Integrated motor drives: state of the art and future trends

With increased need for high power density, high efficiency and high temperature capabilities in Aerospace and Automotive applications, Integrated Motor Drives (IMD) offers a potential solution. However, close physical integration of the converter and the machine may also lead to an increase in components temperature. This requires careful mechanical, structural and thermal analysis; and design of the IMD system. This paper reviews existing IMD technologies and their thermal effects on the IMD system. The effects of the power electronics (PE) position on the IMD system and its respective thermal management concepts are also investigated. The challenges faced in designing and manufacturing of an IMD along with the mechanical and structural impacts of close physical integration is also discussed and potential solutions are provided. Potential converter topologies for an IMD like the Matrix converter, 2-level Bridge, 3-level NPC and Multiphase full bridge converters are also reviewed. Wide band gap devices like SiC and GaN and their packaging in power modules for IMDs are also discussed. Power modules components and packaging technologies are also presented

Haemodialysis-related headache

Dialysis may induce severe headache as a result of a large amount of water and electrolyte shifts. It is important to recognize it because it can be a great problem to the patient and changing dialysis parameters or methods can prevent it. In this study we investigated the frequency and clinical characteristics of headaches occurring during haemodialysis (HD). Thirty female and 33 male patients with chronic renal failure on regular dialysis for at least 6 months in the HD unit of the Internal Medicine Department from 1996 to 2000 participated in the study. The dialysis solution contained acetate in 35 patients and bicarbonate in 28 patients. In all patients capillary dialysers and Cuprophan membranes were used and every session of dialysis lasted 4 h. All patients received the same questionnaire and they were visited randomly. Dialysis headache (DH) diagnosis was made according to the criteria of the International Headache Society. Patients with primary headache and under drug treatment during HD, which can cause headache, were excluded from the study. The frequency of DH, its relation to gender, age, dialysis technique and parameters and its features were investigated. DH was detected in 48% (n=30) of the study group. Compared with dialysis solutions, no difference was found between patients with and without DH. The difference in the pre- and post-dialysis value of urea in patients with DH was statistically significant (P<0.05). Patients with DH showed significantly higher mean systolic and diastolic blood pressure predialysis values in comparison with patients without DH (systolic, P<0.001; diastolic, P<0.01), whereas post-treatment values did not differ between the two groups. Fronto-temporal location, moderate severity, throbbing quality and short duration (<4 h) were the most prevalent features of DH in patients

The influence of age in peripheral facial palsy on brainstem reflex excitability

Background: Neuronal plasticity is expected to be different at different ages and adaptive changes developing after peripheral facial palsy (PFP) may provide a clue in this respect. Aims: To investigate the difference in the reorganization developing after facial nerve damage between patients who developed PFP at childhood-youth and middle-old age. Patients and methods: Twenty-two patients were divided into two groups according to the age-at-onset of PFP; young (PFP 1), and elderly (PFP 2). Two age-matched control groups (C 1 and C 2) comprised of 32 healthy subjects were included in the study. The latency, R2 area, and recovery of the R2 area of the blink reflex were investigated. Statistical analysis : anova and Bonferroni tests were used. Results: The R2 areas were significantly greater on the intact side of the PFP 1 group as compared to that in the control group ( P =0.012). The recovery of R2 component was significantly enhanced on the symptomatic ( P =0.027), and intact ( P =0.041) sides in PFP 1 as compared to that in the C 2 group at the stimulus interval of 600 ms. Significant enhanced recovery was noted at 200 ms stimulus interval on the symptomatic side of the two PFP groups (PFP 1, P =0.05 and PFP 2, P =0.025) and on the intact side of the PFP 1 group ( P =0.035) as compared to that in the control groups. Conclusion : Young age-at-onset of PFP is associated with more prominent excitability changes developing at the neuronal and interneuronal level

Interline hybrid unified power quality conditioner

18th European Conference on Power Electronics and Applications, EPE 2016 ECCE Europe --5 September 2016 through 9 September 2016 -- --This paper proposes a new interline hybrid unified power quality conditioner (IHUPQC) structure to improve the power quality of distribution feeders and to decrease the power ratings/voltages and switching losses of voltage source converters (VSCs). The IHUPQC consists of dynamic voltage restorer (DVR), an isolated dc-dc converter and a shunt hybrid active power filter (SHAPF) with a common dc bus. The inverse park phase locked loop (IP-PLL) technique is used to detect the distortions of signals in both feeders. Sinusoidal pulse width modulation (SPWM) based voltage control and current control are used for DVR and SHAPF respectively. The isolated dc-dc converter has PI controller based simple phase shift (SPS) technique. The proposed structure is designed for 34.5 kV voltage level and simulated by using PSCAD/EMTDC to verify system. © 2016 IEEE and EPE Association

DSP controlled voltage disturbance generator

Voltage disturbance generator (VDG) is a kind of device used to generate voltage disturbances that may occur in the network in order to test and evaluate the performance of the power quality devices such as Dynamic Voltage Restorer (DVR) and Uninterruptible Power Supply (UPS). Some of the voltage disturbance generator systems which are available in the literature and commercially available are complex and expensive while the others are simple, inexpensive but less functional. In this paper, a new transformer based, digital signal processor (DSP) controlled VDG is designed which can generate balanced and unbalanced voltage sag/swell and interruption and can adjust the depth, duration and initiation point of disturbances. The proposed system is composed of bidirectional switches, variable transformers and DSP based controller. 3 phase 20 kVA experimental setup is developed to verify the performance of the designed system with linear and non-linear loads. Moreover, the performance of VDG is also investigated in the compensation tests of DVR and UPS. © JES 2018

Design and implementation of full bridge bidirectional isolated DC-DC converter for high power applications

18th European Conference on Power Electronics and Applications, EPE 2016 ECCE Europe --5 September 2016 through 9 September 2016 -- --This paper proposes the design and implementation of a high power full bridge bidirectional isolated DC-DC converter (BIDC) which comprises of two symmetrical voltage source converters and a high frequency transformer. In the proposed BIDC, a well-known PI controller based single phase-shift (SPS) modulation technique is used in order to achieve high power transfer. Besides, different phase shift methods such as extended phase-shift (EPS) and double phase-shift (DPS) are compared with SPS. Both simulation and experimental results are caried out to verify PI controller based simple phase-shift controlled BIDC prototype that is designed for 300-V 2.4-kW and operating at 20 kHz. © 2016 IEEE and EPE Association

Prevalence of epilepsy in Silivri, a rural area of Turkey

Purpose: To learn the prevalence of epilepsy in Silivri, a western town of Turkey, a randomized door-to-door survey was conducted using a standard questionnaire. The method of the study was adopted from the suggestions of the World Health Organization (WHO) for prevalence studies in developing countries, and the criteria were derived from Guide-lines Sor Epidemiologic Studies on Epilepsy proposed by the Commission on Epidemiology and Prognosis, the International League Against Epilepsy (ILAE) 1993