I am not sure that a Ribbon is a good choice for your design. The situation in which Microsoft created the ribbon was: there was a single view in which the user can operate (the view contains an open Word document or Excel spreadsheet) and there were hundreds of commands, all of which are valid within this single view. So they kept the main view unchanged, but let the user switch between ribbons.
There is indeed the context-sensitive ribbon which gets shown when a user has selected a Table or Graphic or Chart within the current document. But there is still no switching between views, there is just one more valid ribbon for the current view. When you have added a Table in Word and the table is active (the Tabellentools ribbon is accessible), you can still switch to the Start ribbon and use the button for changing the font color, as if you weren't in a table at all. The view still hasn't changed to some kind of different "tab" with different data which have a completely different set of valid actions.
Your situation here is radically different. You have different views, and they don't seem to have common actions. The actions which can be completed are specific to each view. This makes it more logical to have the controls for them coupled with the view, not always accessible on the top. If you had dozens of actions within a single view, it might have made sense to enable the user to switch between multiple ribbons per view, but this doesn't seem to be a problem here.
From this, I would say that the ribbon is the wrong tool for the job. It does not intuitively fit with the structure of your application. But if you still want to use it, you can follow Microsoft's example. But you shouldn't be imitating Word, you should be imitating Outlook. This is the Office application in which there is a switch between completely different views (mails, calender, contacts) with completely different actions. Notice how the tab selectors are in the lower right corner, not on top below the ribbon - this intuitively separates the actions in the top horizontal ribbon from the navigation, and maybe even spares the user a disorienting visual experience while the ribbon switches from the "E-Mail" ribbon to the "Calendar" ribbon.
Note that personally, as a user, I am unhappy with Microsoft's decision to mix view-specific ribbons and common ribbons. The Start, Folder and View ribbons are available in all views (but with different buttons) and works on the elements in the current view; the Send/receive ribbon is available in all views, with the same buttons, and always acts on e-mails. As Microsoft usually does extensive user testing, maybe I am an outlier here, you should decide for yourself if you want to follow their practice or not.