Abstract :
It is believed that the future will bring a rapid growth of load and that this makes the present a suitable moment to analyse city distribution methods, settle a policy of development and consider the possibility of standardization. The main object of the paper is, therefore, to design a system suitable for adoption as a standard and to consider how far existing systems may gradually be brought into line with it. The various sections of a city distribution system are reviewed in sequence from the consumer to the main transmission system (or local power station) under the following headings, particular attention being given to the design of a system lay-out which facilitates expansion to deal with growing load:? (a) The type and voltage of current to be delivered to the consumers. (b) The general lay-out of the low-voltage distribution system. (c) The general lay-out of the high-voltage distribution system for feeding the low-voltage system through transforming centres. (d) The voltage to be adopted for supplying the transforming centres from the main substations on the transmission system. (e) The size and spacing of transforming centres. It is believed that the future will bring a rapid growth of load and that this makes the present a suitable moment to analyse city distribution methods, settle a policy of development and consider the possibility of standardization. The main object of the paper is, therefore, to design a system suitable for adoption as a standard and to consider how far existing systems may gradually be brought into line with it. The various sections of a city distribution system are reviewed in sequence from the consumer to the main transmission system (or local power station) under the following headings, particular attention being given to the design of a system lay-out which facilitates expansion to deal with growing load:? (a) The type and voltage of current to be delivered to the consumers. (b) The general lay-out of the low-voltage distribut- ion system. (c) The general lay-out of the high-voltage distribution system for feeding the low-voltage system through transforming centres. (d) The voltage to be adopted for supplying the transforming centres from the main substations on the transmission system. (e) The size and spacing of transforming centres. The desirable characteristics are then summarized so as to outline the proposed ?standard? system. Suggested standards are also laid down for the capacity of the individual parts in areas of different type and load density. The above is followed by three short studies, based on the detailed calculations necessitated by the main investigation. These deal with (i) the relative costs of the different elements of the distribution system, (ii) the effect of load density on the cost of distribution, and (iii) the relative costs of direct-current and alternating-current distribution. In conclusion, some consideration is given to the general question of bringing existing city distribution systems into line with the proposed standard system with the object of attaining, ultimately, complete standardization of distribution throughout the country.
