Question

Which type of WTG can produce the largest three-phase short-circuit current?

Short answer

Thelargest value of the short circuit current is in case of Type 1 generator.

Step-by-step solution

Define the formula for the short circuit current.

The formula for the short circuit current for the three type of WTG is given as:

${\mathbf{I}}_{\mathrm{sc}}\mathbf{=}\frac{\mathbf{2}\sqrt{2}{\mathbf{V}}_s}{{X^{\text{'}}}_S}$

Here, ${X^{\text{'}}}_S$ is the reactance and ${X^{\text{'}}}_S$

Determine explanation for the answer.

Consider the short circuit current for the type 4 WTG is 1.1 times the current at normal conditions. Also, the type 4 generators have to lowest value of the current among all the 4 types of WTG.

From Table 1 in the textbook. The reactance in case of the type 1 generator has the highest value of the reactance. Then, by the formula the short circuit current will be highest.

Therefore, the largest value of the short circuit current is in case of Type 1 generator.