Search Results (96)

This study presents a modular battery charging system based on a DC–DC buck converter with proportional–integral (PI) control, developed to support hands-on learning in power electronics education. In response to the need for flexible experimental platforms, the system is designed to bridge theoretical concepts of power conversion and control with practical implementation. The proposed setup employs cascaded current and voltage control loops to achieve constant current (CC) and constant voltage (CV) charging modes, while its modular hardware architecture allows modification of key parameters such as inductance, capacitance, and circuit topology. The control algorithms are implemented on a microcontroller, and real-time data acquisition is integrated using the ThingSpeak platform for monitoring system behaviour. Experimental results show that the current control loop recovers to its reference value within approximately 6 ms under abrupt load variations, whereas the voltage control loop settles within approximately 15 ms, demonstrating stable closed-loop performance. In addition, the system successfully charges a 12 V lead-acid battery following a standard CC–CV charging profile. Overall, the proposed experiment kit provides an effective educational platform and a practical basis for further exploration of battery charging strategies and power converter control. Full article

This paper presents a high-efficiency wireless power transfer (WPT) architecture employing a resonant inductive coupling to power smart sensor nodes in remote or sealed environments, where conventional power delivery is unfeasible. The system integrates a photovoltaic (PV) energy source with a step-down DC-DC converter based on the LM2596 buck regulator to adjust the voltage from the PV. The proposed conditioned power system supplies the entire electronic circuit consisting of a PWM modulator based on an NE555, which drives an IR2110 gate driver connected to a Class D power amplifier. The amplifier excites a pair of high-Q resonant coils designed for mid-range inductive coupling. On the receiver side, the inductively coupled AC signal is rectified and regulated through an AC-DC conversion stage to charge a secondary energy storage unit. The design eliminates the need for physical electrical connections, ensuring efficient, contactless energy transfer. The proposed system operates at a resonant frequency of 24.46 kHz and achieves up to 80% transmission efficiency at a distance of 113 mm. The receiver provides a regulated DC output between 4.80 V and 4.97 V, sufficient to power low-consumption smart sensors. Full article

Improving the efficiency of buck–boost converters has long been a major focus in power electronics. To enhance efficiency and overcome existing limitations, this paper proposes a soft-switching technique for a cascaded buck–boost converter (CBBC). The proposed approach integrates high-frequency switching of four gallium nitride (GaN) devices, improving both dynamic and steady-state performance from hardware and control perspectives. First, a soft-switching modulation scheme based on negative-current pulse width modulation (PWM) is implemented by introducing a new switching sequence in the CBBC, controlled by a modulation variable. This scheme ensures that the GaN switches operate under zero-current switching (ZCS) and zero-voltage switching (ZVS) conditions during transitions. Furthermore, the CBBC operating modes are divided into four intervals for modeling and analysis, upon which a model predictive control (MPC) strategy is developed to achieve fast closed-loop regulation of both output voltage and current. To further minimize current ripple and device losses, the MPC cost function is optimized by constraining the control parameters. Experimental results obtained from a 300-W hardware prototype verify the effectiveness and feasibility of the proposed soft-switching control method. Full article

This paper proposes a battery emulator based on a bidirectional non-inverting buck-boost power electronics converter. With the capability of bidirectional operation, it can emulate both charging and discharging processes. The proposed emulator is controlled with the advanced I² dual current-mode control (I²DCMC) algorithm, combined with a feedforward control, which ensures fast and accurate tracking of the voltage and current characteristics of the batteries. The emulator is universal in terms of the various mathematical models of the batteries, which can be implemented in real time. It has no limitations regarding different battery types. Detailed analysis and the design procedure of the proposed battery emulator are presented. The performances of the emulator are validated with simulation and experimental results for three battery types: polymer Li-ion, conventional Li-ion, and lead–acid battery. Both steady and transient states are analyzed, especially transitions between charging and discharging phases. The possibility of simple time scaling of charging/discharging processes is successfully achieved and demonstrated, which is very important in making tests faster, with preserved battery characteristics. Considering its low-cost and user-friendly operation, the proposed emulator can be a good alternative to the real batteries in experimental tests of different power electronics systems. The prototype, which is developed for the experimental verification of the emulator, is designed for and limited to the research of lower power ratings systems of up to 100 W. It is suitable in education to easily demonstrate the behavior of the batteries in multiple scenarios in controlled laboratory conditions. Full article

