Buck Converter with Cubic Static Conversion Ratio.

The paper introduces a step-down converter that exhibits a static conversion ratio of cubic nature, providing an output voltage which is much closer to the input voltage, and at the same duty cycle, compared to a wide class of one-transistor buck-type topologies. Although the proposed topology contains many components, its control is still simple, as it employs only one transistor. A dc analysis is performed, the semiconductor stresses are derived in terms of input and output voltages and output power, revealing that the semiconductor voltage stresses remain acceptable and anyway lower than in other cubic buck topology. All detailed design equations are provided. The state-space approach is used to analyze the converter in the presence of conduction losses and a procedure for calculating the individual power dissipation is provided. The feasibility of the proposed cubic buck topology is first validated by computer simulation and finally confirmed by an experimental 12 V-10 W prototype.

Language as social action: Gertrude Buck, the "Michigan School" of rhetoric, and pragmatist philosophy.

In the late 19th and early 20th centuries, Gertrude Buck and collaborators developed a sociologically and pragmatist-informed approach to language that has been neglected in later scholarship. Buck approached the study of language from the standpoint of pragmatist functional psychology, which is indebted to John Dewey's pragmatism at the University of Michigan, and which views language as a normal, dynamic action of human organisms engaged in necessary cooperative relations with one another. Her approach overcomes the small-minded pragmatism that would criticize figurative or poetic language as impractical, and instead shows how figuration is essential to the particular ways in which language is action that conveys meaning to others and serves broader social functions. Buck's forgotten work helps overcome criticisms of the application of pragmatic action theory to language and literature, sketching how language structure may be explained on the basis of language as a natural social-communicative act, how figurative language is inherent in the normal act of communicating situated bodily experiences to others, and how rhetorical speech and writing contributes to participation in democratic social processes. This paper also indicates how Buck's work has been partially rediscovered in Composition Studies, as well as prefigures later reader-response esthetics and feminist analyses of language.

Flow cytometry study of post-thawed buck spermatozoa: Mito-TEMPO improves cryopreservation performance by controlling apoptosis rate, DNA fragmentation and ROS production.

Sperm cryopreservation is used to spread qualified semen for artificial insemination, but the freezing process reduces sperm quality. This study assessed the efficacy of Mito-TEMPO on post-thawed goat sperm quality. Semen samples divided to five equal groups and after dilution, received different doses of Mito-TEMPO (0, 1, 10, 100 and 1000 µM), and cryopreserved in liquid nitrogen. After thawing, flow cytometry analysis was performed to evaluate sperm mitochondria membrane potential, viability, apoptotic-like changes, DNA fragmentation and ROS concentration. According to the results, Mito-TEMPO (10 and 100 µM) improved (P ≤ 0.05) sperm viability and decreased (P ≤ 0.05) apoptotic-like changes and ROS concentration compared to the other groups. Mitochondria membrane potential was higher (P ≤ 0.05) in groups received 1, 10 and 100 µM Mito-TEMPO. The lowest (P ≤ 0.05) DNA fragmentation was observed in group received 10 µM Mito-TEMPO. In conclusion, mitochondria-targeted antioxidant Mito-TEMPO could be an efficient cryo-additive to enhance flowcytometric quality parameters of post-thawed buck semen.

The Possible Role of Anoxic Alkaline High Subcritical Water in the Formation of Ferric Minerals, Methane and Disordered Graphitic Carbon in a BARB3 Drilled Sample of the 3.4 Ga Buck Reef Chert.

