Stability analysis of thyristor device control systems

In this paper, a new method is presented for the study of the stability of systems controlled by thyristors. A nonlinear continuous data model (Lefevre, Bertrand & Ismail, 1973) is proposed for continuous and discontinuous operations. Generally, the system is represented by its transcendental equations at the consecutive instants tnand tn+1. Solving these equations, a module M is obtained which represents the system stability either locally or globally. A simple software program is presented which simplifies the necessary calculations to a high degree of accuracy.The proposed method is used to study both first- and second-order syvtems. In particular a separately excited DC motor is considered.