Study Design of DC Electrical System for Self-Powered Houses

• Main Author: SETYAWAN (NIM : 13311011); STEVE (NIM : 13311021), AJI
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/19843
• Institution: Institut Teknologi Bandung

A self-powered house needs an efficient electrical grid system, because the power generated from renewable energy sources is limited and the house is not connected to the main grid. The most popular electrical grid system nowadays is AC-grid, which suffers high power loses. This drawback occurs as a result of multiple power mode conversion, introduced by inverter (DC-AC) and adapter (AC-DC). To overcome the problem, a system which eliminates the multiple power mode conversion is needed, in a form of DC-grid system. It would be significantly relevant and efficient as the battery (energy storage) and most of electrical loads run in DC. In addition, the capital investment of DC-grid system <br /> <br /> <br /> will be cheaper. The system is designed to be ready for houses in the remote areas, which has not been electrified yet. In this research, various electrical loads primarily used were studied through a field survey in Desa Karyawangi, Kecamatan Parongpong, Bandung. Those test loads were chosen based on usage intensity and modification simplicity. The DCgrid prototype was built to be compared with AC-grid. The prototype development accomplished by numerous processes : choosing the grid voltage, designing electrical grid, and cable sizing. DC-DC power converters with switching voltage conversion were chosen to reduce the power loses. The LED drivers, with MOSFET as a variable resistor, were designed to deliver fixed output currents. The research showed that LED lamps, TVs, laptops, mobile phones, and electrical <br /> <br /> <br /> stoves were feasible to work in DC-grid system. The power converters which have been designed are DC-DC converters for mobile phones, TVs, and laptops, and LED drivers for LED lamps. Efficiency test showed that switching DC-DC converters were more efficient than linear converters. Power conversion efficiency of DC-DC converters and LED drivers varied between 79% to 93.2%. <br /> <br /> <br /> The average power consumption of DC-grid was lower than AC-grid (40.52% - 85.37%). Through a scheduled usage simulation with 50 A·h, 24 V battery, the DC-grid system ON-time was twice longer than AC-grid system. Also, the capital investment for the DC-grid system was 26.12% lower than AC-grid system.