A Unified Control Performance Index For Planning Multi-Infeed Hvdc System

This paper proposes a unified Control-Performance-Index (CPI) framework for screening modernization alternatives in multi-infeed HVDC (MIDC) system. Electromagnetic-transient (EMT) simulations generate a station-by-fault CPI matrix which is then hierarchically aggregated into event (EvtCPI) and station (StnCPI) indices to rank contingency severity and converter performance, respectively. A reference-score composition integrates the voltage and frequency domains into a single alternative ranking (SysRefScore). The framework is validated on a three-Bipoles system representative of Manitoba Hydro’s prospective upgrades. Results show that the CPI approach yields quantitative rankings across control modes, ratings, and topologies—including mixed LCC-rectifier/VSC-inverter and all-VSC configurations. Among the studied options, the combination of an all-VSC topology, higher rating, and inverter ac-voltage control delivers the most robust post-fault performance under the fault set considered. StnCPI identifies vulnerable converters within the MIDC, while EvtCPI ranks fault severity. A Python automation workflow streamlines the process of CPI framework, enabling reproducible, decision-ready screening for planners.