ABSTRACT
A distribution feeder provides service to unbalanced three-phase, two-phase, and single-phase loads over untransposed three-phase, two-phase, and single-phase line segments. All of the approximate methods of modeling and analysis will assume perfectly balanced three-phase systems. To analyze these conditions as precisely as possible, it will be necessary to model all three phases of the feeder as accurately as possible. This chapter focuses on developing some of the approximate methods. It discusses the development of the exact models and analysis. The chapter has been devoted to the development of some useful techniques for computing the voltage drop and power loss of line segments with uniformly distributed loads and for geometric areas with constant load densities. These techniques are very useful for making quick calculations that will be "ballpark" values. Many times, only a ballpark value is needed. More times than not, once inside the ballpark, more precise values of voltage drop and power loss are needed.