In the event of power outages caused by natural disasters, accidents, or other emergencies, outdoor emergency lighting systems play a critical role in providing illumination to maintain spatial orientation, facilitate evacuation procedures, and help individuals avoid hazardous areas or locate safe shelters. Compared to traditional lighting technologies, LED-based outdoor emergency lighting offers several advantages, including compact size, long operational lifespan, low energy consumption, high safety, resistance to breakage, and the absence of chemical residue or pollution. These characteristics align with contemporary trends in environmental sustainability and energy efficiency. This study proposes a novel LED driver circuit architecture for outdoor emergency lighting applications. The primary circuit topology is based on an improved buck-boost converter integrated with a flyback converter, forming a hybrid buck-boost-flyback configuration. The proposed circuit is capable of recycling the energy stored in the transformer’s leakage inductance, thereby enhancing overall power conversion efficiency. A 12 W (20 V/0.6 A) prototype LED driver circuit was designed and implemented to validate the performance of the proposed system. Experimental measurements, including waveform analysis and efficiency evaluation, demonstrate that the driver circuit achieves a high efficiency exceeding 91%. These results confirm the practical feasibility and effectiveness of the proposed electronic driver for LED-based outdoor emergency lighting applications. Full article

In the design of military, automotive, medical, space, and professional equipment, it is essential to demonstrate that devices can operate for a specific duration with a given level of confidence. Reliability must be considered in the design process, which can involve component selection, component testing, and mitigation techniques such as redundancy and forward error correction (FEC). In modern DC–DC converters, a higher level of reliability is now a mandatory requirement—the ISO 26262, for example, acts as the guidance to provide the appropriate standardized requirements, processes and risk based approach, and it determines integrity levels (known as automotive safety integrity levels or ASILs). The purpose is to reduce risks caused by systematic and random failures to an appropriate level of acceptance. Since the release of MIL-HDBK-217F Notice 2 in 1995, newer standards for predicting failure rates have emerged in the electronic systems reliability market. These updated standards were introduced to address the limitations of the older standards, particularly in relation to advanced component technologies. Numerous studies have shown that the output capacitor bank is one of the most critical components concerning reliability. This work focuses on calculating the failure rates of an output capacitor bank and a MOSFET transistor pair used in a high-current, low-voltage buck converter. The failure rates are calculated using both the latest prediction standard, SN 29500, and the previous MIL-HDBK standard. This comparison serves as a valuable tool for selecting the output capacitor during the early stages of design. Both simulations and experimental setups were employed to measure the temperatures of the components. The SN 29500 standard is particularly beneficial for components operating in harsh environments, as it provides up-to-date failure rate data and stress models. The environmental conditions for the components were defined using a standard point of load (PoL) buck converter for both calculation methods. Results are compared by considering the impact of component temperature and by applying specific parameters such as reference and operating conditions. This kind of comparison is useful for circuit designers, especially in the field of Power electronics when the concept of designing with reliability in mind is adopted. Full article

As power electronics continue to advance, the demand for highly efficient and low-loss DC/DC converters has grown significantly. This article comprehensively analyses ZCS quasi-resonant switch cell losses and efficiency in buck L-type zero-current switching (ZCS) quasi-resonant DC/DC converters. The main part of the study includes a comparative analysis of conduction losses in semiconductor switches of conventional PWM buck converters and zero-current switching (ZCS) quasi-resonant buck converters (L-type), utilizing both specific and generalized design equations. Novel coefficients are introduced that enable the evaluation of static power losses in the classical buck converter compared to those in L-type ZCS buck quasi-resonant converters under identical conditions. The article also discusses design considerations aimed at minimizing static losses. An L-type half-mode zero-current switching (ZCS) buck quasi-resonant DC/DC converter (QRC) is implemented to verify the analytical results. Various simulations were conducted using PSpice in the Texas Instruments simulation environment, along with experimental studies at different switching frequencies and load conditions. The proposed methodology integrates both analytical and simulation approaches to analyze energy losses and key parameters influencing the converter’s efficiency. The obtained results show that the relative error between the analytical, simulation, and experimental results is below 5%. Full article

