A Control Strategy used for Enhancing Reactive Power Management and Power Factor Correction in Large-Scale HVDC Interconnections

In high-voltage direct current (HVDC) transmission, pulse width modulation (PWM) has emerged as the solution for medium power applications due to its simplicity and four-quadrant control. However, as power demands increase, PWM faces limitations in handling larger loads, switching losses and component constraints. To address these issues, the Multilevel Current Reinjection (MLCR) concept has been introduced, offering improved control without the complexity of multilevel voltage source converters. For MLCR systems an innovative control approach is introduced in this paper. It enhances reactive power management and power factor correction in large-scale HVDC interconnections. Through a series of simulations, the control method is tested, demonstrating the ability to maintain stable terminal voltage and power factor across varying real power transfers. This approach extends the flexibility of MLCR systems, ensuring optimal operation even under low power conditions by dynamically adjusting converter settings.