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虚拟同步直驱风机低频振荡机理分析及阻尼补偿控制

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电力系统自动化 2024年第2期48卷 95-104页

作者：王子骏庄可好辛焕海李少林齐琛程雪坤浙江大学工程师学院浙江省杭州市310027 浙江大学电气工程学院浙江省杭州市310027 中国电力科学研究院有限公司北京市100192 国网冀北电力有限公司电力科学研究院北京市100045

虚拟同步机技术可有效提升电网的电压支撑能力,但也引入了复杂的低频振荡问题。目前,对传统虚拟同步机的低频振荡研究大多忽略直流侧及机侧动态,难以准确刻画虚拟同步直驱风机的低频振荡特性。为解决上述问题,首先,建立了计及机侧动态... 详细信息

虚拟同步机技术可有效提升电网的电压支撑能力,但也引入了复杂的低频振荡问题。目前,对传统虚拟同步机的低频振荡研究大多忽略直流侧及机侧动态,难以准确刻画虚拟同步直驱风机的低频振荡特性。为解决上述问题,首先,建立了计及机侧动态和直流电压动态的统一阻尼转矩模型,利用阻尼转矩法揭示了机侧转子动态产生的负阻尼转矩是导致风机低频振荡的主要原因,并分析了各环节对风机低频振荡特性的影响规律。进一步,提出了阻尼补偿控制以削弱机侧动态的负阻尼效应,有效提升了机侧耦合下风机并网系统的稳定性。最后,简要分析了所提控制在多机系统的适用性,并基于MATLAB/Simulink仿真验证了理论分析的准确性和所提控制的有效性。

关键词：低频振荡虚拟同步机直驱风机阻尼转矩法稳定性

Influence of Virtual Synchronous Generators on Low Frequency Oscillations

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CSEE Journal of Power and Energy Systems 2022年第4期8卷 1029-1038页

作者： Hui Liu Dawei Sun Feng Zhao Yunfeng Tian Peng Song xuekun cheng State Grid Wind-Photovoltaic-Energy Storage Hybrid Power Generation Technology Laboratory and State Grid Jibei Electric Power Research Institute(North China Electric Power Research Insititute Co.Ltd) Beijing 100045China State Grid Xinyuan Zhangjiakou Wind PhotovoltaicStorage and Transmission Pilot Power Station Co.LtdZhangjiakou 075000China

By simulating the operating dynamics of synchronous generators(SGs),the use of virtual synchronous gen-rators(VSGs)can help overcome inverter-based generators'shortcomings of low inertia and minimal damping for gridforming ***'stability are very important for their solar and wind electricity ***,the related research primarily focuses on VSGs and their applications for *** has been little research to explore how VSGs effect low frequency oscillations in power transmission *** paper describes a small-signal model of a VSGSG interconnected system,which is suitable for studying low frequency oscillation damping in a power transmission *** on this model,the effects of VSGs on low frequency oscillations are compared with the effects of SGs to reveal the mechanism of how VSGs infuence damping *** influence of each VSG control loop on oscillations is also analyzed in this ***,the low frequency oscillation risks with different types of VSGs are ***,experiments on a real-time laboratory(RT-LAB)platform are conducted to verify the small-signal analysis results.

关键词： Grid-forming inverters low frequency oscillation participation factor renewable electricity small-signal model virtual synchronous generator(VSG)

The phytolith carbon sequestration in terrestrial ecosystems: the underestimated potential of bamboo forest

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Ecological Processes 2023年第4期12卷 230-241页

作者： xuekun cheng Huiru Lv Shuhan Liu Chong Li Pingheng Li Yufeng Zhou Yongjun Shi Guomo Zhou State Key Laboratory of Subtropical Silviculture Zhejiang A&F University Zhejiang Province Key Think Tank: Institute of Ecological Civilization Zhejiang A&F University Key Laboratory of Carbon Cycling in Forest Ecosystems and Carbon Sequestration of Zhejiang Province Zhejiang A&F University School of Environmental and Resources Science Zhejiang A&F University

