SOLAR COOLING SYSTEM OF A CAR

This report is based on the 'Solar Cooling System' project that has been implemented. The report will give an overview to all the processes and constructions of project work. The main objective of this project is to provide cooling in the car by using solar power. Hot day and high temperature will give uncomfortable situation to most people, especially when they get into their car after parking for several hours in open space. The person could not even hoid the steering or sit comfortably on the seat because the things are already heat up. They also feel hot when they open the window during the car moving for saving the fuel or the air conditioning is not functioning. In order to reduce the high temperature, this project will utilize the solar (photovoltaic) energy as a source to the cooling system in a car. The solar (photovoltaic) energy will charge the battery instead of activating the system. The battery will be used as a back up when solar energy is not sufficient and generates other electronic devices in the car.A thermistor that contains in control unit will be used to sense the temperature difference. When the temperature has reached to the temperature that has been set, the cooling system will turn on in order to reduce the temperature inside the carand suck the hot air out. The research and design stage will be complete during the first semester and construction stage will be done during the second semester. The analysis of cooling system to the real application will also be carried out to fulfill the design requirement instead of improving it

A neuro-fuzzy approach for stator resistance estimation of induction motor = pendekatan neuro-fuzzy untuk meramal rintangan stator pada motor induksi

During the operation of induction motor, stator resistance changes incessantly with the temperature of the working machine. This situation may cause an error in rotor resistance estimation of the same magnitude and will produce an error between the actual and estimated motor torque which can leads to motor breakdown in worst cases. Therefore, this project will propose an approach to estimate the changes of induction motor stator resistance using neuro-fuzzy. Then, it will be compared with conventional method like P1 estimator to see the effectiveness. The behaviour of the induction machine will be analyzed when the stator resistance is changed. Based on the changes, a corrective procedure will be applied to ensure the stabilities of the induction motor. Generally, this project can be divided into three main parts which are design of induction motor, design of neuro-fuzzy and PT estimator, and corrective procedure for the induction machine. The Newcastle Drives Simulation Library will be used to design the induction motor model and MATLAB SIMULINK will be used to design the stator current observer. The neuro-fuzzy estimator will be designed based on Sugeno Method Fuzzy Inference System

Current limiter strategy of grid-connected pv system for LVRT Enhancement

A low-voltage ride-through (LVRT) is an ancillary service provided to a power grid to stabilize the grid voltage under weak grid conditions. Under these circumstances, a short-term disturbance is allowed to be ride-through to prevent unnecessary nuisance tripping during weak grid conditions. The main objective of this paper is to propose an active power curtailment strategy for a 1.038 MW grid-connected photovoltaic (PV) system to enhance the LVRT capability. A simple current limiter was applied to regulate the excessive DC-link voltage while the reactive power was controlled by a PI-tuning controller to maintain the voltage profile. Using MATLAB/Simulink environment, the dynamic behaviors of the proposed system were tested under 70% voltage sag and it was found that the proposed strategy is successful in curtailing the active power during low-voltage conditions and the excessive DC-link voltage can be controlled. Meanwhile, the whole system can maintain its operation without inverter disconnection and the voltage profile was improved even under weak grid conditions

Total serum cholesterol level in patients with major depressive disorder: Simple yet undermined

Human brain cholesterol acts as structural components of cellular membrane, synapse and dendrite formation.Researchers have found a possible association between low serum cholesterol levels and mood disorders though the literature from India in this regard is limited. To estimate serum levels of total cholesterol in patients with major depressive disorder. 75 patients of MDD were compared with equal number of age and sex matched controls. 5 ml of fasting sample of blood was obtained in a plain vacutainer to analyse total cholesterol level by Cholesterol oxidase-peroxidase method. Statistical analysis: The obtained results were tabulated and analyzed by multiple logistic regression analysis, independent t-test, Chi-square test and area under the curve. The mean level of cholesterol in cases (158.85±61.22 mg/dL) which was significantly lower compared to the controls (182.71±40.98 mg/dL) with P <0.01. The symptoms of MDD negatively correlated with lower serum cholesterol level with odds ratio of 0.99. There was statistically significant lower level of cholesterol in the MDD group below 140 mg/dL compared to the control group with P <0.001. As the measurement of total serum cholesterol is simple and cost effective, it can be used as an important biochemical marker for MDD

