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Your search keyword '"Parspour, Nejila"' showing total 135 results
Start Over Author "Parspour, Nejila" Publisher ieee
135 results on '"Parspour, Nejila"'

21. Fault Diagnosis for Power Converter in SRM Drives Based on Current Prediction.

Author

Chen, Hao, Fang, Chenghui, Guan, Guorui, and Parspour, Nejila

Subjects
SWITCHED reluctance motors, FAULT diagnosis, RELUCTANCE motors
Abstract

This article proposes an online diagnosis scheme for transistor faults of asymmetric half-bridge converter (AHBC) in switched reluctance motor (SRM) drives. In order to extract more information from the phase current to identify faults, based on the conventional current measurement method, two novel current measurement methods are presented by reconstructing current sensors. According to the novel current measurement methods, a current prediction method is raised. The phase current at the kth sampling time is available so that the estimated current can be calculated. The fault can be detected and located by analyzing the given and actual switching states, which are deduced by comparing the measured and estimated currents. Compared with existing methods, the proposed scheme can be applied to diagnosis of multiple faults in n-phase AHBC, which can operate at various control strategies and chopping modes. With a single current sensor in each phase, the scheme will not increase the cost and complexity of the SRM drive. Furthermore, the scheme does not require complicated computation, making it easy to implement online. The experimental results confirm the effectiveness and flexibility of the proposed scheme. [ABSTRACT FROM AUTHOR]

Published
2022
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31. A Novel Method to Suppress the Force Ripple of a Switched Reluctance Linear Motor.

Author

Chen, Hao, Liu, Jinfu, Wang, Xing, Li, Xiaodong, Orabi, Mohamed, Li, Ye, Gong, Yuancong, Parspour, Nejila, and Zhang, Jingxin

Subjects
SWITCHED reluctance motors, ADAPTIVE control systems, PERMANENT magnet motors, RELUCTANCE motors, MUTUAL inductance, ELECTROMAGNETIC forces
Abstract

A novel method to suppress the force ripple of switched reluctance linear motors (SRLMs) based on predictive-fuzzy control is proposed in this article. Generally, the force ripple mainly occurs in the commutation area, resulting from the dropping force of the outgoing phase that cannot match the rising force of the incoming phase. The force distribution function (FDF) is a suitable method for controlling the forces of the outgoing phase and incoming forces during the commutation area. However, the controller calculation takes time and the motor shows inductive behavior, so the control signal, which is the reference current in FDF, always lags the reference force, which weakens the effect of the FDF control. Considering this problem, a method of predictive-fuzzy control is proposed in this article. The current can be controlled in advance by predicting the force, which reduces the appearance of the negative electromagnetic force, which is beneficial to improving the efficiency of the motor, and the mutual inductance is also considered in the predictive model. Additionally, a fuzzy controller is employed, and adaptive parameters of the control system are adopted. To validate the proposed control system, experimental verification is performed on a 500 W 6/4 double-sided SRLM, showing that the proposed method has a better force ripple suppression performance than the FDF control. [ABSTRACT FROM AUTHOR]

Published
2022
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47. Analysis of Coil Configurations for a Contactless Thermal Tumor Ablation With Implanted Devices.

Author

Prantner, Michael, Parspour, Nejila, Haen, Sebastian P., Bockeler, Michael, and Hetzel, Jurgen

Abstract

In the wide field of tumor treatment, thermal ablation procedures are very promising. Alternating magnetic fields are used to transfer the energy from outside the patient to the tumor area located anywhere in the body. This energy is converted to heat by implanted devices located in the tumor area. In this paper, the spatial distribution of the magnetic field of different circular coil configurations is analyzed and optimized with focus on patients’ safety and on coil configuration performance. The analysis is based on several performance criteria and is conducted with respect to the worst case scenario of a contactless thermal tumor ablation of deep-seated tumors, in which the energy has to be transferred over a considerably large distance. The magnetic field and the specific absorption rate (SAR) are calculated numerically and the performance criteria are evaluated based on a model of a human body including a tumor area. The most suitable coil configurations for different application scenarios are presented and a thermal analysis is done. Based on this, the minimum required heating power, coil current and number of coil windings, and the corresponding maximum SAR to achieve an adequate rise of tissue temperature are evaluated. For a heating power of 1.45 W, a minimum SAR of 130 mW/kg, a maximum power transfer efficiency of 1.05%, and a maximum coupling coefficient of 0.00695 is achieved. This paper shows the potential to enhance the safety of the patients significantly by choosing the appropriate coil configuration for a specific application scenario. [ABSTRACT FROM AUTHOR]

Published
2022
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