In this paper, a cell balancing topology for a series-connected Lithium-Ion battery string (SCBS) in electric vehicles is proposed and experimentally verified. In particular, this balancing topology based on the modular balancer consists of an intra-module balancer based on a multi-winding transformer circuit and an outer-module balancer based on a switched capacitor converter, both offering the potential advantages and over conventional balancing methods, including short equalization time, simple control scheme, elimination of voltage sensors. In addition, a number of cells in the SCBS can be easily extended in this circuit. Furthermore, a system structure and an operating principle of the proposed topology are analyzed and experimentally verified for three different cases. The voltages of all cells in the SCBS reached the balanced state regardless of the various arrangement of the initial voltage, where the energy efficiency of the circuit reached 83.31%. Our experimental realization of the proposed balancing topology shows that such a technique could be employed in electric vehicles.

The ITER fusion research facility will employ twenty-four, MW-class gyrotrons for electron cyclotron heating of the fusion plasma. Each of these gyrotron will require an RF load for commissioning and periodic maintenance and testing. These loads must dissipate approximately 1 MW of long pulse / continuous RF power with less than 0.5% of the power reflected back into the transmission line. This program is using additive manufacturing to reduce the cost and improve the performance.

In this present paper, the LaVO4:Eu3+,Cr3+ (LV:Eu,Cr) red-orange phosphorsare introduced in WLED fabrication. The LV:Eu,Cr phosphor is synthesized with high-temperature solid-phase reaction. The luminescence properties of the phosphor are monitored with ultraviolet-visible and near-infrared (UV-vis-NIR) measurements. The heat generating in the phosphor sample is also investigated with different power densities of the 980 nm laser. The phosphor exhibits absorption bands at 254 nm and 316 nm, suitable for UV light-emitting diodes (UV LED) applications. The Cr3+ concentrations have noticeable effects on the luminescence of the phosphor. The increasing Cr3+ dosage initiates reduction in Eu3+ emission intensity and luminescence lifetime average. The heat-activated amount in the phosphor is also significant with the higher concentration of Cr3+ ions. When using the LV:Eu,Cr phosphor in white light-emitting model (WLED), the dominant red-orange emission centered at 595 nm is observed, in addition to the blue peak at 453 nm. The luminosity, color rendition, and color uniformity of the WLED light are also discussed. The findings indicate that the phosphor can be combined with other high-efficiency blue and green phosphors to obtain the improved color rendition and luminous performances and used in heat-creating optical applications.

This work presents a novel blue phosphor, Na2MgPO4F: Eu2+ (NMPF: Eu) for violet 405-nm light-emitting diode (LED) devices. The compound is synthesized via a simple one-step sintering process using readily available precursors. Notably, NMPF: Eu exhibits highly efficient and thermally stable blue emission when excited by violet light. The NMPF: Eu is applied to produce a white LED device driven by a 405 nm LED chip and Y3Al5O12: Ce3+ (YAG: Ce) yellow phosphor. The impacts of NMPF: Eu phosphors are investigated by varying their particle size while maintaining consistent doping concentrations. Impressively, the LED prototype displays a substantial reduction in blue light emission while generating white light with enhanced color rendering and luminous properties. These results highlight the suitability and potential of NMPF: Eu as a promising phosphor for widening violet LED applications, especially in generating white light perceptible to the human eyes.

Trong nghiên cứu này, vật liệu graphene (GR) được chế tạo từ thanh graphite sử dụng phương pháp bóc tách điện hóa với các loại điện áp khác nhau đặt vào hai đầu điện cực, bao gồm các điện áp không đổi 6 V, 8 V, 10 V và kỹ thuật thế bậc thang hai giai đoạn từ 0-2 V và 2-10 V trong môi trường ammonium sulfate (NH4)2SO4. Kết quả chế tạo đã được khảo sát bằng các phép đo thế Zeta, kính hiển vi điện tử quét phát xạ trường (FE-SEM), kính hiển vi lực nguyên tử (AFM) và quang phổ Raman để xác định đặc trưng và cấu trúc của vật liệu GR. Thế Zeta thu được của GR-010 có giá trị -47,7 mV cho thấy hiệu quả phân tán trong môi trường nước, hiệu quả này do khả năng liên kết tốt với các ion âm ở bề mặt và biên của GR. Kết quả đo SEM và AFM cũng chỉ ra bề dày trung bình của các tấm GR-010 thu được vào cỡ 1,8 nm tương ứng 3-5 lớp GR, nhỏ hơn so với các mẫu GR-6, GR-8 và GR-10 tương ứng với các điện áp 6 V, 8 V và 10 V. Kết quả phân tích Raman cũng cho thấy mức độ sai hỏng của GR-010 thấp hơn so với GR-6, GR-8 và GR-10 với tỷ số ID/IG = 0,36.

In many industrial applications, induction motors are often required to operate in the magnetic saturation region to meet demands for high load or torque. However, in this region, the characteristics of the motor become nonlinear, rendering traditional control methods based on linear assumptions ineffective. This research focuses on the modeling and control of induction motors under magnetic saturation conditions. The motor model is developed in the d-q reference frame, incorporating nonlinear characteristics of both the stator and rotor. The study also introduces a signal modulation technique for a three-level inverter to enhance voltage conversion efficiency. To address the challenges posed by saturation effects and random disturbances, an enhanced direct torque control (EDTC) algorithm is proposed. This algorithm aims to mitigate the influence of magnetic saturation while maintaining robust performance. The proposed solution is validated through experimental testing conducted on the OPAL-RT system. Results confirm that the EDTC approach ensures the stator flux and speed closely track their reference values, even in the presence of noise. The control system delivers high performance, maintaining total harmonic distortion (THD) of the current within the range of 11% to 16%, underscoring its practicality and efficiency.