Q$5\mathrm{.}1-($Example$-4)$

A three$-$unit suspension insulator string if the capacitance of the link pins to the earth are $20\%$ of the self$-$capacitance of each unit. Assume the total voltage is V$.$

a$)$ Find the voltage distribution and string efficiency.

b$)$ When you design the insulator, if a guard ring is installed and the value of the capacitance to the line of lower link pins is $35\%$ of the self$-$capacitance of each unit. Then, recalculated the redistribution of voltage and the string efficiency.

c$)$ What will happen to the voltage distribution across each unit and the string efficiency if a guard ring is installed, explain your result in part $($b$).$

d$)$ Draw the circuit and show the shunt and self$-$capacitance, cross arms, and the insulators. Also, show the KCL direction on your diagram for both designs.