Bidirectional Switches Research Articles

A novel SVPWM for 3-phase to 5-phase conversion using matrix converter

<span>A novel matrix converter has been developed for 3-phase to 5-phase conversion using a novel space vector pulse width modulation. The matrix converter organized to generate 5-phase AC output voltage from 3-phase input voltage with help of SVPWM method; bidirectional power switches placed in matrix converter controlled by appropriate switching pulse. Space vector pulse width modulation (SVPWM) provides better utilization of applied input voltage, improved output voltage, reduced total harmonic distortion. The bidirectional switch used by the matrix converter decreases stress on the power switch and the influence of harmonic fluctuation in AC output voltage. When compared to traditional approaches, the suggested system offers improved output voltage and current control. Using MATLAB/Simulink and FPGA-cyclone controller, respectively, modelling and experimental results have been given to validate the proposed methodology.</span>

Magnetic Components Reduction in a Three-Phase PFC Converter by Using a Reconfigurable LCL Filter

Three-phase power factor correction (PFC) converters are the front-end stage of the power conversion that are required to be connected to the grid with a proper filter to meet international standards. A high-order <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCL</i> filter is a widely used solution to reduce the component size of the filter although it requires six inductors. In this article, a novel reconfigurable <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCL</i> filter that consists of only three inductors is proposed. The principle of the reconfigurable filter is to fully utilize the converter-side inductors by changing their position from the converter side to the grid side and vice versa. The filter is reconfigured by using three low-frequency (LF) bidirectional switches. The ultimate goal of the proposed topology is to reduce the magnetic components by half and achieve comparable grid current quality as the conventional topology. The proposed PFC topology is verified by a 1-kW experimental prototype. All the experimental results agree with the theoretical concepts and prove that the grid current quality of the proposed topology is comparable with the conventional topology.

EV Battery Chargers, Inverters, Bidirectional Switches, and Passive Components Take Center Stage at ECCE 2022

This year, the fourteenth annual IEEE Energy Conversion Congress and Exposition (ECCE) 2022 was a hybrid event with an in-person meeting in Detroit, MI, USA from 9–13 October. The virtual meet-the-authors sessions took place 17-19 October via Zoom. After two years of virtual meetings, it was encouraging to see researchers, engineers, and professionals from around the world coming together in Detroit to learn about the latest innovations in energy conversion, while networking with old and new friends from industry and academia. The ECCE 2022 general chair was Dr. Emmanuel Agamloh, an associate professor of electrical engineering at Baylor University, Waco, TX, USA.

Novel Multisource DC-DC Converter for All-Electric Hybrid Energy Systems

In this article, a novel nonisolated multiple input dc-dc converter (MIC) is proposed for all-electric hybrid energy storage systems. The proposed MIC is capable of bidirectional operation in noninverting buck–boost configuration and can accommodate the simultaneous energy transfer from multiple sources of different voltage levels to the dc bus. As compared to counterparts, the proposed MIC utilizes a smaller number of inductors and requires only one bidirectional switch to integrate any extra energy storage. Within the framework, a novel voltage transformation, operation modes, and control method are presented in detail. The performance and key features of operation with varying voltage levels and duty cycles of the proposed MIC are numerically verified through a high-fidelity hardware-in-the-loop platform and experimentally validated on an in-house test rig.

A quintuple phase shift modulation scheme in multilevel dual active bridge converter for battery energy storage system

SummaryGenerally, the dual active bridge (DAB) bidirectional DC‐DC converter suffers from harmonics in the high‐frequency link (HFL) conversion stage while operating under any modulation scheme. This paper proposes a quintuple phase shift (QPS) modulation scheme to suppress the harmonics under the whole operating range. A bidirectional auxiliary switch in the low voltage bridge produces a five‐level output, which alleviates harmonic components of HFL current. The total harmonic distortion (THD) analysis is done for various operating conditions and is compared with the conventional modulation scheme, such as single phase shift and dual phase shift. The THD can be reduced in the entire power transmission for the proposed modulation scheme by defining the suitable phase shift ratios. Also, the power flow analysis under QPS modulation is reported in this paper. To validate the proposed approach's theoretical performance, simulation results are obtained under different operating conditions and verified with experimental results. The QPS modulation is implemented using the Spartan 3AN FPGA processor.

