$ssa = Get-SPEnterpriseSearchServiceApplication
$active = Get-SPEnterpriseSearchTopology -SearchApplication $ssa -Active
$clone = New-SPEnterpriseSearchTopology -SearchApplication $ssa -Clone -SearchTopology $active
write-host "we have a clone"
$searchServiceInstance = Get-SPEnterpriseSearchServiceInstance
write-host "we have a search service instance"

New-SPEnterpriseSearchAdminComponent : A positional parameter cannot be found that
accepts argument 'â?SearchTopology TopologyId:
61b33981-a905-44f7-8000-eaa40e7b4676, CreationDate: 12/19/2014 2:18:35 PM,
State: Inactive, Components:  -SearchServiceInstance SearchServiceInstance