Showing papers on "Forward converter published in 2022"
TL;DR: In this article, the authors proposed DC-AC Dual-leg dual-stage conversion (DDC) and DDC-AC Direct single-stage conversions (DSC), which can handle a wide range of voltage.
Abstract: This paper proposes DC–AC Dual-leg dual-stage Conversion (DDC) and DC–AC Direct single-stage conversions (DSC). Conventional energy conversion system has only two-stage conversion, so it has some drawbacks such as huge power loss, less conversion range and lower power rating. So direct conversion, dual-leg step-up and step-up conversions are the solutions to get wide voltage conversion efficiently. The proposed converter can perform the power conversion from battery DC supply into AC with 1:1 ratio, step-up AC, and step-down AC in both directions. Also, it can perform rectifier operation from grid AC supply into DC with 1:1 ratio, step-down DC, and step-up DC. Step-up, step-down and ideal operations are possible within a single circuit; its operation is similar to solid-state DC–AC/AC–DC transformer. The ideal operation, Step-down to Step-up conversion and Step-up to Step-down conversion are possible on both sides, so this converter can handle a wide range of voltage. Power distribution is achieved with voltage regulation between battery/DC-load and AC-load/grid using the proposed control strategy with proper modulation. A prototype model of a 2-kW power rating validates the advantages and feasibility of the proposed methodology.
24 citations
TL;DR: In this paper , a triple-active-bridge converter with an automatic voltage balancing capability for bipolar dc distribution is proposed, which eliminates the need for a dedicated voltage balancing controller and any additional active/passive components.
Abstract: The bipolar dc grid outperforms the conventional unipolar dc distribution in terms of quality, flexibility, efficiency, reliability, transmission capacity, and safety. Despite many advantages, it has a voltage imbalance problem. Unbalanced and asymmetrical load conditions are the major contributors to this imbalance. This article proposes the triple-active-bridge converter with an automatic voltage balancing capability for bipolar dc distribution that eliminates the need for a dedicated voltage balancing controller and any additional active/passive components. Furthermore, along with the bidirectional power flow feature of a converter, the proposed method utilizes the magnetic integration of a converter's existing inductors. This voltage balancing coupled inductor offers the required inductance for power transfer and zero-voltage-switching, over and above provides effective voltage balancing without increasing the magnetic volume of a converter. The proposed method does not require an individual output voltage sensing and moreover; it decreases the complexity by reducing the system from two control variables to one. A 5-kW prototype is tested under an extreme-unbalanced load condition during the steady-state and as well as during transients. The analysis and experimental results are presented to validate the performance.
21 citations
TL;DR: In this paper , a new high-gain transformerless dc/dc boost converter is proposed for PV micro-converter applications, where high voltage-gain is required to boost voltage at higher voltage levels, converter switching devices are under low voltage stress.
Abstract: This article proposes a new high-gain transformerless dc/dc boost converter. Although they possess the ability to boost voltage at higher voltage levels, converter switching devices are under low voltage stress. The voltage stress on active switching devices is lower than the output voltage. Therefore, low-rated components are used to implement the converter. The proposed converter can be considered as a promising candidate for PV microconverter applications, where high voltage-gain is required. The principle of operation and the steady-state analysis of the converter in the continuous conduction mode are presented. A hardware prototype for the converter is implemented in the laboratory to prove the concept of operation.
20 citations
TL;DR: Three specific control schemes are proposed for the dc–dc stage to suppress the SHC, and a 3.3-kW two-stage single-phase PFC converter is fabricated and tested in the lab to verify the effectiveness of the proposed SHC reduction schemes.
