Log Shipping Standby mode I have setup log shipping with standby mode to ship every 15 minutes, but when the log is restored on the secondary server it kills any currently executing queries. 

Is it possible to setup the transaction log restore to start only after any currently running queries finish and to not allow any new connections to the secondary while the log is restoring?
But it possible to setup to restore transaction log after finish of
  current running and this interval time no other user connect secondary
  database.


Yes it's possible, you can read more about it here: Using Secondary Servers for Query Processing