The feasibility study of upgrading primary feeders from radial and open loop to a normally closed-loop arrangement have been explored in this paper. First, three possible feeder arrangements for forming a normally closed loop are discussed, and then the factors that may predominantly affect the system-type upgrading are discussed theoretically. Next, four existing distribution feeders with original radial arrangements, fed by three power transformers that are located at two different distribution substations of Taiwan Power Company (Taipower) are employed as sample systems. To form three types of closed-loop arrangement, all of the four radial feeders were tied together at their ends, two feeders at a time. The power flows, voltage profiles and short-circuit capacities of the feeders under both the tie breaker normally open and closed cases have been evaluated, and the impacts of the upgrading of system type on the distribution system and customers assessed. Finally, the required supporting measures for these kinds of upgrading have been listed, and the most suitable and feasible arrangement was recommended to Taipower.

Precision steel balls are one of the most fundament components for motion and power transmission parts and they are widely used in industrial machinery and the automotive industry. As precision balls are crucial for the quality of these products, there is an urgent need to develop a fast and robust system for inspecting defects of precision steel balls. In this paper, a real-time system for inspecting surface defects of precision steel balls is developed based on machine vision. The developed system integrates a dual-lighting system, an unfolding mechanism and inspection algorithms for real-time signal processing and defect detection. The developed system is tested under feeding speeds of 4 pcs s−1 with a detection rate of 99.94% and an error rate of 0.10%. The minimum detectable surface flaw area is 0.01 mm2, which meets the requirement for inspecting ISO grade 100 precision steel balls.

No abstract

No abstract

No abstract