Abstract: For the two-stage single-phase power factor correction (PFC) converter, its instantaneous input power pulsates at twice the line frequency, generating the second harmonic current (SHC) at the dc-bus port. The dc–dc stage is used to regulate the output voltage or the dc bus voltage in different applications, and the SHC reduction schemes for the dc–dc stage with different control objectives are discussed in this article. When the dc–dc stage regulates the output voltage, it is pointed out that the control bandwidth of the dc–dc stage is required to be high enough and the dc bus capacitor should be large enough to suppress the SHC, and the design of the dc bus capacitor is given. When the dc–dc stage regulates the dc bus voltage, a virtual impedance is added in series with the input/output of the dc–dc stage to suppress the SHC, and a virtual impedance is added in parallel with the dc bus to improve the dynamic performance. The selection and design of the virtual impedances are also given. Based on that, three specific control schemes are proposed for the dc–dc stage to suppress the SHC, and the parameters design method is also presented. Finally, a 3.3-kW two-stage single-phase PFC converter is fabricated and tested in the lab to verify the effectiveness of the proposed SHC reduction schemes.
19 citations
TL;DR: In this article , an ultra-high step-up dc-dc converter with a combination of two stages boost converter, a coupled inductor, and a multiplier cell is proposed, which can achieve high voltage gain, low voltage stress on its power switches, and requiring a smaller inductor on low voltage side of the converter.
Abstract: In this article, an ultrahigh step-up dc–dc converter is proposed with a combination of two stages boost converter, a coupled inductor, and a multiplier cell. The secondary side of the coupled inductor is unified with the multiplier cell. In addition, leakage energy of the coupled inductor is recycled and transferred to output perfectly which causes high-efficiency performance. The main advantages of the converter include its high voltage gain, low voltage stress on its power switches, and requiring a smaller inductor on low voltage side of the converter. Power losses of the inductors are low due to the current sharing between the input inductor and the coupled inductor. Continuity of input current and existence of a common ground between the load and source make the converter suitable for different applications. The converter is compared with the other converters based on an analysis of its operation modes. Validity of the analysis and the converter performance are experimented using a 150-W prototype that converts 20 V from the input side to 400 V in output.
19 citations
TL;DR: In this article , a dual-active-half-bridge (DAHB) converter with voltage balancing is proposed, which is composed of a conventional DAHB converter with an additional inductor and capacitor voltage balancer (LCVB).
Abstract: Conventional dual-active-bridge dc–dc converters require a dedicated voltage balancer or feedback control when they are used for a bipolar LVdc distribution system. This article proposes a dual-active-half-bridge (DAHB) converter with voltage balancing. The proposed converter is composed of a conventional DAHB converter with an additional inductor and capacitor voltage balancer (LCVB). The LCVB is added between the transformer and the output of the DAHB converter. Although the LCVB increases the switch current, it can balance the two output voltages without additional active switching device and feedback control under unbalanced load conditions. In addition, compared with the conventional DAHB converter, the LCVB can increase the zero-voltage-switching range of the DAHB converter and has no detrimental effect on the operation modes and performances. A 2.8-kW prototype was built and tested to verify the performances of the proposed converter.
15 citations
TL;DR: In this paper , a dc-dc boost converter with expandable diode-capacitor voltage multiplier (VM) cells and coupled inductors is presented, where the voltage stresses on all capacitors and semiconductors are reduced significantly.
Abstract: In this article, a novel ultrahigh voltage gain dc–dc boost converter with expandable diode-capacitor voltage multiplier (VM) cells is presented. The diode-capacitor VM cells and coupled inductors are employed in the presented topology to provide a higher voltage gain. Also, the main and the auxiliary power switches of the presented converter operate with zero voltage switching. The coupled inductors' leakage inductances control the rates of the current drop in the voltage multiplier diodes, which decreases their reverse recovery losses markedly. Moreover, the voltage stresses on all capacitors and semiconductors are reduced significantly. In this converter, the number of voltage multiplier cells, and the coupled inductors turn ratios provide three degrees of design freedom. These degrees of freedom are used to set the desired voltage stresses of the semiconductors within the desired range and to provide a high voltage gain at optimum duty cycles. The design and theoretical analysis of the presented converter are discussed. Finally, the performance of the presented converter is validated using a 500 W, 40 V/380 V laboratory prototype converter, and the experimental results confirm the theoretical calculation.
15 citations
TL;DR: In this article , an isolated bidirectional triple-active-bridge (TAB) dc-dc converter composed of three full-bridge modules and a high-frequency planar transformer is proposed to improve the efficiency of the TAB converter by means of conduction loss minimization.
