Principles and Practical Considerations for the Use of Time-Domain Simulation Software Programs in Power System Dynamics Analysis

Dynamic simulations have played an important role for many years in assessing the stability and security of power systems. Such studies are usually performed by power system engineers using mathematical simulation models within available software programs. There are two commonly used time-domain power system simulation software programs:PDT and EMT software programs are widely used to conduct various types of studies in the time-domain. Conceptually, both methods can be based upon a solved load flow of the system being modeled, and the goal is to simulate the system’s dynamic response to a disturbance. However, as it will be explained later in this chapter, there are significant differences in the way that each software program solves the system equations, and this impacts the accuracy and applicability of the results as well as their computational burden.