Hybrid DC-DC Converter Research Articles

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.

The Symmetric Dual Inductor Hybrid Converter for Direct 48V-to-PoL Conversion

This work introduces the symmetric dual inductor hybrid (SDIH) dc-dc converter topology, which is suitable for large conversion ratios where regulation is required, such as direct 48 V to point-of-load (PoL) applications. A dickson-type switched capacitor network is used to effectively produce two interleaved PWM outputs with a greatly reduced voltage amplitude relative to the input voltage, allowing the subsequent magnetic volume to be reduced while retaining modest switching frequencies. Distinct from related variations, part count is significantly reduced while both even and odd order switched capacitor networks can be used with straightforward split-phase control; allowing either network type to achieve complete soft-charging of all flying capacitors. Additionally, charge flow is uniformly distributed through all elements, with equal capacitor and inductor values being preferred. Subsequently this topology is expected to simplify component selection, improve electrical and thermal performance, and reduce cost. Furthermore, analysis is presented that calculates precise phase durations without making small ripple assumptions, revealing up to a 75% timing error in cases where either inductor or capacitor ripple is ignored. Finally, a discrete prototype validates this analysis and demonstrates very high measured power densities of 1,029 W/in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{3}$</tex-math></inline-formula> , 754 W/in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{3}$</tex-math></inline-formula> , and 663 W/in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{3}$</tex-math></inline-formula> for 48 V input and regulated output voltages of 3 V, 2 V, and 1 V, respectively, while switching at a frequency of 750 kHz.

A Common Grounded Voltage Quadrupler ASL/PSC Hybrid Converter With Reduced Voltage Stress

Active switched inductor (ASL) dc-dc converters have very high step-up voltage gain but practically they suffer from high voltage stress across switches because of the resonance caused by the mismatch among the inductor values and switch parameters. This paper presents a new hybrid dc-dc converter topology derived from ASL and passive switched capacitors (PSC). The proposed topology has high step up voltage gain over wide range of duty cycle. The resonance due to mismatch of parameters is eliminated. The proposed converter has low voltage stress, low current stress on circuit elements and common ground between input and output ports. The circuit configuration, operating principle and steady state analysis of the proposed converter are presented. The key performance parameters are compared with that of other high-gain dc-dc converters. A 300W laboratory prototype is developed and experimental verification is carried out for the voltage step-up from 30V to 400V. The closed-loop operation is also verified experimentally and results are presented.

PID Control of Hybrid DC-DC Converter System in Complex Load with Double Reference Time

Abstract: DC-DC converters are circuits that are widely used in energy distribution systems, in industry and technology applications, as well as in household appliances such as computers and televisions, and in uninterruptible power supplies used to feed all these systems. For the design and optimization of DC-DC converter circuits, it is important to create and analyze mathematical models according to the load it is connected to. Simple load structures and circuit structures have been examined and control units have been designed in studies carried out to date. In this study, while the DC-DC converter with a more complex load structure is discussed, mathematical analysis and PID control of DCDC converters with Buck-Boost feature are performed with the same modulation index in different time periods. In the results obtained, it is shown how to create the mathematical models of a system that provides DC-DC energy conversion with a complex load structure and how to formulate the PID control in a system with this complex load structure.

Contributions to the development of a new family of hybrid DC-DC converters

The paper presents a synthesis of the author contributions in developing a new class of DC-DC hybrid converters (HDC) with large voltage conversion ratio. The HDC structures are obtained by introducing commutated inductive and capacitive cells in the classical DC-DC converters. With these topologies, the voltage conversion ratio is larger, at the same duty cycle, compared with the classical converters. The paper presents some of the developed configurations, with unidirectional and bidirectional power flow, and some corresponding applications in renewable energy conversion and automotive industries.

Efficient Hybrid Dual Full-Bridge DC–DC Converters for Pulsed Output Current Applications

This paper presents a hybrid full-bridge DC-DC converter for a wide output voltage range in high efficiency, especially for pulsed output current applications. For the conventional phase-shift-full-bridge DC-DC converter, the hard switching and circulating current lower the efficiency in the wide output conversion ratio. To improve the efficiency of the DC-DC power supply for the pulsed output current, a hybrid DC-DC converter is proposed. On the primary side, two full bridges are integrated by sharing a bridge leg. The circuit on the secondary side is a hybrid rectifier stage. For the pulsed output current with a constant load resistor, a single full bridge works in the low output current. For the large output current, the hybrid two full bridges work together. The circulating current in the hybrid working mode is reduced by a blocking capacitor. The converter is controlled by the phase shift and duty cycle control. All the switches work in zero voltage switching. A prototype is built to verify the performance and control strategy of the converter.

