I want to run a comparative analysis of system performance during disturbance in IEEE 39 New England bus system. I plan to trip a generator, increase PV integration and check its frequency response, incorporating HVDC. However, v 15.1 does not include any HVDC template. How to model it as a component? The template from "HVDC example" itself comes with 2 additional buses; but in my project, I would like to apply it on the existing buses.