In this paper, we aim to determine the parameters of a photovoltaic installation that will ensure the electricity needs of a home equipped with smart equipment. We proposed to study the most efficient installation according to different types of panels and tilt angles. The main objective is to determine the optimal photovoltaic installation regardless of the seasonal variation, and as a secondary objective, the surplus energy should be charged to the network.

Following this case study, we want to fully cover the consumption of electricity required by heat pumps for heating homes with the help of photovoltaic panels connected to the network, and by the possibility of changing the angle of their inclination during the cold period, to be able to reach a production as closer to the pump consumption. The main objective of the study is to determine a balance between consumption and production during the cold season and around it, and as a secondary effect it would be to eliminate as much as possible the electricity obtained with the help of fossil fuels or other much more polluting sources, replacing this energy through the one obtained by the photovoltaic panels.

This study offers a comparative analysis on the LDPC (Low Density Parity Check) codes and Polar codes regarding their efficiency and gives a brief explanation of these error correcting codes. Determining the efficacy of these codes was achieved analyzing BER (Bit Error Rate) towards SNR (Signal to Noise Ratio) making use of Binary Phase Shift Keying (BPSK) in AWGN channel (Additive White Gaussian Noise).

This paper presents a comparative study between Turbo codes and Polar codes used for channel coding in mobile communications, and provides a description of these codes and their main characteristics. The performances of these codes are very close to Shannon capacity performance. The efficiency of Turbo and Polar codes is evaluated in term of bit error rate (BER) for a given value of signal to noise ratio (SNR) over Additive White Gaussian Channels (AWGN) by employing Binary Phase Shift Keying (BPSK) modulation scheme.

A problem encountered in practice is related to the generation of sinusoidal electrical voltage with variable frequency. Generating a variable frequency voltage can be used in different applications as well as in the testing of asynchronous motors. As is known the speed of asynchronous motors depends on the frequency of the power supply to maintain a roughly constant torque. Power voltage value depends on the asynchronous motor type. The power source proposed in the paper is based on two large blocks, namely: a DC/DC convertor and an inverter stage. The DC/DC convertor can generate an output DC voltage of 310V or lower from an input DC voltage of 12 V. The output voltage of the DC/DC converter can be applied then to the inverter power stage obtaining in this case a sinusoidal voltage with amplitude close to 310 V and adjustable frequency. The circuit described in the paper was developed to be used in the learning process of the students that follow study programs in the field of electronics engineering.

In this paper is presented a smart monitoring system that is able to detect, prior to the periodic maintenance service, a set of malfunctions that may negatively influence the quality of the solder joints on PCB but also the process productivity using a reflow soldering equipment. The proposed smart monitoring system use a vibration and temperature sensor, an industrial controller and a program that offers a real time user interface. The smart monitoring system assures with its capabilities a fast intervention of the process operator in order to eliminate all undesired production problems and to assure the quality of the electronic products. This approach is novel and actual as yet were reported in the last period other kind of improvements for the reflowing process.

This paper presents the results obtained by numerical modelling of the surface induction hardening process of a workpiece. We performed numerical modelling by using the ELTA program. In this study, we aimed to establish the electrical parameters in order to optimize the surface hardening process.

The paper proposes an analysis of the heat treatment process (hardening, tempering) of a cylindrical surface with the help of software ELTA. Numerical modelling in the two cases shown, for cooling, the work piece jet of water and compressed air, will help to achieve a better comparison / efficient heating process by means of eddy currents, all at once is underlined the role of specialized software of the design and construction of a induction heating, because it allows us to choose the best solution for the induction heating system.

The periodic electromagnetic field problem in ferromagnetic nonlinear bars is solved by using the iterative method of polarization, the Fourier series decomposition at each iteration, and the harmonics of the electromagnetic field are obtained by solving the integral equation of the eddy currents. The B-H relationship of the ferromagnetic medium and the thermal parameters depends on the temperature. The density of losses results from the solution of the electromagnetic field problem. The procedure has remarkable advantages over commercial software. The numerical results are presented.

During the use of the geothermal energy for hose heating, there are many situations when the temperature of the geothermal water at the extraction point has to be decreased to the usable values. On this path, the authors propose the use of a low power renewable energy system that could be used in many back-up electric power applications. This system does not diminish in any way the efficiency of the house heating system. The proposed system comprises an electro thermal generation unit with TEG (Thermo Electric Generator) modules, a maximum power point tracking system and a storage unit with Li-ion battery. Due to the fact that the geothermal energy is available all the time, the thermal energy recovered with this system may be used as a reliable back-up energy source for low power applications, such as: security transmission systems, monitoring systems to mention only some of the possibilities. The paper shows the operating principle of the systems modeling based on experimental results and a set o simulations results that confirm the usefulness of the proposed equipment.

