by Hossein Soleymani
Original Research
Transformers is one of the key equipment of the power system. Power rating of the transformers varies from KVA to several hundreds of MVA. The transformer is expensive equipment of the power system. Failures of transformer usually lead to substantial profit loss to the utility, potential environmental damage, explosion and fire hazards and expensive repairing or replacement costs, thus, it is desirable that the maximum service life of transformer is required. Condition monitoring of transformer can help to increase the life of the transformer and reduce the maintenance cost. Online monitoring is the record of significant data of a transformer and analysis of data and including the history of the transformer. In this paper percent the different techniques adopted for condition monitoring of transformer.
American Journal of Electrical and Electronic Engineering. 2017, 5(2), 54-58. DOI: 10.12691/ajeee-5-2-5
Pub. Date: May 02, 2017
11484 Views2246 Downloads
by Sandeep C S, Sukesh Kumar A, K Mahadevan and Manoj P
Original Research
Alzheimer’s disease (AD) is the most common cause of dementia and its incidence is increasing worldwide along with population aging. Previous clinical and histologic studies suggest that the neurodegenerative process, which affects the brain, may also affect the retina of AD patients. In this case, the employment of advanced Biomedical Engineering Technology will definitely helpful for making diagnosis. Any disease modifying treatments which are developed are most possibly to be achieving success if initiated early in the process, and this needs that we tend to develop reliable, validated and economical ways to diagnose Alzheimer’s kind pathology. However, despite comprehensive searches, no single test has shown adequate sensitivity and specificity, and it is likely that a combination will be needed. Profiling of human body parameter using computers can be utilised for the early Diagnosis of Alzheimer’s disease. There are lot of tests and imaging modalities to be performed for an effective Diagnosis of the disease. Prominent of them are Magnetic Resonance Imaging Scan (MRI), Positron Emission Tomography (PET), Single Photon Emission CT Scanning (SPECT) and Optical Coherence Tomography (OCT).In the recent studies made on Alzheimer’s disease it is clearly investigated that are some parameter changes on the retina of the eye of the AD patients. In this research we have proposed a new scheme based on Wavelet Networks (WN) for the dimensionality reduction of OCT retinal images for the early Diagnosis of AD.
American Journal of Electrical and Electronic Engineering. 2017, 5(2), 58-63. DOI: 10.12691/ajeee-5-2-4
Pub. Date: April 27, 2017
12724 Views3418 Downloads1 Likes
by Hatem Elaydi
Original Research
Gaza Strip is a small region with limited agriculture land and water resources. Greenhouse technology allows farmers to optimize the use of this land. In this paper a computer-based control and monitoring system is designed and tested to automate drip irrigation. The model greenhouse can be used as a prototype where several sensors are connected to an acquisition and control system using a PC and a data acquisition card. The designed system can be used as a stand-alone system by lay farmers with no technical background where they can command full control through a screen command. The system is set up to handle several crops by using a user screen to adjust certain parameters on the front panel. A web server enables users to remotely monitor and control the greenhouse through VI's from any place in the world with internet access. Moreover, the system periodically generates alarms and automatically sends emails to notify users of the conditions inside greenhouse.
American Journal of Electrical and Electronic Engineering. 2017, 5(2), 48-57. DOI: 10.12691/ajeee-5-2-3
Pub. Date: April 07, 2017
32814 Views4967 Downloads
by N. Schinas
Original Research
This paper presents new control strategies for a variable speed wind turbine (WT) which consists of a doubly fed asynchronous generator. In this kind of generators, the rotor windings are supplied with an appropriate voltage vr through a dc link. There are 2 converters: the rotor-side and the grid-side converter in the dc link. The right pulsation of the rotor-side converter defines the rotor voltage vr in such a way that both real power maximization from the wind speed and nominal voltage are secured at the same time. With all the flux dynamics inside the machine having been included in the generator model, there is a 2-input-2-output system. Based on the dq electric machines analysis theory, the proposed control scheme manages to create 2 single-input-single-output systems with the rotor voltage component in each axis responsible only for real power or voltage nominal value respectively. This is achieved through optimal control theory with the right definition of the cost function. A new control scheme that contains stochastic control principles is proposed for the grid-side controller in which the decoupling of the loops is achieved by means of the grid frequency being regarded as a ‘random’ variable to the voltage control loop and so it has no impact on it. The nonlinear system has been tested in the SIMULINK software under 3 tests: In the first test the wind speed changes and brings about an analogous alteration of the WT output. In the second test there is a short circuit in the grid. According to the new rules, the WT is not disconnected from the grid during the short circuit and continues to produce energy with a very smooth behavior. In the third test, there is a large load disturbance in the grid. Again the WT manages to supply the grid with electrical energy in a nice way. Under all tests the controllers seem to cooperate very well and the variations of the voltage and the frequency are within acceptable limits.
American Journal of Electrical and Electronic Engineering. 2017, 5(2), 40-47. DOI: 10.12691/ajeee-5-2-2
Pub. Date: March 21, 2017
18940 Views2640 Downloads
by Li Lin, Yan Wei and Qiu Dongmei
Original Research
Photovoltaic (PV) systems have been widely used for power generation and renewable energy. Conducted electromagnetic interference (EMI) noise have generated, which affect the performance of other device and the grid. In the paper, the measurement uncertainty of artificial mains network (AMN) has been analyzed. The conducted EMI noise mechanism and noise mitigation methods have been proposed, including transistor filter and well grounding design strategies. The simulation and experiment results show that the conducted EMI noise generated by a certain convert can be suppressed well and pass EN 55011 and EN 55022 standards, thus good realization and validation.
American Journal of Electrical and Electronic Engineering. 2017, 5(2), 34-39. DOI: 10.12691/ajeee-5-2-1
Pub. Date: March 17, 2017
16393 Views2695 Downloads