How to set value of a dynamic field?

I don’t think you need to get the reference to the entire field object. You should be able to just use the field name

if(params.row[Name] !== skuid.$(‘.RichTextField).prop(‘innerHTML’)){            

     params.model.updateRow(params.row, Name, ‘Mytext’);
            skuid.$(‘.RichTextField div.nx-richtext-input’).focus();
        }