sec 0.08 Subtransient reactance unsaturated (saturated) xq" (xq"s) p.u. ( ) 0.31 (0.27) Transient short circuit time constant Tq' sec 0.76 Transient reactance unsaturated (saturated) xq' (xq's) p.u. ( ) 0.88 (0.77) Synchronous reactance xq p.u. 2.53 for 3 winding model xq" = xq' p.u. Open circuit characteristic: (no load curve) Generator voltage UG (based UGn) p.u. 0.64 0.85 1.0 1.12 1.24 1.36 1.51 Excitation current If (based If0) p.u. 0.64 0.9 1.16 1.44 1.9 2.5 4.05

Generator data accuracy and consistency

DOCU (data testing and verification)

BUS 206 MACHINE 1 :T'Q0= 0.1500

** GENROU ** BUS X-- NAME --X BASEKV MC C O N S S T A T E S206 URBGEN 18.000 1 29-42 13-18

MBASE Z S O R C E X T R A N GENTAP1000.0 0.01000+J 0.25000 0.00000+J 0.00000 1.00000

T'D0 T''D0 T'Q0 T''Q0 H DAMP XD XQ X'D X'Q X''D XL4.50 0.070 0.15 0.050 2.50 0.00 1.4000 1.3500 0.5000 0.7000 0.2500

0.1000

S(1.0) S(1.2)0.0900 0.3800

Sensitivity issues

Subtransient and transient time constants for d and q axis affect the transient stability of model (“shape”of response)Saturation factors S(1.0) and S(1.2) influence the behavior of generators in bad voltage-reactive conditions (reactive capability)Inertia constant H affects the frequency response of the modelArmature resistance must be taken into consideration in case of short circuit and breakers duty assessment, as well as for transient period of dynamic simulation

V-curves

(It should be provided by the generator manufacturer)Testing off generation dataSeparate dos based PSSE utilityGood way to test data consistency

Annotations

It should be noted that:

and it should be also noted:

Helpful equations (for unsaturated reactances):

ldqdqqd XXXXXXX >≥>≥>≥ ""''

dddd TTTT ""'' 00 ≥>≥ qqqq TTTT ""'' 00 ≥>≥

d

ddd X

XTT

"'

"" 0 =d

ddd X

XTT

''' 0 =

q

qqq X

XTT

""" 0 =

q

qqq X

XTT

"'

'' 0 =

Annotations

All rotating masses inertia constant H

GD2 is in [tm2]n is in [rpm]Sn is in [MVA]

In case you have inertia time constant (Tj) know that Tj = 2*H

6

22

1037.1

⋅⋅

⋅=nS

nGDH

Thank youThank you