Regenerative Braking for Electric Vehicles (EVs) Using Permanent Magnet Synchronous Machin (PMSM) with Cascaded Half-bridge (CHB) as Bidirectional Traction Converter

Permanent-magnet synchronous motor (PMSM) is broadly adopted in electric vehicles (EVs) due to its superior advantages like providing high efficiency and excellent torque-speed characteristics. Regenerative braking (RB), which is the recovery of the kinetic energy during deceleration, is an efficient method to restore the kinetic energy into the battery to extend the battery and hence the driving range. In this paper, an RB strategy is proposed where the drive shaft’s torque is estimated using a detailed analysis of all the forces acting on an EV along an inclined road. To achieve the maximum electromagnetic torque, the d-axis component of the stator current is set to zero. Then, the three-phase voltages are generated and applied to the stator windings based on the EV demand. To improve the harmonic performance, the multilevel cascaded half-bridge (CHB) converter is used as the bidirectional traction converter. The proposed RB strategy is verified in the operating modes of acceleration, deceleration (braking), and constant speed using MATLAB/Simulink computer simulations and tested with a small-scale experimental rig controlled by TMSF28335 Digital Signal Processor

Non-Integrated and Integrated On-Board Battery Chargers (iOBCs) for Electric Vehicles (EVs) : A Critical Review

The rising Greenhouse Gas (GHG) emissions stemming from the extensive use of automobiles across the globe represent a critical environmental challenge, contributing significantly to phenomena such as global warming and the deterioration of air quality. To address these challenges, there is a critical need for research and development in electric vehicles (EVs) and their associated charging infrastructure, including off-board and on-board chargers (OBCs). This paper aims to bridge the gaps in existing review literature by offering a comprehensive review of both integrated and non-integrated OBCs for EVs, based on the authors’ knowledge at the time of writing. The paper begins by outlining trends in the EV market, including voltage levels, power ratings, and relevant standards. It then provides a detailed analysis of two-level and multi-level power converter topologies, covering AC-DC power factor correction (PFC) and isolated DC-DC topologies. Subsequently, it discusses single-stage and two-stage non-integrated OBC solutions. Additionally, various categories of integrated OBCs (iOBCs) are explored, accompanied by relevant examples. The paper also includes comparison tables containing technical specifications and key characteristics for reference and analysis

Maximum Wireless Power Transmission Using Real-Time Single Iteration Adaptive Impedance Matching

Wireless power transfer (WPT) systems’ efficiency is significantly impacted by non-monotonic variations in the coupling coefficient. For very short distances or strong-coupling cases, the WPT efficiency is minimal at the natural resonant frequency, with two peaks around this frequency, known as the frequency splitting phenomenon. On the other hand, WPT capability decreases for long distances or weak coupling cases. Therefore, adaptive matching is required for WPT systems with varying distances, like wireless charging systems for electric vehicles (EVs). This paper first presents a detailed analysis of the frequency splitting phenomenon by studying the root locations of the WPT system’s transfer function. Then, a real-time fixed-frequency adaptive impedance matching (IM) method is proposed, in which the amplitude and phase of the input impedance is estimated using the average active power, the average reactive power, and the amplitude of input voltage. Unlike traditional search-and-find techniques, the proposed method calculates the optimal IM network parameters only in a single iteration, which improves the convergent speed. A scaled-down 20-Watt prototype controlled by the TMSF2812 is fabricated and used to validate the effectiveness of the proposed method over a wide range of coil-to-coil distances

Effects of Streptozotocin Induced Diabetes on One-Carbon Cycle and Sperm Function

Objective: Diabetic men suffer an increased risk of infertility associated with signs of oxidative damage and decreasedmethylation in sperm pointing to a deficit of the one-carbon cycle (1CC). We aimed to investigate this deficit using micemodels (type 1 and 2) of streptozotocin-induced diabetes.Materials and Methods: In this experimental study, 50 male mice, aged eight weeks, were divided randomly intofour groups: sham, control, type 1 diabetes mellitus (DM1), and DM2. The DM1 group was fed a normal diet (ND) foreight weeks, followed by five consecutive days of intraperitoneal administration of Streptozotocin (STZ, 50 mg/kg bodyweight). The DM2 group was fed a high-fat diet (HFD) for eight weeks, followed by a single intraperitoneal injectionof STZ (100 mg/kg). After twelve weeks, all the mice were euthanized, and study parameters assessed. In the shamgroup, citrate buffer as an STZ solvent was injected.Results: Both types of diabetic animals had serious impairment of spermatogenesis backed by increased DNA damage(P=0.000) and decreased chromatin methylation (percent: P=0.019; intensity: P=0.001) and maturation (P=0.000).The 1CC was deeply disturbed with increased homocysteine (P=0.000) and decreased availability of carbon units[methionine (P=0.000), serine (P=0.088), folate (P=0.016), B12 (P=0.025)] to feed methylations.Conclusion: We have observed a distinct impairment of 1CC within the testes of individuals with diabetes. Wespeculate that this impairment may be linked to inadequate intracellular glucose and diminished carbon unit supplyassociated with diabetes. As a result, interventions focusing on enhancing glucose uptake into sperm cells and providingsupplementary methyl donors have the potential to improve fertility issues in diabetic patients. However, additionalclinical testing is required to validate these hypotheses

