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PSSC 500 PSS®E Introduction to Power Flow and Steady State Analysis.The PSS®E Power Flow and Steady State Analysis courseis designed to familiarize new users with the Power Flowand Fault Analysis features of the PSS®E program.Participants gain experience through handson exercises.
Tab 12 – PV & QV Analyses © 2013 Siemens Industry, Inc All rights reserved Investigate relationship between power transfer and voltages As transfer (or load) increases, system reactive consumption increases and voltages fall Find maximum power transfer level before voltage collapse – knee of the curve Perform many power flow solutions and plot results V Knee of the Curve Transfer Limit © 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) PV Curves P Siemens Power Academy TD – NA - PSSC 500 PSS®E Introduction to Power Flow and Steady State Analysis 12-2 Prepare power flow base case Run DFAX to input subsystem, monitored element and contingency description files Select PV analysis options Initiate calculations View graphical results Siemens Power Academy TD – NA - PSSC 500 PSS®E Introduction to Power Flow and Steady State Analysis © 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) PV Analysis Procedures 12-3 PV Analysis Run Options Power Flow Solution Stopping Criteria Transfer Dispatch Method Subsystem Selection Input & Output Files Siemens Power Academy TD – NA - PSSC 500 PSSđE Introduction to Power Flow and Steady State Analysis â 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) Transfer Increment 12-4 Solution engine – FDNS, FNSL, optimized FDNS Automatic adjustments options for base case & contingency case – taps, area interchange, switched shunts, etc Generator var limit Mismatch tolerance Siemens Power Academy TD – NA - PSSC 500 PSSđE Introduction to Power Flow and Steady State Analysis â 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) PV Analysis – Power Flow Solution Options 12-5 PV Analysis: Transfer Dispatch Methods Dispatch methods: DFAX generation and/or load Scale by machines MW, MBASE, reserve (PMAX-PGEN) Observe MW Limits Economic dispatch (ECDI) file Siemens Power Academy TD – NA - PSSC 500 PSS®E Introduction to Power Flow and Steady State Analysis © 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) Subsystems - source & sink (from DFX file) 12-6 Initial transfer increment - Adjust “dispatch” in source & sink by normal step size Tolerance - If solution at normal step fails to converge, retry from last converged point using binary search technique Negative minimum incremental transfer allowed - Extend PV curve below zero transfer level Siemens Power Academy TD – NA - PSSC 500 PSS®E Introduction to Power Flow and Steady State Analysis © 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) PV Analysis: Transfer Increments 12-7 “Transfer increment tolerance” reached “Maximum incremental transfer” reached “Minimum monitored bus voltage” reached (optional) List of buses defined in MON file Note: Does not use voltage limits in MON file “Branch loading threshold” reached (optional) List of branches defined in MON file Siemens Power Academy TD – NA - PSSC 500 PSS®E Introduction to Power Flow and Steady State Analysis © 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) PV Analysis – Stopping Criteria 12-8 PV Analysis - Graphical Output Select Base & Cont Cases Select Bus or Generator Data Points for Curve Selected Siemens Power Academy TD – NA - PSSC 500 PSS®E Introduction to Power Flow and Steady State Analysis © 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) Select Graph Type 12-9 More Graphics for PV / QV Analysis For multi-graph Siemens Power Academy TD – NA - PSSC 500 PSS®E Introduction to Power Flow and Steady State Analysis © 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) Curves can be displayed singularly or together 12-10 Exporting PV/QV Results to Excel Select data/results to export: Define data/results file Define Excel workbook file Select quantities to export Select Contingencies Siemens Power Academy TD – NA - PSSC 500 PSS®E Introduction to Power Flow and Steady State Analysis © 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) PV or QV Solution Results 12-11 All run options retrieved from PV file Siemens Power Academy TD – NA - PSSC 500 PSS®E Introduction to Power Flow and Steady State Analysis © 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) Retrieving PV Analysis Results from a File 12-12 Use transfer adjustments similar to those in PV analysis Choose a desired incremental transfer level Changes will be applied to base case to create a new power flow at desired transfer level Suitable for detailed investigations after PV analysis Siemens Power Academy TD – NA - PSSC 500 PSS®E Introduction to Power Flow and Steady State Analysis © 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) Model a Given Transfer Level 12-13 QV Curves Develop curves for critical buses by running a series of power flows Model synchronous condenser and vary voltage setpoint Solve power flow and observe MVar output Reactive reserve is difference between reactive supply (Q=0) and minimum point on QV curve Siemens Power Academy TD – NA - PSSC 500 PSS®E Introduction to Power Flow and Steady State Analysis © 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) Useful tool for analyzing voltage collapse 12-14 QV Analysis Procedures Prepare power flow base case Select QV analysis options Begin calculations View graphical results Siemens Power Academy TD – NA - PSSC 500 PSS®E Introduction to Power Flow and Steady State Analysis © 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) Run DFAX to input subsystem, monitored element and contingency description files 12-15 QV Analysis Run Options © 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) Select Study Bus Power Flow Solution Options Input & Output Files Voltage Decrement Siemens Power Academy TD – NA - PSSC 500 PSS®E Introduction to Power Flow and Steady State Analysis 12-16 QV Analysis – Starting and Stopping Decreases voltage setpoint in steps of DLTAV and resolves Stops when solution fails to converge or voltage setpoint reaches VLO Siemens Power Academy TD – NA - PSSC 500 PSS®E Introduction to Power Flow and Steady State Analysis © 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) Sets study bus voltage at VHI and solves power flow 12-17 Select Base & Cont Cases Y-axis Elements Selected Display Q-V Data Points Siemens Power Academy TD – NA - PSSC 500 PSS®E Introduction to Power Flow and Steady State Analysis © 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) QV Analysis Output Options 12-18 Problem 12-1 Q-V Analysis Pick up case EXER12-1.SAV Use Q-V Analysis to create Q-V curve at bus 205 Use EXER12-1.SUB, EXER12-1.MON, EXER12-1.CON to create DFX file Select VHI=1.05, VLO=0.7, and DLTAV=0.01 Select Fixed Slope Decoupled Newton Solution method, applying var limits immediately Leave other solution options at default settings Change plot range for V-axis to 0.7 and 1.1 Change plot range for Q-axis to 600 and 1000, with Grid Step of 50 Make sure “Axis (grid start) place” is at “Bottom.” Based on the curve, what is the minimum shunt compensation required to prevent voltage collapse at Bus 205 during outage of generator at Bus 206 (the only contingency defined in EXER12-1.CON)? Siemens Power Academy TD – NA - PSSC 500 PSSđE Introduction to Power Flow and Steady State Analysis â 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) Determine the minimum reactive compensation needed to maintain converged power flow solution at Bus 205 when generator at Bus 206 is outaged 12-19 Contingency of this generator QV-Analysis Bus Siemens Power Academy TD – NA - PSSC 500 PSS®E Introduction to Power Flow and Steady State Analysis © 2013 Siemens Industry, Inc., Siemens Power Technologies International (Siemens PTI) Problem 12-1 Q-V Analysis (continued) 12-20