Wael A. Salah

PWM SWITCHING STRATEGY FOR TORQUE RIPPLE MINIMIZATION IN BLDC MOTOR

PWM Switching Strategy for Torque Ripple Minimization in BLDC Motor This paper describes a new PWM switching strategy to minimize the torque ripples in BLDC motor which is based on sensored rotor position control. The scheme has been implemented using a PIC microcontroller to generate a modified Pulse Width Modulation (PWM) signals for driving power inverter bridge. The modified PWM signals are successfully applied to the next up-coming phase current such that its current rise is slightly delayed during the commutation instant. Experimental results show that the current waveforms of the modified PWM are smoother than that in conventional PWM technique. Hence, the output torque exhibits lower ripple contents.

Rotor fault diagnosis based on current signatures in squirrel-cage induction motor

One of the most frequently used fault detection methods for induction motor is the current signature analysis. This technique depends upon locating by finite element method and analysis of specific harmonic components in the line current produced by unique rotating flux components caused by faults such as broken rotor bars. The motor current signature analysis method can detect these problems at an early stage and thus avoid secondary damage and complete failure of the motor.

Development of PM brushless DC motor drive system for underwater applications

In this paper, the BLDC motor control using rotor position sensing scheme is discussed. The implemented motor drive is controlled by an 8-bit microcontroller PIC18F4431 for driving the power inverter bridge. The use of microcontroller in the drive system will provide flexible and on-line source code modifications in accordance with the motor and circuit requirements. Hardware implementations which have been built consist of a control board, power inverter board and 6-slot/4-pole permanent magnet brushless motor for underwater applications. The information about rotor positions of BLDC motor is obtained using the built-in Hall Effect sensors mounted inside stator iron. Hence, a proper driving sequence for the BLDC motor has been successfully generated as validated by the experiment.

