This paper describes a procedure for the calculation of the MOSA energy stress during TOV. Laboratory measurements were conducted and a MOSA model was developed in EMTP-RV software. Comparisons between measured and calculated MOSA energy showed a good agreement. A method for the selection of protective levels lower than that of the adopted MOSA design was described. By using this method MOSA with low protection level can be selected without being overstressed by TOV, and, therefore, overvoltage protection of compact line can be improved. According to [7] a MOSA with a rated voltage Ur=342 kV was selected. Calculation results show that the MOSA with Ur=330 kV could also be selected without being overstressed by TOV, for certain durations of TOV. This MOSA has a lower protection level and it reduces SFO and fast-front overvoltages more efficiently. After the selection of the MOSA according to the shown procedure, the study could be performed in order to check if the SFO are reduced to a level acceptable for the compact line. Another alternative for the limitation of SFO is the application of transmission line arresters that can be located along the line at selected points to obtain an adequate overvoltage profile along the line .