Systematic modeling and symbolically assisted simulation of power systems

Large disturbance behavior of power systems often involves complex interactions between continuous dynamics and discrete events. Such behavior can be captured in a systematic way by a model that consists of differential, switched algebraic and state-reset (DSAR) equations. The paper presents a practical object-oriented approach to implementing the DSAR model. Each component of a system can be modeled autonomously. Connections between components are established by simple algebraic equations. Simulation of the model using numerically robust implicit integration requires the generation of partial derivatives. The object-oriented model structure allows this differentiation to be achieved symbolically without sacrificing simulation speed.

I. Introduction

Power systems frequently exhibit interactions between continuous dynamics and discrete events. They are an important class of hybrid systems. Typically the continuous dynamics relate to components that obey physical laws. Event-driven discrete behavior results from logical rules that govern the system. Examples in this latter category include protection logic, supervisory control and saturation limits.