A Simplified Unbalanced Control Strategy of PWM-VSC Based on Line Voltage Calculation

Abstract:

Presently, with regard to the research in control of three-phase PWM-VSC under unbalanced dips, most of the literatures gain the current commands through the phase voltages based on the PQ power theory and the control flow is complicate too much. This paper, based on the instantaneous power analysis of VSC grid-side, calculate the current commands through line voltages and use the line voltages instead of the phase voltages in the feedforward. Not only the equation of current commands calculation is simplified, but also avoids the transformation of line voltages to phase voltages. In addition, this method adopts neither PLL nor coordinate transformation, and current sequential extraction is eliminated by adopting the PR controller in the current loop. In the end, the simulation results testify the efficiency of the proposed scheme in resisting grid voltage harmonics and nullifying fluctuation of dc-voltage.

• Periodical: Applied Mechanics and Materials (Volume 340)
• Pages: 611-616
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.340.611
• Online since: July 2013
• Authors: Qiong Feng Zhu, Xun Bo Fu, Shu Ju Hu, Bin Zhao
• Keywords: Instantaneous Power, Line Voltage, Three-Phase PWM-VSC, Unbalanced Dips

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