DC-DC Converter Research Articles

Microbial fuel cell in long-term operation and providing electricity for intermittent aeration to remove contaminants from sewage

Microbial fuel cells (MFCs) show promise in sewage treatment because they can directly convert organic matter (OM) into electricity. This study aimed to demonstrate MFCs stability over 750 days of operation and efficient removal of OM and nitrogenous compounds from sewage. To enhance contaminant removal, oxygen was provided into the anode chamber via a mini air pump. This pump was powered by the MFCs' output voltage, which was boosted using a DC-DC converter. The experimental system consisted of 12 sets of cylindrical MFCs within a 246L-scale reactor. The boosted voltage reached 4.7 V. This voltage was first collected in capacitors every 5 min and then dispensed intermittently to the air pump for the MFCs reactor in 4 s. This corresponds to receiving average DO concentration reaching 0.34 ± 0.44 mg/L at 10 cm above the air-stone. Consequently, the degradation rate constants (k) for chemical oxygen demand (COD) and biological oxygen demand (BOD) in the presence of oxygen were 0.048 and 0.069, respectively, which surpassed those without oxygen by 0.039 and 0.044, respectively. Aeration also marginally improved the removal of ammonia because of its potential to create a favorable environment for the growth of anammox and ammonia-oxidizing bacteria such as Candidatus brocadia and Nitrospira. The findings of this study offer in-depth insight into the benefits of boosted voltage in MFCs, highlighting its potential to enhance contaminant degradation. This serves as a foundation for future research focused on improving MFCs performance, particularly for the removal of contaminants from wastewater.

Modulation of Wide Voltage Range Interface DC-DC Converter in DC Distribution System

Bipolar DC distribution systems rely on various power sources like photovoltaics and distributed energy storage, each with its unique voltage characteristics. To accommodate these fluctuations, interface converters must adjust over a wide voltage range. The bipolar non-isolated DC-DC converter emerges as a promising solution due to its versatile modulation capabilities, reduced switch voltage stress, and cost-effectiveness. This article explores how wide voltage range regulation is achieved in bipolar DC-DC converters interfacing with bipolar DC power grids. It delves into the operational strategies and modulation techniques employed, ensuring stable output despite varying input voltages. Design considerations and challenges associated with implementing such converters are also discussed. An experimental platform was constructed to validate the proposed methodology. Through rigorous testing and analysis, the effectiveness of the topology's operation mode was confirmed. Real-world data from the experimental setup provided insights into the converter's performance under different operating conditions, supporting its applicability for bipolar DC distribution systems. In summary, this article provides a comprehensive examination of wide voltage range regulation in bipolar DC-DC converters, highlighting their potential to enhance efficiency and reliability in bipolar DC power grids. Through theoretical discussions and practical validation, it contributes to the advancement and adoption of these converters in modern energy systems.

Enhancing hydrogen generation through advanced power conditioning in renewable energy integration

Producing hydrogen using renewable energy is a pivotal move towards cleaner and eco-friendlier energy generation, playing a vital role in safeguarding the environment. This method merges power electronic tools with electrolysers, which are key in enhancing hydrogen creation efficiency. Given that electrolysis operate on direct current (DC) voltage, there's a need for DC-DC or AC-DC converters to guarantee the right voltage and current for optimal electrolysis. This study aims to present a power regulation system tailored for hydrogen production powered by renewable resources. This system consists of two main stages: the matrix converter and the 12-pulse diode rectifier. The matrix converter ensures a controlled intake of current from the alternating current (AC) side, leading to a sinusoidal output with limited harmonic disruption. Additionally, it produces an AC voltage with a controlled magnitude and frequency, designed to suit the 12-pulse diode rectifier that follows. This meticulous voltage control is fundamental, granting enhanced operational adaptability and producing a high-quality waveform to support the electrolysis. Finally, the 12-pulse diode rectifier's task is to transform the AC from the matrix converter into a consistent DC voltage, crucial for effective hydrogen production.