Background Terrestrial ecosystems contain significant carbon storage, vital to the global carbon cycle and climate change. Alterations in human production activities and environmental factors affect the stability of carbon storage in soil. Carbon sequestration in plant phytoliths offers a sustainable method for long-term carbon stabilization. Carbon occluded in phytoliths(Phyt OC) is a kind of carbon that can be stable and not decomposed for a long time, so it is crucial to conduct more in-depth research on *** We undertook a meta-analysis on Phyt OC across global terrestrial ecosystems, analyzing 60 articles, encapsulating 534 observations. We observed notable differences in phytolith and Phyt OC contents across various ecosystems. Bamboo forest ecosystems exhibited the highest vegetation phytolith and Phyt OC content, while soil phytolith content was most prominent in bamboo forests and Phyt OC content in croplands. Human activities, such as grassland grazing, had a lesser impact on soil Phyt OC transport than actions like cutting and tillage in croplands and forests. Our study separated bamboo ecosystems, analyzing their Phyt OC content and revealing an underestimation of their carbon sink *** Notwithstanding our findings, phytoliths' intricate environmental interactions warrant further exploration, crucial for refining ecosystem management and accurately estimating Phyt OC stocks. This deepened understanding lays the foundation for studying phytoliths and the carbon sink dynamics.

关键词： Carbon sequestration Phytoliths PhytOC Terrestrial ecosystem Soil carbon

The phytolith carbon sequestration in terrestrial ecosystems: the underestimated potential of bamboo forest

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Ecological Processes 2023年 872-883页

Background Terrestrial ecosystems contain significant carbon storage, vital to the global carbon cycle and climate change. Alterations in human production activities and environmental factors affect the stability of carbon storage in soil. Carbon sequestration in plant phytoliths offers a sustainable method for long-term carbon stabilization. Carbon occluded in phytoliths(PhytOC) is a kind of carbon that can be stable and not decomposed for a long time, so it is crucial to conduct more in-depth research on *** We undertook a meta-analysis on PhytOC across global terrestrial ecosystems, analyzing 60 articles, encapsulating 534 observations. We observed notable differences in phytolith and PhytOC contents across various ecosystems. Bamboo forest ecosystems exhibited the highest vegetation phytolith and PhytOC content, while soil phytolith content was most prominent in bamboo forests and PhytOC content in croplands. Human activities, such as grassland grazing, had a lesser impact on soil PhytOC transport than actions like cutting and tillage in croplands and *** study separated bamboo ecosystems, analyzing their PhytOC content and revealing an underestimation of their carbon sink *** Notwithstanding our findings, phytoliths' intricate environmental interactions warrant further exploration, crucial for refining ecosystem management and accurately estimating PhytOC stocks. This deepened understanding lays the foundation for studying phytoliths and the carbon sink dynamics.

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Fucosyltransferase 8 regulates adult neurogenesis and cognition of mice by modulating the Itga6-PI3K/Akt signaling pathway

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Science China(Life Sciences) 2024年第7期67卷 1427-1440页

作者： Hongfeng Guo Qihang Sun Xiaoli Huang Xiaohao Wang Feng Zhang Wenzheng Qu Jinling Liu Xuejun cheng Qiang Zhu Wen Yi Qiang Shu xuekun Li The Children’s Hospital National Clinical Research Center for Child HealthSchool of MedicineZhejiang UniversityHangzhou 310052China The Institute of Translational Medicine School of MedicineZhejiang UniversityHangzhou 310029China College of Life Sciences Zhejiang UniversityHangzhou 310058China Binjiang Institute of Zhejiang University Hangzhou 310053China Zhejiang University Cancer Center Zhejiang UniversityHangzhou 310029China

Fucosyltransferase 8(Fut8)and core fucosylation play critical roles in regulating various biological processes,including immune response,signal transduction,proteasomal degradation,and energy ***,the function and underlying mechanism of Fut8 and core fucosylation in regulating adult neurogenesis remains *** have shown that Fut8 and core fucosylation display dynamic features during the differentiation of adult neural stem/progenitor cells(aNSPCs)and postnatal brain ***8 depletion reduces the proliferation of a NSPCs and inhibits neuronal differentiation of aNSPCs in vitro and in vivo,***,Fut8 deficiency impairs learning and memory in ***,Fut8 directly interacts with integrinα6(Itga6),an upstream regulator of the PI3kAkt signaling pathway,and catalyzes core fucosylation of *** of Fut8 enhances the ubiquitination of Itga6 by promoting the binding of ubiquitin ligase Trim21 to *** levels of Itga6 inhibit the activity of the PI3K/Akt signaling ***,the Akt agonist SC79 can rescue neurogenic and behavioral deficits caused by Fut8 *** summary,our study uncovers an essential function of Fut8 and core fucosylation in regulating adult neurogenesis and sheds light on the underlying mechanisms.

关键词： Fut8 adult neural stem/progenitor cells neurogenesis Itga6 PI3K/Akt

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计及转速限值的双馈风机变下垂系数控制策略

电力系统保护与控制 2021年第9期49卷 29-36页

作者：王同森程雪坤电网智能化调度与控制教育部重点实验室(山东大学) 山东济南250061 国网冀北电力科学研究院(华北电力科学研究院有限责任公司) 北京100045 风光储并网运行技术国家电网公司重点实验室北京100045

传统的下垂控制策略在整定调频系数时更多关注双馈风机本身的运行状态,较少考虑风电渗透率和系统扰动变化对风机调频过程的影响,控制方法的适应性有待提高。为此,建立了风电参与调频的电力系统频率响应模型,提出了计及转速限值的双馈风... 详细信息

传统的下垂控制策略在整定调频系数时更多关注双馈风机本身的运行状态,较少考虑风电渗透率和系统扰动变化对风机调频过程的影响,控制方法的适应性有待提高。为此,建立了风电参与调频的电力系统频率响应模型,提出了计及转速限值的双馈风机下垂系数整定方法及控制策略。通过推导调频过程转子转速的极小值和稳态值,确定出使风机转速自行稳定且不触发保护下限的下垂系数范围。然后根据扰动的大小在线调整控制参数,避免风机发生过度响应。在DIgSILENT中建立了系统仿真模型。仿真结果表明所提策略能够有效应对不同的系统扰动情况,保证风机自身运行的稳定性。

关键词：双馈风机下垂控制转速极小值转速稳态值频率特性

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电压环对光伏虚拟同步机系统稳定性的影响

太阳能学报 2021年第3期42卷 311-318页

作者：刘辉孙大卫宋鹏王晓声程雪坤国网冀北电力科学研究院(华北电力科学研究院有限责任公司) 北京100045 国家电网公司风光储联合发电运行技术实验室北京100045

传统的新能源发电设备不具备调频调压能力,为解决这一问题,已有研究提出多种针对光伏逆变电源的稳压与电压穿越策略。在此基础上,为进一步提升光伏电源的调频、孤网运行等方面的能力,有学者提出多种类型的虚拟同步发电机(virtual synchr... 详细信息

传统的新能源发电设备不具备调频调压能力,为解决这一问题,已有研究提出多种针对光伏逆变电源的稳压与电压穿越策略。在此基础上,为进一步提升光伏电源的调频、孤网运行等方面的能力,有学者提出多种类型的虚拟同步发电机(virtual synchronous generator,VSG)控制策略。VSG控制系统中是否存在电压环是区别不同VSG策略的主要特征之一。目前鲜有研究分析VSG控制系统中的电压环对光伏VSG并网稳定性的影响。为补缺这方面的研究,首先对引入和未引入电压环的2种光伏VSG进行小信号建模,通过计算2种VSG模型的特征根,分析电压环及其参数对系统各种潜在振荡模态的影响,尤其对可能诱发高频谐振和次同步振荡的模态进行分析。在此基础上,研究电压环对光伏VSG并网适应性和频率支撑能力的影响。研究结果表明,在电压等级较低、强度较弱的电网中,光伏VSG控制系统中宜引入电压环。