Electric Vehicle Technology Impacts on Energy

This paper presents a nonlinear Integral backstepping control approach based on field oriented control technique, applied to a Double Star Induction Machine ‘DSIM’ feed by two power voltage sources. We present this technique of integral backstepping by using reduced and complete Model of DSIM. The objective is to improve the robustness of machine under internal parameter variation with nonlinear Integral backstepping control. The robustness test results obtained by simulation prove the effectiveness of control with using complete model of DSIM.In the majority of the isolated areas, the diesel generator is the principal source of electric power. For these areas, the price of extension of the electrical supply network is prohibitory and the price of fuel increases radically with insulation. The continuous fall in the prices of the generators based on renewable energy and the increasing reliability of these systems led to a greater use of the sources of renewable energy for the generation of electric power in the isolated areas. The diesel generators can incorporate in a network with other sources in base of renewable energies in order to create a new network known as distributed network. More recently intermittent renewable resources such as the wind power were considered as a distributed generation which is seen as being deployed to reduce the total emissions. The distributed generation equipment sets causing electric disturbances result in destabilizing the global network as well as pollutant, for these reason, system D-FACTS comes to answer all the concern of the customers, manufacturers, suppliers and the managers of the distributed network .This paper presents parameters analysis of 4-level capacitor-clamped boost converter with hard-switching and soft-switching implementation. Principally, by considering the selected circuit structure of the 4-level capacitor-clamped boost converter and appropriate pulse width modulation (PWM) switching strategy, the overall converter volume able to be reduced. Specifically, phase-shifted of 120° of each switching signal is applied in the 4-level capacitor-clamped boost converter in order to increase the inductor current ripple frequency, thus the charging and discharging times of the inductor is reduced. Besides, volume of converters is greatly reduced if very high switching frequency is considered. However, it causes increasing of semiconductor losses and consequently the converter efficiency is affected. The results show that the efficiency of 2-level conventional boost converter and 4-level capacitor-clamped boost converter are 98.59% and 97.67%, respectively in hard-switching technique, and 99.31% and 98.15%, respectively in soft-switching technique. Therefore, by applying soft-switching technique, switching loss of the semiconductor devices is greatly minimized although high switching frequency is applied. In this study, passive lossless snubber circuit is selected for the soft-switching implementation in the 4-level capacitor-clamped boost converter. Based on the simulation results, the switching loss is approximately eliminated by applying soft-switching technique compared to the hard-switching technique implementation.This paper presents the summary of a detailed literature review on the topic of energy conservation project funding as energy conservation is seen as a less important operational activity in many third world countries, particularly in India, because it is still considered to be an unnecessary expenditure. Such an important activity in many organizations in India takes the back seat as there is no clear management vision and policy for energy conservation. When procurement manager is obliged to buy based on L1 policy (Lowest quoted price) most of the Energy Conservation Measures (ECM) are not available at that price. Energy conservation is yet to be everyone’s concern in most of the organizations. When it is supposed to be a top-down approach, in reality it remains some less important activities carried out as a formality. There is a need to have paradigm shift, particularly in the top management and it is time that we do not see it as expenditure to implement an energy conservation project but an investment that will continue to give return as long as the equipment is in operation or the facility is functional. Policies and guidelines need to be modified so that there are no conflicts between the departments for implementing the energy conservation projects.This paper presents a Stand-alone Hybrid Renewable Energy System (SHRES) as an alternative to fossil fuel based generators. The Photovoltaic (PV) panels and wind turbines (WT) are designed for the Malaysian low wind speed conditions with battery Energy Storage (BES) to provide electric power to the load. The appropriate sizing of each component was accomplished using Non-dominated Sorting Genetic Algorithm (NSGA-II) and Multi-Objective Particle Swarm Optimization (MOPSO) techniques. The optimized hybrid system was examined in MATLAB using two case studies to find the optimum number of PV panels, wind turbines system and BES that minimizes the Loss of Power Supply Probability (LPSP) and Cost of Energy (COE). The hybrid power system was connected to the AC bus to investigate the system performance in supplying a rural settlement. Real weather data at the location of interest was utilized in this paper. The results obtained from the two scenarios were used to compare the suitability of the NSGA-II and MOPSO methods. The NSGA-II method is shown to be more accurate whereas the MOPSO method is faster in executing the optimization. Hence, both these methods can be used for techno-economic optimization of SHRES.Attempting to reduce the existing electricity consumption bill, as well as the stability and non-outage grid recharge with the lowest possible cost and suitable quality, is one of the most important goals for those interested in energy around the world. This paper study the circumstances surrounding the Egyptian society to find the best solutions to a achieved this goals, and it was found that solar energy is one of the best alternatives available for energy. Firstly will be study the electricity consumption bill, slice prices and a program was made to calculate the consumption invoice moreover another program for quick estimation to the proposed solar system.The proposed system provides a smart integration between the solar system and grid, where the supply sustainability and the optimal cost are considered. This configuration allows the two sources separately or simultaneously supply the loads depending on photovoltaic extracted energy. Operational analysis of the proposed system will discussed in this paper. The proposed system consists of solar cells, charge controller, batteries and inverter plugged to automatic transfer switches (ATS) using Programmable Logic Control (PLC). The system grantee a safe and reliable load feeding independently on the grid status. The system durability is the most depicted feature through the modelling and experimentally results. A typical case studies for about four years of non-outages photovoltaic-grid hybrid supply (the implemented system) will be presented and discussed.

Hotspot Detection for Wall-Mounted Air-Conditioner System

This paper presents the overall design of the hot spot detection and air flow control for a wall-mounted air-conditioner system. The system is designed to find out the hot areas that will cause the cool air from the air-conditioner not equally distributed to all areas in a room. Therefore, one of the solutions is to control airflow of the air-conditioner so that the cool air could reach to that particular area for cooling purpose. As a result, it will increase the efficiency of the air-conditioner by cooling the hot areas (hotspot) instead of cooling the area that has already cooled. The random air swing in most conventional air-conditioner system does not help much in cooling the hotspot area, however, the proposed system is designed to cater that issue. The experiment has been done on the system by using the highest temperature method to detect the presence of human. The system can detect human based on the generated temperature array. For testing and data analysis, the user interface was developed using Matlab and the real application software was built on a smartphone using Android Studio software in order to control the airflow conveniently.