Boost DC-DC converter with regenerative snubber

To accommodate the wide range of input voltages supplied by redundant batteries and ensure an adequate hold-up time for communication systems during utility power failures, power supplies used in 5 G base stations typically include a front-end boost converter as the first stage and a second-stage isolated converter. In this paper, a new topology for a regenerative snubber in boost converters is proposed. Compared to traditional active or passive snubber topologies, the proposed snubber offers the advantages of having fewer components and occupying less space. Moreover, it does not require additional active devices and can be driven by widely-used commercial PWM control integrated circuits, achieving a higher level of cost-effectiveness and offering increased industrial applications. The final prototype of a power supply for a networking switch hub (as used in 5 G base stations) is fabricated to demonstrate the feasibility of the proposed method.

A Review and Comprehensive Study on DC-DC Converters

Background: DC-DC converters are used in various applications based on their required voltage capabilities ranging from milli volts to thousands of volts. Methods: This review paper discusses various voltage boosting techniques, such as buck-boost, switched inductor, switched capacitors, isolated converters, etc., and provides a detailed evaluation of the literature and comparison of different DC-DC converters. Results: This study reports a number of storage elements included, such as inductors and capacitors as well as switches and diodes. Their features along with methodologies, merits, complexity, efficiency, and voltage gain have been tabulated. A comprehensive study, converter classification based on the characteristics, and a detailed analysis of isolated and non-isolated DC-DC converters have also been provided. Conclusion: As this study provides a comparison of each isolated and non-isolated converter's comprehensive gain, this research may help in future topology optimization for the choice of the ideal converter for applications. In addition, the examination of each isolated and non-isolated converter's comprehensive gain comparison has also been presented in this paper.

A Review on Various Voltage Boosting Topology in DC-DC Converter

Abstract: Step-up DC-DC converters are employed to raise the output voltage level from the input voltage level. Although the basic boost dc-dc converter has advantages like simplicity of implementation, it also has drawbacks like low boost ability and low power density. The literature has reported various topologies which have switched inductor/voltage lift, switched capacitor, voltage multiplier, magnetic coupling, and multistage types. Each converter topology possesses its own advantages and disadvantages with a focus on power density, cost, efficiency, reliability, and complexity depending upon the applications. Demands of such applications are being fulfilled by using new power conversion topologies. Various combinations of such boosting topologies with additional components are complex. This paper provides a simple glance to the basic law and context for the development of future DC/DC converters. This paper has surveyed and classified various topologies according to the voltage-boosting topology and characteristics. The banes and boons of these topologies are also discussed in the paper with the applications of each boosting topology.

Validation of a power conditioning unit for a fuel cell power system

Distributed power systems can be implemented using different renewable energy sources including fuel cell, one of whose important component is a Power Conditioning Unit. This work focuses on designing and implementing a real-time, multi-stage power conditioning unit for fuel cell-based distributed generation system. The multi-stage unit comprises a fuel cell, DC-DC converter and a single-phase DC-AC inverter. This cascaded boost converter implementation efficiently elevates the voltage which is then fed into inverter to get the desired voltage. The Voltage Mode Control and Hysteresis Current Control techniques govern the Power Conditioning Unit implementation. The simulation setup shows an increased efficiency of 2.71% over the existing power conditioning units. The validation of our simulation models are carried out by establishing a prototype model of the fuel cell power system using a reconfigurable computing unit, NI-cRIO thus making the implementation adaptable to design changes. The hardware implementation matches with our simulation results.

Predictive Set Point Modulation Control for Lithium-ion battery Management Systems with DC-DC Converters

Abstract Lithium-ion batteries, widely used in devices such as smartphones, remote controllers, and electric vehicles, often require adjustments to the output voltage to meet the varying demands of different devices. For instance, smartphones dynamically change the battery supply to enhance battery life, and electric vehicles necessitate different load voltages due to frequent start-stop cycles. This introduces the need for DC-DC converters to step up or step down the load voltage. However, this poses challenges to the stability of the bus voltage. In this study, we adopt a method for regulating the bus voltage reference value to predict and stabilize the voltage supplied by lithium-ion batteries. We first model the power supply system of lithium-ion batteries and then design a cascaded control framework for the voltage of DC bus. We introduce a predictive set-point control approach that eliminates the necessity to modify the energy storage system to mitigate voltage fluctuations. Simulation results illustrate that the proposed method effectively mitigates voltage overshoots in the DC bus.