关键词：虚拟同步发电机小信号分析虚拟惯量分布式电源电气振荡电压环

电网对称故障下双馈风力发电机的虚拟同步控制策略

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电力系统自动化 2017年第20期41卷 47-54,125页

作者：程雪坤孙旭东柴建云赵杨阳电力系统及发电设备控制和仿真国家重点实验室清华大学北京市100084

将虚拟同步控制策略运用于双馈感应发电机(DFIG)变频器控制,可使DFIG为电网提供有惯量的频率与电压支撑。但现有虚拟同步控制策略主要关注DFIG对同步发电机机电动态特性的模拟,未考虑DFIG的电磁暂态过程。分析了基于虚拟同步控制的DFIG... 详细信息

将虚拟同步控制策略运用于双馈感应发电机(DFIG)变频器控制,可使DFIG为电网提供有惯量的频率与电压支撑。但现有虚拟同步控制策略主要关注DFIG对同步发电机机电动态特性的模拟,未考虑DFIG的电磁暂态过程。分析了基于虚拟同步控制的DFIG在电网对称故障下的电磁暂态特性,指出了现有虚拟同步控制策略存在的两大缺陷:无法完全模拟同步电机故障暂态下的电磁关系,且无法抑制转子过电流。提出了一种适用于电网对称故障的DFIG暂态电压补偿虚拟同步控制策略,即通过补偿转子控制电压的暂态分量来抵消或削弱转子暂态反电势对转子过电流的影响。通过仿真对比了现有虚拟同步控制策略与所提策略对DFIG的控制效果,证明了所提虚拟同步控制策略不仅具备更好的惯性支撑能力,同时可显著抑制DFIG转子过电流与电磁转矩暂态冲击,并对系统进行无功支撑,有效提高了DFIG不间断运行能力与电网故障恢复能力。

关键词：双馈风力发电机虚拟同步控制电网对称故障转子过电流抑制暂态电压补偿

适用于电网不对称故障的双馈风力发电机虚拟同步控制策略

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电力系统自动化 2018年第9期42卷 120-126页

作者：程雪坤孙旭东柴建云刘辉宋鹏国网冀北电力科学研究院(华北电力科学研究院有限责任公司) 北京市100045 风光储并网运行技术国家电网公司重点实验室北京市100045 电力系统及发电设备控制和仿真国家重点实验室清华大学北京市100084

双馈感应发电机(DFIG)虚拟同步控制策略可使DFIG为电网提供频率与电压支撑,改善其并网特性。现有虚拟同步控制策略的主要目标是模拟同步发电机机电动态特性,未深入探讨电磁暂态过程中如何对DFIG进行控制。分析了电网发生不对称故障时,... 详细信息

双馈感应发电机(DFIG)虚拟同步控制策略可使DFIG为电网提供频率与电压支撑,改善其并网特性。现有虚拟同步控制策略的主要目标是模拟同步发电机机电动态特性,未深入探讨电磁暂态过程中如何对DFIG进行控制。分析了电网发生不对称故障时,基于虚拟同步控制的DFIG的故障特性;得出了现有虚拟同步控制策略难以抑制DFIG故障电流与电磁转矩振荡的结论。在此基础上,提出了一种适用于电网不对称故障的DFIG电压补偿虚拟同步控制策略,该策略通过补偿转子电压的故障分量来改善DFIG转子电压的响应速度,抵消或削弱转子反电势故障分量的影响。仿真对比了现有虚拟同步控制策略与所提出策略的控制效果,验证了所提策略能够显著降低DFIG转子故障电流,抑制电磁转矩的暂态冲击与持续振荡,有效提高DFIG不对称故障穿越能力。

关键词：双馈感应发电机虚拟同步控制电网不对称故障电压补偿