ConverGenT: Automated Topology Generation and Analysis of Hybrid DC–DC Converters

Owing to their high efficiency and high power density, hybrid DC-DC converters are gaining attention in academia and industry. However, no systematic procedure is currently available for creating new converter topologies where the number of inductors and capacitors are different. This paper proposes ConverGenT, an automated topological synthesis and analysis framework for two-phase hybrid DC-DC converters with one inductor, two capacitors consisting of one flying and one output capacitor. Consequently, all the converter topologies of this type are discovered. In contrast to the conventional approach that relies on intuition, this method requires less time and generates a complete set of converter topologies in a systematic manner. These two key advantages ensure that no possible converter topology is missed, making this method superior to the conventional approach. After generating a topology, all information about the converter topologies can be analyzed and verified manually or automatically, and the most suitable topology for a given application can be selected. ConverGenT has identified 62 converter families, each with a maximum of six topologies per family, that outperform conventional converters in certain aspects, with at least eight of these topologies having been published within the last five years. Details on topologies and performance of these converters are in the Appendix.

Topologies and Operations of Hybrid-Type DC–DC Converters Interfacing DC-Current Bus and DC-Voltage Bus

Along with the application of current source converter (CSC), there will be more and more dc-current bus (DCB) for supporting power conversion. The DCB usually provides a common current, and the bidirectional voltage is employed to realize the bidirectional power transmission. In current power system, the dc-voltage bus (DVB) is most widely used DC terminal. Then, it will be foreseeable that topologies which can connect the DCB and the DVB will be urgently needed in the future grid system, such as the dc grid and electric vehicle. However, to connect these two dc terminals, the middle ac power stage is usually required since the power transfer characteristics of these two dc terminals are incompatible. So, the hybrid-type dc-dc converter concept interfacing the DCB and the DVB will be discussed, and the potential hybrid dc-dc converters without or with electric isolation are presented in this paper. Moreover, for these hybrid dc-dc converters, the basic principle for the modulation operation is proposed and analyzed. In addition, by using a non-isolated two-level bidirectional hybrid dc-dc converter and an isolated full-bridge hybrid dc-dc converter as examples, the modulation methods for bidirectional transferred power are illustrated in detail. Finally, simulation and experiment results of the isolated full-bridge hybrid dc-dc converter are used to verify the effectiveness of the proposed hybrid dc-dc converter idea and the corresponding modulation methods.

Hybrid DC-DC Converter with Artificial Intelligence based MPPT Algorithm for FC-EV

Hybrid DC-DC Converter with Artificial Intelligence based MPPT Algorithm for FC-EV

A Current-Source Converter with a Hybrid Dc-dc Converter Interfacing an Electric Vehicle and a Renewable Energy Source

The increasing demand for electricity and the impact of the consumption of fossil fuels leads to the need for approaching new alternatives of energy production, namely energy storage systems (ESS) and renewable energy sources (RES). For this purpose, this paper presents a single-phase current-source converter (CSC) with a hybrid dc-dc converter connected to the dc-link, which not only allows the interface of an electric vehicle (EV) and a RES, but also operates as shunt active power filter (SAPF). The operation as SAPF is performed through the CSC connected to the power grid, compensating some power quality problems that can occur in the electrical installation, namely current harmonics and low power factor. Moreover, the CSC can operate as a grid-tied inverter or as an active rectifier. Regarding the hybrid dc-dc converter, the main role of this power converter is to interface the CSC dc-link with the power converters for the EV and RES interfaces. As demonstrated along the paper, the CSC, combined with the hybrid dc-dc converter, allows the operation as SAPF, as well as the operation in bidirectional mode, specifically for the EV operation, and for injecting power from the RES. In this paper, the power electronics structure is described in detail, and the operating principle is introduced, supported by the description of the control algorithms. The validation results show the proper operation of the CSC as SAPF and the operation of the hybrid dc-dc converter as EV battery charger and discharger, as well as RES interface.