The present article reports Raman spectroscopic observations of siderite, hematite, disordered graphitic carbon and possibly greenalite inside the quartz matrix of a banded iron sample from the BARB3 core drilled inside the 3.4 Ga Buck Reef Chert of the Barberton Greenstone Belt in South Africa. The article also reports Raman spectroscopic observations of quartz cavities, concluding in the presence of water, methane and sodium hydroxide at high concentration leading to pH ~ 15 inside the inclusion, suggesting an Archean water which was strongly basic. FeIII-greenalite may also be present inside the inclusion. The possible role of anoxic alkaline high subcritical water in the formation of ferric minerals and the CO required for the synthesis of molecules of biological interest has been demonstrated theoretically since 2013 and summarized in the concept of Geobiotropy. The present article experimentally confirms the importance of considering water in its anoxic strongly alkaline high subcritical domain for the formation of quartz, hematite, FeIII-greenalite, methane and disordered graphitic carbon. Methane is proposed to form locally when the carbon dioxide that is dissolved in the Archean anoxic alkaline high subcritical water, interacts with the molecular hydrogen that is emitted during the anoxic alkaline oxidation of ferrous silicates. The carbon matter is proposed to form as deposition from the anoxic methane-rich fluid. A detailed study of carbon matter from diverse origins is presented in a supplementary file. The study shows that the BARB3_23B sample has been submitted to ~ 335 °C, a temperature of the high subcritical domain, and that the graphitic structure contains very low amounts of oxygen and no hydroxyl functional groups. The importance of considering the structure of water is applied to the constructions of the Neoproterozoic and Archean banded iron formations. It is proposed that their minerals are produced inside chemical reaction chambers containing ferrous silicates, and ejected from the Earth's oceanic crust or upper mantle, during processes involving subduction events or not.

Effects of Origanum majorana essential oil and antibiotics on the quality of frozen thawed Beni Arouss buck semen.

This study aims to investigate the effects of Origanum majorana (OM) essential oil (EO) at different concentrations and antibiotics on post-thawed Beni Arouss buck semen quality. Semen collection was performed using artificial vagina from eight Beni Arouss bucks. Ejaculates were pooled, divided into 12 equal aliquots, washed and diluted to 400 × 106 sperm/ml (with 7% of glycerol). Skim milk-based extender was supplemented with different concentrations of OM EO (0%; 0.01%; 0.02%; 0.03%; 0.04% and 0.05%) without antibiotics, marked as (CTR-), (M1-), (M2-), (M3-), (M4-) and (M5-), and with 50 mg of streptomycin and 50,000 IU of penicillin per 100 ml, marked as (CTR+), (M1+), (M2+), (M3+), (M4+) and (M5+), respectively. Aliquots were cooled to 4°C, then frozen in 0.25 ml straws with a programmable freezer and finally stored in liquid nitrogen for 48 h. Thawing was performed at 37°C for 30 s. Motility, live sperm, sperm abnormalities, membrane integrity, lipid peroxidation and bacterial growth were evaluated after thawing. Among the tested extenders, M2+ improved all semen quality parameters. Sperm motility, live sperm and membrane integrity increased significantly, while the number of abnormal sperm and bacterial growth decreased significantly. The toxic effect of OM EO, with and without antibiotics, appeared beyond 0.03%. In conclusion, M2+ is recommended to improve the cryopreservation of Beni Arouss buck semen.

Adaptive Neural Backstepping Terminal Sliding Mode Control of a DC-DC Buck Converter.

In this paper, an adaptive backstepping terminal sliding mode control (ABTSMC) method based on a double hidden layer recurrent neural network (DHLRNN) is proposed for a DC-DC buck converter. The DHLRNN is utilized to approximate and compensate for the system uncertainty. On the basis of backstepping control, a terminal sliding mode control (TSMC) is introduced to ensure the finite-time convergence of the tracking error. The effectiveness of the composite control method is verified on a converter prototype in different test conditions. The experimental comparison results demonstrate the proposed control method has better steady-state performance and faster transient response.

Bidirectional Six-Pack SiC Boost-Buck Converter Using Droop Control in DC Nano-Grid.

