Because bulk architectures lack the flexibility and the cost effectiveness that future telephone networks will demand, the importance of distributed, remote power systems will continue to increase Two apparently contradictory trends will influence future compact battery plants The first is increasing product complexity due to the remote and sometimes harsh environment of electronic enclosures The second is intense competitive pressures for lower cost The only way to address both concerns simultaneously is for the power vendors to invest substantial development time into a carefully thought out architecture, to create a well engineered and thoroughly tested system solution A dual voltage architecture capable of providing or omitting a large number of features that must be available in future compact power systems is outlined >

Architecture of a compact battery plant system designed for the diverse customer premise market

Publisher Summary Power systems are a crucial element of any communications network, be the latter large or small, and they are one of the few elements capable of causing a total failure or malfunction of even the most sophisticated network. In general, there are no wholly defined international standards for complete power systems for any given communications service. These tend to be set by individual companies, or national administrations, although they inevitably follow a trend. Where a public AC mains supply exists, it is normal to use this as the primary source of energy for a communications system, although rarely in an unmodified form. The level of standby plant provision is obviously related to the probability and duration of mains failures. Nevertheless, such assessments do give a yard stick to assess the type and nature of AC standby plant necessary to meet given mean time between failure targets. Control systems for modern installations can give standby engine generator plant, which is fully automatic in operation. Built in monitors are typically set to detect that the mains has fallen below say 10%, (or gone above 6%), and signal the engine plant to start. Once the plant has reached stable and optimum operating conditions, the load would be switched to the generator output. Plant can be automatically restored to the normal quiescent condition once the mains have returned to within acceptable limits for a predetermined time or the system can be restored manually as determined by the operator.

Telecommunication power systems

A new battery power plant architecture, defined by the term polyvalent, which provides the benefits of common building blocks while meeting power system applications ranging from small distributed sites to large central office applications is introduced. The plant allows for reduction in training and minimizes proliferation of diverse power equipment in a telephone company's network. The emerging European Telecommunications Standards Institute (ETSI) requirements are discussed, and information on specific areas where the ETSI requirements differ from the standard used in the US are provided. The harmonization of equipment standards will create new opportunities for equipment manufacturers in markets previously closed. >

A new DC power plant architecture for centralized or decentralized applications

Consideration is given to the power distribution scheme of the new international telecommunications center. A comparison is made between the conventional centralized power architecture and the new decentralized type. The comparison is made carefully taking account of major parameters: reliability, cost, influence of power damage, the space occupied, and efficiency. The authors have concluded that a centralized type of power system is the most favorable at present because of lower cost and the smaller amount of space required. >

Power distribution scheme for the KDD's new international telecommunications center

The authors examine the problem of centralization or decentralization of no-break power sources in a telecommunications plant. Hierarchic distribution of power conversion units in the system is also discussed. Two kinds of power systems are compared: one large no-break power plant supplying DC power to all the telecommunication equipment installed in the plant; and many small no-break power plants, each one having the same system architecture as the above-mentioned large plant, but each integrated directly into the telecommunication equipment it supplies. The comparison is made taking into account the major decision parameters, e.g. costs of equipment, plant, operation, maintenance and repair, and costs of obsolescence together with safety, reliability, and availability. The authors propose a solution based on today's state of the art and on the conditions in the foreseeable future, using a decision-making method for a rapidly changing technological environment. >

M. Bonetti

Papers

Telecommunications power system: one large plant or many small ones?