A radial feeder is a type of power distribution system in which electrical power flows from a single source or substation to various endpoints or loads in a unidirectional manner.
The term “radial” is used to describe the structure of the feeder, which resembles the branches of a tree radiating outward from a central point.
The figure below displays basic schematic of a radial feeder.
Key characteristics of a radial feeder
- Single Source: Radial feeders have a single source of power, typically a substation or a primary distribution point. The power flows from this central source to the connected loads.
- Unidirectional Flow: Power flows in only one direction along the feeder, from the source towards the endpoints or loads. This one-way flow simplifies the design and operation of the distribution system.
- Branching Structure: The feeder branches out into different circuits as it extends from the source to the loads. Each branch serves a particular area or set of loads.
- Lower Complexity: Radial feeders are often less complex compared to looped or networked distribution systems. The simplicity of the radial structure makes it easier to design and maintain.
- Reliability and Maintenance: The radial configuration simplifies fault location and restoration processes. In the event of a fault or outage, it is easier to identify and isolate the affected section of the feeder for maintenance or repair.
Cons of Radial Feeders
While radial feeders are common in many distribution systems, they do have limitations, especially in terms of reliability and redundancy. If there is a fault or disruption in the feeder, the entire downstream section beyond the fault may experience an outage until the fault is cleared. To improve reliability, some distribution systems incorporate additional features such as sectionalizing devices, re-closers, and alternative feeders.
In contrast to radial feeders, looped or networked distribution systems provide multiple paths for power flow, offering increased redundancy and reliability. The choice of feeder configuration depends on factors such as the size of the distribution system, the nature of the loads, and the desired level of reliability.