Version 1
: Received: 25 December 2023 / Approved: 25 December 2023 / Online: 26 December 2023 (10:12:13 CET)
How to cite:
Vasilev, B.Y.; Nguyen, T.H. Modification of Direct Control System Based on Three-Level Autonomous Inverter NPC with Random Frequency Commutation. Preprints2023, 2023121942. https://doi.org/10.20944/preprints202312.1942.v1
Vasilev, B.Y.; Nguyen, T.H. Modification of Direct Control System Based on Three-Level Autonomous Inverter NPC with Random Frequency Commutation. Preprints 2023, 2023121942. https://doi.org/10.20944/preprints202312.1942.v1
Vasilev, B.Y.; Nguyen, T.H. Modification of Direct Control System Based on Three-Level Autonomous Inverter NPC with Random Frequency Commutation. Preprints2023, 2023121942. https://doi.org/10.20944/preprints202312.1942.v1
APA Style
Vasilev, B.Y., & Nguyen, T.H. (2023). Modification of Direct Control System Based on Three-Level Autonomous Inverter NPC with Random Frequency Commutation. Preprints. https://doi.org/10.20944/preprints202312.1942.v1
Chicago/Turabian Style
Vasilev, B.Y. and The Hien Nguyen. 2023 "Modification of Direct Control System Based on Three-Level Autonomous Inverter NPC with Random Frequency Commutation" Preprints. https://doi.org/10.20944/preprints202312.1942.v1
Abstract
Adjustable frequency converters are widely used in modern automated asynchronous drives due to their high efficiency and high responsiveness control strategies. Control algorithms for frequency converters are divided into two main groups: constant frequency commutation and random frequency commutation. Research results on various commutation frequencies, conducted using Matlab/Simulink software, show that the use of random frequency commutation provides better efficiency by significantly reducing the amplitude of harmonic oscillations at different frequencies, with a reduction in switching losses in transistors. Currently, a converter with random frequency commutation is being researched and applied in the direct torque control system. The traditional direct control system, based on a two-level inverter, is widely used due to its simplicity and ease of implementation. However, this method results in the output current of the two-level converter, supplied to the motor stator, having many harmonic distortions, leading to strong torque fluctuations regardless of the rotation speed and ultimately causing additional losses in the stator windings and reducing the motor's lifespan. To enhance the efficiency of automated asynchronous drives, this article presents an algorithm for a direct control system based on a three-level NPC inverter using a PI speed regulator. The proposed algorithm's research is validated in the Matlab/Simulink environment. The research results show that in the absence of harmonic filtering, the stator current harmonic distortion coefficient is approximately 11%, and torque fluctuations are less than 5% of the resistive torque. The fluctuations between the two capacitors remain almost unchanged throughout the entire process.
Keywords
random frequency commutation; three-level NPC inverter; direct torque control; harmonic current distortion
Subject
Engineering, Control and Systems Engineering
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
