Power Line Medium Research Articles

Robot poruszający się po napowietrznych liniach energetycznych średniego i wysokiego napięcia

Robot poruszający się po napowietrznych liniach energetycznych średniego i wysokiego napięcia

Design computer network by using powerline

In this paper, a powerline medium computer network system is introduced. By using the AC power supply line which already exist and a special physical interface communication networking among many computer stations can by done conveniently. Based on the analysis of powerline characteristics, the paper discusses the physical interface that is the key technologies connected with computer network. It includes coupled circuit and filter circuit which are the key link of isolating alternating current power and filtering the interfered noise. This system is designed according to CSMA network communication protocol and the high-layer protocol software is discussed in detail. Many experiments as screen conversations, disk files transmission and shared print have proved that the performance of the system is good, the data transmission is correct.

Determination of the optimum packet length and buffer sizes for the consumer electronics bus

Two issues related to the implementation of the consumer electronics bus (CEBus) on a power line medium are considered. These are the determination of (a) optimum packet length and (b) optimum buffer size. The delay-throughput characteristics of each of the three priority classes of messages, i.e., HIGH, STANDARD, and DEFERRED, have been measured by simulation experiments for various packet lengths and buffer sizes. This way optimum packet length and buffer sizes have been deduced. The optimum buffer size at a node corresponds to the best overall performance for messages of all priorities in terms of overflow rates at the buffers of the nodes with respect to increasing offered loads. The optimum packet length has been found to be between 276 and 400 USTs (unit symbol times), i.e., 184 and 286 b. If 276 USTs is assigned as the optimum packet length, the optimum buffer size at each node is found to be between 150 and 200 packets, i.e., approximately 28 to 37 kb. >

Automating the power grid: Real-time communication between customers, the electricity grid, and power plants can cut costs for both supplier and user; the technology options are many

The benefits that would accrue from real-time monitoring and control of the distribution system are listed. The communication techniques that have been investigated for this purpose are seen as falling into four groups: physically connected media, including wire lines, coaxial cable, and fiber-optic cable; power-line media, including distribution-line carrier communication and power-frequency communications; electromagnetic propagation media, including UHF/VHF radio, AM/VHF radio, and spread-spectrum satellite radio; and common-carrier media, primarily telephone company lines. The advantages and disadvantages of each of these techniques are discussed. To illustrate the various factors involved, the author discusses the automation of the Colorado Springs Department of Utilities.