Performance evaluation of a 10 kWp PV power system prototype for isolated building in Thailand

This paper describes the design and testing of a 10 kW_p photovoltaic (PV) system and summarizes its performance results after the first 6 months of operation. This system functions as a stand-alone power system that is used to supply electricity for isolated buildings and is designed for integration with a micro-grid system (MGS), which is the future concept for a renewable energy-based power network system for Thailand. The system is comprised of the following components. An array with three different types of PV modules consisting amorphous thin film of 3672 W, polycrystalline solar cell of 3600 W and hybrid solar cell of 2880 W, making up a total peak power of 10.152 kW. In addition, there are three grid-connected inverters of 3.5 kW each, three bi-directional inverters of 3.5 kW each and an energy storage system of 100 kWh. After the first 6 months of system operation, it was found that all the components and the overall system had worked effectively. In total, the system had generated about 7852 kWh and the average electricity production per day was 43.6 kWh. The average efficiency of amorphous thin film panel, polycrystalline panel, hybrid solar cell panel and entire PV panel system was 6.26%, 10.48%, 13.78% and 8.82%, respectively. From the analysis of the daily energy production, daily energy consumption and energy storage, the results seem to indicate that there was some mismatching between energy supply and demand in the system. However, this can be overcome by integrating the system to a micro-grid network whereby the energy from the system can be diverted to other loads when there is a surplus and additional energy can be drawn from external sources and fed to the system when the internal supply is insufficient.     

Data Adaptive Linear Decomposition Transform

Cadzow, J. A., and Yammen, S., Data Adaptive Linear Decomposition Transform, Digital Signal Processing12 (2002) 494–523In this paper a novel method for decomposing one-dimensional data sequences is developed. It is of the wavelet variety with important distinctions. A standard wavelet transform entails down-sampling the responses of two fixed structured filters to the sequence being decomposed to produce the half length detail sequence and a coarse sequence. The new transform entails processing down-sampled data by an optimum interpolation filter which seeks to approximate the odd indexed sequence elements by a linear combination of neighboring even indexed elements. The resulting interpolation error sequence of half length plays the role of the wavelet detail sequence. Unlike a traditional wavelet transform, the interpolation filter employed is adapted to the data being analyzed. This data dependency typically produces improved performance relative to traditional wavelet transforms. This enhanced performance is demonstrated on a number of standard test signals. Furthermore, this new transform is computationally efficient due to the inherent parallel structure of the data decomposition method.     

Performance of a 500 kWP grid connected photovoltaic system at Mae Hong Son Province, Thailand

This paper summarises the first eight months of monitoring of the PHA BONG photovoltaic generation project, a 500 kW_p photovoltaic pilot plant, in Mae Hong Son province, Thailand. The local grid in this remote area in the North West of Thailand is very limited in its capacity and cannot be enlarged. It has been in operation since 20 March 2004 by feeding into 400 V_AC, 22 kV medium voltage grid. The system consist of a photovoltaic array 1680 modules (140 strings, 12 modules/string; 300 W/module), power conditioning units and battery converter system. During the first eight months of this system's operation, the PV system generated about 383,274 kWh. The average of generating electricity production per day was 1695.9 kWh. It ranged from 1452.3 to 2042.3 kWh. The efficiency of the PV array system ranged from 9 to 12%. The efficiency of the power conditioning units (PCU) is in the range from 92 to 98%. The final yield (Y_F) ranged from 2.91 to 3.98 h/d and the performance ratio (PR) range from 0.7 to 0.9.