In Karma Automotive, we use two OPAL-RT setups for in-house Power Electronics development: Fast Prototyping Tool (FPT) and Hardware-in-the-Loop (HIL). FPT is used to develop application software and capture and study fast phenomena while the HIL is used to test both engineering-level and production-level software. Our presentation is an overview of our purpose in using OPAL-RT setups, our development and testing of the setups, and our use of OPAL-RT setups for product development programs.