Constant Switching Frequency and Torque Ripple Minimization of DTC of Induction Motor Drives  with Three-level NPC Inverter

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Direct torque control (DTC) of induction motor is prominent to offer instant torque and flux control with a simple control structure. However, this scheme suffers from two major drawbacks namely high torque ripple and variable switching frequency of the inverter, especially during low-speed operation. During the low-speed condition, the positive torque slope is very steep and torque overshoot occurs frequently resulting in the torque ripple become of great significance. This paper proposes a new and effective technique to reduce the torque ripple by integrating the alternate switching technique to the inverter switching status to limit the torque slope surge. By varying the frequency and duty cycle of the alternate switching, the rate of surge can be controlled resulting in the chances of overshoots, and selection of reverse voltage vector can be avoided. The feasibility of the proposed technique has been validated using MATLAB/Simulink software and through experimental results. The results show the proposed alternate switching technique minimizes over 40% reduction in the torque ripple while maintaining the simple structure of DTC.

Section: Introductionmentioning

confidence: 99%

Torque ripple minimization in direct torque control at low-speed operation using alternate switching technique

Aihsan

Jidin

Alias

et al. 2022

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“…FOC strategies are widely used in many modern high-performance AC drive applications, especially TPIM electric drives, due to their high accuracy. When compared to the traditional direct torque control (DTC) strategy, TPIM drives achieve high performance with a constant switching frequency and low torque ripples [24], [25]. In order to control the two-phase motor using the FOC strategy, two unbalanced transformation matrices have been presented and used in [15].…”

Section: Irfoc Of the Yctpim Drive During Igbt-scfmentioning

confidence: 99%

“…Using (25), the stator and rotor d-q voltage equations and the electromagnetic torque equation can be written as ( 26)-(32).…”

Section: Small-signal Stability Analysis (Sssa)mentioning

confidence: 99%

Vector-controlled Y-connected three-phase induction motor drives: small-signal stability study during IGBT short-circuit fault

Naghavi

Ghanbari

Ebrahimi

et al. 2023

<p>The stability analysis is one of the most important elements to describe the performance of AC drive systems under both dynamic and steady-state operating circumstances. This is particularly essential because electric motors operate over a wide range of speeds and utilize complex control systems such as field-oriented control (FOC). This study establishes a small-signal stability analysis (SSSA) in a 1-horsepower vector-controlled Y-connected three-phase induction motor (YCTPIM) drive during an insulated gate bipolar transistor short-circuits failure (IGBT-SCF). In the beginning, a vector control system that is based on the indirect rotor FOC (IRFOC) method is described for post-fault functioning of the YCTPIM while the IGBT-SCF is taking place. After that, a small-signal model of the system that has been provided is explored. This model is based on a voltage-current model, and it is constructed by linearizing the non-linear dynamic equations of the system. During IGBT-SCF, an IRFOC strategy as well as SSSA operations are carried out on the 1-HP, 380 V, and YCTPIM. In this research, both analytical and simulation-based methodologies are applied.</p>

“…The proposed control structure can be illustrated as shown in Figure 3. The switching frequency of inverter will be determined by the carrier frequency [21]. It should be noted that the carrier frequency is set at a constant and high frequency to establish high control bandwidth.…”

Section: Proposed Balancing Control Strtategymentioning

confidence: 99%

Multi-carrier switching strategy for high-bandwidth potential balancing control of multilevel inverters

Tahir

Jidin

Jamil

2021

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<span lang="EN-US">This paper confers on investigation of a direct torque control (DTC) of induction motor drive by 3 level neutral point clamp (NPC) multilevel inverter. The imbalance problem may deteriorate the electric drive performances which might cause a short circuit condition. Various balancing control strategies were proposed, however, most of them employed complex space vector modulation (SVM) and hysteresis-based controller that generates variable switching frequencies. The proposed method will offer a reliable balancing control strategy with a constant switching frequency, and moreover, it will provide excellent electric drive performances. This research proposed a new multi carrier switching modulation strategy that establish a high-band-width control for neutral point potential in the NPC inverter. Potency of the proposed high-bandwidth potential balancing strategy is validated through the MATLAB/SIMULINK environment.</span>