Journal of Electrical Engineering ›› 2019, Vol. 14 ›› Issue (3): 23-32.doi: 10.11985/2019.03.004

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Research on the Multi-target Grid-connected Control Method of NPC Three-level Inverter Based on Model Prediction under Non-ideal Grid Conditions

YAN Han,LÜ Jianguo(),DING Jinyong,MA Binghui,YAN Yiran   

  1. School of Automation, Nanjing University of Science and Technology, Nanjing 210094 China
  • Received:2019-09-01 Online:2019-09-25 Published:2019-11-21
  • Contact: Lü Jianguo E-mail:jianguolyu@njust.edu.cn

Abstract:

To improve the quality of output current and power of grid-connected inverter and suppress the fluctuation of the mid-point voltage in the DC-link under the non-ideal grid conditions, the predictive model of the output current of the inverter and the unbalanced voltage of the DC-side are derived. And to adapt the different application environment, the current reference calculation method is discussed for three independent control targets, i.e., balanced and sinusoidal three-phase output current and stable output active and reactive power. Compared with the traditional control method, model predictive control method can control the output current and midpoint voltage uniformly, which decreases the complexity of parameter design and simplifies the control structure. The simulation results show that proposed model predictive control method can achieve good grid-connected control of output current and power under different control targets in non-ideal grid conditions, and balance the DC-link midpoint voltage.

Key words: Non-ideal grids, three-phase three-level grid-connected inverters, multi-target, model predictive control, mid-point voltage

CLC Number: