Exploring Coordination of LCC and VSC HVDC Systems for Reliable Power Transfer Under Variable Load Conditions

Renewable energy sources such as solar and wind are increasingly adopted to reduce emissions, but their integration into power grids presents significant challenges. High Voltage Direct Current (HVDC) systems offer economically and technically efficient solutions for bulk power over long-distance transmission, offering lower losses, higher controllability, and cost-effective long-distance power transmission compared to traditional alternating current (AC) systems. This paper investigates the coordination of HVDC systems based on Line Commutated Converters (LCC) and Voltage Source Converters (VSC) technologies to enable power transmission between two areas, addressing load variability due to renewable generation under various operating conditions associated with renewable energy generation. The power flow controllers for both LCC and VSC HVDC were implemented in MATLAB/Simulink to highlight the benefits of coordinated operation under different case studies. Simulation results analyze the performance of the coordinated LCC/VSC system, emphasizing its potential for modern grids with high levels of renewable energy penetration.