Thailand Electrical Engineering Journal (TEEJ)

Design and Installation of a Reconfiguration System for Solar PV Panels to Reduce the Effect of Partial Shading

Suthida Namuangrak — 2024-12-09

Currently, there has been an increased installation of solar panels to generate clean electrical energy and reduce electricity costs of consumers. However, due to environmental limitations, there may be instances of partial shading on the solar panels, leading to a decrease in the overall electricity production efficiency of the system. To address this issue, this study is conducted on designing and installing a reconfiguration system for solar PV panels to mitigate the impact of partial shading. There are four types of solar panel array configurations considered in this work consisting of series-parallel type A, series-parallel type B, total cross-tied type A, and total cross-tied type B. Additionally, eight patterns of partial shading are considered to examine the effectiveness of the reconfiguration system in reducing the impact of partial shading and enhancing power generation efficiency. The results revealed that the total cross-tied configuration presented the highest power generation efficiency when compared to the series-parallel configuration.

Analysis of Performance and Operating Temperature Losses of Solar Cell Modules A Case Study in Bangkok Area

Patinya Sakwan — 2025-01-13

The study analyzed the energy production performance of
a 32.4 kWp solar photovoltaic (PV) system installed on the roof of the
Chitralada Institute of Technology building, which consisted of multi-crystalline silicon (m-Si) solar cells. The PV system had been in operation for 4 years. The purpose was to assess the system's efficiency and operating temperature losses. The average daily solar irradiance varied throughout the months, with a peak of 410 watts per square meter in April and a minimum of 305 watts per square meter in September.
The monthly energy production of the PV system reached its highest at 3,925 kilowatt-hours per kilowatt peak (kWh/kWp) and its lowest at 2,978 kWh/kWp. From the analysis, it was found that the reference yield (kWh/kWp) was 0.736, and the net solar energy yield (kWh/kWp) was 0.563. The performance ratio (PR), which represents the system's efficiency, was calculated to be 0.712. Additionally, the operating temperature losses were determined to be 0.067. The operating temperature losses (0.067) reflect the reduction in energy production caused by the increase in the operating temperature of the PV system. This value indicates the fraction of energy lost due to the temperature effect during the system's operation.

A simple square-rooting circuits using available commercial devices

Chaiwat Sakul — 2024-12-09

This paper proposes two square-rooting circuits consisting of AD844 and CD4007. Principle of operation of the proposed circuits is based on the square-law characteristic of MOS transistor within CD4007. The first square root circuit gives the output signal negative. The second circuit works give the output signal positive. Simulation results based on LTspice program agree well with theoretical anticipation.

The Improvement Method of Skin Cancer Detection by Machine Learning

Chokemongkol Nadee — 2024-12-09

This paper proposed the method for improving skin cancer detection by finding the edges of skin regions with snake algorithm with several machine learning methods for analyze skin cancer disease by design dataset and used a machine learning model using the nearest neighbor (KNN) method, artificial neural networks (ANN), Adaptive Boosting (AdaBoost), Stochastic Gradient Descent (SGD), and Logistic Regression. By this method, the mass binding technique was applied from the value of the assigned weight from the learning data and obtained the score, matrix assessment model, method of the snake algorithm and the set of parameters to find the edges of the skin cancer images based on the basic geometric shapes to solves the problem found that the standard accuracy, recall, F1 score, and area under the curve used to generate weight vectors to find learning guidelines. Learning groups and test results based on a set of skin image data were used for testing of 1,372 images of normal skin, 1,432 images of skin cancer, 254 images of dermatitis skin were used as the learning data set and another group of test image is used as test data set of 600 images are used for increase detection efficiency. From this research, the developed program can analyze the test images with a high speed and yielded the accuracy of the data in the learning base and outside the learning base at 99.74% and 83.3% respectively.