The current power grid is facing many challenges that it was not designed or engineered to handle which range from congestions and major blackouts to the overwhelming increase in demand and security concerns. The curr...The current power grid is facing many challenges that it was not designed or engineered to handle which range from congestions and major blackouts to the overwhelming increase in demand and security concerns. The current electric grid was established before the 1960’s. It is believed that the electric grid is the most complex and gigantic machine ever made in human history;it consists of wires, cables, towers, transformers and circuit breakers installed together in outdated manner. During the 60’s, computers and sensors were used to monitor and slightly control the grid;however, fifty years later these sensors are considered less than ideal. Presented here is a review of the smart grid communication network in terms of configuration, bandwidth and latency requirements as well as the technology used. We simulate the access layer of the smart grid net-work and show that no single available communication technology can be used for all layers of the smart grid;thus, different technologies for different layers are needed. A new protocol for optimizing the smart grid is recommended.展开更多
The radiating cable (or leaky feeder) is the leading solution for distributed broadband wireless access in underground mines and tunnels. The traditional radiating cable has equally spaced slots along its axis radiati...The radiating cable (or leaky feeder) is the leading solution for distributed broadband wireless access in underground mines and tunnels. The traditional radiating cable has equally spaced slots along its axis radiating evenly. However, with the new requirement for tracking and localization of miners, this paper shows how to modify the leaky feeder to function as a beam forming antenna array by appropriately optimizing the slot spacing. Optimizing the leaky feeder slot distances using Genetic algorithm has a good impact on the channel parameters, making it an excellent choice for leaky feeder antennas. Linear, as well as bent practical leaky feeder shapes, were considered, and we tested five different optimization algorithms and compared side lobe energies, varying the slot distance which had an impact on side lobe level. Also, we derived the expression for the BER, spectral efficiency and throughput considering a time-varying wireless channel. We observed that as the radius of curvature of the feeder increased (approaching a straight line), the spectral efficiency decreased as expected. Interestingly different optimization algorithms perform differently at different carrier frequencies. An optimization method should be chosen according to the required goal to be achieved (maintaining uniform equal power along the cable, or a more directed beam, or using a certain frequency of operation).展开更多
文摘The current power grid is facing many challenges that it was not designed or engineered to handle which range from congestions and major blackouts to the overwhelming increase in demand and security concerns. The current electric grid was established before the 1960’s. It is believed that the electric grid is the most complex and gigantic machine ever made in human history;it consists of wires, cables, towers, transformers and circuit breakers installed together in outdated manner. During the 60’s, computers and sensors were used to monitor and slightly control the grid;however, fifty years later these sensors are considered less than ideal. Presented here is a review of the smart grid communication network in terms of configuration, bandwidth and latency requirements as well as the technology used. We simulate the access layer of the smart grid net-work and show that no single available communication technology can be used for all layers of the smart grid;thus, different technologies for different layers are needed. A new protocol for optimizing the smart grid is recommended.
文摘The radiating cable (or leaky feeder) is the leading solution for distributed broadband wireless access in underground mines and tunnels. The traditional radiating cable has equally spaced slots along its axis radiating evenly. However, with the new requirement for tracking and localization of miners, this paper shows how to modify the leaky feeder to function as a beam forming antenna array by appropriately optimizing the slot spacing. Optimizing the leaky feeder slot distances using Genetic algorithm has a good impact on the channel parameters, making it an excellent choice for leaky feeder antennas. Linear, as well as bent practical leaky feeder shapes, were considered, and we tested five different optimization algorithms and compared side lobe energies, varying the slot distance which had an impact on side lobe level. Also, we derived the expression for the BER, spectral efficiency and throughput considering a time-varying wireless channel. We observed that as the radius of curvature of the feeder increased (approaching a straight line), the spectral efficiency decreased as expected. Interestingly different optimization algorithms perform differently at different carrier frequencies. An optimization method should be chosen according to the required goal to be achieved (maintaining uniform equal power along the cable, or a more directed beam, or using a certain frequency of operation).
