High Frequency Resonance Damping Method for Voltage Source Converter Based on Voltage Feedforward Control

Abstract

High frequency resonance (HFR) is a subsistent problem which affects the operation of the voltage source converter (VSC) connected to the parallel compensated grid. The appearance of HFR introduces a significant high frequency component in the grid voltage, thereby the operation of VSC system will be seriously affected. For enhancing the operation capability of VSC system, an HFR damping method based on the voltage feedforward control is proposed in this paper, which can reshape the VSC system impedance effectively in a wideband range. Besides, different with the existing HFR damping methods, the proposed method introduces a correction factor instead of the series virtual impedance with fixed value, so that the effect of impedance reshaping is irrelevant to the parameters of controlled object. In addition, this paper analyzes the fundamental control performance of VSC system after equipping the proposed method, for verifying that the proposed method will not worsen the fundamental control. Experimental results are given to validate the effectiveness of the proposed damping method.

Admittance Remodeling Strategy of Grid-Connected Inverter Based on Improving GVF

“…However, with the continuous enhancement of weak grid characteristics, the interaction frequency band between grid impedance and system expands, and the negative effects of GVF and phase-locked loop on gridconnected inverters are intensified and interactive coupling occurs [29,30]. The inverters need to be able to operate stably under the condition of wide-range transformation of grid impedance [31]. In this case, the influence of GVF on inverters cannot be ignored.…”