A new Look-up Table-Direct Power Control Strategy for Three-Level NPC Rectifier Using Predictive DPC

Inhalt:
In this paper, a combined control strategy (conventional look-up table-direct power control (LUT-DPC) with predictive direct power control (P-DPC)) for a three level NPC rectifier under ideal grid voltage is proposed and discussed. When the conventional LUT-DPC and its conventional switching table are used, a high total harmonic distortion (THD) of the input currents and fluctuations in the reactive power waveform during the beginning part of each odd sector are obtained. Therefore, a predictive direct power control (P-DPC) is applied during the beginning part of each odd sector to eliminate the fluctuations in the reactive power waveform and to achieve low THD of grid currents. Then, by using Matlab/Simulink, comparative simulation results are given to validate the performance and effectiveness of the proposed method (LUT-DPC with P-DPC).