Need help to identify which is the active load balancer from PowerShell cmdlets

Take a look at the System.Failover.get_failover_state() call. For the device you are making the call on it will return the FailoverState of standby, active, forced offline, offline, or unknown. With PowerShell, you can do something like this (assuming you've initialized the snapin already)

$ (Get-F5.iControl).SystemFailover.get_failover_state();

-Joe