  This paper focuses on the Partitioned-Solution Approach (PSA) employed for
the Time-Domain Simulation (TDS) of dynamic power system models. In PSA,
differential equations are solved at each step of the TDS for state variables,
whereas algebraic equations are solved separately. The goal of this paper is to
propose a novel, matrix-pencil based technique to study numerical stability and
accuracy of PSA in a unified way. The proposed technique quantifies the
numerical deformation that PSA-based methods introduce to the dynamics of the
power system model, and allows estimating useful upper time step bounds that
achieve prescribed simulation accuracy criteria. The family of
Predictor-Corrector (PC) methods, which is commonly applied in practical
implementations of PSA, is utilized to illustrate the proposed technique.
Simulations are carried out on the IEEE 39-bus system, as well as on a 1479-bus
model of the All-Island Irish Transmission System (AIITS).
