Search Results (1,444)

This research explores a phase-shift-based discontinuous PWM method used for 24 V battery-powered onboard micro inverters, which are critical for thermally limited applications like micromachines, where efficient heat dissipation and compact size are paramount. Discontinuous pulse width modulation (DPWM) reduces switching losses by clamping the phase voltage to the DC bus in order to improve inverter efficiency. Due to the change in power factor at different operating points from motors or the inductor load, the use of only one DPWM method cannot achieve the optimal efficiency of a three-phase voltage source inverter (3ph-VSI). This paper proposes a generalized DPWM method with a continuously adjustable phase shift angle, which extends the six traditional DPWM methods to any type. According to different power factors, the proposed DPWM method is divided into five power factor angle intervals, namely [−90°, −60°], [−60°, −30°], [−30°, 30°], [30°, 60°], and [60°, 90°], and automatically adjusts the phase shift angle to the optimal-efficiency DPWM mode. The power factor is calculated by means of the Synchronous Reference Frame Phase-Locked Loop (SRF-PLL) method. The switching losses and harmonic characteristics of the proposed DPWM are analyzed, and finally, a 24 V onboard 3ph-VSI experimental platform is built. The experimental results show that the efficiency of DPWM methods can be improved by 3–6% and the switching loss can be reduced by 40–50% under different power factors. At the same time, the dynamic performance of the proposed algorithm with a transition state is verified. This method is particularly suitable for miniaturized inverters where efficiency and thermal management are critical. Full article

This work introduces a non-isolated high step-up dc-dc interleaved boost converter combining magnetic coupling and voltage multiplier cells (VMCs). The proposed topology features a transformer with two primary windings of equal turns, interconnected to each other, enabling improved current sharing, and multiple secondary windings that contribute to extending the voltage gain. A three-winding coupled inductor is integrated into the design, while VMCs not only boost the output voltage but also significantly reduce the voltage stresses on the switches, eliminating the need for extreme duty ratios. The converter exhibits inherent modularity, allowing for voltage gain adjustments either through the turns ratio of the coupled inductor or by incorporating additional VMCs. An in-depth analysis of the topology is derived, and an experimental prototype rated at 48 V/400 V, 25 kHz, and 1 kW is implemented to verify and validate the theoretical claims, achieving an efficiency of 95.12% at full-load conditions. Full article

Current ringing in dual-active bridge (DAB) converters significantly degrades efficiency and reliability, particularly due to resonant interactions in the magnetic tank impedance network. We propose a novel impedance resonant channel shaping technique to suppress the ringing by systematically modifying the converter’s equivalent impedance model. The method begins with establishing a high-fidelity network representation of the magnetic tank, incorporating transformer parasitics, external inductors, and distributed capacitances, where secondary-side components are referred to the primary via the turns ratio squared. Critical damping is achieved through a rank-one modification of the coupling denominator, which is analytically normalized to a second-order form with explicit expressions for resonant frequency and damping ratio. The optimal series–RC damping network parameters are derived as functions of leakage inductance and winding capacitance, enabling precise control over the effective damping factor while accounting for core loss effects. Furthermore, the integrated network with the damping network dynamically shapes the impedance response, thereby attenuating ringing currents without compromising converter dynamics. Experimental validation confirms that the proposed approach reduces peak ringing amplitude by over 60% compared to the conventional snubber-based methods, while maintaining full soft-switching capability. Full article

As renewable energy sources become more prevalent, maintaining the sustainable and reliable operation of power systems has become as a major challenge. Modern grid-connected converter systems are particularly prone to losing synchronization when encountering large disturbances, which is a huge threat to the stability of the power grid, which is mainly based on renewable energy. This paper studies the impact of filter inductors on the synchronous stability of grid-connected converter systems, hoping to help us better connect renewable energy to the power grid. First, the existing synchronization stability model of grid-following (GFL) converters is extended by incorporating filter inductance modeling. Based on this model, a mathematical relationship between the phase-locked loop’s (PLL) frequency deviation and the filter inductance at the moment of fault is established, and a predictive method for GFL frequency deviation considering filter inductance is proposed. Furthermore, the impact of filter inductance on synchronization stability is systematically investigated through two key indicators: power angle overshoot and critical fault voltage, revealing the variation trends of transient stability under different operating conditions. Finally, the analytical results are validated through Matlab/Simulink simulations, providing theoretical guidance for the design of sustainable and robust renewable energy grid integration strategies. Full article

