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The underground electricity distribution cables are subjected to stress and pressure as they are laid underneath the earth. Due to many factors, these cables create different types of faults that i...

Wireless mesh networks have numerous advantages in terms of connectivity as well as reliability. Traditionally the nodes in wireless mesh networks are equipped with single radio, but the limitations are lower throughput and limited use of the available wireless channel. In order to overcome this, the recent advances in wireless mesh networks are based on multi-channel multi radio approach. Channel assignment is a technique that selects the best channel for a node or to the entire network just to increase the network capacity. To maximize the throughput and the capacity of the network, multiple channels with multiple radios were introduced in these networks. In the proposed system, algorithms are developed to improve throughput, minimise delay, reduce average energy consumption and increase the residual energy for multi radio multi-channel wireless mesh networks. In literature, the existing channel assignment algorithms fail to consider both interflow and intra flow interferences. The limitations are inaccurate bandwidth estimation, throughput degradation under heavy traffic and unwanted energy consumption during low traffic and increase in delay. In order to improve the performance of the network distributed optimal congestion control and channel assignment algorithm (DOCCA) is proposed. In this algorithm, if congestion is identified, the information is given to previous node. According to the congestion level, the node adjusts itself to minimise congestion. &nbsp

This paper reviews about the bidirectional on-board chargers for electric vehicles. The chargers are of two types: on-board chargers and off-board chargers. The overall size, weight and cost of the onboard chargers can be reduced using integrated on-board chargers where the drive train components are used for propulsion as well as for charging. Four-quadrant operation of the drive is possible using the bidirectional converters in the drive train. Regenerative braking control in the integrated on-board chargers aids in proper utilization of braking energy, which in turn increases the driving range of the vehicle. Various on-board chargers are presented and their working, advantages and limitations are discussed here.

In this paper, a topology is formed by series-connected numbers of the suggested basic unit. In order to generate all (even and odd) voltage levels, two units are connected with two different operating frequencies. Phase disposition-based sinusoidal pulse width modulation technique with different carrier arrangement is preferred to get the driving pulses of the switches in stage generation part to achieve different level of the output. Finally, the performance of the topology is verified by comparing the simulation results with experimental results. As a result, it is confirmed that the authors topology is better compared to traditional topology in view point of size, reliability, and efficiency.

Diabetes occurs among different age group populations due to insulin usage in the body. The pancreas produces insulin to convert the food into glucose, and it is observed by the blood cells to produce energy. In some people, the pancreas produces less insulin, and they are called type I diabetic patients. Hence, those people are suffering from type I diabetes and are advised to take insulin regularly through injection. But they don’t know the exact quantity of insulin to be taken on their day-to-day basis. The consumption level of insulin varies for every individual. The single individual consuming insulin also varies every day based on their regular activities, food, stress level, exercises, etc. Only through a regular blood test the patients may know the insulin level in their body. The patient needs the advice of physicians every day to change the consumption of insulin. It is difficult to get an appointment with the physicians to meet and know their blood glucose level and the quantity of insulin required for their bodies. Thus, there is a need for a computer-aided diagnosis system to solve this struggle among type I diabetic patients. By using the proposed system, hospitals could reduce the inpatients during critical times, while they visit the physicians only for testing the insulin level. The proposed IoT-based machine learning algorithm is suitable to efficiently handle the condition to predict the glucose level of the human body and suggest the quantity of insulin required for the diabetic patient. The patients are advised to access the system from anywhere without a physician’s help. The proposed technique is accurately predicting the required insulin level to assist diabetic patients. Insulin conception varies among the patients when they are fasting, after meals, and during sickness. First, patients should know their type of insulin. The patient must check the blood glucose level through the glucometer, and this has been recorded in the system to track the status. The noninvasive Dexcom G4 platinum sensor is used to update the patient’s glucose level reading every minute, and it will be displayed in an android device application. The patient’s glucose level is compared with the parameters in the dataset under different categories. In order to reliably predict the dosage of insulin needed for the patient on a specific day, the machine learning algorithm found an exact pattern-matching criterion. The graphical user interface collects the daily activities of the patients and analyzes their previous history of insulin consumption to make a wise decision on insulin calculation. The statistical results are projected through the graph which denotes the insulin dosage conceived by the patients on a particular period. This helps the physicians to suggest quick solutions during the time of admit due to any other illness in a hospital. The historical data enables the physicians and patients to act smoother in handling the diabetic disease. The proposed system improves the economy of the country by saving the life of diabetic patients.

