Detection et localisation des discontinuites dans la simulation temps reel des circuits d'electronique de puissance.

摘要

One of the main sources of inaccuracies in a real-time simulation of power electronic circuits comes from the switching of electronic switches in the circuit. In a fixed step simulation, switching delays may be experienced that lead to the degradation of the simulation results. Consequently, it is of the utmost importance to locate these discontinuities to improve the overall precision of the simulation.A new algorithm that solves these two problems is proposed in this document. It is based on a method used in the field of robotics and uses non-linear system control principles. It detects and locates discontinuities in the following step, based on previous time steps. Moreover, as it uses a polynomial equation for the localisation, it can detect in the time step a number of discontinuities equal to the order of the polynomial.This algorithm has the merit to be totally independent from the numerical method used to solve the differential equations set of the simulation itself. Therefore, it can be used with different methods without compromising its efficiency and its accuracy.Further tests will show that this new algorithm meets its goals with a better accuracy then current algorithms, without incurring significant delays in the simulation. The latter is important in real-time simulations, since time-constrains must not be exceeded for any reason, and accuracy must not be attained at the price of an important additional work load.Many localisation algorithms have been proposed which generally have two common problems. First of all, the time step following the discontinuity must be evaluated in order to locate the discontinuity secondly, these localisation algorithms being somewhat rudimentary, at most one discontinuity can be localised in any simulation time step. If an even number of discontinuity are present in a given time step, detection is impossible.Keywords: real-time simulation, switches, fixed step simulation, switching delays, discontinuities, localisation