This study presents the design and experimental evaluation of a 10 MHz voltage regulator module (VRM) that incorporates a solenoid inductor embedded within a printed circuit board (PCB). To verify the performance of the inductor, a test PCB was fabricated and characterized using a vector network analyzer (VNA), with measurement data processed through 2x-thru de-embedding technique. A 10 MHz VRM was then implemented to assess the impact of the embedded inductor on system efficiency. Comparative measurements were conducted between two VRMs—one employing a surface-mounted (SMT) inductor and the other a PCB-embedded inductor. The SMT-based system achieved a peak efficiency of 65.24% at a load current of 800 mA, whereas the PCB-embedded inductor version reached 70.43% at 900 mA, reflecting an improvement of 5.19%. The VRM with an embedded inductor experienced less efficiency degradation under heavy load conditions, demonstrating superior energy delivery stability. These findings confirm the practical benefits of integrating solenoid inductors within a PCB for high-frequency, high-efficiency power conversion. Full article

Constant on-time (COT) buck converters offer fast transient responses and a simple architecture but face challenges like switching frequency variation, instability with low-equivalent series resistance (ESR) capacitors, and DC output voltage offset. This paper reviews advanced COT control techniques developed to overcome these limitations. We examine methods for frequency stabilization (e.g., adaptive on-time, phase-locked loop), stability with low-ESR capacitors (e.g., passive and active ripple injection, virtual inductor current), and improved DC regulation (e.g., offset cancellation). This review also covers techniques for optimizing transient response and multiphase architectures for high-current applications. Full article

Lung cancer remains a leading cause of mortality worldwide, driven by increased tobacco use, industrialization, and air pollution. Despite advancements in diagnostics and treatments, effective therapies are still lacking. Reactive oxygen species (ROS) play a dual role in cancer development, regulating key signaling pathways and activating cell death pathways, making them a promising target for new drugs. Research shows that wild-type NRF2/KEAP1 lung tumors, which account for about 60% of lung malignancies, are sensitive to ROS induction, and mutated EGFR1 lung tumors exhibit high ROS levels. Proteolysis-targeting chimeras (PROTACs) have emerged as a promising alternative to small molecule inhibitors (SMIs) for cancer treatment, addressing limitations like undruggability and drug resistance. However, these face challenges such as limited cell penetration and potential toxic side effects. Nanotechnology has introduced “nano-PROTACs,” enhancing tissue accumulation, membrane permeability, and controlled release. In this review, the keystones of ROS in lung cancer will be summarized. Also, a potential therapy for tumors with wild-type NRF2 involving the delivery of ROS inductor nano-PROTAC will be designed. This potential therapy could suppose a potential therapeutic strategy for lung cancer patients with these genetic characteristics. Full article

Implantable medical devices present several technological challenges, one of the most critical being how to provide power supply and communication capabilities to a device hermetically sealed within the body. Using a battery as a power source represents a potential harm for the individual’s health because of possible toxic chemical release or overheating, and it requires periodic surgery for replacement. This paper proposes a batteryless implantable device powered by an inductive link and equipped with bidirectional wireless communication channels. The device, designed in a 180 nm CMOS process, is based on two different pairs of mutually coupled inductors that provide, respectively, power and a low-bitrate bidirectional communication link and a separate, high-bitrate, one-directional upstream connection. The main link is based on a 13.56 MHz carrier and allows power transmission and a half-duplex two-way communication at 106 kbps (downlink) and 30 kbps (uplink). The secondary link is based on a 27 MHz carrier, which provides one-way communication at 2.25 Mbps only in uplink. The low-bitrate links are needed to send commands and monitor the implanted system, while the high-bitrate link is required to receive a continuous stream of information from the implanted sensing devices. The microchip acts as a hub for power and data wireless transmission capable of managing up to four different neural recording and stimulation front ends, making the device employable in a complex, distributed, bidirectional neural prosthetic system. Full article

