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Inversion of the nodal admittance matrix by the use of state equations
Author(s) -
Neill T. B. M.,
Bond D. J.
Publication year - 1973
Publication title -
international journal of circuit theory and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.364
H-Index - 52
eISSN - 1097-007X
pISSN - 0098-9886
DOI - 10.1002/cta.4490010305
Subject(s) - admittance parameters , modified nodal analysis , nodal analysis , mathematics , laplace transform , matrix (chemical analysis) , admittance , state variable , mathematical analysis , rational function , control theory (sociology) , electrical impedance , nodal , computer science , voltage , physics , engineering , electronic engineering , medicine , materials science , thermodynamics , control (management) , quantum mechanics , artificial intelligence , composite material , anatomy
Abstract Previous methods 1–4 for inverting the nodal admittance matrix when the elements are rational functions of the Laplace transform variable s used pivotal techniques. Problems of numerical stability made this type of approach suitable only for quite small circuits. A new method based on diagonalizing the A‐matrix of a set of state equations defining the circuit has greatly improved stability. The state equations are derived directly from the nodal equations using a newly developed algorithm. These equations are then used to compute the inverse of the nodal admittance matrix as a matrix of rational functions of s . An example is presented of the application of these methods to a system of 21 degrees of freedom.