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Introduction and First Lecture ECE 633 MODELING AND SIMULATION OF POWER SYSTEM COMPONENTS August 23, 2005 Oleg Wasynczuk Contact Information Oleg Wasynczuk 1285 Electrical Engineering Purdue University West Lafayette, IN 47907-1285 Office/Lab: 765 494-3475 Lab EE58 [email protected] Include ECE633 in subject line http://shay.ecn.purdue.edu/~wasynczu Computer Requirements Ready access to computer with Simulink Version 6 (R14)* – preferred Simulink Version 5 (R13) - acceptable Ability to email compressed folders containing reports and Simulink models (.doc, .pdf, and .mdl files) * We will not use any of the many optional toolboxes Questionnaire – email before Session 2 Name, major, degree objective, expected date of graduation Degree of familiarity with (a) Matlab, (b) Simulink 1 - no clue, 2- ketbd, 3-basics, 4-adept, 5-expert Other simulation languages you use and degree of familiarity Thesis topic (if known), current research and/or job related projects, description of technical interests,… Course expectations Grading 70% Approximately 10 Simulink-based projects Late work will be penalized at 20% per day unless prior arrangements are made 15% Midterm 15% Final Cheating Policy You may discuss projects, including results, with fellow students; however, Sharing of models is not permitted No two people should have the same models Report must be your own thoughts and words First occurrence results in stern warning Second occurrence results in non-passing grade for course Office/Lab Hours (EE58) Tuesday/Thursday 1:30-3:30 pm (tentative) Pre- or Co-requisites by Subject Pre-requisite Co-requisite Junior or senior course in electric machinery and/or power systems such as ECE 321, 425, or 432 Graduate course in energy conversion such as ECE 610 Please let me know if you have questions/concerns Course Outline Will follow spirit of published course outline (see web site) Major topics to be covered include: Distributed- and lumped-parameter models of transmission lines Single- and three-phase transformers Magnetic saturation Induction machines (and drives) Synchronous machines (and drives) Required Text Chee-Mun Ong, Dynamic Simulation of Electric Machinery Using Matlab Simulink, Prentice Hall, 1998, ISBN 0-13-723785-5. First Reading Assignment Read Chapters 1 and 2 before Session 2 Modeling Philosophy for Dynamic Simulation of Power System Components Modeling Versus Simulation Modeling Expression of relevant physical principles in mathematical form (PDE’s, ODE’s, AE’s, circuit/block diagrams) along with pertinent initial/boundary conditions Simulation Application of suitable numerical algorithms to generate numerical solution to set of models Always an approximation (round-off, truncation errors) Synchronous Machine Models Distributed Parameter Coupled Circuit Steady State Z R jX Ee j ~ I ~ V dx f ( x, u) dt ~ ~ V Ee j ZI Power Electronic Models Detailed dxi f ( xi , si ); xi (t0i ) Tx i 1(tfi 1 ) dt (tfi , si 1 ) g( xi , si ) Average Value dx f ( x, u) dt Simulation Approaches Finite-Element-Based Approaches (Ansys, Maxwell, …) Circuit-Based Approaches (Spice, EMTP, Saber, PSIM, Simplorer) System-Based Approaches (Simulink, ACSL, Dymola) Block-diagram and/or differential equation oriented Extensive set of tool boxes including ASMG (Simulink, ACSL) Power System Blockset (Simulink) … Finite-Element Based Approaches FEA M 4000-10000 Nodes da Sa u dt Simulation Approaches Finite-Element-Based Approaches (Ansys, Maxwell, …) Circuit-Based Approaches (Spice, EMTP, Saber, PSIM, Simplorer) System-Based Approaches (Simulink, ACSL, Dymola) Block-diagram and/or differential equation oriented Extensive set of tool boxes including ASMG (Simulink, ACSL) Power System Blockset (Simulink) … Circuit-Based Approaches Circuit-Based Approaches Example Subsystem (Motor Controller) Circuit-Based Approaches Circuit-Based Approaches Resistor-Companion Circuit Circuit-Based Approaches Update Formula iS g1 g 2 g 3 g S i S i7 i 8 i9 gS g1 g2 g 4 g5 g6 g 3 v1 v2 v5 k 1 O(n3) computational complexity where n = number of non-datum nodes Simulation Approaches Finite-Element-Based Approaches (Ansys, Maxwell, …) Circuit-Based Approaches (Spice, Saber, PSIM, Simplorer) System-Based Approaches (Simulink, ACSL, Dymola) Block-diagram and/or differential equation oriented Extensive set of tool boxes including ASMG (Simlink, ACSL) Power System Blockset (Simulink) PLEX (Simulink) … System-Based Approaches Hierarchical system definition System-Based Approaches Common Simulink Component Models System-Based Approaches System-Based Approaches When user starts model, Simulink applies selected integration algorithm to approximate solution at discrete but not necessarily uniform instants of time General Multi-step Update Formula: x k 1 p 1 i x i 0 k i p 1 h i f x k i , t k i i 1 Explicit if 1 0 Implicit algorithms require solution of nonlinear equation (dimension = number of states) at each time step. Newton-Raphson iteration generally used. System-Based Approaches Choice of coefficients determines name of algorithm Many different algorithms out there See Appendix A for brief introduction System-Based Approaches Stiff System: A system with both fast and slow dynamics Stiffly Stable Integration Algorithm: the ability to increase the time step after fast transients subside Stiffly Stable Algorithms are implicit! System-Based Approaches Computational Complexity System-Based Approaches System-Based Approaches Simulink Fixed-Step Algorithms Shampine and Reichelt, The MATLAB ODE Suite, SIAM J. Sci. Comput., Vol. 18, No. 1, pp. 1-22, January 1997. System-Based Approaches Simulink Variable-Step Algorithms Shampine and Reichelt, The MATLAB ODE Suite, SIAM J. Sci. Comput., Vol. 18, No. 1, pp. 1-22, January 1997. Simulation Approaches (Conclusion) Co-simulation Finite Element/Circuit Circuit/System Distributed Heterogeneous Simulation Any combination of the above mentioned approaches