This paper gives a review on the various modulation techniques that have been used to eliminate lower-order harmonics in multilevel inverters. The output voltage with high quality can be achieved using multilevel inverters. The selection is based on switching losses, power losses, noise, etc. Many authors proposed different modulation techniques such as sine triangular, selective harmonic selection (SHE), model predictive control techniques, space-vector-based modulation techniques. This paper presents a detailed review of existing harmonic elimination methods as well as concludes with the best method.

Wireless mesh networks have numerous advantages in terms of connectivity as well as reliability. Traditionally, the nodes in wireless mesh networks are equipped with a single radio, but the limitations are lower throughput and limited use of the available wireless channel. To overcome this, the recent advances in wireless mesh networks are based on a multi-channel multi-radio approach. Channel assignment is a technique that selects the best channel for a node or to the entire network just to increase the network capacity. To maximize the throughput and the capacity of the network, multiple channels with multiple radios were introduced in these networks. In this work, algorithms are developed to improve throughput, minimize delay, reduce average energy consumption, and increase the residual energy for multi-radio multi-channel wireless mesh networks.

DC to AC control change is a key job in the cutting edge set up of age, transmission, appropriation, and use. DC to AC control converters assume key job in variable recurrence drives, uninterruptible power supplies, cooling, and high-voltage DC control transmission, electric vehicle drives, and static VAR compensators. This paper exhibits a survey on most significant topologies and strategies of control of inverters.

The employments of Multilevel DC Link Inverters offer dependable points of interest attributable to the expansion in the highest levels at the yield output voltage and are broadly acknowledged for industrial applications. The execution of these bores on high when contrasted with the routine conventional two-level inverters because of their drawbacks. Be that as it may, the expanded number of devices, complex PWM control, and voltage-adjusting issue are a portion of the hindrances. This paper goes for presenting another topology, which can perilously decrease the switch number by introducing a module called polarity generation module. This topology gives a DC voltage fit as a fiddle of a staircase which approximates the corrected state of a directed sinusoidal wave to the extension inverter, which thusly interchanges the extremity to deliver an AC voltage with low THD and switching loss. The topology is tested by adopting a choice of control techniques and enhanced execution of the proposed inverter contrasted with the overarching topologies. The FPGA has been selected to verify the proposed inverter with modulating technique due its advanced futures and computing facility. For validation, simulation and experimental results are offered.

Multilevel inverter plays a crucial role in industrial applications. The performance of cascaded multilevel inverter (CMLI) with reduced switch count is analyzed in this paper. If the switches have been increased the switching loss and THD will increase. The preferred topology is simulated for seven level and fifteen level by considering isolated DC source and PV. The reduced % THD is identified compare to other topologies. Four switches continuously working at fundamental switching frequency is considered as one of the advantage of the topology.

In recent years multilevel inverters have been extensively worn in high voltage and high power applications for their unique performance. Reliability of the power electronic equipment is very essential to make sure that inverter operation should be stable and it is most important to detect and locate the faults as speedily as possible. This paper deals with open switch-fault finding method in a multilevel inverter using wavelet transformation tool. A fault diagnosis procedure is proposed and executed using MATLAB.

The performances of multilevel inverters (MLIs) are of high competence when compared to the conventional two-level inverters due to reduced harmonic distortions, lower electromagnetic interference, and higher dc link voltages. However, the increased number of components, complex PWM control, and voltage-balancing problem, component failure in the circuit are some of the disadvantages. The topology preferred in this chapter provides a dc voltage in the shape of a staircase which approximates the rectified shape of a commanded sinusoidal wave to the bridge inverter, which in turn alternates the polarity to produce an AC voltage with lesser total harmonic distortion. This topology requires fewer components and hence it leads to a reduction of overall cost and complexity particularly for higher output voltage levels. The component fault diagnostic procedure is developed using wavelets transform tool. Finally, the experimental prototype is developed and validated with the simulation results for different loading conditions.