This paper proposes a bidirectional boost-buck converter employing a six-pack SiC intelligent power module using droop control in DC nano-grids. The topology is constructed as a cascaded structure of an interleaved boost converter and buck converter. A six-pack SiC intelligent power module (IPM), which is suitable for the proposed cascaded structure, is adopted for high efficiency and compactness. A hybrid control scheme, in which holding a particular switch always results in a turn-off or turn-on state according to the boost mode and the buck mode, is employed to reduce the switching losses. By applying the hybrid control scheme, the number of switching operations of the switches can be minimized. Since switchover of the current controller is not required, smooth transition is enabled not only from the buck mode to the boost mode but also vice versa. As a parallel control, a secondary control is employed with DC droop control, which has a trade-off relationship between voltage sag and current sharing. It is possible to enhance the accuracy of current sharing while effectively regulating the DC link voltage without voltage sag. This is verified experimentally using two modules as laboratory prototypes, of which the power rating is 20 kW each.

Continuous Adaptive Finite-Time Sliding Mode Control for Fractional-Order Buck Converter Based on Riemann-Liouville Definition.

This study proposes a continuous adaptive finite-time fractional-order sliding mode control method for fractional-order Buck converters. In order to establish a more accurate model, a fractional-order model based on the Riemann-Liouville (R-L) definition of the Buck converter is developed, which takes into account the non-integer order characteristics of electronic components. The R-L definition is found to be more effective in describing the Buck converter than the Caputo definition. To deal with parameter uncertainties and external disturbances, the proposed approach combines these factors as lumped matched disturbances and mismatched disturbances. Unlike previous literature that assumes a known upper bound of disturbances, adaptive algorithms are developed to estimate and compensate for unknown bounded disturbances in this paper. A continuous finite-time sliding mode controller is then developed using a backstepping method to achieve a chattering-free response and ensure a finite-time convergence. The convergence time for the sliding mode reaching phase and sliding mode phase is estimated, and the fractional-order Lyapunov theory is utilized to prove the finite-time stability of the system. Finally, simulation results demonstrate the robustness and effectiveness of the proposed controller.

Occurrence, molecular characterization and antimicrobial-resistance pattern of Staphylococcus species isolates from buck semen.

Staphylococcus aureus is one of the most prevalent pathogens, and a causative agent of a variety of infections in humans and animals. Most studies concentrated on characterization of staphylococcus isolates and its antimicrobial resistance from various illness of veterinary importance, but there is no specific study that is available on isolates from reproductive tract of small ruminants and especially its semen. Hence, in the current study, a total of 48 semen samples were collected from healthy bucks of different breeds to investigate the occurrence of S. aureus. Antimicrobial resistance and virulence of the Staphylococcus isolates were determined to assess the adverse effects of them on buck fertility. The bacterial isolates were tentatively confirmed as Staphylococcus spp. based on the Gram's staining, growth on Mannitol salt agar and catalase test. Overall, 75% (n = 36) of the samples were positive for Staphylococcus spp. from the total 48 buck semen ejaculates from different breeds and among them 23 (63.89%) were coagulase-negative (CoNS) and 13 (36.11%) were coagulase-positive Staphylococcus (CoPS) strains. The species identified by molecular characterization are S. aureus, S. chromogenes, S. haemolyticus, S. sciuri, S. simulans, and S. epidermidis from buck semen. Further, these isolates exhibited varying degrees of multidrug resistance genotypically as well as phenotypically. The presence of antibiotic resistance and virulence genes may pose a potential threat to reproductive health of animals, the animal handlers and livestock keepers, while simultaneously highlighting the need for vigilant monitoring of these isolates at the time of semen cryopreservation.

Effect of the donor's age and type of extender (egg yolk versus clarified egg yolk) over the sperm quality of Majorera bucks preserved at 4°C: In vitro results and fertility trials.

