Lee, KB Song, JH Choy, I Yoo, JY 2024-01-21T11:42:40Z 2024-01-21T11:42:40Z 2021-09-05 2001-10 0278-0046 https://pubs.kist.re.kr/handle/201004/140153 A direct torque control algorithm for three-level inverter-fed induction motors is presented. Basic voltage selection methods similar to two-level inverter provoke some problems such as stator-flux drooping phenomenon and undesirable torque control deterioration appeared, especially at low-speed operation. To overcome these problems, an algorithm with the basic switching sectors subdivided and intermediate voltage vectors applied is proposed in this paper. This algorithm basically considers applications in which direct torque-controlled induction motors are fed by three-level inverters with maximum switching frequency lowered around 1 kHz. An adaptive observer is also employed to bring better responses at the low-speed operation, by estimating some state variables and motor parameters which take a deep effect on the performance of the low-speed operation. Simulation and experiment results verify effectiveness of the proposed algorithm. English IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC Improvement of low-speed operation performance of DTC for three-level inverter-fed induction motors Article 10.1109/41.954565 1 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, v.48, no.5, pp.1006 - 1014 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 48 5 1006 1014 scie scopus 000171386400017 2-s2.0-0035471272 Automation & Control Systems Engineering, Electrical & Electronic Instruments & Instrumentation Automation & Control Systems Engineering Instruments & Instrumentation Article direct torque control induction motor low-speed operation three-level inverters