Selective Harmonic Elimination technique is one of the control methods applied in Voltage Source Inverters to eliminate the harmonics. However, finding the solutions for the harmonic reduction is a difficult problem to be solved. This paper presents an efficient and reliable Evolutionary Algorithms based solution for Selective Harmonic Elimination (SHE) switching pattern to eliminate the lower order harmonics in Pulse Width Modulation (PWM) inverter. Determination of pulse pattern for the elimination of lower order harmonics of a PWM inverter necessitates solving a system of nonlinear transcendental equations. Evolutionary Algorithms are used to solve nonlinear transcendental equations for PWM-SHE. In this proposed method, harmonics up to 19th are eliminated using Evolutionary Algorithms without using dual transformer. The experimental results are obtained and are validated with simulations using PSIM 6.1 and MATLAB 7.0.

In a wireless network the most challenging issue is Channel assignment. The channel assignment problem is codependent with the routing problem. We need to compute again the channel assignment as and when the traffic pattern changes. Anyways, previously followed channel assignment algorithms will assign channels from scratch. It will end up with an entirely dissimilar configuration of nodes; in turn it will disturb the action of the particular network. It takes little time to create links and to establish new channels. This time is significant in assigning links for wireless networks. This leads to channel reassignment. This algorithm considers the existing channel assignment and tries to go along with the new stream of traffic flow design in the finest possible way by changing the channel on a restricted number of radios. In order to provide node stability, we used entropy function. In this paper, we demonstrate a channel reallocation algorithm with node permanency and appraise its performance by using NS2. Experimental outcomes show that the node stability can progress the performance of network when compared with the earlier methods.

Multilevel converters tender advantages in terms of the output waveform quality due to the increased number of levels used in the output voltage modulation and have been widely accepted for high-power high-voltage applications. This paper introduces topology in multilevel dc link inverter (MLDCLI), which can significantly reduce the switch count and improve the performance. The preferred topology provides a dc voltage with the shape of a staircase approximating the rectified shape of a commanded sinusoidal wave, to the bridge inverter, which in turn gives the required alternating waveform. This topology requires fewer components compared to traditional Multi level Inverters (MLI).Therefore, the overall cost and complexity are significantly reduced particularly for higher output voltage levels. Finally, Matlab/Simulink and XILINX are used as a simulation and compiler architecture of control circuit embedded in FPGA. Simulation and experimental results for fifteen-level inverter are presented for validation.

This paper deals with comparison of responses of the PI and the PID controlled bidirectional DC-DC converter systems. A coupled inductor is used in the present work to produce high gain. Open loop and closed loop controlled systems with PI and PID controllers are designed and simulated using Matlab tool. The principles of operation and simulation case studies are discussed in detail. The comparison is made in terms of rise time, fall time, peak overshoot and steady state error. Full Text: PDF DOI: http://dx.doi.org/10.11591/ijpeds.v7.i1.pp56-65

Voltage source inverter (VSI) fed induction motors are widely used in variable speed applications. Space Vector Pulse Width Modulation (SVPWM) has become the successful techniques to construct three phase sine wave Voltage Source Inverter (VSI) parallel to control three-phase induction motor using v/f control. Because of the low maintenance and robustness induction motors have many applications in the industries. The speed control of induction motor is more important to achieve maximum torque and efficiency. VSI fed induction motor produces a pulsating torque due to the application of non sinusoidal voltages. Among the various modulation strategies Space Vector pulse width Modulation Technique is the efficient one because it has better spectral performance and output voltage is more closed to sinusoidal. Torque pulsation is strongly influenced by PWM technique used. This paper compares the torque ripples of convectional space vector PWM with hybrid PWM techniques. In hybrid PWM both continuous PWM and discontinuous PWM techniques are employed. The open loop V/f control of induction motor with hybrid PWM shows better reduction in torque ripples when compared with conventional space vector PWM technique. The simulated design is tested using MATLAB 7.8.