This study assessed the effect of donor´s age and two different extenders in the sperm quality of chilled semen in Majorera bucks. In experiment 1, semen was individually processed from 5 young (10-12 months old) and 4 mature (3-5 years old) bucks and then was diluted in two different extenders: EY (Tris-glucose, 12% egg yolk) and CEY (Tris-glucose, 12% clarified egg yolk) and cooled at 4°C; semen quality (sperm motility, percentages of alive spermatozoa, acrosome status and abnormal spermatozoa) was evaluated at 24, 48, 72 and 96 hr after cooling. In experiment II, 72 Majorera goats were assigned to four experimental groups: for groups 24-EY (n = 18) and 24-CEY (n = 18), goats were inseminated with EY and CEY cooled semen for 24 hr, respectively, while for groups 72-EY (n = 18) and 72-CEY (n = 18), goats were inseminated with EY and CEY cooled semen for 72 hr, respectively. In vitro results confirmed that only ejaculate volume and sperm concentration were significantly different between young and mature bucks. In addition, semen quality was similar between both diluents, presenting values for the first 48 hr similar to that recorded in fresh samples. The fertility rate was around 70% after 24 hr (4°C) in both groups, but the kidding rate was significantly lower (44.4%, p < .05) in goats inseminated with EY diluent preserved for 72 hr. Our results showed that the semen samples may be stored at 4°C in media with egg yolk or clarified egg yolk, and, therefore, the use of clarified egg yolk may represent a valid alternative to chill semen samples. Finally, young bucks (older than 10-12 months) of Majorera breed could be successfully used in breeding programmes with similar efficacy to older males.

Validation of double freezing protocol for Beetal buck (Capra hircus) spermatozoa.

The study aimed to validate the double versus single freezing protocol for Beetal buck (Capra hircus) spermatozoa in tris-citric acid (TCA) based extender both in terms of quality and fertilization potential. Computer-assisted sperm motion and kinematic (CASA) variables, i.e. total (%), and progressive motilities (TM and PM, %) and rapid velocity (RV, %), average path (VAP, µm/s), straight line (VSL, µm/s) and curved line velocities (VCL, µm/s), straightness, (VSL/VAP, %) and linearity, (VSL/VCL, %) as well as supra-vital plasma membrane integrity (SV-PMI, %), mitochondrial membrane potential (MMP, %), viable/intact acrosome (V-IACR, %) and DNA integrity (DNA-I, %) had significantly greater values (p < .05) during single freeze-thawing as compared with the double freeze-thawing at 0, 30, 90, 150 and 210 days, respectively. All CASA and other assays alone did not show significant differences (p > .05) between both freeze-thaw cycles at all treatment durations, respectively. No statistical significance (p > .05) was observed for the in vivo fertility between single (n = 84/141 = 59.72%) and double freeze-thawing (n = 72/136 = 52.9%) cycles, respectively. In conclusion, sperm motion, kinematics, plasma membrane, acrosome, mitochondria and DNA integrities and in vivo fertility are acceptable after the double freezing protocol despite being lower than after one freeze cycle in Beetal buck.

The Effects of Different Doses of ROCK Inhibitor, Antifreeze Protein III, and Boron Added to Semen Extender on Semen Freezeability of Ankara Bucks.

In the presented study, the effects of ROCK inhibitor Y-27632, antifreeze protein III, and boron at two different doses were investigated on the spermatological parameters of Ankara buck semen after freeze−thawing. Ejaculates were collected from bucks using an electroejaculator during the breeding season. The ejaculates that showed appropriate characteristics were pooled and used in the dilution and freezing of semen. The extender groups were formed by adding two different doses of three different additives (ROCK inhibitor Y-27632, 5 and 20 µM; antifreeze protein III, 1 and 4 µg/mL; boron, 0.25 and 1 mM) to the control extender. The semen was diluted with the different extenders at 35−37 °C and loaded into straws. Sperm samples frozen in liquid nitrogen vapors, following equilibration, were stored in liquid nitrogen. It was observed that extender supplementation improved post-thaw motility of Ankara buck semen after freeze−thawing. Differences were significant (p < 0.01) for 5 and 10 µM doses of ROCK inhibitor (71.82% and 74.04 % motility), as well as for 0.25 and 1 mM doses of boron (76.36% and 72.08% motility), compared to the control group (66.15% motility). With respect to the evaluation of acrosomal integrity and mitochondrial activity after freeze−thawing, although supplementation provided protection at all doses, the efficacy was not statistically significant (p > 0.05). It was observed that DNA damage was improved by antifreeze protein III at 1 µg/mL (1.23% ± 0.23%) and by boron at all doses (0.25 mM: 1.83% and 1 mM: 1.18%) compared to the control group (3.37%) (p < 0.01), following the thawing process. In the present study, it was determined that some additives added to the extender provided significant improvements in buck spermatozoa motility and DNA damage after thawing.

