Transient and Frequency Analysis of Multi-Coil Systems by Means of Generalized Circuit Elements and Eigenvectors

摘要

A complex eigenvector method is presented which has been developed into a circuit analysis program suitable for transient and frequency analysis of multi-coil systems which may contain a large number of mutual inductances and stray capacitances. Relevant modeling problems are discussed. Systems of this type usually have a large eigenvalue spread. It is shown that conventional numerical integration methods for such stiff systems would require an excessive number of time steps. A generalized branch concept is created to reduce the effort required for programming and data specifications. It makes it possible to write a simplified matrix state equation by inspection in a simple numerical form which is completed by the program. Multi-input multi-output state variable feedback as well as non-linear and time dependent circuit parameters are within the capabilities of this method. The computer program has been used to evaluate the damping characteristics, natural frequencies and voltage distribution for the ohmic heating coil system of the Doublet III fusion research device under various transient and periodic excitation conditions. (ERA citation 05:005173)