1: Overhead of 3-o transmission line has three insulators and the ratio of= 5 .If the...

 

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1: Overhead of 3-o transmission line has three insulators and the ratio of= 5 .If the voltage between the steel pin of the second insulator and tower is 33 kV and if the break down voltage of each insulator is 23 kV. 1- This string is fail in its work and in order to avoid this fail check the two methods below and find which method makes the string more efficient a- By using a gourd ring, which leads to add one air capacitance of 0.2C b- By increasing the number of insulator to four instead of three 2- If the voltage between the steel pin of the second insulator and tower is 33 kV and using a gourd ring , which leads to add one air capacitance of Cg, find the value Cg in terms C to make the efficiency of string 100 % 2: A three phase , 50HZ, 132 kV and transmission line 200km along consists of 1.2 cm diameter and spaced equilaterally at a distance of 3 m .the line has surface irregularity factor = 0.82 . The barometric pressure is 72 cm of Hg and the temperature of 20 cm find the power loss by using peek's formula and Peterson's for: 1- Fair weather 2- Stormy weather When Fis the factor which varies with ratio (V/Vc) as given by: 0.6 0.8 14 1.0 1.2 1.6 1.8 2.0 2.2 0.012 0.018 0.05 0.08 0.30 1.0 3.5 6.0 8.0 F 3: Write the true and false for the statement bellow and correct the false statement: 1- The strain insulator used are used where the conductors are dead line or at intermediate anchor towers. 2- Corona is partial breakdown of air 1: Overhead of 3-o transmission line has three insulators and the ratio of= 5 .If the voltage between the steel pin of the second insulator and tower is 33 kV and if the break down voltage of each insulator is 23 kV. 1- This string is fail in its work and in order to avoid this fail check the two methods below and find which method makes the string more efficient a- By using a gourd ring, which leads to add one air capacitance of 0.2C b- By increasing the number of insulator to four instead of three 2- If the voltage between the steel pin of the second insulator and tower is 33 kV and using a gourd ring , which leads to add one air capacitance of Cg, find the value Cg in terms C to make the efficiency of string 100 % 2: A three phase , 50HZ, 132 kV and transmission line 200km along consists of 1.2 cm diameter and spaced equilaterally at a distance of 3 m .the line has surface irregularity factor = 0.82 . The barometric pressure is 72 cm of Hg and the temperature of 20 cm find the power loss by using peek's formula and Peterson's for: 1- Fair weather 2- Stormy weather When Fis the factor which varies with ratio (V/Vc) as given by: 0.6 0.8 14 1.0 1.2 1.6 1.8 2.0 2.2 0.012 0.018 0.05 0.08 0.30 1.0 3.5 6.0 8.0 F 3: Write the true and false for the statement bellow and correct the false statement: 1- The strain insulator used are used where the conductors are dead line or at intermediate anchor towers. 2- Corona is partial breakdown of air