I found where the problem was, it came from my settings that do not exist. Thank you for your time and help.
$styleFirstRow = array('bgColor'=>'#6086B8');
$PHPWord->addTableStyle('myTable', $styleTable, $styleFirstRow);
$styleCellFirstRow = array('valign'=>'center');
$styleCell = array('valign'=>'center');
$styleTextFirstRow = array('name'=>'Lucida Sans Unicode', 'color'=>'white','size'=>12);
$styleParagprapheFirstRow = array('align'=>'center');
$table->addCell(2200, $styleCellFirstRow)->addText('Type du rapporteur', $styleTextFirstRow, $styleParagprapheFirstRow);