Control of variable speed drive (VSD) based on diode clamped multilevel inverter using direct torque control and fuzzy logic

Torque ripple reduction is one of the major challenges in switching table-based direct torque control (DTC) while operating for open phase faults of an induction motor, as the switching vectors are unevenly distributed. This can be minimized by increasing the level of the inverter and with the use of multi-phase motors. Fuzzy logic-based DTC is another solution to the above problem. In this paper, a comparative analysis is done between switching table-based DTC (ST-DTC) and fuzzy logic-based DTC for increasing the performance during open phase faults of a five-phase induction motor. The result shows that in fuzzy logic-based DTC with a two-level inverter, the torque ripple is reduced by 5.164% as compared with ST-DTC with a three-level inverter. The fuzzy logic-based DTC with the three-level inverter also gives better performance as compared with fuzzy logic-based DTC with the two-level inverter. The current ripple also reduced by 9.605% with respect to ST-DTC. Thus, fuzzy logic-based DTC is more suitable and cost effective for open phase fault-tolerant drives.

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Performance improvement of direct torque control for induction motor drive via fuzzy logic-feedback linearization

COMPEL The International Journal for Computation and Mathematics in Electrical and Electronic Engineering ◽

10.1108/compel-04-2018-0183 ◽

2019 ◽

Vol 38 (2) ◽

pp. 672-692 ◽

Cited By ~ 8

Author(s):

Abdelkarim Ammar

Keyword(s):

Fuzzy Logic ◽

Robust Control ◽

Feedback Linearization ◽

Control Algorithm ◽

Direct Torque Control ◽

Torque Control ◽

Motor Drive ◽

Induction Motor Drive ◽

Content Type ◽

Control Approach

Purpose This paper aims to propose an improved direct torque control (DTC) for the induction motor’s performance enhancement using dual nonlinear techniques. The exact feedback linearization is implemented to create a linear decoupled control. Besides, the fuzzy logic control approach has been inserted to generate the auxiliary control input for the feedback linearization controller. Design/methodology/approach To improve the DTC for induction motor drive, this work suggests the incorporation of two nonlinear approaches. As the classical feedback linearization suffers while the presence of uncertainties and modeling inaccuracy, it is recommended to be associated to another robust control approach to compensate the uncertainties of the model and make a robust control versus the variations of the machine parameters. Therefore, fuzzy logic controllers will be integrated as auxiliary inputs to the feedback linearization control law. Findings The simulation and the experimental validation of the proposed control algorithm show that the association of dual techniques can effectively achieve high dynamic behavior and improve the robustness against parameters variation and external disturbances. Moreover, the space vector modulation is used to preserve a fixed switching frequency, reduce ripples and low switching losses. Practical implications The theoretical, simulation and experimental studies prove that the proposed control algorithm can be used on different AC machines for variable speed drive applications such as oil drilling, traction systems and wind energy conversion systems. Originality/value The proposed DTC strategy has been developed theoretically and realized through simulation and experimental implementation. Different operation conditions have been conducted to check the ability and robustness of the control strategy, such as steady state, speed reversal maneuver, low-speed operation and parameters variation test with load application.

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