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This study presents a mathematical model of a parabolic trough solar collector with photovoltaic cells integrated into its solar receiver. A case study is presented, utilizing meteorological data obtained from the localities of Cuernavaca and Mexicali in Mexico. The results demonstrate moderately variable electrical and thermal energy production for Cuernavaca (387.93 kWh to 239.38 kWh and 1036.11 kWh to 641.26 kWh, respectively). In contrast, the production of electrical and thermal energy in Mexicali exhibited considerably greater fluctuations (515.16 kWh to 177.69 kWh and 1424.39 kWh to 448.88 kWh, respectively). Furthermore, a parametric study is presented, which analyzes the impact of solar receiver geometry and mass flow on the model's behavior. The results demonstrate that the pipe length exerts the most significant influence on the electrical and thermal power output (1.21 kW to 2.22 kW and 3.7 kW to 6.9 kW, respectively). Additionally, the diameter has an impact on the thermal power output (5.23 kW to 7.1 kW) and the electrical and thermal efficiency (0.18 to 0.15 and 0.54 to 0.74, respectively). Modifying the mass flow facilitates the enhancement of electrical power and efficiency (1.54 kW to 1.72 kW and 0.16 to 0.18, respectively) while concurrently preventing a significant reduction in thermal power and efficiency (5.4 kW to 5.3 kW and 0.56 to 0.55, respectively). A script with the developed model is provided. [ABSTRACT FROM AUTHOR]

In the field of structural damage detection through vibration measurements, most existing methods demand extensive data collection, including vibration readings at multiple levels, strain data, temperature measurements, and numerous vibration modes. These requirements result in high costs and complex instrumentation processes. Additionally, many approaches fail to account for model uncertainties, leading to significant discrepancies between the actual structure and its numerical reference model, thus compromising the accuracy of damage identification. This study introduces an innovative computational method aimed at minimizing data requirements, reducing instrumentation costs, and functioning with fewer vibration modes. By utilizing information from a single vibration sensor and at least three vibration modes, the method avoids the need for higher-mode excitation, which typically demands specialized equipment. The approach also incorporates model uncertainties related to geometry and mass distribution, improving the accuracy of damage detection. The computational method was validated on a steel frame structure under various damage conditions, categorized as single or multiple damage. The results indicate up to 100% accuracy in locating damage and up to 80% accuracy in estimating its severity. These findings demonstrate the method's potential for detecting structural damage with limited data and at a significantly lower cost compared to conventional techniques. [ABSTRACT FROM AUTHOR]

The main contribution of this paper is to present a simple algorithm that theoretically and numerically assesses the switching angles of an inverter operated with the SPWM technique. This technique is the most widely used for eliminating harmonics in DC-AC converters for powering motors, renewable energy applications, household appliances, etc. Unlike conventional implementations of the SPWM technique based on the analog or digital comparison of a sinusoidal signal with a triangular signal, this paper mathematically performs this comparison. It proposes a simple solution to solve the transcendental equations arising from the mathematical analysis numerically. The technique is validated by calculating the total harmonic distortion (THD) of the generated signal theoretically and numerically, and the results indicate that the calculated angles produce the same distribution of harmonics calculated analytically and numerically. The algorithm is limited to single-phase inverters with unipolar SPWM. [ABSTRACT FROM AUTHOR]

This paper aims to propose a new sizing approach to reduce the footprint and optimize the performance of an LCL filter implemented in photovoltaic systems using grid-connected single-phase microinverters. In particular, the analysis is carried out on a single-phase full-bridge inverter, assuming the following two conditions: (1) a unit power factor at the connection point between the AC grid and the LCL filter; (2) a control circuit based on unipolar sinusoidal pulse width modulation (SPWM). In particular, the ripple and harmonics of the LCL filter input current and the current injected into the grid are analyzed. The results of the Simulink simulation and the experimental tests carried out confirm that it is possible to considerably reduce filter volume by optimizing each passive component compared with what is already available in the literature while guaranteeing excellent filtering performance. Specifically, the inductance values were reduced by almost 40% and the capacitor value by almost 100%. The main applications of this new design methodology are for use in single-phase microinverters connected to the grid and for research purposes in power electronics and optimization. [ABSTRACT FROM AUTHOR]

