Radial ăn phân phối được đặc trưng bởi chỉ có một con đường cho năng lượng chảy từ nguồn (trạm biến áp phân phối) cho từng khách hàng. Một hệ thống phân phối điển hình sẽ bao gồm một hoặc nhiều các trạm biến áp phân phối bao gồm một hoặc nhiều "ăn" Các thành phần của các feeder. có thể bao gồm sau đây: | 21 Distribution System Modeling and Analysis William H. Kersting New Mexico State University Line Impedance Shunt Admittance Line Segment Models Step-Voltage Regulators Transformer Bank Connections Load Models Shunt Capacitor Models Power-Flow Analysis Modeling Radial distribution feeders are characterized by having only one path for power to flow from the source distribution substation to each customer. A typical distribution system will consist of one or more distribution substations consisting of one or more feeders. Components of the feeder may consist of the following Three-phase primary main feeder Three-phase two-phase V phase and single-phase laterals Step-type voltage regulators or load tap changing transformer LTC In-line transformers Shunt capacitor banks Three-phase two-phase and single-phase loads Distribution transformers step-down to customer s voltage The loading of a distribution feeder is inherently unbalanced because of the large number of unequal single-phase loads that must be served. An additional unbalance is introduced by the nonequilateral conductor spacings of the three-phase overhead and underground line segments. Because of the nature of the distribution system conventional power-flow and short-circuit programs used for transmission system studies are not adequate. Such programs display poor convergence characteristics for radial systems. The programs also assume a perfectly balanced system so that a single-phase equivalent system is used. If a distribution engineer is to be able to perform accurate power-flow and short-circuit studies it is imperative that the distribution feeder be modeled as accurately as possible. This means that three-phase models of the major components must be utilized. Three-phase models for the major components will be developed in the following sections. The models will be developed in the phase frame rather than applying the method of symmetrical components. Figure .