Abstract: This article presents the design, development, and optimization of pulsewidth modulation (PWM) scheme of an isolated bidirectional triple-active-bridge (TAB) dc–dc converter composed of three full-bridge modules and a high-frequency planar transformer. This article aims at improving the efficiency of the TAB converter by means of conduction loss minimization. The approach utilizes multiple control variables as degrees of freedom for the converter modulation. The optimization is based on the minimization of the true rms current, formulated using generalized harmonic approximation technique. The approach constitutes of two steps: the modulation pattern with least algorithmic complexity for efficiency maximization is first found depending on the operating load and gain condition, and, subsequently, the optimum control variables are calculated using the gradient descent algorithm applied on the identified modulation pattern. An 800-W TAB converter proof-of-concept is built to verify all theoretical considerations and model-oriented analysis. While the converter has an input dc bus voltage of 160 V, the two output ports of the converter can deliver 400 W each at voltage levels of 110–130 V and 18–27 V, respectively. With the implementation of the proposed optimal phase-duty control, the experimental results show a nonunity gain light load efficiency increment up to 6.1% compared with the conventional modulation technique.
14 citations
TL;DR: In this paper , the authors proposed a low voltage charging technique for DC/DC converter for electric vehicles, where the dc/dc converter and BSC can be decoupled by turning off the converter while changing the battery.
Abstract: It has been suggested that the main battery voltage of electric vehicles is increased from 400 to 800 V to improve the charging speed and driving distance. However, the secondary components in the dc/dc converter of the on-board charger have high voltage stresses due to the increased battery voltage. Therefore, this article proposes a low voltage charging technique. The previously designed and optimized dc/dc converter for 400 V battery is used to charge 800 V battery. The battery stack is divided into two modules. Dc/dc converter charges one of two modules alternatively using the battery selection circuit (BSC). Since the BSC has low voltage stresses, the proposed converter can have low voltage stresses on all the dc/dc and BSC parts. Moreover, the dc/dc converter and BSC can be decoupled by turning off the dc/dc converter while changing the charged battery. Therefore, the loss of BSC can be minimized by operating it with low frequency because the switching frequency of BSC can be independent of that of the dc/dc converter. The design process can also be simpler owing to decoupling operation. The LLC converter was adopted for dc/dc converter with 3.3 kW output to verify the proposed technique.
12 citations
TL;DR: In this article , a triple-switch triple-mode (TS-TM) high step-up dc-dc converter is proposed, which consists of three switches, four diodes, two magnetically coupled inductors, and three capacitors.
Abstract: In this article, a new triple-switch triple-mode (TS-TM) high step-up dc–dc converter is proposed. The proposed converter consists of three switches, four diodes, two magnetically coupled inductors, and three capacitors. This converter can provide a high voltage conversion ratio with high power efficiency and low voltage stress across the power semiconductor components. Due to the low voltage stresses of the power semiconductors and implementing the coupled inductors technique, the proposed converter is a low-cost and high-efficient structure in comparison to the other similar TS-TM structures. In order to clarify the advantages of the proposed converter, the required mathematical calculations and comparison results with similar converters are presented. Also, a novel TS-TM with transformer is proposed to overcome the electromagnetic interface problems. Furthermore, a 500 W experimental prototype is built and its performance with different values of duty cycles is tested to prove the claimed features of the proposed converter. A total of 94.5% maximum power efficiency of the assembled prototype has been obtained at 260 W output power.
11 citations
TL;DR: In this paper , a virtual impedance-based control scheme was proposed to increase both the input impedance and output impedance of the dc-dc converter, and the experimental results were provided to verify the effectiveness of the proposed SHC reduction control scheme.
