Universidade Federal do Rio Grande do Sul, Dep to

Differential-algebraic equations (DAE) systems arise naturally from modelling many dynamic systems and are more difficult to handle than ordinary differential equation (ODE) systems. For instance, it is well known that difficulty arises when DAE's are solved with inconsistent initial values. Furthermore, the solution of high-index problems requires specially designed integration methods or index reduction, which are usually limited. In this work, alternatives for initialising and solving general high-index DAE systems are studied and a new algorithm for index analysis and reduction is introduced