Protection Hardware-in-the-Loop Validation for Inverter-Dominated Transmission Systems of Hawai’i Island

The increasing penetration of Inverter-Based Resources (IBRs) presents complex challenges to traditional grid protection, especially regarding the interplay between IBR over-current protection and overall system reliability. This paper introduces a real-time approach to developing and validating Control and Protection (C&P) functions for IBRs and their associated devices within the Hawaii Island transmission system, a grid rapidly transitioning to IBR-dominated generation. Our objective was to achieve protection reliability equivalent to existing schemes, targeting fault clearance within 5 cycles (83ms), defined by dependability, security, and fast fault clearance. Validation occurred in a real-time Protection Hardware-in-the-Loop (PHIL) testbed, uniquely marrying advanced inverter protection with established system protection schemes. This sophisticated environment integrated commercial Siemens SiProtec relays within a detailed Hawaiian Electric Company’s transmission network model. Comprehensive testing covered balanced and unbalanced faults at critical locations. Key achievements included precise circuit breaker control using actual trip/block commands via real-time Generic Object Oriented Substation Events (GOOSE) messaging, and recloser logic for temporary/permanent faults.