instantiate chrome object in powershell
You can start a process by name and even pass it a parameter, like this:
Start-Process "chrome.exe" "www.google.com"
if you are fine with a 3rd party dll you could use Selenium which has also a Chromdriver, that gives you the same kind of control over Chrome as through InternetExplorer.Application COM
There is also a PowerShell wrapper for Selenium available on CodePlex