High-speed photothermally triggered bidirectional current switching in VO2/AlN/Si-based heterostructure device

The bidirectional current switching (BCS) of a two-terminal device based on a vanadium dioxide (VO2) thin film can be realized by harnessing the photothermally induced phase transition of VO2, triggered by laser pulses. Although this photothermally controlled BCS can achieve a large on-state current and high on/off current ratio compared to those obtained by other implementation approaches, a low repetition rate (< 10 Hz) and slow response time (tens of milliseconds) still restrict its practical use. To tackle these issues, we analyzed the fundamental cause of the performance limit of the BCS through simulations using COMSOL Multiphysics and found that the thermal conductivity of the substrate and the critical temperature of the VO2 film were mainly responsible for the switching speed of the BCS. On the basis of this analysis, we fabricated a VO2-based heterostructure device on a silicon substrate with a buffer layer of aluminum nitride. We measured the transient responses of the device current switched by directly irradiating the device with near-infrared laser pulses under various conditions. The highest-ever repetition rate (100 Hz) could be attained in a 50 mA BCS with 5 ms laser pulses. The response time was also remarkably improved to < 1 ms.

A Solid-State Bipolar Pulse Power Generator for Dielectric Barrier Discharge Applications

This article provides a distinctive unipolar/bipolar high voltage pulse power generator (PPG) architecture that produces exponential waveform with a rise time in the range of nanosecond. The setup is fit for dielectric barrier discharge applications, in practice. In this work, a push-pull circuit with a three-winding transformer is utilized on the charging side, as well as a quasi-resonant between the transformer leakage inductance and the capacitor on the discharging side to boost the voltage gain. As a result of the two windings on the primary side, and the bidirectional switches on the high voltage side, the tool offers either unipolar or bipolar high voltage pulses from a relatively low dc source. In addition to accomplishing the high gain objective, the effort focuses on lowering the number of circuit elements in contrast to previously studied topologies. The generator functions in discontinuous conduction mode, which enhances system efficiency by allowing complete positive and/or negative waves to be generated while lessening conduction losses. The pulse generator operation intervals are described in depth. The simulation results will demonstrate how this topology outperforms the prior models. Moreover, a 1000-V experimental prototype is also implemented to validate the projected PPG-enhanced properties in real-time.

MiRNAs as Biomarkers in Diabetes: Moving towards Precision Medicine

Diabetes mellitus (DM) is a complex metabolic disease with many specifically related complications. Early diagnosis of this disease could prevent the progression to overt disease and its related complications. There are several limitations to using existing biomarkers, and between 24% and 62% of people with diabetes remain undiagnosed and untreated, suggesting a large gap in current diagnostic practices. Early detection of the percentage of insulin-producing cells preceding loss of function would allow for effective therapeutic interventions that could delay or slow down the onset of diabetes. MicroRNAs (miRNAs) could be used for early diagnosis, as well as for following the progression and the severity of the disease, due to the fact of their pancreatic specific expression and stability in various body fluids. Thus, many studies have focused on the identification and validation of such groups or "signatures of miRNAs" that may prove useful in diagnosing or treating patients. Here, we summarize the findings on miRNAs as biomarkers in diabetes and those associated with direct cellular reprogramming strategies, as well as the relevance of miRNAs that act as a bidirectional switch for cell therapy of damaged pancreatic tissue and the studies that have measured and tracked miRNAs as biomarkers in insulin resistance are addressed.

A novel structure for multi-level inverter with reduced components

ABSTRACT This paper introduces a new structure of a multi-level inverter (MLI) to generate high-level AC voltages using a low number of switches with a quasi-sine waveform. The small number of driver circuits utilised in bidirectional switches is a salient characteristic of this inverter. Also, the number of conducting switches at each voltage level is low in this structure. This results in lower conduction losses of the switches. The proposed topology can be used as the cascaded structure with different approaches to select the value of voltage sources. Power losses are discussed for the proposed structure. To compare the proposed multi-level inverter and demonstrate its superiority, a comparison has been made with some recently presented topologies. According to the comparison results, the advantage of the proposed structure is producing high voltage levels with a smaller number of switches and driver circuits. To prove the suitable performance of the proposed MLI, a 21-level symmetric and 37-level asymmetric inverter containing 14 switches are designed and simulated in the MATLAB/Simulink program. A laboratory prototype for each of these inverters is implemented. The experimental results finely verify the simulations. Besides, an accurate comparison with recently introduced multilevel inverters has been carried out to confirm the effectiveness and superiority of the proposed structure.

