Georgia Power

About: Georgia Power is a company organization based out in Atlanta, Georgia, United States. It is known for research contribution in the topics: Electric power transmission & Voltage. The organization has 73 authors who have published 66 publications receiving 932 citations. The organization is also known as: Georgia Railway and Power Company.

Soil Thermal Properties And Their Effect On Thermal Stability And The Rating Of Underground Power Cables

Abstract: Accurate measurements of soil thermal properties are essential for proper rating of under- ground power cables. The two most important soil pro- perties affecting cable ampacity are,thermal resistivi- ty and thermal stability. In the cable industry the most frequently used device for measuring the thermal resistivity is the thermal probe. Resistivity measure- ments made with a thermal probe are compared with val- ues using an ASTM guarded hot plate. The comparison of the data is excellent for dry soils and for soils with high moisture contents where moisture migration caused by a temperature gradient is not a problem. The dif- ference in resistivity measurements for soil with low moisture content results from moisture migration and it points out the difficulty of making accurate thermal resistivity measurements when moisture migration is present. Thermal resistivity measurements made in the field are compared with measurements taken on recompacted samples in the laboratory. Results show that accurate soil resistivities can be measured in the laboratory as long as the field dry density and moisture content are carefully reproduced. Ampacity calculations based on moist soil condi- tions can be inadequate if moisture migration in the soil takes place. A large-scale laboratory test pro- gram was carried out to identify soil properties and cable heat flux values leading to moisture migration. Results of the test program help identify drying times for the soil adjacent to the A knowledge of the drying time as a function of heat flux generated within the cable will help the utility en- gineers to identify the potential for a thermal run- away condition. Experimental thermal stability results are compared to a new theoretical study that models the heat and moisture transport process in the soil. surface of the cable.

Ampacity of Electric Power Cables in Vertical Protective Risers

Abstract: A method is presented to compute the ampacity of an electric power cable located in both vented and nonvented circular protective risers. While techniques for calculating the ampacity of underground cables and overhead lines are well established, techniques for rating the riser portion of a cable circuit have not been as thoroughly studied. Usually cable ampacities are based on the assumption that the underground portion of the circuit will be cooler than the portion located in the riser. Therefore, approximate derating factors are used to reduce the underground cable circuit ampacity when risers are present.

Parallel Operation of Customer Generation

Abstract: The paralleling of customer generation with an electric utility requires that the customer and utility communicate and cooperate on the operating and protective relaying problems associated with the interconnection. A utility point of view on the operating and protective relaying problems with emphasis given to protective relaying schemes for the customer-utility interface is presented. The protection requirements and operating limitations of six different interface schemes are discussed.

Normal and Short Circuit Operating Characteristics of Metallic Shielded Solid Dielectric Power Cable

Abstract: Experimental results are presented on the normal and short circuit operating characteristics of metallic shielded solid dielectric power cable. Test data on thermal runs of single conductor shielded power cable under typical installation conditions confirm published ampacity data1, and hence the theoretical procedure2 employed for calculating the ampacity of single conductor cable with circulating current losses. The thermal runs also point out the possible adverse effect on the cable of operating at a high interface temperature for an extended period of time.