Under the global green energy transition, the integration of renewable energy and multi-terminal HVDC systems has intensified grid strength challenges, exacerbating the inherent vulnerability of Line-Commutated Converter-based HVDC (LCC-HVDC) to commutation failure (CF)—a critical threat to bulk power transmission reliability. While China leads in LCC-HVDC deployment, recent grid complexities and ultra-high-voltage DC (±800 kV/8000 MW) expansion demand advanced solutions. This paper addresses these challenges by validating the novel Controllable Line-Commutated Converter (CLCC) technology, developed by the China Electric Power Research Institute. CLCC integrates hybrid semiconductor control to actively suppress CFs, as proven in the ±500 kV Ge-Nan project through artificial AC fault tests, demonstrating immunity to CF under both CLCC and conventional LCC modes. However, scaling CLCC to ultra-high-voltage applications requires further research. To bridge this gap, a physical dynamic simulation platform for CLCC-HVDC systems is developed. The platform supports algorithm optimization, coordinated control design, and technical validation for CLCC’s application in UHVDC projects. Key contributions include: Primary design of CLCC physical dynamic model; Parameter selection aligned with simulation requirements; PSCAD/EMTDC-based digital validation. This work establishes a critical pathway for enhancing CLCC’s scalability in large-scale HVDC grids, offering theoretical and practical insights for mitigating cascading failures in renewable-dominated power systems.