Quadratic-Boost-Zeta Converter Based on Coat Circuit for High Voltage Gain Applications

This paper proposes a DC-DC step-up converter with a high voltage gain for solar and fuel cell systems. This converter combines a Zeta converter with one basic cell of the coated circuit and a Quadratic-Boost converter by a high-frequency transformer. The outputs of these two converters are connected in a series to boost the output voltage of the combined DC-DC converter. The proposed converter not only can achieve higher voltage gain but also acquire lower voltage stress on the semiconductor devices. Therefore, the devices with lower conduction resistances. Moreover, the circuit is made so that the outputs of each part of the converter keep the same properties as those of the converter that came before the combination, ensuring that each converter's known benefits are maintained. The proposed topology has one switch, which keeps the number of components low. The simulation of 240-watt, input voltage 30-volt, and 100kHz using the PLECS program is obtained to confirm the theoretical analysis of the proposed converter.

КОМП’ЮТЕРНЕ ТА ФІЗИЧНЕ МОДЕЛЮВАННЯ БЕЗДРОТОВОГО ЗАРЯДНОГО ПРИСТРОЮ ЄМНІСНОГО ТИПУ ДЛЯ МАЛОГАБАРИТНОГО ЕЛЕКТРОТРАНСПОРТНОГО ЗАСОБУ

The work considers one of the possible approaches to the creation of a capacitive type wireless charger, which allows for non-contact charging of batteries of small-sized vehicles: electric carts, electric scooters, electric scooters. The basis of the development of such a device is the operation of the hybrid DC-DC converter circuit, which operates at a high frequency (550 kHz), transfers energy to the charging circuit using two capacitive elements and allows receiving a constant regulated voltage on the load, which can be either lower or and more input DC voltage. A prototype of such a device has been developed and the results of its experimental research are given, which confirm the possibility of using this scheme for wireless charging of the battery. A Simulink computer model of such a device has been developed, which takes into account the real values of all parameters of the developed prototype and uses the basic model of a lithium-ion battery. According to the results of the calculations, it was determined that for the developed device of the capacitive type, and the largest losses occur in the inductor coils, the value of efficiency, which characterizes the efficiency of the process of transferring electrical energy from the primary power source to the battery, at the initial stage of its charging (when the parameter of the state of the battery SOC =50%) is 80%. References 10, figures 5.

Design and simulation of low-ripple dual active bridge DC-DC converter

Design and simulation of low-ripple dual active bridge DC-DC converter

Sigmoid function model of parallel-connected DC-DC converters and analysis of their dynamic characteristics.

Because of the manufacturing variations of circuit elements and the effects of parasitic parameters, the switching elements of parallel-connected modules cannot be synchronously switched. Consequently, the characteristics of these converters, which are multi-mode, high-order systems, cannot be comprehensively described using reduced-order models based on the symmetry of circuit topology and parameters. It is also difficult to fully describe the characteristics of these systems using discrete mapping models and averaged models. Therefore, we developed a smooth, sigmoid function-based continuous-time model for systems comprising parallel-connected buck converters with average current-sharing control. The proposed model provides a unified description of the continuous and discontinuous conduction modes of the system. The criteria for ensuring the stability of the system were derived based on the Floquet theory. The nonlinear dynamic behavior of the system and the effects of the key parameters on the stability of the system were investigated. The results showed that the system may undergo period doubling bifurcation, border collision bifurcation, and Neimark-Sacker bifurcation as the system parameters varied. The theoretical analysis and simulation results were verified experimentally. Our results provide a basis for the configuration of controller parameters.

A High-Gain DC-DC Converter for Fuel-Cell for Submarines

In this research paper, we present a novel high-gain DC-DC converter designed for fuel cell applications in submarines. Fuel cells offer significant advantages for submarine power systems due to their high efficiency, silent operation, and capability to function without atmospheric oxygen. The proposed converter enhances the low voltage output of fuel cells to meet the higher power demands of submarine systems. This paper details the structure of the converter, operational modes, and simulation results. The converter demonstrates substantial improvements in voltage gain and efficiency, making it a suitable solution for advanced submarine power applications.

