I am using VMware Workstation 15.5.7, i have a windows 7 VM that cannot recognize USB 3.0. I have attempted to load the drivers from Intel to no avail. My web searches for vmware usb 3.0 mostly bring really old workstation info (that does not work for 15) or VMsphere info.
Can anyone point me to a relevant document for installing USB 3.0 on a Windows 7 64bit VM on workstation 15?
I'm not quite sure what you are asking for help on. Workstation has support for USB 3 under the particular VMs settings "USB Controller" > "USB compatibility" So far as Workstation goes that (aside from perhaps installing tools on the VM) should be the only 'workstation' related thing you would need to worry about by default.
So far as Windows 7 goes, it doesn't ship with native USB 3 support so you'd need to add/install any related drivers for said device inside the Win7 guest after ensuring the above...but even then some USB 3 devices will revert to work (at slower speeds) via USB 2 and not all recent USB 3 devices have compatible Windows 7 drivers.
You also haven't specified your host OS or said if the device works on the host (prior to attempting to attach it to the VM). While you're at it you might as well specify the device you are trying to attach this way so people can better attempt to aid you... there are certain devices, such as USB NICs, which you can't always pass-through even these days