This article reviews converter circuits with power factor correction considering issues that arise in implementing such circuits. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) procedure are employed for the review. Six topologies with power factor correction were considered including boost, buck, buck-boost, Cük, dual boost, and totem pole bridgeless. The main findings highlight various implementation alternatives for these converters, taking into account complexity, performance, control strategies, and applications. Additionally, the review identified studies based on simulation and hardware implementation. Several alternatives exist for research to improve energy conversion circuits using conventional techniques such as PI controllers or novel controllers using artificial intelligence techniques such as neural networks. Finally, it should be noted that converter circuits with power factor correction are crucial for developing various electrical and electronic devices in domestic and industrial applications. Full article

This study explored wide input voltage range step-down converters, which are crucial for supplying low-voltage power to microcontrollers, communication modems, and other low-power electronic circuits in modern vehicles that feature a diverse range of battery voltages, from 12 V to 90 V. Specifically, it focuses on converters suitable for devices employing 2G to 5G communication modems that typically require a 4 V supply. This article conducted a review of existing step-down converter technologies, focusing on the comparative analysis of synchronous versus asynchronous switched-inductor converters. Experimental data on 14 different converters is presented, where theoretical efficiency predictions are compared with empirical measurements. Using the dataset of 326 points gathered through experimental evaluation enabled evaluation of the accuracy of the efficiency estimating mathematical model, which demonstrated 73% accuracy for input voltages ranging from 12 V to 90 V and output currents from 0.1 A to 2 A. Further analysis demonstrated that estimating power losses in milliwatts enhanced the model’s accuracy, as indicated by a 94% correlation between measured and calculated power losses and an 87% correlation of measured power losses with measured temperature. This study provides insights that will guide both the authors and readers in developing more efficient DC-DC step-down converters, optimized for modern automotive applications. Full article

Generating chaos from originally non-chaotic systems is a promising issue. Indeed, chaos has been successfully applied in many fields to improve system performance. In this work, a Buck converter is chaotified using a combination of the switching piecewise-constant characteristic and of anticontrol of chaos feedback. For electromagnetic compatibility compliance reasons, this feedback control method is able, at the same time, to achieve low spectral emissions and to maintain a small ripple of the output voltage and the inductance current. This new feedback implies a fast and non-linear switching action of the Buck MOSFET on a period of the ramp generator. Thus, it is essential to analyze its thermal performance. This is why we propose an original analysis of the influence of anticontrol of chaos and switching frequency variation on junction temperature: we investigate the correlation between the lifetime of the power electronic switching component and its thermal stress due to the addition of chaos. It appeared that a reduction in the current ripple did not degrade the MOSFET junction thermal performance, despite the fast switching of the MOSFET. Furthermore, a small degradation in the MOSFET lifetime was indicated for chaotic behavior versus periodic behavior. Thus, this leads to the conclusion that using anticontrol of chaos produces a low accumulated fatigue effect on a Buck converter semiconductor. Full article

UV-C LEDs, which offer short-wavelength characteristics and serve as an alternative to traditional UV mercury lamps, represent a new light source for applications in space decontamination and surface disinfection. This paper presents the design and development of a UV-C LED lamp driver circuit configured to operate with a DC-input voltage source for sterilization and germicidal purposes. The primary circuit integrates a modified buck converter with a flyback converter, resulting in an innovative single-stage, single-switch DC-DC power converter. Additionally, the proposed electronic driver recovers energy stored in the transformer’s leakage inductors, enhancing overall circuit efficiency. A prototype driver circuit with a 3.3 W power rating (10 V/330 mA) is developed for a UV-C LED lamp intended for sterilization and germicidal applications with a DC-input voltage source. The experimental results from the prototype circuit, tested at an 18 V DC input, confirm the functionality of the proposed electronic driver for UV-C LED sterilization and germicidal lighting. Additionally, the circuit achieves efficiency exceeding 91%. Full article

