No, raising your voice is not the same thing as yelling, because in some cases, raising your voice can be a mere effort to be heard, or to prove a point, or just a means of getting your point across in a slightly more aggressive way without necessarily being threatening, whereas yelling is a behavior that is engaged in with the explicit purpose of being aggressive and trying to dominate someone. Yelling refers to shouting in a loud and sharp voice when someone loses their temper, whereas raising your voice may also mean speaking loud and clear (with emphasis).