UTILIZATION OF AUTOMATIC DIFFERENTIATION IN VTB SIMULATION ENVIRONMENT

摘要

This paper presents an application of a symbolically assisted computational procedure. Specifically, an Automatic Differentiation technique is used to generate Algebraic Companion models in a time domain simulation algorithm. The ACF is a generalization of the resistive companion forms used in time-domain simulators. The method has been implemented within the VTB simulation environment. The Algebraic Companion form results from the proper integration of the differential equations of any system component (implicit integration). The process requires the computation of the jacobian (sensitivity) matrices of the system component. Since modern power circuit components are often nonlinear, the efficient computation of the derivatives affects greatly the overall computational efficiency. This paper presents an application of the automatic differentiation technique, which results in large savings in the computation of the required derivatives and eliminates human intervention and therefore the possibility of errors. The algorithm for efficient generation of the Algebraic Companion models, which utilizes automatic differentiation method and enables VTB users to introduce their own models, is described. Sample results are also provided to illustrate the use and effectiveness of the developed software.