The optimization of DC-DC converters is crucial for enhancing their performance and efficiency in various applications. This study focuses on the sensitivity analysis of DC-DC converters to parametric variations, which plays a key role in designing robust and efficient systems. The methodology involves developing a simulation model that describes the behavior of converters under different conditions and analyzing the effects of parameter variations through simulation tools. Sensitivity analysis of DC-DC converters involves understanding the sources of harmonics, modeling the converter, analyzing the harmonic content, and implementing mitigation techniques. By combining theoretical analysis with practical design modifications, engineers can optimize DC-DC converters for improved performance, efficiency, and compliance with electromagnetic compatibility standards. Examples of harmonic analysis of the main types of DC-DC converters—Buck, Boost, and Buck-Boost—are discussed in the manuscript. Based on a study of the influence of harmonics in the operating modes, ratios have been derived to be applied during design. In this respect, the research presented is useful for designers and for use in power electronics education. Full article

This paper proposes a design for a platform-based Multi-phase Interleaved Synchronous Buck Converter (MISBC). A custom platform was developed to compare the theoretical performance of a MISBC circuit simulated with Multisim to a prototype that was built at Western Sydney University. The work disclosed in this manuscript describes some steps adopted during the selection of each component and technical considerations taken during the design of the Printed Circuit Board (PCB). The platform designed has a maximum power output of 260 Watts, with a buck reduction of the nominal voltage from 97 Volts to 24 Volts at a maximum switching frequency of 50 kHz. This switching frequency is achieved with an open-loop circuit configuration coupled with synchronized signal generators, used to validate the dead band required between the activation of each set of transistors implemented in a half-bridge configuration. A summary of the results based on the duty cycle required to achieve the buck voltage desired highlights the advantages of each operating mode of the MISBC circuit. Here the theoretical performance is compared against the data acquired during functional evaluations of the prototype, making possible future interpretations of the ideal control algorithm required to maximize the performance output of MISBC circuits. Full article

Improving microelectronic technologies has created various micro-power electronic devices with different practical applications, including wearable electronic modules and systems. Furthermore, the power sources for wearable electronic devices most often work with electrical energy obtained from the environment without using standard batteries. This paper presents the structure and electrical parameters of a circuit configuration realized as a prototype of a low-power AC-DC conversion circuit intended for use as a power supply device for signal processing systems that test various biomedical parameters of the human body. The proposed prototype has to work as a wearable self-powered system that transfers electrical energy obtained through mechanical vibrations in the piezoelectric generator. The obtained electrical energy is used to charge a single low-voltage supercapacitor, which is used as an energy storage element. The proposed circuit configuration is realized with discrete components consisting of a low-voltage bridge rectifier, a low-pass filter, a DC-DC step-down (buck) synchronous converter, a power-controlling system with an error amplifier, and a window detector that produces a “power-good” signal. The power-controlling system allows tuning the output voltage level to around 1.8 V, and the power dissipation for it is less than 0.03 mW. The coefficient of energy efficiency achieved up to 78% for output power levels up to 3.6 mW. Experimental testing was conducted to verify the proposed AC-DC conversion circuit’s effectiveness, as the results confirmed the preliminary theoretical analyses and the derived analytical expressions for the primary electrical parameters. Full article

This paper evaluates the open- and closed-loop DC–DC converter operation within a DC coupling multilevel inverter architecture to obtain an infinite-level stepped sinusoidal voltage. Adding a cascade controller to the DC–DC converter should reduce the settling time and increase the number of levels in the output voltage waveform; it could decrease the speed error and phase shift concerning the sinusoidal reference signal. The proposed methodology consists of implementing an experimental multilevel inverter with DC coupling through a single-phase bridge inverter energized from a BUCK converter. Trigger signals for the two converters are obtained from a control circuit based in an ATMEGA644P microcontroller to explore its capabilities in power electronics applications. A digital controller is also implemented to evaluate the operation of the BUCK converter in open and closed loop and observe its influence in the stepped sinusoidal output voltage. The evaluation is performed to energize a resistive load with common output voltage in multilevel inverters, i.e., 3, 5, 7, 11, and infinity levels. Results show that during the design stage, fast dynamic elements, like the storage capacitor, can be used to obtain a minimum THD because the settling time is sufficiently fast, the speed error remains small, and there is no need for a controller. A digital controller requires processing time, and although in theory it can reduce the settling time to a minimum, the processor introduces latency in the control signals generation, producing the opposite effect. Controller complexity of the digital controller must be considered because it increases processing time and influences the efficiency of the closed-loop operation. Full article