A comprehensive review of synchronization methods for grid-connected converters of renewable energy source

Recent interest in the integration of renewable energy sources (RES) into the power grid has raised concerns in synchronization of the various RES. Grid variables such as voltage, phase angle and frequency should be continuously monitored to guarantee correct operation and synchronization of power converters connected to the power grid. Numerous synchronization methods have been presented over the years to address issues such as unbalanced condition and frequency variation. This paper presents a review of past studies on synchronization methods for grid-connected converters together with their control and modeling techniques. Various estimation techniques for phase angle, frequency and harmonic are discussed and examined. Key challenges for a smart and efficient synchronization are briefly overviewed and possible future works are also recommended. A consolidated review is the particular focus of this paper, as is the provision of information on the best method for synchronizing grid-connected converters

Optimization of radial distribution network with distributed generation using particle swarm optimization considering load growth

This article presents a combination of particle swarm optimization (PSO) algorithm and the backward/forward sweep power flow (BFSPF) approach to determine the optimal bus location and size of distributed generation (DG) in a radial distribution network (RDN) considering the load growth. The analysis of the proposed optimization framework is performed using MATLAB and tested on the 33–bus RDN subject to minimize the power losses. The solutions accomplished through the experiments considering four case studies show significant reductions in the system’s total power loss and improvement in desired bus voltage profiles. With the installation of DG, the percentage of reduction in power loss is 47.38% compared to the system’s power loss without DG. The DG size and location to be installed are determined at the 6th bus location with 2.59 MW. The results show that power losses will increase with the increase in load demand. The findings reveal that load growth does not influence the optimal location of the DG. However, the sizes of DGs need to be revised when considering growth in load conditions

Time-variant online auto-tuned pi controller using pso algorithm for high accuracy dual active bridge dc-dc converter

The proliferation of clean energy and environmentally friendly transportation has contributed to the development of electric vehicles (EVs) including the EV DC charger system. A dual active bridge (DAB) is a DC-DC converter that has the required features for an EV DC charger. A proportional-integral (PI) controller is a common method in power electronics applications, including DAB. However, the manual tuning of PI parameters using Ziegler-Nichols (ZN) needs a lengthy time and the tuning values are practical and well-functioning at the tuning point only. Moreover, the fixed gains in offline tuning cannot fully control the system output as needed and do not guarantee the robustness of the system. This paper proposes a time-variant online auto-tuned PI controller using a particle swarm optimization (PSO) algorithm for the 200 kW DAB system. The DAB performance with the proposed controller is evaluated in terms of steady-state error, eSS and dynamic performance under various reference voltages at different loads and load step changes. Comparative analysis between the proposed method and manual tuning performance are presented. A hardware-in-the-loop (HIL) experimental circuit is built to validate the simulation results. The DAB with the proposed method produces 64% higher accuracy and 40% faster response compared to manual tuning. tuning

The use of end-tidal capnography to monitor non-intubated patients presenting with acute exacerbation of asthma in the emergency department.

STUDY OBJECTIVE To determine if the slope of Phase II and Phase III, and the alpha angle of the expiratory capnographic waveform, as measured via computer-recognizable algorithms, can reflect changes in bronchospasm in acute asthmatic non-intubated patients presenting to the emergency department (ED). METHODS In this prospective study carried out in a university hospital ED, 30 patients with acute asthma were monitored with clinical severity scoring and peak flow measurements, and then had a nasal cannula attached for sidestream sampling of expired carbon dioxide. The capnographic waveform was recorded onto a personal computer card for analysis. The patients were treated according to departmental protocols. After treatment, when they had improved enough for discharge, a second set of results was obtained for capnographic waveform recording. The pre-treatment and post-treatment results were then compared with paired-samples t-test analysis. RESULTS On the capnographic waveform pre- and post-treatment, there was a significant difference in the slope of Phase III (p < 0.001) and alpha angle (p < 0.001), but not in the Phase II slope (p = 0.35). There was significant change in peak flow meter reading, but it was poorly correlated with all the capnographic indices. CONCLUSION The study provides some preliminary data showing that capnographic waveform indices can indicate improvement in airway diameter in acute asthmatics in the ED. Capnographic waveform analysis presents several advantages in that it is effort-independent, and provides continuous monitoring of normal tidal respiration. With further refined studies, it may serve as a new method of monitoring non-intubated asthmatics in the ED