Abstract: In the ac–dc–ac converter system, the second harmonic current (SHC) is generated by the ac–dc rectifier and the dc–ac inverter. If the SHC propagates to the intermediate dc–dc converter, the current stress of the power switches will be increased, and the conversion efficiency will be degraded. Therefore, it is necessary to suppress the SHC in the dc–dc converter. In this article, the generation and propagation mechanism of the SHC in the ac–dc–ac converter system is analyzed. Then, from a perspective of control bandwidth and dc bus port impedance, the basic ideas for reducing the SHC in the dc–dc converter with different control targets are proposed. Based on that, the virtual-impedance-based control scheme is proposed to increase both the input impedance and output impedance of the dc–dc converter. In addition, the realization and design guideline of the virtual impedance is presented. Finally, a single-phase 3-kVA ac–dc–ac converter system is fabricated and tested in the lab. The experimental results are provided to verify the effectiveness of the proposed SHC reduction control scheme.
TL;DR: A Split DC-Link Dual Active Bridge (SDLDAB) based multiport converter (MPC) is proposed in this paper to interface two solar PV modules, and a battery bank with dc microgrid.
Abstract: A split dc-link dual-active-bridge (SDLDAB)-based multiport converter (MPC) is proposed in this article. The intended application of the SDLDAB converter is to interface two solar photovoltaic (PV) modules and a battery bank with a dc microgrid. Depending upon the prevailing atmospheric condition, these two solar PV modules can be operated at their maximum power points. This is achieved by maintaining appropriate voltages at the input terminals of the two PV modules. A high-frequency transformer is employed to provide high voltage gain between the dc microgrid and PV as well as battery ports. A direct power flow path is established between the solar PV modules and the battery without involving the transformer. The transformer current is minimized by appropriately modulating the switching sequence of the SDLDAB. Detailed simulation studies are carried out to predict the performance of the system. A laboratory prototype of the SDLDAB having 1-kW power rating is fabricated. The performance of the MPC is validated by carrying out detailed experimental studies on the developed prototype.
TL;DR: In this article , an input-oriented power sharing control scheme with fast-dynamic response is proposed for ensuring both the power sharing ability and the fast dynamic performance of the ISOP DAB dc-dc converter.
Abstract: With some advantages, such as electric isolation, high efficiency, and fast dynamic response, the input-series output-parallel (ISOP) dual-active-bridge (DAB) dc–dc converter has been regarded as one of the most promising candidates for connecting the medium voltage terminal and the low voltage terminal. For the ISOP DAB dc–dc converter, the existing control strategies are mainly focusing on the equivalent power sharing control, but the fast-dynamic response is not included and the decoupling between the regulation of input voltage and the adjustment of output voltage is not eliminated significantly. In this article, the average model of this ISOP DAB dc–dc converter is presented first, which can be employed to analyze the power distributions of this modular topology clearly. Then, an input-oriented power sharing control scheme with fast-dynamic response is proposed for ensuring both the power sharing ability and the fast-dynamic performance of the ISOP DAB dc–dc converter in this article. Compared with the existing methods, this proposed scheme can also significantly reduce the coupling between the power sharing control and the output voltage regulation. In addition, an inductance-estimating method is proposed for ensuring the power sharing performance of the ISOP DAB dc–dc converter. Finally, the experimental results are provided to verify the effectiveness of the proposed input-oriented power sharing control with fast-dynamic response for the ISOP DAB dc–dc converter system.
TL;DR: In this paper , the authors proposed three specific control schemes for the dc-dc stage to suppress the second harmonic current (SHC) in a two-stage single-phase power factor correction (PFC) converter.
Abstract: For the two-stage single-phase power factor correction (PFC) converter, its instantaneous input power pulsates at twice the line frequency, generating the second harmonic current (SHC) at the dc-bus port. The dc–dc stage is used to regulate the output voltage or the dc bus voltage in different applications, and the SHC reduction schemes for the dc–dc stage with different control objectives are discussed in this article. When the dc–dc stage regulates the output voltage, it is pointed out that the control bandwidth of the dc–dc stage is required to be high enough and the dc bus capacitor should be large enough to suppress the SHC, and the design of the dc bus capacitor is given. When the dc–dc stage regulates the dc bus voltage, a virtual impedance is added in series with the input/output of the dc–dc stage to suppress the SHC, and a virtual impedance is added in parallel with the dc bus to improve the dynamic performance. The selection and design of the virtual impedances are also given. Based on that, three specific control schemes are proposed for the dc–dc stage to suppress the SHC, and the parameters design method is also presented. Finally, a 3.3-kW two-stage single-phase PFC converter is fabricated and tested in the lab to verify the effectiveness of the proposed SHC reduction schemes.