Design and Implementation of Hybrid DC-DC Converter: A Review

The advancement in Power Management Integrated Circuit (PMIC) has driven the DC-DC conversion technology into a System-on-Chip (SoC) solutions, leveraging CMOS technology scaling from 180nm to 22nm and on-chip passive element integration. Concurrently, as the applications demand smaller form factor solution towards device portability with optimized power qualities, switched-capacitor-inductor hybrid architectures with fully-integrated passives have become a popular choice for a compact and high efficiency converter solution, in contrast to bulky and discrete component based alternatives. This article reviews the latest advancements in hybrid dc-dc topologies, specifically for low-power applications to address the downsides such as charge sharing loss, high current ripple, limited conversion ratio, low power density and efficiency. An overview of capacitor and inductor technology is discussed in terms of on-chip parasitic losses, and miniaturization. A comprehensive comparison in the state-of-the-art hybrid dc-dc converter work is tabulated with power density and efficiency as the primary performance metrics, highlighting their operability in low-power applications. Moreover, a discussion is included with quantified benchmarks to justify the viability of converters, along with the future recommendation of realizing ultra-high switching frequency for smaller footprint inductor and design approach to resolve the current tradeoff bottlenecks.

High Power Parallel Hybrid DC-DC Converter

The parallel hybrid converter (PHC) is gaining popularity for high voltage direct current (HVdc) applications. The PHC features low energy storage requirement and low conduction losses in the sub-modules (SMs). Moreover, the PHC requires lower number of SMs and switching devices. However, the existing PHC configuration needs harmonic voltage injection in the chain-links (CLs) to feed the ac grid, thereby injecting harmonic currents into the main DC-link. Additionally, the existing PHC lacks dc fault-tolerant capability. A new front–to-front dc-dc configuration called as parallel hybrid dc-dc converter (PHDC) for HVdc application is presented. The proposed PHDC eliminates the need of harmonic voltage injection and provides the dc fault-tolerant capability. Furthermore, the proposed PHDC requires lesser energy storage and smaller interlinking transformers than in the PHC used for ac-dc application. The detailed mathematical analysis with design procedure considering the dc-dc conversion application is presented. The authenticity of the proposed dc-dc converter is verified by both analytical and simulation studies. Finally, a three phase front-to-front experimental setup is tested for different operating conditions and results are presented.

An Overview of Hybrid DC-DC Converters: From Seeds to Leaves

An Overview of Hybrid DC-DC Converters: From Seeds to Leaves

A Symmetrical Double Step-Down Converter With Extended Voltage Conversion Ratio

The Hybrid DC-DC converter, especially with multiple inductors targeting high current delivery, has the advantages of high efficiency and power density with a large voltage conversion ratio (VCR), due to the combination of the benefits of both switched-capacitor-based and inductor-based buck converters. However, a higher number of inductors means that the energizing time for each inductor has more limitations, resulting in a relatively narrower VCR range. To reduce the conduction loss and extend the voltage conversion ratio scope, this paper presents a symmetrical double step-down (SDSD) converter with a VCR range up to 1/3, regulating an output voltage interval of 0.5 V-0.8 V from a 2.7 V-4.2 V Lithium-ion battery. This converter, implemented in 65 nm CMOS, occupies a core active area of 1.53 mm2. This work obtains 86.5% peak efficiency and 326 mA/mm2 maximum current density, with an effective switching frequency of 3 MHz.

Analysis and Design of a Two-Phase Series Capacitor Dual-Path Hybrid DC-DC Converter

Inthis article, a two-phase series capacitor dual-path hybrid dc–dc converter with the step-down ratio of less than 1/6 is proposed for the first time. In this converter, the output current is divided into capacitance- and inductance-path, so the average value and ripple of inductance current are reduced. On the same time, the conduction loss caused by inductance equivalent series resistance (ESR) is also reduced. The addition of series capacitor leads to desirable characteristics, including lower switching stress, switching loss, parasitic output capacitance loss on <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> , automatic phase current balancing, duty ratio extension, etc. A 120 W prototype has been designed to demonstrate theoretical analysis. Obtained efficiency was up to 93.18% at full load. Experimental results show good agreement with theoretical analysis and high feasibility of proposed converters.

Efficient GaN-based hybrid DC-DC converter with simple and low-cost bootstrap gate drivers for LED lighting applications

This paper presents a 40 V-to-8 V GaN-based hybrid DC-DC converter design using 5-to-1 Dickson switched-capacitor structure. The converter, supporting a wide range of output voltage up to the input voltage, is suitable for LED driver applications in smart homes. We propose simplified and minimal gate driving schemes for N level Dickson switched-capacitor scheme where the number of gate driver chips is limited to only 3 that leads to a substantial decrease of circuit board size and cost. Detailed loss analysis, considering soft charging effect from the output inductor, is presented. To examine the effectiveness of the proposed scheme, a GaN-based hybrid DC-DC converter prototype is implemented and experimentally verified using commercial LED lamps. The circuit offers a peak efficiency of over 94% and a peak current of ∼1A at an output range from 4 V to 28 V from a 40 V input for the simplified gate driving scheme. The converter prototype using the minimal gate driving scheme achieves a peak efficiency of ∼93% with ∼43% reduction in gate driver chips and ∼35% reduction in gate driver area, promising a compact and low-cost solution for future LED drivers.

