Question

What is the formula of the area of each ring short-circuiting the bars?

(a) area of each ring short-circuiting the bars = (0.7-0.9) * area of damper bar

(b) area of each ring short-circuiting the bars = (0.8-1) * area of damper bar

(c) area of each ring short-circuiting the bars = (0.7-1) * area of damper bar

(d) area of each ring short-circuiting the bars = (0.8-0.9) * area of damper bar

I got this question in exam.

My query is from Design of Rotor topic in division Design of Synchronous Machines of Design of Electrical Machines

Answer 1

The correct answer is (b) area of each ring short-circuiting the bars = (0.8-1) * area of damper bar

Explanation: First the area of damper bars is calculated first. Next the area of damper bars is multiplied by a value between 0.8-1 to obtain the area of each ring short-circuiting the bars.