Breeding soundness examination (BSE): a decision-making tool that requires a particular guideline for male goats.

Breeding soundness examination (BSE) is a common evaluation to predict the reproductive ability of male livestock. The generated guideline for BSE is specified for each animal species to enhance the performance of BSE. However, there is no particular BSE guideline for bucks yet; then, the BSE guidelines for ram and bull are commonly used for bucks. This investigation was conducted to determine the main BSE characteristics and the appropriate age range for assessment in Boer goats. For this purpose, semen was collected using electro-ejaculation, and seminogram variables (semen-BSE traits) were evaluated using conventional methods. The association between common testicular biometric variables (TBVs) and semen-BSE traits were assessed using Pearson's correlation coefficients and multiple linear regression. Logistic regression was used to test the validity of TBVs for the BSE of Boer goats. In this study, a strange appearance of the head of sperm, known as "rod-in-head" (RIH), was observed. The results showed that the appropriate age range for performing BSE in bucks is 12-30 months. Moreover, scrotal length in the range of 10-15.9 cm was the eligible TBV to be used as a predictor for semen-BSE traits. It was suggested that developing a BSE guideline for bucks is necessary for unbiased selection in performing BSE.

Positive effect of autologous platelet rich plasma on Saanen buck semen cryopreservation in non-breeding season.

The objective of the current study was to evaluate the effect of autologous platelet-rich plasma (PRP) addition into soybean lecithin based extender on buck semen at post-thaw. Semen samples were collected from eight Saanen buck, and each semen sample was split into four equal aliquots and diluted with different concentrations of PRP supplemented extenders [no PRP (control), 0.5 × 107/ml PRP, 1 × 107/ml PRP, or 2 × 107/ml PRP]. Motility, plasma membrane functional integrity, acrosome integrity, mitochondrial membrane potential, DNA integrity and malondialdehyde concentrations (MDA) were measured and analyzed at post-thaw. The results showed that 2 × 107/ml PRP group had a positive effect on motility (62.41 ± 4.24), membrane functional integrity (71.11 ± 2.90), mitochondrial membrane potential (69.70 ± 1.99), DNA integrity (7.22 ± 0.93) and MDA levels (2.56 ± 0.73) at post-thaw (P < 0.05). The results of the study demonstrated that autologous PRP has a protective effect on cryopreservation of buck spermatozoa and the fertility effects are worthy of further study.

Ferulago angulata extract improves the quality of buck spermatozoa post-thaw and counteracts the harmful effects of diazinon and lead.

During cryopreservation, spermatozoa are exposed to chemical or physical stress that has adverse effects on the quality of mammalian spermatozoa. Recently, much attention has been paid to environmental contaminants (ECs) in livestock, because of their detrimental effects on livestock productivity and fertility. ECs like diazinon (DZN) and lead acetate (LA) are considered ubiquitous and induced oxidative stress, which decreases spermatozoa quality. Since Ferulago angulata extract (FAE) has antioxidant properties, the present study investigated the effect of FAE supplementation in a freezing extender, in the presence or absence of DZN + LA, during cryopreservation, on the quality and fertility ability of buck spermatozoa after thawing. Pooled ejaculates were diluted with a freezing extender and supplemented with FAE (0.002%, w/v) in the presence or absence of DZN (100 µM) + LA (12.5 µM). Post-thaw spermatozoa parameters, ROS production, fertilization ability, and developmental competence of oocytes inseminated with FAE/DZN + LA treated spermatozoa were calculated. The results demonstrated that FAE improves cryopreserved spermatozoa motility, viability, membrane integrity, fertilizability, and developmental competence, and reduced spermatozoa ROS production in the presence or absence of DZN + LA. Besides, FAE significantly restored the adverse effects of DZN + LA exposure during cryopreservation on inner cell mass (ICM) count, trophectoderm (TE) cell count, total cell number (TCN), and the ratio between ICM to TCN. In conclusion, FAE on its own resulted in an improvement in the buck spermatozoa's quality and fertility. Therefore, the addition of FAE, as a natural antioxidant to buck semen extender, can increase spermatozoa cryotolerance and post-thaw resistance even when exposed to ECs.

