Aqui está o que acabei fazendo. Ele pesquisa o valor de várias propriedades do evento para o texto e as mostra no console:
$search = "hyper"
Get-EventLog -LogName system -after (Get-Date).AddDays(-1) | Where-Object { $_.Category.ToLower().Contains($search.ToLower()) -or $_.Message.ToLower().Contains($search.ToLower()) -or $_.Source.ToLower().Contains($search.ToLower())} | Format-Table -AutoSize -Wrap
Exemplo de saída:
Index Time EntryType Source InstanceID Message
----- ---- --------- ------ ---------- -------
4751 Aug 10 09:13 Information Microsoft-Windows... 23 NIC /DEVICE/{FD82EC81-DC0D-4655-B606-0AA9AF08E6CC} (Friendly Name: Microsoft Hyper-V Network Adapter) is now operational.
4750 Aug 10 09:13 Information Microsoft-Windows... 11 The description for Event ID '11' in Source 'Microsoft-Windows-Hyper-V-Netvsc' cannot be found. The local computer may not have the necessary registr...
4749 Aug 10 09:13 Information Microsoft-Windows... 24 NIC /DEVICE/{FD82EC81-DC0D-4655-B606-0AA9AF08E6CC} (Friendly Name: Microsoft Hyper-V Network Adapter) is no longer operational.
Sou novo no powershell, por isso pode não ser o melhor mas funciona. Espero que isso salve outra pessoa algum tempo.