O. Wasynczuk, E. A. Walters, PC Krause and Associates, Inc; H. J. Hegner, Naval Surface Warfare Center A new approach of automatically generating state-space models of power circuits and systems is presented. In this approach, the composite system state equations are established algorithmically given the standard node incidence matrix and elementary branch data (e.g. resistances, inductances, back emf’s). The resulting state equations can be solved using a variety of numerical techniques or commercially available computer simulation programs. An example system consisting of a three-phase generator and rectifier load is used to illustrate this approach. Experimental verification is also provided. Proceedings 32nd Intersociety Energy Conversion Engineering Conference, vol. 1, July 1997, pp....
Read MoreAn Automated State Model Generation Algorithm for Simulation/Analysis of Power Systems with Power Electronic Components
S. D. Pekarek, E. A. Walters, T. L. Skvarenina, O. Wasynczuk, PC Krause and Associates, Inc. In this paper, a recently developed algorithmic method of deriving the state equations of power systems containing power electronic components is described. Therein the system is described by the pertinent branch parameters and the circuit topology; however, unlike circuit-based algorithms, the difference equations are not implemented at the branch level. Instead, the composite system state equations are established. A demonstration of the computer implementation of this algorithm to model a variable-speed, constant-frequency aircraft generation system is described. Because of the large number of states and complexity of the system, particular attention is placed on the development of a model structure which provides optimal simulation efficiency. SAE Transactions Journal of Aerospace, sec. 1, vol. 107, Month 1998, pp....
Read MoreContinuous State-Space Modeling of Switched Electric Networks
J. Jatskevich, O. Wasynczuk, E. A. Walters, C. E. Lucas, PC Krause and Associates, Inc. An Automated State Model Generator (ASMG) is a tool for modeling and analysis of lumped-parameter power-electronic-based systems. In this modeling approach, the minimal state-space representation of the overall system is generated automatically and updated dynamically based upon the topological state of the system. However, due to the changing topology, simulation of a switched circuit using the ASMG requires the concatenation of solutions to the initial value problems (IVPs) corresponding to the time intervals between commutations. In this paper, a transformation of state variables is derived such that the states are continuous throughout the simulation process. This feature eliminates the need to re-initialize the ODE solver. The continuous state algorithm is verified on a high-pulse-count power supply and sets the stage for state-space averaging and system-level analysis of switched circuits. Proceedings IEEE International Conference on Control Applications, vol. 1, September 2000, pp....
Read MoreAutomated State Model Generator for Simulation and Analysis of Power Electronic Systems
J. Jatskevich, University of British Columbia; O. Wasynczuk, Purdue University; C. E. Lucas, E. A. Walters, PC Krause and Associates, Inc. An algorithmic method of developing the state equations of complex power circuits and systems has recently been developed. In this approach, referred to as he Automated State Model Generator (ASMG), the system is described by the pertinent branch parameters and the circuit topology; however, unlike existing circuit-based approaches, the difference equations are not implemented at the branch level. Instead, the composite system state equations are established automatically and updated dynamically for each new topology of the switching network. Since the state equations are available, linearization, eigensystem analysis, and model-order reduction can be performed quickly and conveniently at the system level. In addition, it becomes possible to identify the operational modes of converters and inverters based on the cyclically repeated sequence of topologies. The ASMG includes a built-in switching logic for common power-electronic switching devices. The proposed simulation approach is particularly effective when modeling advanced power electronic systems that include special-purpose multi-phase electrical machines, transformers, and other components that are not available in the libraries of commonly used circuit simulators. An ASMG toolbox that is compatible with MATLAB/SIMULINK has been developed and used to implement a detailed simulation of a 6-phase generator/rectifier system. Proceedings 6th International Conference of Computational Methods for the Solution of Electrical and Electromagnetic Engineering Problems, September 10-12, 2003, Split, Croatia, WIT Press, pp....
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