Export SharePoint List to CSV and Upload to Document Library

You can try below Powershell script to export list and run it periodically using task scheduler.  

Add-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue

#Get the Web
$web = Get-SPWeb -identity "http://sp2013/sites/team"

#Get the Target List
$list = $web.Lists["CustomList36"]

#Array to Hold Result - PSObjects
$ListItemCollection = @()

#CAML Query
$spQuery = New-Object Microsoft.SharePoint.SPQuery
$spQuery.ViewAttributes = "Scope='Recursive'";
$spQuery.RowLimit = 2000
$caml="<Where><Eq><FieldRef Name='Department'/><Value Type='Text'>D1</Value></Eq></Where>"
$spQuery.Query = $caml

#Get All List items
$listItems=$list.GetItems($spQuery)
foreach($item in $listItems) {
	$ExportItem = New-Object PSObject 
	$ExportItem | Add-Member -MemberType NoteProperty -name "Title" -value $item["Title"]
	$ExportItem | Add-Member -MemberType NoteProperty -Name "Department" -value $item["Department"]
	
	#Add the object with property to an Array
	$ListItemCollection += $ExportItem
}
#Export the result Array to CSV file
$ListItemCollection | Export-CSV "c:\Backup\ListData.csv" -NoTypeInformation                       

#Dispose the web Object
$web.Dispose()

Export