Tag

$tax_query = array(
	'relation' => 'AND',
	array(
		'taxonomy'         => 'post_tag',
		'terms'            => 'electricity',
		'field'            => 'term_taxonomy_id',
		'operator'         => 'AND',
		'include_children' => false,
	),
	array(
		'taxonomy'         => 'category',
		'terms'            => 'news',
		'field'            => 'slug',
		'operator'         => 'AND',
		'include_children' => true,
	),
);