A voltage source inverter-fed induction motor produces a pulsating torque due the application of no sinusoidal voltages. Torque pulsation is strongly influenced by switching fashion employed. This paper presents the simplified hybrid pulse width modulating technique for the reduction of torque ripples in an induction mo tor. In conventional space vector pulse width modulating (CSVPWM) technique (0127-7210) the zero states are divided equally and give rise to continuous modulating technique. The hybrid PWM is a combination of both continuous and discontinuous PWM techniques. To modulate the required voltage vector calculation of magnitude and angle are required which is complex. In this paper a simplified algorithm based on the concept of imaginary switching times is implemented. To validate this method simulation has been carried out in MATLAB 7.8 on v/f control of induction motor.

This paper presents an efficient and reliable evolutionary-programming-based algorithm for specific harmonic elimination (SHE) switching pattern. This method eliminates the considerable amount of lower order line current harmonics in pulse width modulation (PWM) inverter. Determination of pulse pattern for the elimination of some lower order harmonics of a PWM inverter necessitates solving a system of nonlinear transcendental equations. Evolutionary Programming is used to solve nonlinear transcendental function for PWM-SHE. In this proposed method 11th and 13th harmonics are eliminated using evolutionary programming. Simulation results using Matlab/Simulink are carried out to validate the solution.

Tuberculosis Control Program, Western Australia.To assess the effectiveness and efficiency of tuberculosis (TB) surveillance in immigrants.Retrospective descriptive analysis of records of immigrants who first registered with the Tuberculosis Program from January 1994 to December 1995, having entered Western Australia on health undertakings (nonlegal contracts signed by those determined during premigration screening to require post-arrival evaluation).Of 1,344 immigrants on health undertakings for TB in the period, 587 (44%) had findings directly related to TB through pre-migration screening, 69 of whom required treatment for active disease. Another 443 (33%) had chest X-ray changes for which TB could not be excluded. Of the remaining 314 (23%), 172 had poor quality X-rays. Post-arrival assessment and follow-up of the whole group detected four of seven additional cases of active TB, 373 persons (28%) requiring on-going surveillance, 667 (50%) with non-TB conditions and 280 (21%) with normal chest X-rays.Migrant surveillance for TB in Australia is effective in detecting active disease and identifying a high-risk subgroup requiring further evaluation. Efficiency can be improved and high compliance achieved with simple administrative changes. Routine pre-migration Mantoux testing is inappropriate, and its inclusion in post-arrival assessments should be a national policy decision.

State Tuberculosis Control Programme, Western Australia.To ascertain baseline information, applicability and efficacy of preventive therapy for tuberculosis (TB) under indirectly supervised treatment in Western Australia.Retrospective analyses of records of persons with TB infection who were prescribed preventive therapy for the period 1993-1996 inclusive, using simple descriptive statistics.Preventive therapy was given to 411 persons after screening for TB due to on-arrival migrant surveillance (269), contact tracing (59), tuberculin surveys (59) and other reasons (24). Six-month isoniazid monotherapy (HMT) was prescribed for 403 and multidrug regimens for the remaining eight. Excepting 34 whose compliance was unknown, varying degrees of treatment non-adherence were found in 90 (24%) of the remaining 369 persons given HMT, including 36 (10%) with under five months of total medication. Minor adverse drug effects occurred in 32 (9%) subjects and contributed to the non-adherence in 23 of these. One person has since developed active TB.Preventive therapy in Western Australia conformed to generally accepted guidelines. Varying degrees of non-adherence to HMT occurred in 24% of persons, but 90% completed adequate therapy under indirect supervision. Non-adherence is significantly related to adverse drug effects.

Nowadays multilevel inverters (MLIs) have been preferred over conventional two-level inverters due to reduced harmonic distortions, lower electromagnetic interference, and higher DC link voltages. However, the increased number of components, complex PWM control, voltage-balancing problem, and component failure in the circuit are some of the disadvantages. The topology suggested in this paper provides a DC voltage in the shape of a staircase that approximates the rectified shape of a commanded sinusoidal wave to the bridge inverter, which in turn alternates the polarity to produce an AC voltage with low total harmonic distortion and power loss. This topology requires fewer components and hence it leads to the reduction of overall cost and complexity particularly for higher output voltage levels. The component fault diagnostic algorithm is developed using wavelets transform tool. Finally an experimental prototype is developed and validated with the simulation results. Keywords: Field programmable gate array (FPGA), In-phase disposition (IPD) PWM, Least number of switching devices, Multi level inverter, Total harmonic distortion, Wavelet transform tool