Group Regulation of Urban 4-KV Feeders

The best way, theoretically, to maintain ideal voltage conditions on a given feeder is to equip each of its phases with a regulator. However, other factors in addition to voltage regulation must be considered in a practical co-ordinated design. The engineering approach toward accomplishing a purpose with the minimum physical facilities must be adhered to both in improving an old substation and in designing a new one. A very strong incentive to streamline and simplify substations as an outgrowth of congested conditions in old stations and as a means of reducing time and money requirements in building new ones, finds an ally in the closely coupled and densely loaded condition of today´s distribution system. The availability of economical and reliable tap-changing equipment and the existence of short distribution feeders together permit, by group regulation, realization of very significant simplifications of substation design, construction, and operation. The preceding examples of conversion to group regulation have three important points in common: 1. The underlying reasons for the changes have been to make space and/or eliminate indoor oil-filled equipment. 2. The work to regroup the feeders by bus section voltage has been an engineering problem only, inasmuch as the change from open-type bus work to metal-enclosed switchgear required moving the feeders physically within the three stations regardless of voltage requirements. 3. Voltage conditions have improved thus far as normal development and changes of the distribution system have occurred during group operation.