The field emission current in a vacuum ($I_T=\alpha E^2/e^{\beta /E}$, where $\mathsf{\alpha }$ and $\beta$ are constants) depends on the electric field strength E. In other words, the differential resistance ${(d{I}_T/dV)}^{-1}$ in a vacuum does not follow Ohm’s law. Therefore, the relationship governing the capacitance and current between two electrodes in a vacuum is an intriguing research topic. In this study, we constructed an interface structure in which contact areas and non-contact vacuum areas coexisted by adhering two Si wafers and measuring the capacitance characteristics of this structure. A volatile capacitance appeared at the interface, with the contact areas contributing to positive capacitance and the vacuum areas contributing to negative capacitance. The tunneling current passing through the interface played an important role in the formation of the negative capacitance. Full article

This paper proposes a compact inductor design for LC-tank injection-locked frequency multipliers (ILFMs) fabricated using a 0.18 μm CMOS process. The ILFMs use an 8-shaped inductor with two lobes, suppressing the magnetic field generation. Its contents cover one ×2, one ×3, and one ×6 ILFM. The first ×2 ILFM circuit uses the orthogonal transformer consisting of an 8-shaped inductor and a non-twisted inductor. The total area is 1.137 × 0.797 mm². The input locking range is from the incident frequency of 1.6 to 3.0 GHz to provide a signal source from 3.2 GHz to 6 GHz. The second ×3 ILFM uses the orthogonal transformer and occupies an area of 1.29 × 0.76 mm². The output locking range is from 9 GHz to 19.8 GHz. This third ×6 ILFM uses a trifilar consisting of two 8-shaped inductors in perpendicular layout and a non-twisted inductor. The ×6 ILFMs show interference noise suppression via a core two-turn 8-shaped inductor and save die area. The die area is 0.843 × 0.981 mm². At V_DD = 1.3 V and an input power of 0 dBm, the output locking range is from 5.16 GHz to 5.388 GHz. In all the investigated ILFMs, no varactors are added to the LC resonator for a wide-band locking range design. The phase noises of the input signal and the output signal of the ILFM are in agreement with the theoretical value. Full article

Hybrid electric vehicles (HEVs) have gained significant attention for their superior energy efficiency and are becoming a predominant mode of urban transportation. The DC/DC converter plays a critical role in HEV energy management systems, especially in matching the voltage levels between the battery and DC bus. This paper proposes a novel high-gain DC/DC converter with a wide input voltage range based on coupled inductors. The innovation lies in the integration of a resonant cavity and the simultaneous realization of zero-voltage switching (ZVS) and zero-current switching (ZCS), effectively reducing both voltage/current stresses on the power switches and switching losses. Compared with conventional topologies, the proposed design achieves higher voltage gain without extreme duty cycles, improved conversion efficiency, and enhanced reliability. Detailed operating principles are analyzed, and design conditions for voltage stress reduction, gain extension, and soft switching are derived. The simulation model has been conducted in a PSIM environment, and a 300 W experimental prototype, implemented using a dsPIC33FJ64GS606 digital controller, has been established and demonstrates 93% peak efficiency at a 10 times voltage gain. The performance and practical feasibility of the proposed topology have been evaluated by both simulation and experiments. Full article

