Robust Analytical LUT‐Based DPC for a Weak‐Grid‐Connected DFIG with Low‐Cost Implementation

ABSTRACT

This paper focuses on analytical lookup‐table (LUT)‐based direct power control (DPC) of a grid‐connected doubly‐fed induction generator (DFIG) driven by two‐level voltage source inverter (2L‐VSI). The proposed strategy effectively mitigates the inherent limitations associated with pulse‐width modulation (PWM)‐based methods by considering the model of the 2L‐VSI. Its robustness is also enhanced compared to non‐analytical LUT‐based DPC methods, for which the stability has not been confirmed. The stability of the entire system (DFIG and 2L‐VSI) is proved. It is based on simple formulas, rendering the PWM algorithm useless and requiring reduced implimentation computational requirements. The proposed DPC has a fixed switching frequency. It is sensorless for rotor currents and does not require flux estimation. It is independent of DFIG parameters and speed. This features enhances system reliability, and reduce the material used for the driving because it requires reduced computational means and less number of current sensors. This method is effective under various grid disturbances, whether occurring individually or simultaneously. The effectiveness of the presented method is validated via simulations.