A Unified Energy-Based Control Strategy for Modular Multilevel Converters in Multi-Terminal DC Grids Under Diverse Network Configurations
Authors:
- Shabab Samimi
- Saeed Hosseinnataj
- Reza Farajpour
- François Gruson
- Johan Boukhenfouf
- Xavier Guillaud
- Frédéric Colas
Abstract
This paper investigates energy-based station-level control of modular multilevel converters (MMCs) in multiterminal high-voltage direct-current (MTDC) grids with heterogeneous DC-side configurations. Reliable station-level control is required to ensure stable power flow under vary-ing operating modes and AC- and DC-side disturbances. In practical MTDC systems, MMC stations must accommodate DC-voltage and power control while interfacing with diverse DC infrastructures, including cables, overhead lines, and DC circuit breakers (DCCBs). However, most existing control approaches rely on a single averaged-arm MMC model and assume fixed DC-side dynamics, limiting their applicability during transients and across different network characteristics. To address these challenges, a unified station-level modeling and control framework is proposed to explicitly accounts MMC operating modes and key DC-side elements by enabling effective decoupling between internal MMC dynamics and DC-side behavior. ling between internal MMC dynamics and DC-side behavior. Time-domain simulations of a representative MMC station validate the effectiveness of the proposed approach
