Development of a Series Braking Resistor to Eliminate Control Interference in Multi-Infeed HVDC Systems Considering the AC Three-Phase Fault—An Actual Case Study

Abstract

The integration of converter facilities into power systems has warranted a growing need to address the control interference phenomenon. In this study, we propose a facility-based approach to mitigate the control interference between adjacent high-voltage direct current (HVDC) units in a multi-infeed HVDC system. The proposed method uses a series braking resistor (SeBR) as a preventive measure to restore control when a fault occurs in one HVDC unit within a multi-infeed HVDC system, thereby enabling stable operation of adjacent HVDC units. The developed SeBR model incorporates an inductor component and is divided into Stages 1 and 2 to overcome the frequency reduction issue associated with the long-term deployment of conventional R-based SeBRs. Additionally, if the fault continues to affect the control of adjacent HVDC units despite the application of a blocking stage in the faulted HVDC unit, switch controller logic circuits are designed considering the deployment of Stage 2 of the proposed SeBR. The effectiveness of the proposed SeBR is validated based on the detailed modeling and verification of actual HVDC systems via a case study. The results validate the superior performance of the proposed SeBR over other methods in ensuring a continuous stable operation of the system.