TL;DR: In this paper , the authors proposed a universal solar converter suitable for application in both in the dc or single-phase ac grids using the same terminals, and the experimental results demonstrate the ability of operation in ac or dc grids with main correspondent modes.
Abstract: This article presents a novel concept of a universal solar converter suitable for application in both in the dc or single-phase ac grids using the same terminals. The idea lies in the utilization of the same semiconductors in the dc–dc and in the dc–ac configuration, resulting in minimal redundancy. Possible semiconductor stages are considered. The particular attention is focused on the output filter design along with proper protection circuit selection for dc and ac grids. The design example and comparative analysis between dc–dc, dc–ac, and universal solutions are given. The experimental prototype of the universal solar converter that is rated for 3.6 kVA power in the ac mode and 5 kW in the dc mode is presented. The experimental results demonstrate the ability of operation in ac or dc grids with main correspondent modes. Possible fields of application along with main benefits are addressed in conclusions.
TL;DR: A dual-dc output three-phase three-level ac–dc converter is proposed for low-frequency pulsed power decoupling applications and operation principles, modulation, and control strategies of the ac–DC converter are analyzed in detail.
Abstract: A dual-dc output three-phase three-level ac–dc converter is proposed for low-frequency pulsed power decoupling applications. One of the dc output is connected to the dc pulsed load, whereas the other one is used as power decoupling port and connected to the decoupling capacitor. The voltage of the power decoupling dc port can vary in a wide range to reduce the value and volume of the power decoupling capacitor. A buck/boost converter is employed to interface the power decoupling port with the dc pulsed load. A modified space vector pulsewidth modulation strategy is proposed for the ac–dc converter, based on which independent voltage and power regulation of the two dc outputs is achieved. The steady-state power is directly fed to the dc load with single power conversion stage, and the low frequency pulse power is fed to the power decoupling port. As a result, high-power quality and efficient power decoupling with reduced power conversion stages are achieved. Operation principles, modulation, and control strategies of the ac–dc converter are analyzed in detail. A prototype is built and tested to verify the effectiveness and feasibility of the proposed ac–dc converter for pulsed load.
TL;DR: In this paper , a non-isolated switched inductor cell integrated high step-up voltage gain DC-DC converter with a charge pump mechanism is discussed, and the performance and small signal modeling of the converter in continuous conduction mode are extensively investigated, and voltage gain calculations for the two operational modes are derived.
Abstract: In this paper, a non‐isolated switched inductor cell integrated high step‐up voltage gain DC‐DC converter with a charge pump mechanism is discussed. The continuous conduction mode of the input current is a beneficial aspect of this converter, which is appropriate for electric vehicles, renewable energy, and LED applications. The proposed converter works in two distinct operating modes and provides a flexible range of voltage gain ratios. The performance and small‐signal modeling of the converter in continuous conduction mode are extensively investigated, and voltage gain calculations for the two operational modes are derived. The Markov technique is used to evaluate the converter reliability, component failure rates, and mean time to failures. The proposed converter is evaluated with the existing converters in terms of voltage, and current stress of each component, voltage gain, total component stress factor, component count, and reliability. The proposed converter's hardware prototype has been developed. To validate the theoretical calculations, the converter's simulation and experimental results are discussed. The converter has a maximum output voltage of 110 V and a switching frequency of 50 kHz. The converter's peak efficiency is 94.5%.
TL;DR: In this article , a single-switch DC-DC boost converter structure operating under the high voltage gain and the low duty ratio is proposed using the PI control technique, which reduces the voltage stress and dynamic losses in the power semiconductors.
