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关键词： 无线充电   高频电源   超负荷运行功率   换能有效面   脉冲辐射  

摘要： 针对无线充电过程中高频电源的超负荷运行会导致设备损坏、降低高频电源的运行稳定性问题,设计无线充电用高频电源超负荷运行功率测量系统。分别设计高频激励模块、运行功率采集模块、超负荷测量单元,完成无线充电用测量系统的应用部件设计。在超负荷测量单元中建立高频换能有效面,确定功率脉冲辐射力的实际数值水平,实现高频电源超负荷运行功率的测量。实验结果表明,设计系统可以实现5%、10%、15%、20%、25%五类超负荷运行功率的测量,测量结果曲线与超负荷情况下的电量曲线基本一致,在解决高频电源超负荷运行所带来的充电设备损坏问题方面具有较好的应用价值。

关键词： 电力设施破坏   外力破坏   经济损失   电力供应   盗窃案件   电缆线   变压器   涉案金额  

摘要： 近年来,供电企业的电力设施由于工程施工、小偷盗窃等原因屡屡遭到外力破坏,不仅给供电企业造成了经济损失,同时也严重影响了电力的持续稳定供应。1案例概述在湖南娄底就曾发生过多起电力设施被偷盗的案件。曾某某等6人先后共同或伙同其他人员在娄底城区、湘乡市、涟源市、怀化市等地多次盗窃电缆线、变压器,导致多处电力设备被破坏,之后将赃物卖给谭某某,涉案金额近63万元。

关键词： 风电功率   深度学习   区间预测   复合非交叉   分位数回归   ReLU罚函数  

摘要： 为进一步提升风电功率区间预测精度,提出一种基于混合分位数回归长短期记忆神经网络的风电功率短期区间预测方法。通过同时考虑复合、平滑和非交叉3个特点对传统分位数回归模型进行改进,首先使用平滑函数代替弹球损失函数,使长短期记忆神经网络更易于拟合分位数回归模型。然后构建复合目标函数,使其能在给出多个分位数的条件下不重复训练多个独立模型。接着利用ReLU罚函数进行非交叉约束来避免分位数交叉现象的发生。最后将改进后的分位数回归与长短期记忆神经网络相结合并应用于中国甘肃省某风电场,运行结果表明所提模型在不同置信水平下对应PICP和PIAW分别提高了4.17个百分点和降低了2.31 MW,验证了方法的有效性。

关键词： 110kV   变压器   低压侧   C相线圈   匝间短路   纵差差动保护   本体重瓦斯   瓦斯继电器  

摘要： 1故障简述2024年8月18日18时50分21秒,某变电站2号110k V主变压器跳闸,双套纵差差动保护动作、本体重瓦斯动作、瓦斯继电器内明显集气。故障时天气阴,线路均无跳闸,站内无操作。根据现场故障调查情况及试验数据结果,初步判定为该变压器低压侧C相线圈绕组发生了匝间短路。

关键词： 电力系统   谐波电压互感器   性能优化   分压器优化设计   谐波测量负荷控制  

摘要： 本文围绕谐波电压互感器的测量精度、抗干扰能力及工程应用进行了深入研究,提出并验证了多项优化措施。研究表明,优化分压器结构和材料选择可有效降低谐波测量误差,提高高频响应特性;改进电容补偿设计能显著提升带载能力,减少测量偏差;通过负荷控制和数字滤波技术,可增强抗干扰能力,提高谐波信号提取的准确性。试验结果表明,优化后的谐波电压互感器在不同工况下均能保持较高测量精度,满足电能质量监测和继电保护的技术要求,对提高电网稳定性具有重要工程价值。

关键词： Zero voltage switching   Inductors   MOSFET   Circuits   Switches   Control systems   Inductance   Transformers   Parasitic capacitance   Rectifiers   Light load   multimode control (MMC)   phase-shifted full-bridge (PSFB) converter   zero-voltage switching (ZVS)  

摘要： This article proposes a multimode control (MMC) scheme to resolve the narrow zero-voltage switching (ZVS) range of the lagging-leg switches in the conventional phase-shifted full-bridge (PSFB) converter. This article analyzes and establishes ZVS process model and then transitions the converter operating mode based on the model to achieve ZVS over the full-load range without the need for resonant inductors and auxiliary circuits. A prototype PSFB converter with a rated output power of 480 W and an output voltage of 13.5 V is designed and implemented in this article with the aim of verifying the accuracy and effectiveness of the model and control scheme. The experimental results demonstrate that the MMC scheme, in comparison to the conventional two-mode control, is capable of filling the ZVS vacuum gap during light load and suppresses hard switching oscillations. Also, the efficiency improves by 0.31%-31.13% during light load.