Heating with high frequency induction has a large variety of applications like melting, heating and hardening metals. Heating by high frequency induction can be made in the complex automated manufacturing systems that can increase productivity and quality of the workpieces. Surface hardening of the workpiece is one of the most important application of induction heating. This project has the main goal of the authors to present an automated surface hardening system used for a cylindrical workpiece using the SolidWorks computer aided design software.

This paper presents considerations on the possibility to use thermoelectric generators at low temperatures to recover waste heat recovery applications, especially from geothermal energy. Thermoelectric generators have a satisfactory efficiency, when they are usually used in conditions with high gradient of temperatures. However, there are many applications, which lose important quantities of energy even at low temperatures, in the order of tens of degrees. To evaluate the operation of a thermoelectric generators modules set, the authors have realized an experimental prototype and investigate its electrical output characteristic at low temperature differences. The purpose of this study was to investigate the possibility to obtain electricity, into an isolated place, but with practical possibility to assure temperature gradients.

This paper presents some considerations on the use of a Maximum Power Point Tracking circuit for a thermoelectric generator. The authors present experimental results obtained with a thermoelectric generator that comprises an array of thermoelectric generation modules used then to model and simulate a circuit that extracts the maximum output electric power for a low temperature difference range. The circuit that assures an interface between thermoelectric generator and a DC load is a boost switched mode power supply. This paper do not cover the stabilization of the output voltage or current of the power supply, but emphasize on the match between output resistance of the TEG array and the input of the switched mode power supply. The paper presents also a set of simulation results that shown the operation mode of the proposed circuit.

This paper presents aspects related to computer aided design of inductive electro-thermal systems using 3D finite element modelling of the inductive heating process and design of experiments. The process is modelled by using specialized software for numerical analysis of the coupled thermal and electromagnetic fields, which implies a high computation cost. Design of experiments techniques based on Box-Behnken design are applied to predict the temperature gap in the work piece, by making use of the 3D model. The optimization performed on the predicted model reveals the parameters necessary for achieving high performance and minimum design cost for the electro-inductive system, using a reduced number of the high cost model evaluations.

This paper describes the coupling between the numerical modeling of the induction heating process, using a Matlab-PDE software development, with a statistical model, which uses the Design of Experiments (DOE) concept, based on the Minitab-Full Factorial software, offering optimal solutions as regards the inductive electrothermal equipment.

This paper presents an effective procedure for analyzing the operation of the medium frequency heating system for ferromagnetic pieces. Given the non-sinusoidal shape of the output voltage of the inverter, it was taken into account the harmonics of capacities within the system, selecting the most important ones. At the working frequency of the installation, the depth of penetration of the electromagnetic field is very low compared to the other geometric dimensions and therefore it is suggested the adoption of a uniform environment for this superficial area. The thermal diffusion problem has been solved analytically, using the separation of the solution in spatial eigenfunctions.

The paper presents the results obtained by the authors in order to optimize the reflow soldering process using nitrogen to assure high quality lead free joints between the pins of the SMT electronic devices and the PCB pads. The soldering may be accomplished in air or into a nitrogen atmosphere, this last case being the solution that gives better connections. For practice purposes, since this technology increases the production costs, it is important to be known, at least with a good approximation, the quantity of nitrogen that must be used in the reflow soldering process for a specific situation. Based on experimental result, the paper shows authors recommendations that can be considered further for the production quality and cost optimization.

The paper is a continuation of the research reported by the authors regarding the eddy-current heating analysis of a ferromagnetic piece heating equipment. The previous results were dedicated to circular conductors, whereas, in the present paper bars of any the cross-section shape are considered. The electromagnetic field depth of penetration being sufficiently small in comparison with the other geometrical dimensions of the bar, we will take into account only a zone in the vicinity of the bar surface, having a thickness of five times the depth of penetration. Along this depth, the problem is one-dimensional and a combined numerical and analytical approach will result in an extremely efficient procedure for the analysis of the electromagnetic field problem coupled with the thermal diffusion one.

The paper presents considerations useful to design low power induction heating system. Despite of the fact that an induction heating system exhibits nonlinearities, the paper uses a linear model in order to obtain an easier way of design. Thus, the series resonant inverter used in the induction heating system is modelled as a high frequency alternating voltage source. The same assumption is made on the load circuit that includes the induction coil and the ferromagnetic device subjected to the thermal processing. The model of the load is reduced to a linear resistive inductive circuit for a specific temperature, based on the simulation results offered by Flux 2D program. The program Flux 2D solve the thermal problem coupled with the eddy currents problem and the simulation results are used to derive the resistive and inductive effect of the load. In general, since the values of the equivalent resistance and inductance for the load are small, the authors take into account all the main parasitic elements of the electronic component parts that appear on the power path of the induction heating system. Paper comprises simulation and experimental results of a low power induction heating system that are in good agreement with the theoretical analysis.