How to generate the report file name of an invoice in Odoo 10? 

The desired result should be that a concept invoice is called: "concept_invoice" and that the accepted invoice is named something like: "INV_(invoice_name/numer)_MyCompany.

somehting like: (object.state in ('open','paid')) and ('INV'+(object.number or '').replace('/','')+'.pdf')?