关键词： Light emitting diodes   Lighting   Wireless communication   MOSFET   Inverters   Mathematical models   Rectifiers   Capacitors   Timing   RLC circuits   Constant current (CC)   dual-customization   special rectifier   wireless power transfer (WPT)  

摘要： Due to the advantages of safety and convenience, wireless power transfer technology is a good candidate for underwater LEDs driving. A wireless LED driver with a single constant current (CC) output value cannot enable LEDs to achieve brightness variation. This letter proposes a reconfigurable rectifier based communication-free wireless LED driver with dual-customization CC outputs. By simply controlling the special rectifier on the receiver, the proposed driver can be selectively configured into two LCC-S-S three-coil structures with different specifications, allowing LEDs to work in energy-saving mode and lighting mode, respectively. In addition, the control unit for mode switching is located at the receiver, making the system communication-free and ideal for underwater LEDs driving. An experimental prototype with dual-customization CC outputs of 0.6 A for energy-saving mode and 1 A for lighting mode is fabricated to verify the feasibility of the proposed wireless LED driver.

关键词： MOSFET devices  

摘要： A ferroelectric buried oxide is demonstrated to considerably enhance the tunability of the threshold voltage in FD-SOI transistors. The polarization mechanism makes the rate of change of threshold voltage with back-gate voltage increase tremendously from 4-5 % to more than 50 %. Our model and simulations show that with 1 V applied on the ground-plane, the threshold voltage is shifted by half a volt, which dramatically improves power consumption and speed.

关键词： III-V semiconductor materials   Aluminum nitride   Etching   Logic gates   Surface treatment   Capacitance   Surface morphology   Logic   HEMTs   MOSFET   GaN   E-mode   p-channel   subthreshold swing  

摘要： In this work, an enhancement-mode (E-mode) p-channel GaN metal-oxide-semiconductor field-effect transistor (p-MOSFET) with a maximum ON-state current (ION) density of 10.5 mA/mm, threshold voltage (V-TH) of - 2.45 V, and I-ON /I-OFF ratio of 10(8) is demonstrated on a commercial GaN wafer designed on a p-GaN HEMT. Furthermore, we present a novel E-mode p-FET featuring an AlN insertion layer within the p-GaN layer. The AlN layer introduces extra capacitance in the conducting channel and decreases the body factor m of devices. The p-GaN/AlN/p-GaN/AlGaN structure reduces the equivalent channel capacitance, achieving a minimum point-by-point subthreshold swing (SS) of 60 mV/dec. Compared with that of the conventional p-GaN channel FET, the SS decreases from 225 to 105 mV/dec over three orders, the V-TH shifts to - 3.05 V, the I-ON /I-OFF ratio increases to 2 x 10(8), and the device also has an ultralow off-state leakage current in the range of 10(-8) mA/mm. The proposed structure is compelling for GaN-based complementary metal-oxide-semiconductor (CMOS) logic and power devices.

关键词： Modulation   Vectors   Inverters   Clamps   Topology   Insulated gate bipolar transistors   MOSFET   Hybrid inverters   multilevel modulation   open-winding permanent magnet synchronous motor (OW-PMSM)  

摘要： This article conducts a research on high-precision modulation of open-winding permanent magnet synchronous motor (OW-PMSM) drives fed by two isolated dc sources with unequal dc-link voltage. To enhance the performance while considering the cost of the drive, the high-voltage-side inverter (INV1) adopts IGBTs as switching devices and the low-voltage-side inverter (INV2) adopts low-cost MOSFETs as switching devices. Based on the developed OW-PMSM drive, high-precision modulation strategies for the voltage ratios of 2:1 and 3:1 are proposed in this article. In the proposed modulation strategies, the vector planes generated by the dual inverters are divided twice and the reference voltage vector is allocated according to the specific subsector. INV1 adopts clamping modulation and INV2 adopts high-frequency modulation, which can fully utilize the high-voltage characteristic of IGBT and the high switching frequency characteristic of MOSFET to fulfill multilevel and high-precision outcome. The proposed drive and modulation strategies are verified through experiments.