Trade-offs in HVDC Protection System Design – Investigation into Protection Margin and Threshold Setting for Future DC Grids

Multiterminal HVDC networks will become a crucial technology for integrating renewable energy sources into existing power systems. To ensure the uninterrupted operation of these grids, protection systems must quickly and selectively detect and isolate faults to limit their impact. Achieving this requires adequate selection and tuning of a suitable protection function or combination of protection functions for each application. This paper describes how speed and reliability indicators can be used to efficiently determine convenient combinations of complementary protection functions which can be employed to enhance their performance. The limitations of the voltage derivative function when implemented to protect long cables are explained. Then, a case study based on a proposed multiterminal…