Abstract: In this study, a switched capacitor (SC)‐based single‐switch DC–DC boost converter structure operating under the high voltage gain and the low duty ratio is proposed using the PI control technique. High current and voltage stresses across the power switches and power diodes can be reduced by using the projected SC block. In addition, the proposed converter can achieve high voltage gain through shorter duty cycles, which directly reduces the voltage stress and dynamic losses in the power semiconductors. On the other hand, because the proposed converter includes a single power switch under different output powers and different loads, the control process is simpler than multiswitch structures. With the proposed converter, an output voltage of 10 times greater rather than the input voltage is obtained at 0.57 of the duty cycle. In this study, the fundamental functions of the proposed converter and the controller design steps are analyzed mathematically and tested in MATLAB/SIMULINK environment. As a result of the analysis, it was determined that the proposed topology works with a high performance at high frequency and variable load ranges. To validate the proposed converter and theoretical calculations, a 200‐W prototype was established under a continuous conduction mode (CCM) working state, with 48‐VDC input voltage and 400‐VDC output voltage. Finally, the simulation results were tested and verified through the experimental results.
TL;DR: In this article , a push-pull series connected (PPSC) ac-dc converter is proposed for high-voltage direct current applications, where each converter phase unit is connected to its corresponding phase on the ac side via a center-tapped single-phase transformer.
Abstract: This article introduces a push–pull series connected (PPSC) ac–dc converter intended for high-voltage direct current applications. The proposed topology requires fewer submodules compared to a standard modular multilevel converter (MMC) to withstand the same dc voltage. Each converter phase unit is connected to its corresponding phase on the ac side via a center-tapped single-phase transformer which also provides the galvanic isolation needed in most applications. The required arm inductance can be merged into the transformer leakage inductance avoiding the need for additional inductors. In this article, both the design and operation of the converter are discussed in detail. Furthermore, a comparison of the PPSC and MMC in terms of energy storage requirements and efficiency is presented. The converter concept and the control strategy proposed is validated by computer simulations using the piecewise linear electrical circuit simulation (PLECS) simulation package as well as through experiments on a small-scale, 300-V, 2-kW laboratory prototype.
TL;DR: In this paper , a non-isolated high gain DC-DC converter based on coupled-induction and built-in transformer with voltage multiplier cell (VMC) is presented for renewable energy applications, especially solar photovoltaic (PV) sources.
Abstract: A non‐isolated high gain DC‐DC converter based on coupled‐inductor (CI) and built‐in transformer (BT) with voltage multiplier cell (VMC) is presented for renewable energy applications, especially solar photovoltaic (PV) sources. In this circuit, the BT used in addition to the coupled inductor improves the design flexibility. It enhances the voltage gain with the simultaneous action of CI and BT, compared to converters that include BT or CI. Also, the formation of voltage multiplier cell with the series combination of secondary windings of the CI and BT, switched capacitors and the diodes give an extra voltage gain to the converter. This converter structure adds the turns ratios in voltage gain expression and does not entail a reverse recovery issue with the leakage energy. The active clamped circuit recycles this leakage energy to alleviate the switching stresses. Consequently, active clamping provides add‐on features like improved converter efficiency with ZVS operation and further voltage gain. The converter principle of operation and the design procedure of all components are presented. Finally, a 400 W laboratory prototype with input voltage range 24–40 V and output 400 V is developed and illustrated the effectiveness of the converter at a switching frequency of 100 kHz.
TL;DR: In this article , a multiport dc-dc converter (MPC) with four ports suitable for renewable energy applications is presented. And the converter includes a bidirectional buck-boost converter to charge/discharge an energy storage.
Abstract: This article presents a multiport dc–dc converter (MPC) with four ports suitable for renewable energy applications. The converter is composed of two boost converters and a switched capacitor. The converter includes a bidirectional buck–boost converter to charge/discharge an energy storage. In the design procedure of the converter, existence of a common ground between the load and input ports, high voltage gain and continuous current of the ports are introduced, which make the converter appropriate for more applications. The converter boosts voltage with high gain in all of its operation modes. In addition, it operates in unbalanced conditions such as different powers and voltage levels of the input sources. According to the used switching strategy, controlling input power of the sources and output voltage is possible. Furthermore, the converter switches between charging and discharging modes automatically. To validate the feasibility and effectiveness of the proposed MPC, a prototype with 250 W nominal power is prepared. The converter boosts 20–400 V in all of the experimented modes.
