Publications (162) View all
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Conference Proceeding: An Experimental Implementation of d-q axis Wavelet Packet Transform Hybrid Technique for 3Ф Power Transformer Protection
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ABSTRACT: A successful development and implementation of d-q axis components and wavelet packet transform (WPT) based hybrid technique for power transformer protection is introduced in this paper. In this approach, the high frequency sub-band contents of d-q axis components of the differential current is extracted using the WPT. This characterization helps to provide enough information to efficiently detect and discriminate internal faults from inrush currents in power transformers. This hybrid method provides accurate information with only one level of the Wavelet Packet Transform (WPT) of the d-q components of the differential current for power transformer protection. A real-time experiment is carried out for different normal and abnormal operating conditions such as inrush and internal faults for different cases of loading to test the efficacy of the proposed algorithm. The experimental results show fast, accurate, and reliable responses to all different types of disturbances that may occur in power transformers.2012 IEEE Industry Applications Society Annual Meeting (IAS 2012); 10/2012 -
Article: Depression and Its Association with Socio-Demographic Characteristics among Type 2 Diabetes Mellitus Patients of Bangladesh.
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ABSTRACT: Diabetes mellitus is being increasingly recognized as a serious global health problem and is frequently associated with co-morbid depression. A cross sectional study was conducted among 178 adult type 2 diabetes mellitus patients attending Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders (BIRDEM), Dhaka, Bangladesh to find out influence of socio-demographic characteristics for occurrence of depression among them. Data were collected through face-to-face interview. Depressive symptoms were measured using Centre for Epidemiological Studies Depression Scale. Proportion of depression was found 34.8% which included 20.2% with severe depression and 14.6% with mild to moderate depression. Both mild to moderate and severe depression were significantly more common in female, odds ratios were 2.72 (95% CI=1.13-6.53) and 5.94 (95% CI=2.49-14.20), respectively. Currently not married respondents were also suffered from higher depressive symptoms. For mild to moderate depression odds ratio was 4.38 (95% CI=1.46-13.18) and for severe depression odds ratio was 9.51 (95% CI=3.69-24.50). Among socio-demographic characteristics marital status was identified as the best predictor of depression, which was followed by education upto secondary level, female sex and primary education. Depression was identified as a significant health problem among adult type 2 diabetes mellitus patients. Its association with socio-demographic characteristics should be considered while planning therapeutic approaches for diabetic patients.Mymensingh Medical Journal 07/2012; 21(3):490-6. -
Conference Proceeding: An Experimental Method for Differential Protection of 3ϕ Power Transformers using Wavelet Packet Transform (WPT)
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ABSTRACT: In this paper, the use of wavelet packet transform (WPT) based algorithm of power transformer protection is presented. This algorithm succeeded to provide a way to develop a differential relay to detect internal faults automatically that may occur in the power transformers. Moreover, it has the ability to discriminate between the inrush currents and the fault currents. Accurate information can be provided in each level of the WPT to predict any failures in the power transformer. In this algorithm, the second level frequency sub-bands is not needed. Only the first level sub-band frequencies are sufficient signature to provide a faster detection of the faults. A real-time experimental investigation has been carried out in the laboratory for different cases of normal and abnormal operating conditions, such as magnetizing inrush, and internal faults for different cases of loading to test the efficacy of the algorithm25th Canadian Conf. on Electrical and Computer Eng. (CCECE 2012), IEEE; 04/2012 -
Article: The Development of a d-q axis WPT-Based Digital Protection for Power Transformers
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ABSTRACT: This paper presents the analysis and development of a new digital differential protection for three phase power transformers. The proposed digital protection is based on extracting high frequency sub-band contents present in the d-q axis components of the differential currents in order to identify internal faults. The desired high frequency sub-band contents are extracted using a single-stage wavelet packet transform (WPT), which offers parameterizing the energy in the high frequency sub-band contents using a finite number of coefficients. The WPT coefficients contain information that offer accurate, fast, and reliable detection and classification of transient disturbances, including magnetizing inrush and internal fault currents that may be experienced by three phase power transformers. The d-q WPT-based digital differential protection is implemented for off-line performance evaluation using differential currents collected from a 5 kVA, 3 phase , laboratory power transformer. Off-line test results demonstrate accurate, fast, and reliable detection, classification, and response to different types of fault and non-fault currents. These encouraging performances of the d-q WPT-based digital differential protection are obtained with simple implementation, reduced computational burdens, and small memory requirements.IEEE Transactions on Power Delivery 01/2012; pp(99):1. · 1.35 Impact Factor -
Conference Proceeding: Wavelet Packet Transform Algorithm Based Differential Protection of 3 phase Power Transformers
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ABSTRACT: This paper presents the usage of wavelet packet transform (WPT) based method to sensitize the transients resulting from inrush and fault currents in power transformers. This characterization will efficiently help in developing differential relays to automatically discriminate internal faults from inrush currents. This method can provide accurate information in each level of the WPT to predict any failures ahead of time so that the necessary actions can be taken to prevent outages and reduce down times. A real-time laboratory experiment on a 5KVA transformer has been done for different operating cases to test the efficiency of the algorithm20th Annual Newfoundland Electrical and Computer Eng. Conference (NECEC 2011) IEEE; 11/2011
