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关键词： 虚拟同步机   功率振荡   动态阻尼  

摘要： 随着可再生能源的不断渗透,大量电力电子变换器通过虚拟同步机(VSG)技术来提供惯量支撑。针对多个VSG并联系统的有功功率振荡问题,提出一种基于动态阻尼增强的VSG并联系统功率振荡抑制方法。首先,建立多VSG的并联模型,分析系统有功功率振荡机理;然后,阐述所提控制方法原理,分析其功率振荡抑制机理;最后,通过仿真和实验验证了所提控制方法的正确性和有效性。

关键词： 同步电动机   保护设定   案例  

摘要： 随着我国烯烃产业规模的逐步扩大,造粒单元挤压造粒电动机功率往往都在1 MW以上,如果选用异步机,需要配套相应电压等级的电容器以提高功率因数。同步机的选用,可以省去配套电容器,同时也能够将功率因数保持在0.9以上,提高了电能质量。因此大功率同步电动机在造粒电动机的选用中日益广泛,随着同步机的选用占比增加,其保护设定是否合理,可靠变得尤为重要。结合案例对同步电动机的保护设定进行讨论。

关键词： ZL114A-0.6Y合金   超声功率   微观组织   力学性能  

摘要： 针对ZL114A-0.6Y合金力学性能不足问题,研究连续超声振动功率对ZL114A-0.6Y合金微观组织及力学性能的影响,探讨其作用机制。结果表明,超声振动功率对ZL114A-0.6Y合金的微观组织影响显著。随着超声功率增加,α-Al枝晶先减小后增大,枝晶形状由树枝状、花瓣状向粒状、细小等轴状转变。1200 W超声功率处理后微观组织最好,晶粒尺寸最小,且共晶Si形貌呈短棒状,分布均匀。另外,Y相体积有所减小,大部分以Al_(3)Y化合物点状、块状存在于Al-Si相晶界处。超声振动功率对合金力学性能影响显著,1200 W超声处理后合金力学性能最佳,平均显微硬度(HV)为124.26,平均抗拉强度为314 MPa,平均伸长率为5.3%。

关键词： 海上风电场   电压源型换流器   多端直流   功率平滑   功率分配  

摘要： 相比目前已有的工程而言,未来的海上风电场容量将更大,且离岸距离也更远,而基于电压源换流器的多端直流输电系统可以经济有效地联接广域分布的海上风电场,大规模地传输波动的风能至各陆地电网。以大型海上风电场送出为研究对象,提出一种结合电压源换流器和电池储能的多端柔性直流输电系统,给出系统的功率流控制方法,实现网侧换流器的功率分配及功率平滑输出。最后,基于RTDS硬件在环实验平台构建一个四端直流输电测试系统,并用实验验证所提多端柔性直流输电系统功率流的控制效果。

关键词： 750kV变压器   铁心   夹件   在线监测  

摘要： 本文中作者介绍了一起750kV变压器铁心及夹件缺陷的诊断及处理情况,通过带电处理、停电诊断试验及停电处理,消除了750kV主变压器铁心及夹件缺陷,为该类型缺陷提供了经验借鉴。

关键词： 风电并网   北方苍鹰算法   变分模态分解   混合储能   模糊控制  

摘要： 为解决风电场并网时的功率波动影响电网稳定性的问题,提出一种基于北方苍鹰(northern goshawk optimization,NGO)算法优化变分模态分解(variational mode decomposition,VMD)参数的混合储能功率分配策略。首先,按照风电场并网技术规范,采用自适应平均滤波法对风力发电功率进行滤波,并由滤波后的并网功率计算出波动功率。然后,采用NGO优化VMD算法中分解模态数K值和二次惩罚因子α值的最优值组合,将波动功率信号经VMD分解后实现在锂电池和超级电容器的功率分配,最后,采用双重模糊控制对混合储能系统(hybrid energy storage system,HESS)的荷电状态(state of charge,SOC)进行优化,完成HESS功率的二次分配。仿真结果表明,该控制策略不仅能够满足风电并网最大功率波动要求,还可以保持SOC维持在合理范围,实现HESS长期安全运行。

