public function login()
{
    if ($this->validate()) {
        return Yii::$app->user->login($this->getUser(), 0);
    }
    return false;
}

'user' => [
        'identityClass' => 'appmodelsUser',
        'enableAutoLogin' => true,
    ],

'user' => [
      'identityClass' => 'appmodelsUser',
      'authTimeout' => 60 * 60 * 24 * 100, //100 дней для примера
],

'user' => [
    'identityClass' => 'appmodelsUser',
    'enableAutoLogin' => true,
    'identityCookie' => ['name' => '_identity', 'httpOnly' => true]
],

public static function findIdentity($id)
{
    return static::findOne($id);
}