This paper is a summary of the last ten years of work on the study of parabolic trough collectors (PTCs) and compound parabolic collectors (CPCs) coupled to photovoltaic and thermal solar receiver collectors (SCR-PVTs). While reviewing the state of the art, numerous review papers were found that focused on conventional solar receiver collector (SRC) technology for solar thermal generation. However, there is a lack of review papers summarizing SRC-PVT hybrid technology for solar electric/thermal generation, which would be beneficial for researchers interested in this area of research. This paper provides a review of SRC-PVT hybrid technologies. The theoretical foundations for analyzing and modeling PTC and CPC concentrators coupled to SRC-PVT are described, with an emphasis on modeling through thermal resistances and energy balances. Additionally, this section provides a concise overview of previous studies that have addressed the modeling of PTC and CPC collectors coupled to SCR-PVT, as well as experimental information useful for the validation of new mathematical models of SRC-PVT. [ABSTRACT FROM AUTHOR]

Permanent magnet motors have become very important in recent years due to the popularization of electric vehicles in the context of the efforts to transition to zero-emission transportation. This has encouraged researchers and hobbyists to learn about electric motor design. However, designing electric motors is not a simple task, as the information to achieve it is not easily available to everyone and it is usually complicated to understand. For that reason, this paper presents the equations and a basic process to design radial flux surface-mounted PM synchronous motors. This design method is the result of combining and organizing information from previous publications to create a relatively simple design guide. The result is a table of equations and a series of general guidelines that were verified by designing and simulating a 500 W eight-pole 2.6 Nm average torque dual-rotor motor and a 20 W four-pole 106 mNm single-rotor motor. The simulations validated the equations and the design method presented in this paper to be used by those interested in the field of electric motors and vehicles; therefore, in the future, others may contribute with improvements, particularizations or optimizations of this methodology, or even create their own. [ABSTRACT FROM AUTHOR]

This paper presents a mathematical analysis of how energy return in grid-connected single-phase photovoltaic systems affects the sizing of passive components. Energy return affects the size of the link capacitor, making it larger than reported in the literature. One of the main points of this article is that an inverter connected to the grid using a DC–DC converter with an appropriate link capacitor is analyzed. The energy return is caused by the value (in Henry units) of the L-filter, which is also analyzed in this paper. The analysis shows that there is a link between the value of the L-filter and the voltage of the DC bus. The analysis assumes two conditions: (1) the DC bus voltage is always higher than the peak value of the grid sinusoidal voltage, and (2) there is a unity power factor at the connection point between the grid and the L-filter. To operate in an open loop, a compensation phase angle is calculated and introduced in the single-phase inverter modulation; this phase angle compensates the phase shift caused by the L-filter, avoiding the use of a phase-locked-loop (PLL) control system. The L-filter ripple current is evaluated by Fourier analysis, and the DC bus ripple voltage is evaluated by considering the energy returned to the link capacitor. The results of the analyses are compared with existing methods reported in the literature. The results also show that, to minimize the value of the L-filter, the DC voltage must be almost equal to the maximum voltage of the grid. Equations to assess the value of the DC-link capacitor and the L-filter in function of their ripples are developed. The results were verified with simulations in Simulink and experimentally. [ABSTRACT FROM AUTHOR]

The main contribution of this paper is the inductive compensation of a wireless inductive power transmission circuit (IPT) with resonant open-loop inductive coupling. The variations in the coupling coefficient k due to the misalignment of the transmitter and receiver are compensated with only one auxiliary inductance in the primary of the inductive coupling. A low-power prototype was implemented with the following specifications: input voltage Vin = 27.5 V, output power Po = 10 W, switching frequency f = 500 kHz, output voltage Vo = 12 V, transmission distance d = 1.5 mm. Experimental results varying the distance "d" with several values of the compensation inductor demonstrate the feasibility of the proposal. An efficiency of 75.10% under nominal conditions was achieved. This proposal is a simple compensation topology for wireless chargers of cellular phones presenting small distances between the transmitter and receiver. [ABSTRACT FROM AUTHOR]

The main contribution of this paper is the assets of the current and voltage ripples in a buck converter with an LED load. The results indicate that the ripples are different and that it is possible to reduce the passive filter concerning the model of the LED as a simple resistance. The paper presents the design and simulation of a buck converter as a power supply for an LED lamp. Modeling the LED as a resistor and a voltage source (SVRM), the equations to calculate the components of the circuit using the SVRM model are presented, where the Fourier series and phasors are used to calculate the output filter. The equations are validated with SPICE simulations. The results indicate that the SVRM model for the LED load affects the calculation of the output filter of the buck converter as well as the voltage and current ripples, making it a more precise design alternative to the proposed development. [ABSTRACT FROM AUTHOR]

