How to specify encodings when saving Word file in Powershell?

Question

PowerShell

Hello,
I am creating a document using a PowerShell script through the Word.Application COM object and I can’t figure out how to specify the encoding in the .SaveAs() method. I write like this:

...
$SaveFormatTXT = [Enum]::Parse([Microsoft.Office.Interop.Word.WdSaveFormat], “wdFormatText”)
$Encoding = [Enum]::Parse([Microsoft.Office.Core.MsoEncoding], "msoEncodingUTF8")
...
$MSWord = New-Object -ComObject Word.Application
$MSWord.Documents.add()
$Selection = $MSWord.Selection
$Selection.TypeText("бла бла бла")
$MSWord.ActiveDocument.SaveAs([ref]$($LocalSignatureFile + ".txt"),[ref]$SaveFormatTXT,[ref]$Encoding)

And I get an error:
"Exception calling "SaveAs" with "3" argument(s): "Parameter value is out of range"
Without specifying $Encoding, the document is saved, but all Cyrillic is visible as "????".
How to use this method?