In this paper, we propose a generalized index independent stability condition for a descriptor systemwithout any transformations of system matrices. First, the generalized Lyapunov equation with a specific right-handed matrix form is considered. Furthermore, the existence theorem and the necessary and sufficient conditions for asymptotically stable descriptor systems are presented. Finally, some suitable examples are used to show the validity of the proposed method.Keywords: generalized Lyapunov equation, descriptor systems, index independent stability condition I. INTRODUCTIUON The singular system model is a natural representation of dynamical systems and can better describe a large class of systems than state-space ones do. Studying the stability problem for singular systems is much more complicated than that for state space systems because it requires consideration not only of stability but also regularity absence of impulses for continuoustime singular systems and causality for discrete-time singular systems which may affect the stability of the system. For these reasons, many studies have investigated the generalized Lyapunov equation and stability of descriptor systems [1][2][3][4]. When the stability and control design problems of a descriptor system are considered, the standard Lyapunov equation is extended to the generalized Lyapunov equation [5][6][7][8][9]. Such descriptor systems naturally occur in many applications, such as multi-body dynamics, electrical circuit simulation, chemical engineering, and semi-discretization of partial differential equations [10][11][12]. The
GALE (Generalized Algebraic Lyapunov Equation),has been considered for the stability analysis, wherein E, A, G are given matricesand X is an unknown matrix. Many numerical algorithms have been developed to solve the GALE with a nonsingular matrix E. However, little attention has been paid to the generalized Lyapunov equation for a singular matrix E ([1, [13][14][15][16][17] [14]. Unfortunately, these equations are limited to pencilswith an index of at most one [1,6,14,15]. Recently,a projected Lyapunov equation,the existence of a solution for stability therein, and its applications have been investigated [17,18]. This method is independent of anindex; however, the primary difficulty in applying these approaches [1,6,14,15,17,18] is that the Weierstrass canonical form [19] needs to be found before aa solution of the Lyapunov equation can be obtained. Therefore, the objective of this paper is to propose a generalized index independentstability condition for a descriptor system without transformation of the system matrices into a Weierstrass canonical form.In this paper, we propose the necessary and sufficient conditions for the asymptotic stability of descriptor systemswith any index, without any transformations. The generalized Lyapunov equation with a specific right-handed matrix form is discussed, and the existence of the solution is proved. In section 2, the descriptor system and the mathematical preliminaries are discus...