A multi-path switched-capacitor-inductor hybrid DC-DC converter with reduced inductor loss and extended voltage conversion range

A multi-path switched-capacitor-inductor hybrid DC-DC converter with reduced inductor loss and extended voltage conversion range

Modeling and control of a hybrid DC/DC/AC converter to transfer power under different power management strategies

&lt;span&gt;A hybrid DC/DC/AC converter connected to the grid without a three-phase transformer is controlled. The decentralized control method is applied to the hybrid DC-DC converter such that the maximum power of PV flows to the grid side. This controller must charge and discharge the battery at the proper time. It must also regulate DC-link voltage. An additional advantage of the proposed control is that the three-phase inverter does not need a separate controller such as PWM and SPWM. A simple technique is used for creating the desired phase shift in the three-phase inverter, which makes the active and reactive power of the inverter controllable. A new configuration is also proposed to transmit and manage the generation power of PV. In this&lt;br /&gt;scheme, the battery and fuel cell are employed as an auxiliary source to manage the generation power of PV. Finally, a real-time simulation is performed to verify the effectiveness of the proposed controller and system by considering the real characteristics of PV and FC.&lt;/span&gt;

Review on non-isolated DC-DC converters and their control techniques for renewable energy applications

In recent times, the need for energy consumption is drastically increasing to fulfill the global requirements of commercial and domestic consumer demands. Energy generation using conventional methods such as oil and gas are not appreciated in the modern era since they are the major contributors for pollution and global warming. To tackle these issues, energy generation using hybrid renewable energy is being opted and studied universally. However, renewable energy sources have their fair share of drawbacks such as photovoltaic systems rely on the surrounding irradiance and temperature, wind system experiences irregular wind speed, and fuel cells are expensive and less efficient. Also, the energy extracted from renewable sources persist with stochastic behavior. To deal with these issues, researchers utilize different power electronic devices such as inverters, active power filters, voltage regulators, power quality conditioners, and DC-DC converters. Among these power electronic devices DC-DC converters are highly effective for DC voltage regulation and to improve the efficiency of renewable energy systems. Appropriate selection of the DC-DC converter is an important factor that has significant contribution in overall performance of the power systems. Besides, the selection of an efficient DC-DC converter topology, for its optimum operation integration of a suitable control technique is equally important. This paper highlights the characteristics of available and on-going trends of non-isolated converters that includes buck-boost, single ended primary inductor converter, cuk, z-source, zeta, and hybrid DC-DC converters based on the performance parameters that are analyzed using MATLAB Simulink. Control techniques that include proportional integral derivative (PID), slide mode control (SMC), model predictive control (MPC), state space modeling (SSM), and fuzzy logic control (FLC) are also discussed considering the parameters settling issue, response time and complexity while integrating with non-isolated DC-DC converters in power systems.

Hybrid DC-DC Converter with Low Switching Loss, Low Primary Current and Wide Voltage Operation

A full-bridge converter with an additional resonant circuit and variable secondary turns is presented and achieved to have soft-switching operation on active devices, wide voltage input operation and low freewheeling current loss. The resonant tank is linked to the lagging-leg of the full bridge pulse-width modulation converter to realize zero-voltage switching (ZVS) characteristic on the power switches. Therefore, the wide ZVS operation can be accomplished in the presented circuit over the whole input voltage range and output load. To overcome the wide voltage variation on renewable energy applications such as DC wind power and solar power conversion, two winding sets are used on the output-side of the proposed converter to obtain the different voltage gains. Therefore, the wide voltage input from 90 to 450 V (Vin,max = 5Vin,min) is implemented in the presented circuit. To further improve the freewheeling current loss issue in the conventional phase-shift pulse-width modulation converter, an auxiliary DC voltage generated from the resonant circuit is adopted to reduce this freewheeling current loss. Compared to the multi-stage DC converters with wide input voltage range operation, the proposed circuit has a low freewheeling current loss, low switching loss and a simple control algorithm. The studied circuit is tested and the experimental results are demonstrated to testify the performance of the resented circuit.