关键词： 光伏发电预测   时序卷积网络   Transformer   确定性预测   概率预测  

摘要： 提出了一种基于时序卷积网络(TCN)和Transformer结合的短期光伏发电功率预测方法。分析了风速、雨量、太阳辐照度、云量等影响光伏发电功率的主要因素;利用TCN提取序列的全局空间特征并采用Transformer提取序列中的长期依赖关系的时序特征,提出TCN-Transformer复合模型以实现高精度的光伏功率预测,并将其应用于光伏发电的确定性预测与概率预测中;通过澳大利亚沙漠知识太阳能中心(DKASC)数据集进行仿真分析。结果表明,改进后的TCN-Transformer模型在不同天气条件下均表现出优异的预测性能,有效提高了光伏功率的短期预测精度。

关键词： 电力电子固态变压器   功率均分控制   电能  

摘要： 针对一种可接入分布式新能源发电系统的模块级联型三端口单相电力电子固态变压器电路拓扑,提出了一种功率/潮流均分控制策略,实现了高压电网侧端口、低压交流用户侧端口及400V直流侧端口三者之间电能双向自由流动,并且优先使用分布式新能源的电能;同时,实现了高压电网侧端口单位功率因数。理论分析、仿真及实验均验证了所提出的新型电力电子固态变压器控制技术方案的良好性能与可行性。

关键词： Couplings   Transconductance   Silicon   MOSFET   Logic gates   Silicon-on-insulator   Electric potential   Radio frequency   Data models   Space charge   Body-contacted   compact model   dynamically depleted silicon-on-insulator (DDSOI)   RF   symmetric BSIM-SOI   transconductance  

摘要： In this work, we present a physical understanding and a robust surface potential coupling relationship essential to accurately capture the transconductance in body-contacted (BC) dynamically depleted silicon-on- insulator (DDSOI) MOSFETs for varied body biases. It is observed that the crossover of transconductance for varied body biases occurs before the peak transconductance is reached for devices operating particularly in the saturation region. This phenomenon is investigated in detail and attributed to partial-depletion-to-full-depletion transition in the silicon body that occurs before the peak transconductance is reached, in the saturation region of operation. The proposed coupling relationship effectively captures this behavior, ensuring symmetry of the overall model around V-ds = 0 V and correct harmonic characteristics in linear and saturation regions, which are critical for RF IC design. An enhanced mobility model with improved body bias dependency has also been proposed that helps in the accurate validation of transconductance. The model is validated with state-of-the-art industry hardware data from GlobalFoundries. The model has been integrated into our new industry standard symmetric BSIM-SOI compact model framework.

关键词： Degradation   Neurons   Stress   MOSFET   Silicon-on-insulator   Logic gates   Temperature measurement   Semiconductor device measurement   Current measurement   Thermal stresses   Band-to-band-tunneling (BTBT)   on regime (I-ON)   reliability   silicon on insulator (SOI)   spiking neural network (SNN)   subthreshold (SS) regime  

摘要： Low-power operations are essential for implementing large spiking neural networks (SNNs) in real-world applications. An area and energy-efficient demonstration of a functional liquid state machine (LSM) for spoken word detection using the band-to-band-tunneling (BTBT)-based neuron was proposed earlier. For a product-level demonstration of the BTBT regime operating chips, the variability and reliability of neurons emerge as noteworthy concerns for neuromorphic processors due to the potential implications for performance degradation over time. In this work, we characterize and compare the reliability of partially depleted (PD) silicon on insulator (SOI) transistors in the BTBT and on-regime ( Undefined control sequence I-ON ) regimes. The drain current fractional degradation ( Delta I-D/I-D) increases with an increase in voltage and thermal stress in the BTBT and Undefined control sequence I-ON regime. The reaction-diffusion-drift (RDD) framework is used to estimate device degradation under operating bias conditions. At operating bias, a similar to 17% fractional degradation is observed in the BTBT regime operation for ten years, comparable to the degradation observed in the Undefined control sequence I-ON regime. Finally, we analyzed the impact of device degradation on the SNN performance.