A Capacitive Active Power Filter Control Strategy for High Voltage Converter Stations

With the large-scale integration of renewable energy, High Voltage Direct Current (HVDC) systems face new challenges such as harmonic distortion and reactive power fluctuations. This paper analyzes the mechanism of harmonic over-limit issues in HVDC converter stations, revealing that relying solely on passive filters is insufficient to effectively suppress harmonic amplification. A capacitive active power filter (C-APF) harmonic control strategy is proposed, addressing the current situation where SVGs are integrated into the system through step-up transformers at high voltage levels. Compared to traditional resistive active power filter (R-APF) control, CAPF demonstrates superior performance, particularly when the inductance of the SVG branch is large. The application of C-APF control in high-voltage SVGs provides a flexible and efficient solution for harmonic suppression and dynamic voltage regulation, ensuring stable and reliable operation of the system in complex grid environments.