随着“双碳”战略推进,我国大力发展风电、光伏等新能源。处于电网末端的新能源场站因缺乏交流电源支撑,需依赖柔性直流输电技术(modular multilevel converter-high voltage direct current,MMC-HVDC)实现并网,但电力电子变流器的广泛...随着“双碳”战略推进,我国大力发展风电、光伏等新能源。处于电网末端的新能源场站因缺乏交流电源支撑,需依赖柔性直流输电技术(modular multilevel converter-high voltage direct current,MMC-HVDC)实现并网,但电力电子变流器的广泛应用引发了高频谐振的问题。首先,针对新能源场站经柔直并网中的高频谐振问题,建立了包含电磁式电压/电流互感器及其二次电缆在内的MMC孤岛系统主回路与控制环节的数学模型。其次,用π型电路等效电磁式电压/电流互感器二次电缆并对其进行特性分析。然后,对综合考虑电磁式电压/电流互感器二次电缆的MMC孤岛系统展开稳定性分析,明确了电磁式电压/电流互感器二次电缆的传变特性导致孤岛系统发生高频谐振的机理。最后,在PSCAD/EMTDC中进行仿真验证。结合现场试验,证明了所提电磁式电压/电流互感器二次电缆引起孤岛系统高频谐振机理的准确性。展开更多
新质生产力以其科技驱动、创新引领、绿色低碳和融合发展等特点,对我国科技产业创新、技术人才培养、推动高质量发展、应对全球竞争具有不可替代的作用。2025年中央一号文件提出:以科技创新引领先进生产要素集聚,因地制宜发展农业新质...新质生产力以其科技驱动、创新引领、绿色低碳和融合发展等特点,对我国科技产业创新、技术人才培养、推动高质量发展、应对全球竞争具有不可替代的作用。2025年中央一号文件提出:以科技创新引领先进生产要素集聚,因地制宜发展农业新质生产力。释放出新质生产力在农业领域的引领作用。当前,在经济全球一体化背景下,我国农产品出口贸易拥有广阔的市场空间和发展潜力。然而,随着国际竞争的加剧,传统生产和贸易模式难以满足发展需求,农产品出口面临产品附加值低、品牌影响力不足、质量安全隐患以及贸易壁垒等问题。新质生产力拥有创新性突出、绿色可持续性显著、智能化程度高的特征。其在农业领域的应用,为解决我国农产品出口贸易问题带来新契机。本文将探讨如何运用新质生产力解决我国农产品出口面临的问题,从而实现农产品出口贸易高水平发展。借助新质生产力,通过推动农产品深加工技术创新、利用数字化技术打造品牌、升级农业生产技术保障质量安全、加强农产品质量标准体系建设应对贸易壁垒等举措,能够提升我国农产品在国际市场的竞争力,推动我国农产品出口贸易实现高水平发展,促进我国农业领域可持续发展。New quality productivity, driven by science and technology, led by innovation, green, low-carbon and integrated development, plays an irreplaceable role in innovation in China’s science and technology industry, training technical personnel, promoting high-quality development and responding to global competition. The no. 1 document of the Central government in 2025 proposes: to lead the agglomeration of advanced production factors with scientific and technological innovation, and to develop new quality agricultural productivity according to local conditions. Release the leading role of new quality productivity in the agricultural field. At present, under the background of global economic integration, China’s agricultural export trade has a broad market space and development potential. However, with the intensification of international competition, the traditional production and trade mode is difficult to meet the development needs, and the export of agricultural products is faced with problems such as low added value, insufficient brand influence, potential quality and safety risks and trade barriers. New quality has the characteristics of outstanding innovation, significant green sustainability and high degree of intelligence. Its application in the agricultural field brings new opportunities to solve the problem of China’s agricultural products export trade. This paper will discuss how to use the new quality productivity to solve the problems faced by China’s agricultural export, so as to achieve the high-level development of agricultural export trade. With the help of new quality productivity, promoting agricultural deep processing technology innovation, the use of digital technology to build brand, upgrade agricultural production technology to ensure quality and safety, to strengthen the construction of agricultural product quality standard system to trade barriers, can enhance the competitiveness of agricultural products in the international market, promote the development of agricultural products export trade to achieve high level, and promote the sustainable development of agriculture in China.展开更多
文摘随着“双碳”战略推进,我国大力发展风电、光伏等新能源。处于电网末端的新能源场站因缺乏交流电源支撑,需依赖柔性直流输电技术(modular multilevel converter-high voltage direct current,MMC-HVDC)实现并网,但电力电子变流器的广泛应用引发了高频谐振的问题。首先,针对新能源场站经柔直并网中的高频谐振问题,建立了包含电磁式电压/电流互感器及其二次电缆在内的MMC孤岛系统主回路与控制环节的数学模型。其次,用π型电路等效电磁式电压/电流互感器二次电缆并对其进行特性分析。然后,对综合考虑电磁式电压/电流互感器二次电缆的MMC孤岛系统展开稳定性分析,明确了电磁式电压/电流互感器二次电缆的传变特性导致孤岛系统发生高频谐振的机理。最后,在PSCAD/EMTDC中进行仿真验证。结合现场试验,证明了所提电磁式电压/电流互感器二次电缆引起孤岛系统高频谐振机理的准确性。
文摘新质生产力以其科技驱动、创新引领、绿色低碳和融合发展等特点,对我国科技产业创新、技术人才培养、推动高质量发展、应对全球竞争具有不可替代的作用。2025年中央一号文件提出:以科技创新引领先进生产要素集聚,因地制宜发展农业新质生产力。释放出新质生产力在农业领域的引领作用。当前,在经济全球一体化背景下,我国农产品出口贸易拥有广阔的市场空间和发展潜力。然而,随着国际竞争的加剧,传统生产和贸易模式难以满足发展需求,农产品出口面临产品附加值低、品牌影响力不足、质量安全隐患以及贸易壁垒等问题。新质生产力拥有创新性突出、绿色可持续性显著、智能化程度高的特征。其在农业领域的应用,为解决我国农产品出口贸易问题带来新契机。本文将探讨如何运用新质生产力解决我国农产品出口面临的问题,从而实现农产品出口贸易高水平发展。借助新质生产力,通过推动农产品深加工技术创新、利用数字化技术打造品牌、升级农业生产技术保障质量安全、加强农产品质量标准体系建设应对贸易壁垒等举措,能够提升我国农产品在国际市场的竞争力,推动我国农产品出口贸易实现高水平发展,促进我国农业领域可持续发展。New quality productivity, driven by science and technology, led by innovation, green, low-carbon and integrated development, plays an irreplaceable role in innovation in China’s science and technology industry, training technical personnel, promoting high-quality development and responding to global competition. The no. 1 document of the Central government in 2025 proposes: to lead the agglomeration of advanced production factors with scientific and technological innovation, and to develop new quality agricultural productivity according to local conditions. Release the leading role of new quality productivity in the agricultural field. At present, under the background of global economic integration, China’s agricultural export trade has a broad market space and development potential. However, with the intensification of international competition, the traditional production and trade mode is difficult to meet the development needs, and the export of agricultural products is faced with problems such as low added value, insufficient brand influence, potential quality and safety risks and trade barriers. New quality has the characteristics of outstanding innovation, significant green sustainability and high degree of intelligence. Its application in the agricultural field brings new opportunities to solve the problem of China’s agricultural products export trade. This paper will discuss how to use the new quality productivity to solve the problems faced by China’s agricultural export, so as to achieve the high-level development of agricultural export trade. With the help of new quality productivity, promoting agricultural deep processing technology innovation, the use of digital technology to build brand, upgrade agricultural production technology to ensure quality and safety, to strengthen the construction of agricultural product quality standard system to trade barriers, can enhance the competitiveness of agricultural products in the international market, promote the development of agricultural products export trade to achieve high level, and promote the sustainable development of agriculture in China.