SWPU: A 126.04 TFLOPS/W Edge-Device Sparse DNN Training Processor With Dynamic Sub-Structured Weight Pruning

When deploying deep neural networks (DNNs), edge devices training is practical to improve model adaptivity for various user-specific scenarios while avoiding privacy disclosure. However, the training computation is intolerable for edge devices. It inspires sparse DNN training (SDT) into the limelight, which reduces training computation by dynamic weight pruning. Generally, SDT has two strategies based on the pruning granularity: the structured or the unstructured. Unfortunately, both of them suffer from limited training efficiency due to the gap between pruning granularity and hardware implementation. The former is hardware-friendly but has a low pruning ratio, indicating limited computation reduction. The latter has a high pruning ratio, but the unbalanced workload decreases utilization and irregular sparsity distribution causes considerable sparsity processing overhead. This paper proposes a software-hardware co- design to bridge the gap for improving the efficiency of SDT. On the algorithm side, a sub-structured pruning method, achieved with hybrid shape-wise and line-wise pruning, generates a high sparsity ratio and keeps the hardware-friendly property. On the hardware side, a sub-structured weight processing unit (SWPU) effectively handles the hybrid sparsity with three techniques. First, SWPU dynamically reorders the computation sequence with hamming-distance-based clustering, balancing the irregular workload. Second, SWPU performs runtime scheduling by exploiting the feature of sub-structured sparse convolution through a detect-before-load controller, which skips redundant memory access and sparsity processing. Third, SWPU performs sparse convolution by compressing operands with spatial disconnect log-based routing and recovers their location with bi-directional switching, avoiding the power-consumed routing logic. Synthesized with 28nm CMOS technology, SWPU can enable 0.56V-to-1.0V supply voltage with a maximum frequency of 675 MHz. It achieves a 50.1% higher pruning ratio than structured pruning and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.53\times $ </tex-math></inline-formula> higher energy efficiency than unstructured pruning. The peak energy efficiency of SWPU is 126.04TFLOPS/W, outperforming the state-of-the-art training processor by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.67\times $ </tex-math></inline-formula> . When training a ResNet-18 model, SWPU reduces <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.72\times $ </tex-math></inline-formula> energy and offers <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4.69\times $ </tex-math></inline-formula> speedup than previous sparse training processors.

Model Control and Digital Implementation of the Three Phase Interleaved Parallel Bidirectional Buck–Boost Converter for New Energy Electric Vehicles

In recent years, the imminent environmental problems and increasing attention to the global energy crisis have prompted the need for new opportunities and technologies to meet higher demands for clean and sustainable energy systems. As a result, new energy electric vehicles have been developed to replace fossil fuel cars. Therefore, this paper presents a three-phase interleaved parallel bidirectional buck–boost converter, which is the core factor of electrical energy flow regulation and management between the battery pack and motor drive inverter within the high voltage direct current bus and converts the voltage from two directions. Corresponding circuit topology, mathematical model, and control strategy are analyzed in three operation states: charge buck, discharge boost, and electric energy interaction modes. The digital implementation with double closed loop, power feedforward compensation, and bidirectional switching logic are realized by XDPTM Digital Power Controllers XDPP1100-Q040 of Infineon Technologies AG. Finally, the experimental results of the proposed converter clearly show that it achieves the objectives, namely, the feasibility and practicality of the system.

Triple Fano resonances metasurface and its extension for multi-channel ultra-narrow band absorber

Metasurface excited multiple Fano resonances has become a hot spot and has been widely investigated and applied in the field of optics. A metasurface designed in this paper is composed of a silicon cuboid etched with an akin rhombus hole and deposited periodically on the silica substrate. By introducing symmetry breaking, the symmetry-protected BIC is transformed into the quasi-BIC, and triple sharp Fano resonances, corresponding to 1357 nm, 1421.7 nm, and 1588.8 nm respectively, with spectral contrasts of nearly 100 % are excited. Their maximum Q-factor can reach ∼ 3 × 104. Results of multipole decomposition show that the triple Fano resonances are dominated by magnetic dipole (MD) or electric quadrupole (EQ). Additionally, by modifying the polarization angle of the incident light, the metasurface performs excellently as a bidirectional optical switch. By adding the aluminum layer under the original structure, an ultra-narrowband absorber is created with a maximum absorption rate of ∼ 100 %. The sensing performance of the absorber is studied, yielding the maximum sensitivity of 255 nm/RIU and the maximum figure of merit (FOM) of 477 RIU−1. The proposed metasurface and its extension structure are potential to be applied in as high-performance biosensors, optical switch, and coherent thermal radiation.