Semen quality and total microbial load: An association study in important Indian Goat breeds during different seasons.

The invasion of the male urogenital tract by microorganisms, and its subsequent effects on sperm fertilising ability, has not been well discussed in bucks. The present study was conducted to assess the bacterial load in fresh semen of the 2-6 years old bucks. For conducting the experiment, semen ejaculates from 18 bucks (6 from each breed namely Jakhrana, Jamunapari and Barbari) were used. We collected 5 ejaculates from each buck in each season (Summer-April to June, Rainy-July to Sept and Winter-November to January). Semen was collected with the artificial vagina (AV) method, and separate AV was used for each buck every time. The semen collection frequency was once in a week. Immediately after initial evaluation, collected semen samples were transferred to the microbiology laboratory of the institute. Thereafter, the semen samples were subjected to bacteriological examination to assess the microbial load. The results of the current study indicate that the microbial load in the semen was significantly (p < 0.05) higher in the Jamunapari bucks and in aged bucks. Bacteriospermia in different seasons was not significantly varied; however, nonsignificant increase in microbial load during the rainy season was observed. Overall, the average bacterial load in the semen of Jamunapari, Barbari and Jakhrana bucks was found 540.50 ± 55.88 CFU/ml, 391.81 ± 46.33CFU/ml and 388.93 ± 44.71 CFU/ml respectively. No significant difference in bacterial counts in the subsequent ejaculates among bucks was observed. Moreover, correlation analysis revealed that the proportions of motility, viability, plasma membrane integrity and acrosomal integrity were negatively influenced by the increased bacterial contamination of buck semen.

Determination of oxidative stress parameters and DNA fragmentation on post-thawed buck semen in the presence of ram seminal plasma and fetal calf serum.

The aim of the study was to investigate the efficiency of ram seminal plasma and fetal calf serum on freezing of buck semen. Twenty ejaculates were collected using an electro-ejaculator and split into six groups. While FCS additive was not used in A1, A2 and A3 groups, 10% FCS was added to B1, B2 and B3 groups. These groups were then edited according to whether the buck or ram SP was involved. The design of the groups was done as follows: Group A1 (control 1), group A2 without buck SP, group A3 containing ram SP instead of buck SP. Groups B1 (control 2), B2 and B3 were the FCS added forms of these groups. Progressive sperm motility percentages in Group A1 and Group B2 were found to be higher when compared to the lowest Group B3. There were no significant differences between the groups in neither the levels of reactive oxygen species nor the enzyme and glutathione activities. In conclusion, the lack of statistical difference between the groups suggested that despite the supplements used but only when the buck spermatozoa structure was healthy, the cell could preserve acrosome, DNA and the integrity of membrane.

Thymus satureioides and Origanum majorana essential oils improve the quality of Beni Arouss buck semen during storage at 4°C.

