Adaptive Harmonic Current Compensation Method for Wind Farm Integrated Hybrid HVDC System

Wind power development presents large-scale characteristics. In order to enhance the electrical quality of wind farm integrated hybrid HVDC system and reduce the footprint and cost of platforms, this paper proposes an adaptive harmonic current compensation method. Firstly, the topology structure and harmonic characteristics of the hybrid HVDC system are introduced, where the high-voltage valve group adopts uncontrolled diode rectifier (DR) inverter and the low-voltage valve group adopts modular multilevel converters. Then, the sliding window iterative Discrete Fourier Transform (DFT) harmonic detection method and the adaptive harmonic compensation control strategy based on it are presented. Finally, a model of the hybrid HVDC grid system is built in the PSCAD/EMTDC which to verify the effectiveness of the adaptive harmonic current compensation control strategy based on sliding window iterative DFT in steady-state and dynamic operation of the system. The study shows that this control strategy provides a new option for the filtering method of the hybrid HVDC system.