Design philosophy enhances distribution network in Italy

摘要

ENEL Distribution in Italy, in cooperation with CESI (Milan, Italy), has developed a new standardized design for environmentally friendly low-cost high-/medium-voltage (HV/MV) distribution substations. The goal includes minimizing the visual impact, electromagnetic field and audible noise emission of HV/MV substations and MV networks. ENEL also expects to reduce the capital and operation and maintenance (O&M) costs by limiting network redundancy and reducing energy losses. The design improvements will comply with the 1999 Electricity and Gas Authority service standard, increasing service quality. Operationally, it is not easy to supply all MV feeders from adjacent HV/MV substations due to the length of time required to locate and manually close the load disconnectors on long feeders. In addition, adjacent feeders might not have sufficient thermal capacity to supply the total load or maintain voltage at an acceptable level. Previous design practices may adversely affect consumers who are exposed to voltage dips and supply interruptions. ENEL's fault statistics confirm that 90% of all supply interruptions can be attributed to the MV network and MV/LV substations. Hence, in 1999, ENEL Distribution started an MV network automation project to install remote control facilities to disconnectors at 50,000 MV/LV distribution substations (25% of the total number of substations installed).