This study compares ripple port, stacked switched capacitor, and capacitive energy storage architectures for active power decoupling, comparing the number of components, performance, energy density, DC-link capacitor reduction, efficiency, and frequency operation to highlight their main benefits and drawbacks for single-phase grid-connected applications. The overview reveals equivalent effective energy density without electrolytic capacitors, as well as enhanced simplicity, performance, and durability, thereby providing stacked switched capacitors as an attractive power-decoupling alternative for multi-stage connected applications, based on the principle that its individual buffer capacitors absorb and deliver energy without tightly constraining their individual terminal voltages, while maintaining a narrow range voltage at the buffer DC port. [ABSTRACT FROM AUTHOR]

There is currently a growing interest in replacing the internal combustion engine with electric motors in transportation applications. However, there are different problems related to electric motors for this application. One of them is the oversizing of the energy decoupling system since to ensure that the decoupling capacitor can store the power fluctuations, the capacitance required by the system is usually oversized. This leads to preference for the use of capacitors with construction technologies that have a lower lifetime than the remaining elements of the propulsion system, directly affecting the reliability of the system. In this article, the energy flow handled by the decoupling capacitor is analyzed considering the critical case of operation of an induction motor to minimize the capacitance required by the propulsion system; emphasizing the conditions that generate a higher energy return, from the motor mode of the electric machine to the decoupling capacitor. From the energy analysis, an equation for the capacitor calculation is obtained, involving proportionality factors that relate to the different operating powers, reducing up to 62.2% of the capacitance value required by the decoupling system, under conditions of maximum energy return in motor mode, compared to existing equations in the literature. [ABSTRACT FROM AUTHOR]

Currently, the design of resonant power converters has only been developed while operating in the steady state, while the design operating in the transient stage has not been considered nor reported. This paper is interested in testing the performance of the resonant circuits operating in the transient stage and finding applications where benefits can be obtained from this form of operation. One application in which it is possible to obtain benefits from designing resonant circuits in the transient state is in the area of frequency multiplication. Usually, to achieve frequency multiplication, it is necessary to resort to complex methods and special devices that increase the complexity of the design and the total cost of the circuit. This paper evaluates the performance of a series RLC resonant circuit operating in the transient stage and with an underdamped response acting as a frequency multiplier, where the oscillation frequency of the current in the resonant tank is "n" number of times the switching frequency of the square voltage source at the input with a duty cycle of D = 50%. To validate the analysis, a circuit was designed to deliver an output power of 30 watts to a resistive load, where the switching frequency of the square voltage source at the input was 500 kHz. Since a multiplier value "n" equal to fifteen was chosen, the current in the resonant tank reached an oscillation frequency of 7.5 MHz. The design methodology was validated by simulations in SPICE, complying with the established design parameters. [ABSTRACT FROM AUTHOR]

Nowadays the efficient use of energy is a major issue in applications such as electric vehicles. However, there are some phenomena that affect electric vehicle performance. One of those phenomena is the torque ripple of electric motors, which interferes with traction and the suspension system (causing vibration that stresses this system), and it can also introduce electric current harmonics into the battery, reducing its life, since torque ripple is partly a consequence of non-sinusoidal back EMF. For those reasons this is a topic worth investigating. The torque ripple of permanent magnets (PM) motors can be reduced in design or through control. Since control techniques have been reviewed and design methods have not, this paper presents a comparison of several design techniques to reduce torque ripple by different approaches and categorize them to show the characteristics of each group. A discussion is then made about the advantages and disadvantages of the designs, in general, as well as some comments about the missing, but important information, in the papers, such as the effects on efficiency. The study shows that a combination of methods provide the best results, although it complicates fabrication and suggests that this is a promising line of future investigation on torque ripple reduction methods. [ABSTRACT FROM AUTHOR]

The most common problems with magnetic cores in high-stress applications are changes in their permeability and low saturation flux density, forcing designers to use special nanocrystalline cores, which raises the overall cost of the circuit. This paper evaluates the performance of a low-cost magnetic material composed of unsaturated polyester la mination resin COR61-AA-531EX and 200 mesh iron powder with a grain size of 74 µm, which has magnetic properties of the so-called "soft magnetic composites", which have good magnetic characteristics in high-frequency and high-stress applications. This composite material was used for the elaboration of magnetic cores for the inductors of a resonant converter, which aims to achieve a high power factor, where in this type of application, there are large current and voltage excursions in the magnetic components that vary between high and low frequencies, being a suitable application for testing the inductors with a magnetic core of resin/iron powder. The converter was designed to operate off-resonance at different switching frequencies from 300 kHz to 800 kHz to feed a resistive load with a power output of 19 watts. The operation of the circuit was experimentally validated using a resistive load at the output, validating the theoretical analysis and achieving a power factor above 98%. [ABSTRACT FROM AUTHOR]