TL;DR: In this paper , the authors proposed a non-isolated step-up DC/DC converter that can be used in low-voltage distributed power systems and many other applications requiring stepup DC and DC conversion.
Abstract: Distributed energy resources have been broadly developed in recent years for supporting DC and AC microgrids. Unfortunately, most of them produce low output DC or AC voltages, and interfacing converters are required. These are implemented either in single‐stage or dual‐stage configurations. Step‐up converters are the essential section in dual‐stage designs, which their producing gain is important. Improving the boost factor and efficiency as well as decreasing the number of required components and electrical stresses on power components are the most critical challenges in designing such topologies. Continuing past efforts, this paper proposes a new non‐isolated step‐up DC/DC converter that can be used in low‐voltage distributed power systems and many other applications requiring step‐up DC/DC conversion. The topology requires only one power switch located on the converter's low voltage (LV) side. Hence, it can be easily selected from LV ratings, low on‐resistance power semiconductors. Besides, the converter operates with a continuous input current, which is a valuable feature in connection with current‐sensitive voltage resources. Compared with the recently proposed topologies, the topology provides better conversion gain and efficiency. In this article, the operating principle of the introduced converter is comprehensively investigated. Also, in order to examine the converter performance, experimental results will be presented and analyzed. For this purpose, a 400 V/400 W prototype has been designed and built. Results confirm the above claims and show that the converter efficiency equals 96.1%, and it produces high output voltage gain about 12 times.
TL;DR: In this paper , a DC-DC converter with an innovative topology for automotive applications is proposed, which can behave either in stepdown or in step-up mode, presenting in both cases a high gain between the input and output voltage.
Abstract: In this paper, a DC-DC converter with an innovative topology for automotive applications is proposed. The goal of the presented power converter is the electrical storage system management of an electric vehicle (EV). The presented converter is specifically compliant with a 400 V battery, which represents the high-voltage primary source of the system. This topology is also able to act as a bidirectional power converter, so that in this case, the output section is an active stage, which is able to provide power as, for example, in the case of a low-voltage battery or a supercapacitor. The proposed topology can behave either in step-down or in step-up mode, presenting in both cases a high gain between the input and output voltage. Simulation results concerning the proposed converter, demonstrating the early feasibility of the system, were obtained in a PowerSIM environment and are described in this paper.
01 Jul 2022
TL;DR: In this article , a high-frequency isolated modular multilevel dc-dc converter is proposed for large step ratio, medium voltage DC-dc applications, where only a fraction of the voltage source modules are switched in each fundamental ac period enabling high effective frequencies to be achieved.
Abstract: In this article, a novel high-frequency isolated modular multilevel dc–dc converter is proposed for large step ratio, medium voltage dc–dc applications. The proposed converter is based on the recently introduced class of converters termed the current shaping modular multilevel dc–dc converter (CS-MMC). In the CS-MMC, no string inductors are required and only a fraction of the voltage source modules are switched in each fundamental ac period enabling high effective frequencies to be achieved. The proposed converter builds on this earlier work by introducing a new topology featuring galvanic isolation using only a low voltage, high-frequency, three-winding transformer, and imposing dc flux canceling within the transformer. This article describes the converter architecture, its operating principles, and a control design. Experimental results are provided from a 1250V to 145V, 50 kHz laboratory-scale prototype with a peak measured efficiency of 96.8% at 2.8 kW.
20 Mar 2022
TL;DR: In this article , a high voltage gain bidirectional DC-DC converter for the electrical vehicle (EV) application is proposed, which has a wide voltage gain range, low voltage stress on the power semiconductor devices, and a common ground between the ground of the input and output side.
Abstract: In this paper, a high voltage gain bidirectional DC-DC converter for the Electrical Vehicle (EV) application is proposed. The converter provides the merits of both switched-inductor and switched-capacitor converters. The proposed converter has a wide voltage gain range, low voltage stress on the power semiconductor devices, and a common ground between the grounds of the input and output side. Besides, synchronous rectification is adopted to obtain zero voltage switching (ZVS) during turn on and turn off dead time and thereby, efficiency of the converter is increased. The operating principle of the converter is provided in both step up and step-down mode and then, voltage gains of the converter are derived for two modes. Finally, a 96W converter with a constant high-voltage side (240V) and low-voltage side (18∼24V) has been built to demonstrate the experimental validation of our proposed design.
