Assessing the impacts of nonlinear loads on power quality in commercial buildings-An overview

The characteristics and effects of nonlinear loads in the commercial office environment are discussed. The interaction of distorted currents drawn by these loads with the power system are described. An approximate approach for evaluating potential problems within a given facility is discussed, which, while not rigorous, can be used as a screening tool by building designers and engineers to make assessments of the potential for harmonic problems. Effects of high relative levels of harmonic current generation in commercial buildings include harmonic voltage distortion, transformer and motor overheating, and neutral conductor overloading. Reasonable estimates of the impacts of nonlinear loads can be made from generalized harmonic current source characteristics of three basic nonlinear types. Interactions with the electric power system can be predicted with simplified representations of the building electrical system.<>