Multiphase Electric Motor Drive with Improved and Reliable Performance: Combined Star-Pentagon Synchronous Reluctance Motor Fed from Matrix Converter

This paper investigated and demonstrated an electric drive topology with inherently high reliability and improved performance. The topology combines a five-phase combined star-pentagon synchronous reluctance machine (SynRM) and a power electronic “matrix” converter without vulnerable electrolytic capacitors, which are often a point of failure of conventional drives. This drive is suitable for harsh environments, with possibly high ambient temperatures and limited maintenance. In this paper, an accurate model of the five-phase combined star-pentagon SynRM was introduced considering the effect of magnetic saturation and cross saturation on dq-flux-linkages. The five-phase combined star-pentagon SynRM will be connected to a three-to-five-phase indirect matrix converter (IMC) and the indirect field-oriented control based on a space vector pulse width modulation was applied. The introduced SVM commutates the bidirectional switches of the IMC at zero current which enhance and minimize the switching losses. The performance of the proposed drive system was studied and experimentally validated at different loading conditions. Finally, the reliability, cost, and performance of the proposed drive system were compared with the conventional drive system (three-phase star-connected SynRM fed from rectifier-inverter).

A single‐phase p‐type ac–ac converter with reduced components count and high boost factor

AbstractThis paper proposes a new single‐phase direct step‐up ac–ac converter by modifying the p‐type impedance source. It provides a high boost factor as well as high efficiency, while only six parts are required to design it, involving just two bidirectional power switches. A safe commutation method has been applied to power switches to make the converter snubber‐free and high efficient. Input and output harmonic filters are no longer required since input and output currents variate continuously with small ripple and low total harmonic distortion (THD). The proposed topology only modulates the output voltage amplitude, not the phase and frequency, so the output frequency is identical to the input frequency and constant. Thus, it can be utilized in step‐up conversion applications, like inductive power transmission from low ac voltage sources. Input and output have the same ground, which is a good protective feature. In this paper, the operating principle of the converter is demonstrated. Experimental results have been represented to evaluate the performance of the converter. For this purpose, an experimental prototype has been fabricated. Results are investigated and compared with other previous step‐up ac–ac converters. Results confirm the theory, operating principle, and performance of the converter.

Multistate Circularly Polarized Luminescence Switching through Stimuli-Induced Co-Conformation Regulations of Pyrene-Functionalized Topologically Chiral [2]Catenane.

Aiming at the construction of novel circularly polarized luminescence (CPL) switches with multiple switchable emission states and high dissymmetry factors (glum ), topologically chiral [2]catenanes were employed as the key platform to construct a novel multistate CPL switching system. Taking advantage of the precise co-conformation regulations of the resultant pyrene-functionalized [2]catenanes under different external stimuli, reversible transformations between three emission states with different CPL performances, i.e. the initial "closed" form with a |glum | value of 0.012, the "open" form with an almost complete turn-off of CPL emission, and the "protonated" form with a boosted |glum | value of 0.022, were successfully realized. This study demonstrates the successful construction of not only the first topological chirality-based CPL switch, but also a novel bidirectional CPL switch, thus providing a promising platform for the construction of novel chiral materials.

Multistate Circularly Polarized Luminescence Switching through Stimuli‐Induced Co‐Conformation Regulations of Pyrene‐Functionalized Topologically Chiral [2]Catenane

AbstractAiming at the construction of novel circularly polarized luminescence (CPL) switches with multiple switchable emission states and high dissymmetry factors (glum), topologically chiral [2]catenanes were employed as the key platform to construct a novel multistate CPL switching system. Taking advantage of the precise co‐conformation regulations of the resultant pyrene‐functionalized [2]catenanes under different external stimuli, reversible transformations between three emission states with different CPL performances, i.e. the initial “closed” form with a |glum| value of 0.012, the “open” form with an almost complete turn‐off of CPL emission, and the “protonated” form with a boosted |glum| value of 0.022, were successfully realized. This study demonstrates the successful construction of not only the first topological chirality‐based CPL switch, but also a novel bidirectional CPL switch, thus providing a promising platform for the construction of novel chiral materials.