This paper presents a survey of the articles published in the period 2013–2021 related to the application of the teaching–learning-based optimization (TLBO), which reproduces the dynamics that occur in a classroom with the teacher and the student. This paper uses the algorithm to optimize some objective functions related to the design in the electronics field. A total of 62 papers were reviewed and some graphs were generated to summarize the most relevant of these articles. These have been classified into five categories based on the areas of electronic engineering, such as power electronics, control, electromagnetism, digital electronics, and analogue electronics. Electronic engineering has been becoming increasingly relevant in world technological development, for example, in electric vehicles or generating electricity from renewable energy sources to counteract the environmental impact that non-renewable sources generate. The TLBO algorithm has attracted the interest of a large number of researchers due to its efficiency, speed, and low initialization parameter requirements. This article is composed of two stages, the first is a summary of the information on electronics, in general, encompassing all its areas, and the second focuses on the algorithm applied to multilevel inverters; for each stage, graphs and tables are shown. [ABSTRACT FROM AUTHOR]

This paper presents the design of a maximum power point-tracking (MPPT) technique for DC–DC converters that are used in energy-harvesting systems based on thermoelectric generators. This technique is based on the analysis of the characteristics of the converter to measure the open-circuit voltage indirectly. The main contribution of this article is that the algorithm measures the voltage at the maximum power point without the need to disconnect the source of the circuit, as happens when the fractional open-circuit voltage (FOCV) technique is used. The algorithm is based on a predetermined initial duty cycle, which is applied to the circuit, and the input voltage and input current are read. With these values, the open-circuit voltage and short-circuit current are calculated with equations obtained from the circuit. Then, it calculates the duty cycle at the maximum power point and applies it to the circuit. If this duty cycle does not obtain the maximum power from the circuit, the algorithm starts a second stage based on fuzzy logic to calculate an increase or decrease in the duty cycle. The designed technique was evaluated using a topology based on a DC–DC flyback converter variant and was compared with the P&O technique and obtained better results. The designed technique provides between 3.9% and 5.6% more power to the load than the P&O technique in a 20 W system. [ABSTRACT FROM AUTHOR]

The excessive use of fossil fuels has caused great concern due to modern environmental problems, particularly air pollution. The above situation demands that different areas of research aim at a sustainable movement to reduce CO 2 emissions caused by non-renewable organic fuels. A solution to this problem is the use of Electric Vehicles (EV) for mass transportation of people. However, these systems require high-power DC/DC converters capable of handling high current levels and should feature high efficiencies to charge their batteries. For this application, a single-stage converter is not viable for these applications due to the high current stress in a switch, the low power density, and its low efficiency due to higher switching losses. One solution to this problem is Multiphase Converters, which offer high efficiency, high power density, and low current ripple on the battery side. However, these characteristics are affected by the current imbalance in the phases. This paper is focused on the study of the effects of the current imbalance in a Multiphase Buck Converter, used as an intermediate cover between a power supply and the battery of an EV. Analyzing the efficiency and thermal stress parameters in different scenarios of current balance and current imbalance in each phase. [ABSTRACT FROM AUTHOR]

Capacitive technology for wireless power transmission has been shown to be a good option for charging the batteries of electric vehicles. It offers better coupling between the transmitter and the receiver than inductive power transmission. On the other hand, it has some disadvantages; for example, it is very sensitive to the distance between plates. Several ideas have recently been proposed to overcome this disadvantage. However, a proper analysis methodology is still lacking, as is a proper design procedure for the circuits used in capacitive transmission. In this paper, an analysis and design methodology is presented for applying the Z-tank resonant circuit to capacitive power transmission, and the theoretical design methodology is based on normalized equations with respect to the operating resonance frequency. The analysis methodology and design procedure result in a circuit where the resonance frequency remains constant despite changes in the distance between the capacitive plates. The simulation results validate the proposal; to ensure robust, realistic simulation results, parasitic elements were considered in all reactive components, and robust models were built for the switching elements, such as MOSFETs and diodes. The results show that the multi-resonant characteristic of the circuit achieves maximum energy transfer and high efficiency. [ABSTRACT FROM AUTHOR]

