A Modeling Toolkit for Comparing Ac vs. Dc Electrical Distribution Efficiency in Buildings

This paper describes a new modeling toolkit for comparing the performance and electrical efficiency of AC, DC and hybrid AC/DC distribution systems for buildings, Building Electrical Efficiency Analysis Model (BEEAM). To account for harmonics in currents or voltages arising from nonlinear devices, the toolkit implements harmonic power flow along with nonlinear device behavioral descriptions derived from empirical measurements. This article describes the framework, network equations, device representations, and an implementation of the toolkit in an open source software package, including a component library and graphical interface for creating circuits. Simulations of electrical behavior, device and system efficiencies using the toolkit are compared with experimental measurements, emulating a small office environment under a variety of operating and load configurations. Based on the correspondence between simulation and measurement, the toolkit is being proposed by the authors as a potentially useful tool for comparing efficiency in AC, DC and hybrid AC/DC distribution systems in buildings.