Conception and Experimental Validation of a Standalone Photovoltaic System Using the SUPC5 Multilevel Inverter

In this work, an advanced pulse width modulation (PWM) technique was developed to provide the auto-balancing of the capacitors voltages of the five-level split-packed U-Cells (SPUC5) single-phase inverter, and then, the latter was applied to a photovoltaic (PV) system in standalone mode to evaluate its performance in this kind of application. The SPUC5 inverter makes use of only five switches (four active bidirectional switches and one four quadrant switch), one DC source and two capacitors to generate five levels of output voltage and a current with a quasi-sinusoidal waveform which reduces the total harmonic distortion (THD) without the need to add filters or sensors, and also reduces its cost compared to the other multilevel inverters. In the proposed system; the incremental conductance (INC) algorithm is combined with a DC/DC boost converter to reach the maximum power (MP) of the PV array by tracking the MP point (MPP). The offered concept has been constructed and then simulated in the MATLAB/Simulink environment to evaluate its efficiency. According to the results, the self-balancing of the capacitors voltages has been achieved. A comparative study was performed with the traditional PWM technique. The proposed PV system has been validated by experimental results.

Self-Reverse-Blocking Control of Dual-Gate Monolithic Bidirectional GaN Switch With Quasi-Ohmic on-State Characteristic

Converter topologies such as current-source rectifiers and inverters require switching devices with bipolar voltage blocking and unidirectional current conduction capability. Recently available dual-gate GaN monolithic bidirectional switches (MBDSs) can mimic such self-reverse-blocking (SRB) behavior if the MBDS’ two gates are controlled accordingly, but thus need twice the number of gate signals and gate drive circuits. Therefore, we propose cascode-diode control (i.e., without additional sensing or gate drive circuitry) of one MBDS gate using a cascode configuration with a low-voltage silicon Schottky diode. The resulting SRB-MBDS features quasi-ohmic conduction characteristic and single-gate control. We provide static and dynamic measurements of a discrete proof-of-concept realization (600-V, 190-m <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mathrm{\Omega }$</tex-math></inline-formula> GaN MBDS; 40-V, 10-A silicon Schottky diode) that demonstrate the proposed SRB-MBDS’ feasibility.

Fault-Tolerant Reconfiguration Topology and Control Strategy for Symmetric Open-Winding Multiphase Machines

This paper introduces a fault-tolerant reconfiguration topology and control strategy for symmetric open-winding multiphase machines. Bidirectional switching devices are proposed to connect the inverter bridge legs on different ends when the open-circuit fault occurs, and the reconfigured circuit can regenerate the missing voltage phasors due to the faults. Furthermore, to prevent overcurrent problems on the reconfigured bridge legs and maximize the torque output capability of the reconstructed system, winding currents are optimized with zero-sequence component injection during fault-tolerant operation. The experiments implemented on the five-phase system validate that the proposed fault-tolerant scheme is effective and has higher torque output capability compared with the traditional fault-tolerant solutions.

A nearest level control technique for an asymmetric source configuration of multi-level inverter topology

In this paper, an asymmetric source configuration of Multilevel Inverter (MLI) topology has been proposed. It consists of eight unidirectional switches, two bidirectional switches and four isolated DC sources. By considering 1:5 and 1:4 source configurations, the inverter produces 25-level and 21-level outputs respectively with the same switching action. For producing negative voltage levels, there is no requirement of separate backend H-bridge and inherently produces both positive and negative voltage levels. The main advantage of this topology is that in every state, only four switches are in ON mode and else are in OFF state. It also gives less per unit Total Standing Voltage (TSV) and thereby cost requirement of semiconductor devices can become decreases. For generating gate pulses, the simple Nearest Level Control (NLC) has been used by considering the round function. This technique is basically a fundamental switching frequency technique thereby switching losses are greatly reduces as compared with high switching frequency Pulse Width Modulation (PWM) techniques and it is particularly suitable for large number of levels. With this control technique, there is no inrush current has been developed at the input of DC sources. Finally, with step change in Modulation Index (MI) values the proposed topology with two different source configurations have been validated through MATLAB/Simulink platform.