Results 11 to 20 of about 18,724 (162)

Simulation analysis of the relationship between the sampling time and tracking error of the model predictive control in inverter [PDF]

open access: yes, 2017
模型预测控制(Model Predictive Control,MPC)是电压型逆变器(Voltage Source Inverter,VSI)电流跟随控制装置定频调制的典型方法,得到了广泛的应用。论文使用统计的方法研究MPC的采样时间与跟踪误差(方差)的函数关系。该函数关系是研究和解决逆变器切换优化问题的基础。仿真结果可得出采样时间与跟踪误差呈线性关系的结论。Model Predictive Control (MPC) is a typical method of voltage source ...
吴奕锴, 吴靖南, 康文
core   +1 more source

断路器容性电流开断能力研究

open access: yesGaoya dianqi, 2022
容性电流开断能力,特别是C2级开断能力,已成为断路器满足工程需求的关键指标,因开断过程中易发生重击穿故障而导致试验失败的风险较大,故需对其容性开断能力进行评估。基于容性电流特点,文中采用“恢复电压”及“最小临界电压”评估其开断容性电流能力,且“恢复该电压”低于“最小临界电压”时,断路器具有开断容性电流的能力。采用电场及气流场耦合分析方法,断路器开断性能进行评估,得到试验工况下“恢复电压”均小于“最小临界电压”,表明该断路器具有容性电流开断能力,顺利通过C2级试验验证,进一步表明采用“最小临界电压 ...
郭自豪   +8 more
doaj  

基于熔断器的组合式直流开断技术研究与验证

open access: yesGaoya dianqi, 2023
直流断路器是交直流混合配电网组网的关键,然而在考虑技术经济性时,当前直流配电断路器仍沿用高压直流输电等级断路器拓扑方案的思路不再适用,亟需开发经济型直流开断技术,实现中压直流配电断路器成本和性能的平衡。文中针对交直流混合配电网直流侧故障电流经济高效开断这一关键问题,基于直流熔断器和强迫过零开断技术,提出一种基于熔断器的组合式直流开断方案,该方案采用直流熔断器与转移开关并联后再与直流负荷开关串联的形式,利用低成本的直流限流熔断器开断大电流,减轻直流负荷开关的开断要求,进而降低整机成本 ...
王昊晴   +4 more
doaj  

Optimal Control of Residents’ Controllable Load Resources Considering Different Demands of Users [PDF]

open access: yes, 2023
Optimizing the controllable load resources of residents on the demand side is a major aspect of virtual power plant (VPP). It is an important means to improve the utilization rate of new energy such as wind power and photovoltaic power, to achieve carbon
HUANG He   +5 more
core   +1 more source

Invulnerability of small-world network against cascading failure based on nonlinear load-capacity model [PDF]

open access: yes, 2014
To investigate the invulnerability of small-world networks against cascading failure, an improved nonlinear load-capacity model was introduced. Under the rule of local weighted load redistribution, the influence of weight coeffi-cient, capacity ...
Jia-sheng WANG   +3 more
core   +1 more source

机械式高压直流断路器开断性能试验研究

open access: yesGaoya dianqi, 2020
高压直流断路器是多端直流输电及高压直流系统联网的基础和安全保障,它不仅要能够开断短路电流而且要能够开断小负载电流,实现对高压直流系统的保护及控制功能。文中在振荡回路中对机械式高压直流断路器开断大电流及小电流的性能进行了测试。分别测试机械式高压直流断路器开断17.5 kA和开断50 A电流时的恢复电压值和恢复电压变化率。在试验中发现机械式高压直流断路器开断17.5 kA电流时可以在叠加高频振荡电流后的第1次过零点处开断,但是在开断50 A电流时需要在第2次电流过零点处才能开断。开断50 ...
高俊珍   +4 more
doaj  

Study of Collection and Qualitative-Quantitative Method on Volatile Organic Compounds in Relay Material [PDF]

open access: yes, 2015
继电器内绝缘塑料件、漆包线的绝缘漆层在使用过程中或高温工作环境下产生的过量挥发性有机化合物是影响继电器可靠性的最重要因素之一。本学位论文根据企业实际需求建立了继电器材料中挥发性有机化合物的采集与分析定量方法,取得了以下成果: (1)运用顶空加热-气相色谱-质谱(HS-GC-MS)仪器联用系统建立了继电器材料中挥发性有机化合物的采集与分析定量方法。优化并确定了顶空进样针的加热温度、顶空加热炉加热样品瓶的温度、顶空加热炉加热样品瓶的时间、顶空样品瓶盖的隔垫、塑料米和漆包线样品量等关键分析条件 ...
苏清兴
core  

The collective application of shorebird tracking data to conservation

open access: yesConservation Biology, EarlyView.
Abstract Addressing urgent conservation issues, such as the drastic declines of North American migratory birds, requires creative, evidence‐based, efficient, and collaborative approaches. The abundance of over 50% of monitored North American shorebird populations has declined by over 50% since 1980. To address these declines, we developed a partnership
Autumn‐Lynn Harrison   +71 more
wiley   +1 more source

Marketing stategy on inovance low-voltage frequency converter [PDF]

open access: yes, 2015
摘要 近年来,随着国民经济和工业发展的内在需求,国内自动化行业蓬勃发展,以变频器为代表的工业自动化设备越来越受到重视并广泛应用,市场孕育了像汇川、英威腾,新时达等上市企业,市场总量以GDP两倍的速度,每年保持着10%以上的增长率。 国务院2012年8月6日印发的《节能减排“十二五”规划》具体目标中明确提到:到2015年,单位工业增加值(规模以上)能耗比2010年下降21%左右,主要产品(工作量)单位能耗指标达到先进节能标准的比例大幅提高,三相异步电动机的能效从90%提升到92%-94%。同时 ...
胡波
core  

Biodiversity‐driven spatial conservation planning to delineate temporally stable regions

open access: yesConservation Biology, EarlyView.
Abstract The accelerating loss of biodiversity underscores the critical need for effective conservation strategies, particularly in the face of climate change and anthropogenic pressures. We devised a conservation planning framework that adopts a temporal stacking approach to species distribution models and landscape connectivity analyses. These models
Mattia Iannella   +5 more
wiley   +1 more source

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