Implementation of Virtual Instruments as a Power Quality Analysis Tool

Virtual instruments (VI) offer flexibility to engineers in the tasks of measurement and monitoring in many fields of study and various industries. The use of graphical programming in VI helps create a user-defined solution that caters to specific needs. VI increases productivity and decreases costs for test, control and design applications by integrating software, such as the National Instrument Laboratory VI Engineering Workbench (LabVIEW), modular measurement and control hardware with different connections, such as PXI, PCI, USB and Ethernet. The harmonic components need to be measured to analyze power quality. The electrical supply that flows through non-linear loads produces harmonics that disturb the functions of other equipment connected to the same supply. The harmonic, voltage and current VIs that are available in the LabVIEW software are used to analyze power quality, so that appropriate actions can be taken to reduce disturbances. The power equipment is remotely monitored using the VIs. The data are analyzed at the low power side, in contrast to traditional power quality analysis tools, which analyze data at the captured side. This approach can provide a safer operation for system users.

A survey of energy conservation and management options for Malaysia

ABSTRACT The electrical energy consumption in Malaysia has increased sharply in the past few years, and modern energy-efficient technologies are desperately needed for the national energy policy. This article presents a comprehensive picture of the current status of energy consumption and various energy conservation options viable for the Malaysian environment. A detailed survey is made to assess the consumption pattern and the existing techniques for energy efficiency. Based on the survey, the feasibility of improving the available systems and adopting new programs in different sectors is investigated. The proposed options are then categorized into four main sectors such as building, industrial, electrical and transportation. The study reveals the fact that the energy conservation policy of the country has been fairly improved in the last ten years. However the country has to pay more attention to this area and make urgent measures to adopt more energy-efficient technologies in various sectors.

Energy efficiency practices in power supplies: Scenario and solution

ABSTRACT Most household electronic products and office equipment circuitry are operated internally at a low direct current (DC) voltage. However, they are designed to be plugged directly into wall outlets with alternating current (AC). AC to DC conversion is performed by devices called DC power supplies. Energy efficiency is a serious concern for most electrical and electronic appliances that require power supplies to operate. The majority of end users consume excess energy because of inefficient, bulky, and outdated power supply systems. A great gap exists in studies on energy saving in power supply design and selection. This article presents an overview of power supply energy consumption patterns and the effects of different operation modes on overall system power consumption. Recommendations for achieving an efficient energy system are presented.

The Malaysian Energy Scenario and the Need for a SCADA System

There is a need to ensure efficient utilization and diversification of energy sources while minimizing its waste. The electrical energy consumption in Malaysia has increased sharply in the past few years, and modern energy-efficient technologies are desperately needed for the national energy policy. The development of Supervisory Control and Data Acquisition (SCADA) systems is essential to ensure smooth operation of any energy system. This article outlines the present status of energy utilization in Malaysia and introduces the SCADA system as one of the promising energy management tools for the future.

Improvement of Transformerless 200W SMPS Using CUK DC-DC Converter

This paper presents the design of transformer less DC-DC converter for 200 W SMPS application. The converter circuit based on CUK topology which is basically combination of buck and boost converter topologies. The proposed converter converts input DC voltage of 50 V or less to a 5 V stable and ripple free load current. The output also is a load independent. A fast switching and low ON-resistance power MOSFETs was used to step down voltage. The power switches operated at high frequency, and the PWM control IC was used to provide the operating signal for the switch. In this paper the concept of basic Cuk converter is reviewed, subsequently the derivation of the proposed converter is presented. And the simulation results of the power circuit are analyzed and discussed.