If you expect your PowerShell query to return an exceptionally large results set that might take longer than 2 minutes to retrieve. You can increase the OperationTimeout on your target DC by performing the following steps:
Login to the target DC
Browse to "%Windir%\ADWS\Microsoft.ActiveDirectory.WebServices.exe.config" and edit it
Increase the "OperationTimeout" parameter value based on your needs. The default value is 2 minutes.
After that restart ADWS using the following PowerShell commands