This paper focuses on the development of a high-conversion-efficiency DC/DC boost converter, which features high-voltage boost ratio conversion and employs soft-switching technology to reduce conversion losses. In the proposed design, the conventional energy storage inductor used in traditional boost converters is replaced with a coupled inductor, and an additional boost circuit is introduced. This configuration allows the converter to achieve a higher voltage conversion ratio under the same duty cycle, thereby enhancing the voltage gain of the converter. Additionally, a resonance branch is incorporated into the converter, and by applying a simple switching signal control, zero-voltage switching (ZVS) of the main switch is realized. To decrease the switching losses typically found in hard-switching high-voltage boost ratio converters, the proposed design enhances overall power conversion efficiency. The operation principle of this novel high-voltage boost ratio soft-switching converter is first examined, followed by the component design process. The converter’s effectiveness is then confirmed through simulation in PSIM. Finally, experimental testing using the TMS320F2809 digital signal processor demonstrates that the main switch achieves ZVS, validating the practical viability of the design. The converter operates under a full load of 340 W, achieving a conversion efficiency of 92.7%, demonstrating the excellent conversion performance of the developed converter. Full article

This paper investigates and characterizes a tunable inductor structure based on coupled-line configurations, referred to as a coupled-line tunable inductor (CLTI). By integrating switches along the coupled-line paths, the mutual inductance can be selectively enabled or disabled, providing a means for active inductance modulation. Spiral inductors with one-turn and two-turn cores were used in conjunction with inner-coupled-line placements to explore different coupling configurations. The test structures were implemented using printed circuit board (PCB) technology, and their performance was analyzed through electromagnetic simulations and vector network analyzer (VNA) measurements. The results confirm that switch-controlled coupled lines enable effective inductance tuning, with a measurable reduction in inductance when the coupled-line path is activated. In the switch-OFF state, only minimal performance degradation was observed due to parasitic effects. These findings provide useful insights into the practical behavior of coupled-line tunable inductors and suggest their applicability in RF circuits and adaptive analog systems, particularly where integration and compact tunability are desired. Full article

This paper presents the design and implementation of a bidirectional resonant converter with enhanced dynamic response to electric vehicles (EV). The proposed system comprises an assembly of four switches, a capacitor, and an inductor on both the primary and secondary sides of the transformer. The value of C-L-L-C was calculated using the first harmonic approximation method. Moreover, the small-signal analysis method was used to design the control system and analyze the dynamic performance of the system. Closed-loop control algorithms for voltage and current loops with synchronous rectifiers (SRs) were designed and implemented on a 32-bit microcontroller (STM32G474RET6). A 70 kHz, 400 W prototype is built with a peak conversion efficiency of 95.05% using SR in the forward mode. Without SR, the peak conversion efficiency was 93.57% in the forward mode and 93.04% in the reverse mode. In the forward mode, the proposed algorithm reduced the settling time to 15 ms, in contrast to the 40 ms associated with the conventional algorithm; in the reverse mode, the proposed algorithm reduced the settling time to 10 ms, in contrast to the 15 ms associated with the conventional algorithm. Full article

Background/Objectives: Ferroptosis is a regulated form of cell death that occurs in the state of oxidative–antioxidative imbalance of an organism. The main components of ferroptosis are lipid peroxidation and iron accumulation. Cells experiencing ferroptosis show swelling, shrunken mitochondria with an abnormal structure, atrophic cristae, dense mitochondrial membranes, and ruptured outer membrane. Ferroptotic cells demonstrate a normal nucleus size without nuclear concentration, and neither condensation nor chromatin margination. Ferroptosis is regulated by multiple protein, genetic, and metabolic factors. The aim of this article is to present ferroptosis as a model of cell death occurring in various conditions and diseases. Methods: A literature search of PubMed, Web of Science was performed. Search terms included “ferroptosis”, “lipid peroxidation”, “iron”, and “cell death”. Results: Ferroptosis affects the onset, course, progression, and treatment of diseases, including neurodegenerative diseases, cancer diseases, autoimmune diseases, and hemorrhages. By using appropriate ferroptosis moderators, it is possible to influence the course of the disease in patients. Conclusions: By understanding the ferroptosis phenomenon well, it is possible to regulate its occurrence by considering the action of oxidative and antioxidant factors. A comprehensive understanding of ferroptosis and the factors regulating this process should be the goal in therapy for many diseases. Full article