$sqlinstancename = "MSSQL13.MSSQLSERVER"
$SQLBinPath = (Get-ItemProperty ([io.path]::combine("HKLM:\SOFTWARE\Microsoft\Microsoft SQL Server", $sqlinstancename, "Setup"))).SQLBinRoot

$param = @{
    ExclusionExtension = "mdf", "ldf", "ndf" , "bak", "trn"
    ExclusionProcess = (Get-Item (Join-Path $SQLBinPath "sqlservr.exe"))
    ExclusionPath = "C:\Windows\Cluster"
}

Set-MpPreference @param