TL;DR: In this paper , a voltage gain interleaved soft switched DC-DC Boost converter without auxiliary switch is proposed, and the converter efficiency is equal to 97.6% at nominal power.
TL;DR: In this article , a step-up dc/dc converter dedicated to dc offshore wind farms is proposed, with the combination of half-bridge submodules, thyristors, diodes, and transformer.
Abstract: In this letter, a high-power step-up dc/dc converter dedicated to dc offshore wind farms is proposed, with the combination of half-bridge submodules, thyristors, diodes, and transformer. Compared with the other promising dc/dc topologies, the device numbers, costs, losses, and energy storage requirement are greatly reduced. The operation principle is introduced. The effectiveness and validity are confirmed by simulation and experimental results.
TL;DR: In this paper , an optimal design of the DAB converter is proposed to provide minimal reactive power in addition to reduced weight and size for the converter magnetic components in order to assure the DC-DC conversion stage of battery electric vehicles' powertrains.
Abstract: The dual active bridge DC-DC converter is a promising power converter used in several applications. Much research has been focusing on the study of such a converter from different angles. In this paper, an optimal design of the DAB converter is proposed to provide minimal reactive power in addition to reduced weight and size for the converter magnetic components in order to assure the DC-DC conversion stage of battery electric vehicles’ powertrains. Two modes of operation are considered in order to fulfill such a requirement and minimize reactive power of the converter (circulating current/conduction losses): an optimal extended phase shift (EPS) modulation along with an optimal triangular phase shift (TrgPS) modulation. The operation of the DAB converter under the two modes is being driven using a model predictive controller. Simulation results using MATLAB/Simulink presented in the paper show that the operation of the DAB converter for such an application is optimal when operating under optimal TrgPS modulation. In addition to the aforementioned features, it also solves many other concerns, such as transient load fluctuation and input voltage disturbance effects, and provides ease of control.
TL;DR: In this article , the authors presented a novel high gain bidirectional switched Z-source DC-DC converter, which utilizes switched-capacitor concept with inductors for high voltage gain.
Abstract: The DC-DC converters are the essential modules in electric vehicles, grid interface of renewable energy sources and DC power supplies. This paper presents a novel high gain bidirectional switched Z-source DC-DC converter. The proposed bidirectional converter utilizes switched-capacitor concept with inductors for high voltage gain. The proposed bidirectional converter presents wide operating range of operation in both boost and buck mode of operation. The proposed converter has common ground between input and output, and uses only 5 active switches and 4 passive elements with reduce switch voltage stress. The current drawn from the low voltage side input source is continuous with reduced ripple. The operating principle, circuit analysis, design, mathematical model and closed loop operation of the proposed converter are presented. The proposed converter is verified through computer simulation and laboratory experiments. The simulation and experimental results are presented.
TL;DR: In this paper , a split dc-link dual-active-bridge (SDLDAB)-based multiport converter (MPC) is proposed to interface two solar photovoltaic (PV) modules and a battery bank with a dc microgrid.
Abstract: A split dc-link dual-active-bridge (SDLDAB)-based multiport converter (MPC) is proposed in this article. The intended application of the SDLDAB converter is to interface two solar photovoltaic (PV) modules and a battery bank with a dc microgrid. Depending upon the prevailing atmospheric condition, these two solar PV modules can be operated at their maximum power points. This is achieved by maintaining appropriate voltages at the input terminals of the two PV modules. A high-frequency transformer is employed to provide high voltage gain between the dc microgrid and PV as well as battery ports. A direct power flow path is established between the solar PV modules and the battery without involving the transformer. The transformer current is minimized by appropriately modulating the switching sequence of the SDLDAB. Detailed simulation studies are carried out to predict the performance of the system. A laboratory prototype of the SDLDAB having 1-kW power rating is fabricated. The performance of the MPC is validated by carrying out detailed experimental studies on the developed prototype.