This paper presents a theoretical analysis of a DC-DC flyback converter variant applied in energy harvesting based on thermoelectric generators. The main contribution of the article is the analysis and obtaining the equations of the behavior of the converter with a rearrangement of the elements of the traditional flyback converter in such a way that the converter only processes part of the energy while the other part is delivered directly to the load. This is achieved by connecting the secondary of the flyback in series with the load, and this assembly, in turn, is placed in parallel with the primary and the voltage source. This configuration means that the topology can only be a boost topology; however, there are benefits such as partial power processing (R2P2) and reduced stress on converter components in both voltage and current; all this leads to increase the efficiency. A Low Frequency Averaging Analysis (LFAA) was used to determine the behavior of the proposed circuit, and a simple equivalent circuit to analyze was obtained. In order to validate the theoretical analysis, a circuit was simulated in Spice and implemented in an 18 W prototype. Experimental results showed that the converter has an efficiency of 92.65%. Moreover, the rearranged flyback processed only 56% of the input power. [ABSTRACT FROM AUTHOR]

The cascade multilevel inverters are widely used in industrial manufacturing processes for DC-AC conversion. Therefore, the reliability and efficiency improvement, optimized control, and fault-tolerant strategies are areas of interest for researchers. The fault tolerance strategies applied to cascade multilevel inverters are classified as material redundancy and analytical redundancy. This paper presents the use of the Z-source converter as a fault reconfiguration method applied to a cascade multilevel inverter. On the one hand, the proposed approach has the characteristic of combining the use of material redundancy (modifying the output voltage by changing the Z-source operation), and on the other hand, it has the use of analytical redundancy (modifying the switching sequence of the multilevel inverter, changing from symmetrical to asymmetrical operation mode). This approach has been validated by experimental results of the system under fault-free conditions and employing the Z-source converter as the main fault reconfiguration element. The proposed fault reconfiguration strategy allows the cascaded multilevel inverter to continue to operate even in the presence of a fault by having continuous operation. [ABSTRACT FROM AUTHOR]

The main contribution of this paper is to show a new AC/DC converter based on the rearrangement of the flyback converter. The proposed circuit only manages part of the energy and the rest is delivered directly from the source to the load. Therefore, with the new topology, the efficiency is increased, and the stress of the components is reduced. The rearrangement consist of the secondary of the flyback is placed in parallel with the load, and this arrangement is connected in series with the primary side and the rectified voltage source. The re-arranged flyback is only a reductive topology and with no magnetic isolation. It was studied as a power supply for LEDs. A low frequency averaged analysis (LFAA) was used to determine the behavior of the proposed circuit and an equivalent circuit much easier to analyze was obtained. To validate the theoretical analysis, a design methodology was developed for the re-arranged flyback converter. The designed circuit was implemented in a 10 W prototype. Experimental results showed that the converter has a THDi = 21.7% and a PF = 0.9686. [ABSTRACT FROM AUTHOR]

This paper focuses on the main reasons of low efficiency in a current-fed DC-DC resonant converter applied to photovoltaic (PV) isolated systems, comparing the effects derived by the overlapping time in the gate-signals (gate-source voltage) combining silicon (Si), silicon carbide (SiC), and gallium nitride (GaN)-based power devices. The results show that unidirectional switches (metal–oxide–semiconductor field-effect transistors (MOSFETs) plus diode) present hard switching as a result of the diode preventing the MOSFET capacitance of being discharged. The effectiveness of the converter was verified with a 200-W prototype with an input voltage range of 0–30.3 V, an output voltage of 200 V, and a switching frequency of 200 kHz. The reduction losses by applying GaN versus Si and SiC technologies are 66.49% and 53.57%, respectively. Alternatively, by applying SiC versus Si devices the reduction loss is 27.84%. Finally, according to the results, 60% of losses were caused by the diodes on both switches. [ABSTRACT FROM AUTHOR]

In order to solve the trajectory tracking task in a wheeled mobile robot (WMR), a dynamic three-level controller is presented in this paper. The controller considers the mechanical structure, actuators, and power stage subsystems. Such a controller is designed as follows: At the high level is a dynamic control for the WMR (differential drive type). At the medium level is a PI current control for the actuators (DC motors). Lastly, at the low level is a differential flatness-based control for the power stage (DC/DC Buck power converters). The feasibility, robustness, and performance in closed-loop of the proposed controller are validated on a DDWMR prototype through Matlab-Simulink, the real-time interface ControlDesk, and a DS1104 board. The obtained results are experimentally assessed with a hierarchical tracking controller, recently reported in literature, that was also designed on the basis of the mechanical structure, actuators, and power stage subsystems. Although both controllers are robust when parametric disturbances are taken into account, the dynamic three-level tracking controller presented in this paper is better than the hierarchical tracking controller reported in literature. [ABSTRACT FROM AUTHOR]