Design and implementation of AC voltage dependent current order limiter at Pacific HVDC Intertie

This paper presents design and implementation of AC-voltage dependent current order limiter at the Pacific WDC Intertie. Reactive power and inertial support to the Celilo HVDC terminal have been limited because of new operating requirements for hydropower plants on the lower Columbia River. Under these operating conditions, a large set of contingencies was identified when the PDCI can be contributing to AC voltage collapse in the lower Columbia area and to north-south power oscillations. On August 10, 1996, a WSCC system outage occurred under similar generating conditions. To correct the PDCI dynamic response, we designed and implemented the AC-VDCOL function in the PDCI pole controls. The system studies demonstrated consistent benefit of the new controls for the system stability and dynamic performance. The system tests confirmed AC-VDCOL benefit.