Impact of Stress and Material Porosity on Double Boost DC-DC Converter Technology to Enhance Field-Effect Heterotransistors and Heterodiodes Density

Currently, several critical issues in solid-state electronics, such as improving the performance, reliability and density of integrated circuits elements like diodes, field-effect transistors, and bipolar transistors are being intensively addressed. One effective approach to reduce the dimensions of integrated circuits elements is to manufacture them in thin film heterostructures with an optimal manufacturing regime. In this paper, we explore methods to increase the density of field-effect heterotransistors and heterodiodes in the framework of a double boost DC-DC converter. We consider manufacturing this converter in a heterostructure with a specific configuration, where several required areas of the heterostructure should be doped by diffusion or ion implantation. Subsequently, the dopant and radiation defects should be annealed using an optimized scheme. Based on this approach, we provide recommendations for determining the optimal annealing time to achieve the best compromise between increasing density of integrated circuits elements and minimizing local overheating during their operation. We also propose a method to reduce the mismatch-induced stress in the heterostructure. We present an analytical approach to analyze mass and heat transport in heterostructures during the manufacturing of integrated circuits, accounting for mismatch-induced stress. This approach allows for the consideration of spatial and temporal variations in the parameters of technological processes, as well as their nonlinearity.

A Review on Coupled Inductor-Based High Step-Up DC-DC Converters for Renewable Energy Sources

Renewable energy sources are increasingly being embraced due to their environmental advantages, characterized by clean energy production, including solar energy, fuel cells, and wind turbines. High step-up DC-DC converters are commonly employed in conjunction with these sources to elevate their unregulated output voltage to a high and regulated level. This is especially true for converters based on coupled inductors, which are able to achieve high voltage with a low duty cycle. This paper provides a comprehensive review on the coupled inductor-based high step-up DC-DC converters. This review involves five widely used topologies, namely stacked converters, cascaded converters, multi-winding converters, interleaved converters, and integrated converters. It is evident that the researchers proposing these converters aim to enhance the overall efficiency of the renewable energy system by achieving a high voltage gain with a low duty cycle, thereby reducing conduction losses, mitigating stress on switches, alleviating voltage spikes across the main switches, and recycling the leakage energy. However, it is noteworthy that some of the proposed circuit designs are complex and involve a high number of components resulting in increase in cost and size of packaging. Additionally, some proposed circuits could not effectively achieve the aforementioned objectives. This paper serves as a valuable resource for researchers, offering an overview of the latest developments in the high step-up converters based on coupled inductor, which may help them to identify potential research gaps.

Rancang Bangun Pengisian Tegangan Baterai Handphone (HP) Metoda Buck Konverter DC-DC Tipe FC75

Mobile phone (HP) battery manufacturing specifications have a charging current capacity maximum parameter CAh(maks.) = 800 mAh and maximum voltage Vbat(max.) = 3.7 volts dc reduces to 2.02 volts dc requires recharging. In this research HP battery voltage was recharged using the FC75 dc-dc buck converter method, starting from a voltage of Vbat(initial) = 2.02 volts until the final battery voltage was charged at Vbat(final) = 3.713 volts. The HP battery charge voltage parameter Vch comes from the output voltage of the FC75 dc-dc buck converter the parameter Vo(conv.) is expressed as Vo(conv.) = Vch. The purpose of using the FC75 dc-dc buck converter is to electronically convert the lower Vo(conv.) charger voltage (buck) to the larger Vi(conv.) input voltage to control the HP battery charger output power equal to the input power. The results of the research on controlling the output power of the HP battery charger of Po(conv.) = Pi(conv.) = 0.579 watts, there was an increase in the final charger voltage Vokonv.(final) along with the increase in the final HP battery voltage Vbat(final) being charged. The increase in the final charger voltage reaches Vokonv.(final) = Vbat(final) = 3.713 volts, the final charger current becomes Ich(final) = 0.156 A and remains towards the HP battery during charging with a difference in the decrease in charger current towards the HP battery of ∆Ich = 0.009 A relatively small is still profitable, because it avoids back current to the charger voltage.

