Study of dependence of magnetic properties on seeding temperature in fine particles of Cu0·25Co0·25Zn0·5Fe2O4

Using a combination of X-ray diffraction, room temperature/low temperature Mössbauer studies and d.c. magnetization, the structural and magnetic properties of nano-sized Cu_0·25Co_0·25Zn_0·5Fe₂O₄, prepared using the coprecipitation method at different seeding temperatures, have been studied. Formation of α-Fe₂O₃ in these samples is observed to be very sensitive to the seeding temperature and is totally suppressed at a seeding temperature of 333 K. These results are explained in terms of the rate of coprecipitation of the different components as a function of temperature. Since α-Fe₂O₃ is antiferromagnetic, the presence and quantity of this impurity is also observed to deteriorate the overall magnetic properties of the spinel phase.     

Real-time simulation platform for photovoltaic system with a boost converter using MPPT algorithm in a DSP controller

Recently, real-time simulation of renewable energy sources are indispensible for evaluating the performance of the maximum power point tracking (MPPT) controller, especially in the photovoltaic (PV) system in order to reduce cost in the testing phase. Nowadays, real time PV simulators are obtained by using analog and/or digital components. In this paper, a real-time simulation of a PV system with a boost converter was proposed using only the digital signal processor (DSP) processor with two DC voltage sources to emulate the temperature and irradiation in the PV system. A MATLAB/Simulink environment was used to develop the real-time PV system with a boost converter into a C-program and build it into a DSP controller TMS320F28335. Besides, the performance of the real-time DSP-based PV was tested in different temperature and irradiation conditions to observe the P-V and V-I characteristics. Further, the performance of the PV with a boost converter was tested at different temperatures and irradiations using MPPT algorithms. This scheme was tested through simulation and the results were validated with that of standard conditions given in the PV data sheets. Implementation of this project helped to attract more researchers to study renewable energy applications without real sources. This might facilitate the study of PV systems in a real-time scenario and the evaluation of what should be expected for PV modules available in the market.