[Grammar] use 'a' or 'an' in front of an acronym

[woodme]

In my research, “model predictive control” is usually writen as "MPC" which is a control method in many fields.

The question is that whether I should use "a MPC model" or "an MPC model".

 

[emsr2d2]

You should use "an" because the first sound of "MPC" is "em". Before a vowel sound (the "e" of "em"), use "an".
Before "model", use "a".