This study aims to investigate the effects of essential oils (EOs), extracted from Thymus satureioides (TS) and Origanum majorana (OM), on Beni Arouss buck semen quality stored in skimmed milk at 4°C. EOs were extracted by hydro-distillation, and the chemical compounds were determined. Ejaculates were collected from six Beni Arouss bucks, once a week for 10 weeks, and they were pooled, divided into five equal aliquots and diluted to 400 × 106 sperm/ml with skimmed milk supplemented with 0.01% of OM EO, 0.01% of TS EO, 0.05% of OM EO and 0.05% of TS EO. Non-supplemented skimmed milk was considered as a control. Semen motility, kinematic parameters, viability, abnormality, membrane integrity and lipid peroxidation were evaluated at 0, 4, 8, 24, 28, 32 and 48 hr of liquid storage at 4°C. The main EO components were carvacrol (31.7%), thymol (28.0%) and borneol (14.4%) for TS, and terpinene-4-ol (31.2%), γ-terpinene (17.4%) and α-terpinene (12.7%) for OM. The results highlighted a dose-dependent effect of TS and OM EOs on all semen quality parameters. 0.01% of both EOs had a beneficial effect on the sperm preservation stored at 4°C compared with control (p < .05) excepted for the straight-line velocity. The 0.05% EO addition had harmful effects during storage particularly for TS EO. In conclusion, 0.01% of TS and OM EOs are recommended to improve the Beni Arouss buck semen preservation at 4°C.

DC Voltage Sensorless Predictive Control of a High-Efficiency PFC Single-Phase Rectifier Based on the Versatile Buck-Boost Converter.

Many electronic power distribution systems have strong needs for highly efficient AC-DC conversion that can be satisfied by using a buck-boost converter at the core of the power factor correction (PFC) stage. These converters can regulate the input voltage in a wide range with reduced efforts compared to other solutions. As a result, buck-boost converters could potentially improve the efficiency in applications requiring DC voltages lower than the peak grid voltage. This paper compares SEPIC, noninverting, and versatile buck-boost converters as PFC single-phase rectifiers. The converters are designed for an output voltage of 200 V and an rms input voltage of 220 V at 3.2 kW. The PFC uses an inner discrete-time predictive current control loop with an output voltage regulator based on a sensorless strategy. A PLECS thermal simulation is performed to obtain the power conversion efficiency results for the buck-boost converters considered. Thermal simulations show that the versatile buck-boost (VBB) converter, currently unexplored for this application, can provide higher power conversion efficiency than SEPIC and non-inverting buck-boost converters. Finally, a hardware-in-the-loop (HIL) real-time simulation for the VBB converter is performed using a PLECS RT Box 1 device. At the same time, the proposed controller is built and then flashed to a low-cost digital signal controller (DSC), which corresponds to the Texas Instruments LAUNCHXL-F28069M evaluation board. The HIL real-time results verify the correctness of the theoretical analysis and the effectiveness of the proposed architecture to operate with high power conversion efficiency and to regulate the DC output voltage without sensing it while the sinusoidal input current is perfectly in-phase with the grid voltage.

A Bidirectional Versatile Buck-Boost Converter Driver for Electric Vehicle Applications.

This work presents a novel dc-dc bidirectional buck-boost converter between a battery pack and the inverter to regulate the dc-bus in an electric vehicle (EV) powertrain. The converter is based on the versatile buck-boost converter, which has shown an excellent performance in different fuel cell systems operating in low-voltage and hard-switching applications. Therefore, extending this converter to higher voltage applications such as the EV is a challenging task reported in this work. A high-efficiency step-up/step-down versatile converter can improve the EV powertrain efficiency for an extended range of electric motor (EM) speeds, comprising urban and highway driving cycles while allowing the operation under motoring and regeneration (regenerative brake) conditions. DC-bus voltage regulation is implemented using a digital two-loop control strategy. The inner feedback loop is based on the discrete-time sliding-mode current control (DSMCC) strategy, and for the outer feedback loop, a proportional-integral (PI) control is employed. Both digital control loops and the necessary transition mode strategy are implemented using a digital signal controller TMS320F28377S. The theoretical analysis has been validated on a 400 V 1.6 kW prototype and tested through simulation and an EV powertrain system testing.