Transcriptional drug repositioning and cheminformatics approach for differentiation therapy of leukaemia cells.

Differentiation therapy is attracting increasing interest in cancer as it can be more specific than conventional chemotherapy approaches, and it has offered new treatment options for some cancer types, such as treating acute promyelocytic leukaemia (APL) by retinoic acid. However, there is a pressing need to identify additional molecules which act in this way, both in leukaemia and other cancer types. In this work, we hence developed a novel transcriptional drug repositioning approach, based on both bioinformatics and cheminformatics components, that enables selecting such compounds in a more informed manner. We have validated the approach for leukaemia cells, and retrospectively retinoic acid was successfully identified using our method. Prospectively, the anti-parasitic compound fenbendazole was tested in leukaemia cells, and we were able to show that it can induce the differentiation of leukaemia cells to granulocytes in low concentrations of 0.1 μM and within as short a time period as 3 days. This work hence provides a systematic and validated approach for identifying small molecules for differentiation therapy in cancer

Highly degradable porous melt-derived bioactive glass foam scaffolds for bone regeneration

A challenge in using bioactive melt-derived glass in bone regeneration is to produce scaffolds with interconnected pores while maintaining the amorphous nature of the glass and its associated bioactivity. Here we introduce a method for creating porous melt-derived bioactive glass foam scaffolds with low silica content and report in vitro and preliminary in vivo data. The gel-cast foaming process was adapted, employing temperature controlled gelation of gelatin, rather than the in situ acrylic polymerisation used previously. To form a 3D construct from melt derived glasses, particles must be fused via thermal processing, termed sintering. The original Bioglass® 45S5 composition crystallises upon sintering, altering its bioactivity, due to the temperature difference between the glass transition temperature and the crystallisation onset being small. Here, we optimised and compared scaffolds from three glass compositions, ICIE16, PSrBG and 13–93, which were selected due to their widened sintering windows. Amorphous scaffolds with modal pore interconnect diameters between 100–150 µm and porosities of 75% had compressive strengths of 3.4 ± 0.3 MPa, 8.4 ± 0.8 MPa and 15.3 ± 1.8 MPa, for ICIE16, PSrBG and 13–93 respectively. These porosities and compressive strength values are within the range of cancellous bone, and greater than previously reported foamed scaffolds. Dental pulp stem cells attached to the scaffold surfaces during in vitro culture and were viable. In vivo, the scaffolds were found to regenerate bone in a rabbit model according to X-ray micro tomography imaging

PV/Battery Grid Integration Using a Modular Multilevel Isolated SEPIC-Based Converter

Photovoltaic (PV) plants can be built rapidly when compared with other conventional electrical plants; hence, they are a competent candidate for supplying the electricity grid. The output power of the PV modules can be used in plug-in electric vehicles (PEVs) DC charging stations to reduce the burden on the electricity grid, particularly during peak load hours. To integrate PV modules and electric vehicles (EVs) with the electricity grid, the modular multilevel converters (MMCs) topologies producing staircase voltage waveforms are preferred as they are able to deliver less total harmonic distortion (THD) and higher efficiency in addition to lower voltage stress on semiconductor switches. In conventional centralized MMC topologies, a direct connection to a high-DC-link input voltage is required which is not appropriate for PV plants. A new MMC topology for PV/EV/grid integration is proposed in this paper, where the individual PV arrays are directly connected to each phase of the AC grid to harvest the maximum available power point. A current-source converter (CSC) based on a single-stage isolated SEPIC converter is adopted as the submodule (SM) for the proposed MMC topology given its outstanding features, such as low input ripple current, high efficiency, high power factor, and flexible output voltage higher or lower than the input voltage. The single-stage SMs can operate in both DC/DC and DC/AC operating modes. Proper controllers for each mode of operation are designed and applied to supply constant current from either the PV modules or the battery cells by eliminating the second-order harmonic component. The performance of the proposed converter is verified by simulations and a downscaled prototype controlled by TMSF28335 DSP