IMC based robust and innovative control strategies for higher-order DC-DC converter in DC microgrid applications

The extensive practice of DC-DC converter interfacing circuits to maintain DC link voltage in DC microgrid applications introduces unavoidable voltage regulation problems due to its nonlinearity. These unregulated voltages demean the performance and result in an unstable system. This brief proposes an internal model control (IMC) non-linear approach based robust proportional-integral-lead (PI-Lead) controller design for regulating a practical fifth-order DC-DC boost converter. The main innovation of this paper is the developed procedure for designing controller. The prominent feature of IMC filter coefficient is to fulfil the desired level of gain margin and phase margin to show the trade-off between performance and robustness. The proposed controller's performance is evaluated in the presence of uncertain disruptions and its effectiveness is verified by comparing it with the some conventional proportional-integral (PI) as well as with recently published IMC-proportional-integral-derivative (IMC-PID) and IMC-proportional integral derivative double derivative (IMC-PIDD2) controllers. The applicability of the proposed control methodology has been validated under varying supply and load current levels in presence of parametric uncertainty using a MATLAB/Simulink tool along with a low-cost microcontroller DSP F280379D based laboratory prototype.

MPPT Charge Controller using Fuzzy Logic for Battery Integrated with Solar Photovoltaic System

In comparison to other Renewable Energy (RE) resources, solar energy has become the most prominent and prospective source for generating electricity, substituting conventional sources. However, solar Photovoltaic (PV) energy production is dependent on solar irradiance and cell temperature. By implementing the Maximum Power Point Tracking (MPPT) algorithm, it is achievable to maximize the power from solar PV. In spite of this, there is still a slower convergence rate, a significant fluctuation around Maximum Power Point (MPP), and a drift issue caused by rapid irradiance variations in solar PV. In order to prevent oscillation and attain a steady state and continuous output of the PV module, a Fuzzy Logic (FL)-based MPPT has been designed in this work. With the buck converter as the DC-DC converter and the lead acid battery as the input, the Perturb & Observe (P&O) MPPT method is selected. The overall design will be developed using Matlab Simulink, and the efficiency of the FL-MPPT charge controller will be evaluated under constant and step irradiance. Additionally, the battery's State of Charge (SOC) will be monitored to prevent overcharging and discharge. In addition, the effectiveness of the controller will be evaluated with and without the MPPT method. On the basis of simulation results obtained from constant and step irradiance levels, the FL-MPPT charge controller with the P&O algorithm and the lead acid battery as the load was able to maintain maximum system efficiency while extending battery life. The FL-MPPT charge controller obtained about 96% efficiency for both irradiance profiles, whereas the system without the FL-MPPT algorithm only achieved 42% efficiency.

Wind turbine with line-side PMSG FED DC-DC converter for voltage regulation

Wind turbine with line-side PMSG FED DC-DC converter for voltage regulation

A compensator design and stability margin monitor for digitally controlled DC-DC converters

ABSTRACT In this paper, an automatic direct digital design approach for compensators is presented to achieve a lookup table proportional – integral – derivative controller. Additionally, a correlation-based stability margin monitor with adaptive sliding window smoothing is proposed to increase the identifiable range for bandwidth detection. The proposed automatic compensator design approach meets the expected phase margin and crossover frequency and considers limit-cycle oscillation conditions throughout the design process. The digital controller with the direct digital design was implemented on a field programmable gate array to validate the approach and alternative design capabilities. Experimental results show that the direct digital design yields a higher crossover frequency than digital redesign. The best transient response performance can be obtained if a proper integral gain is designed. The digital controller with ASWS was fabricated using the TSMC 1P6M 0.18-μm standard CMOS process. Further experimental results show that the proposed ASWS provides a significantly more accurate identified frequency response by using narrow windows at low frequencies and expansive windows at high frequencies.