在未来可再生电能传输和管理微网(future renewable electric energy delivery and management,FREEDM)中固态变压器间会因输出电压偏差及输出阻抗的不匹配而产生环流,孤岛模式下尤为严重,为此,在下垂控制器中引入固态变压器(solid stat...在未来可再生电能传输和管理微网(future renewable electric energy delivery and management,FREEDM)中固态变压器间会因输出电压偏差及输出阻抗的不匹配而产生环流,孤岛模式下尤为严重,为此,在下垂控制器中引入固态变压器(solid state transformer,SST)间输出电压偏差反馈调节,减小输出电压相角差和幅值差;采用基于模糊控制理论的瞬时环流反馈,进行动态虚拟阻抗调节,使得SST输出阻抗按额定功率精确匹配。仿真及分析表明,电压偏差反馈调节配合动态虚拟阻抗控制可以有效地抑制SST间环流,同时提高SST输出电压的稳定性。展开更多
Smart grid was proposed as a practical form of future power distribution system. Evaluating the reliability of smart grids was of great importance and significance. A revised fault tree model was proposed to distingui...Smart grid was proposed as a practical form of future power distribution system. Evaluating the reliability of smart grids was of great importance and significance. A revised fault tree model was proposed to distinguish and separate grid-connected operation mode and islanded operation mode of smart grids,focusing on the perspective of the consumers. A hierarchical Monte Carlo simulation method for reliability evaluation was also proposed based on the proposed fault tree model. A case of reliability evaluation for the future renewable electric energy delivery and management( FREEDM) system was carried out and analyzed. The proposed methods can be applicable to other forms of smart grids.展开更多
文摘在未来可再生电能传输和管理微网(future renewable electric energy delivery and management,FREEDM)中固态变压器间会因输出电压偏差及输出阻抗的不匹配而产生环流,孤岛模式下尤为严重,为此,在下垂控制器中引入固态变压器(solid state transformer,SST)间输出电压偏差反馈调节,减小输出电压相角差和幅值差;采用基于模糊控制理论的瞬时环流反馈,进行动态虚拟阻抗调节,使得SST输出阻抗按额定功率精确匹配。仿真及分析表明,电压偏差反馈调节配合动态虚拟阻抗控制可以有效地抑制SST间环流,同时提高SST输出电压的稳定性。
文摘Smart grid was proposed as a practical form of future power distribution system. Evaluating the reliability of smart grids was of great importance and significance. A revised fault tree model was proposed to distinguish and separate grid-connected operation mode and islanded operation mode of smart grids,focusing on the perspective of the consumers. A hierarchical Monte Carlo simulation method for reliability evaluation was also proposed based on the proposed fault tree model. A case of reliability evaluation for the future renewable electric energy delivery and management( FREEDM) system was carried out and analyzed. The proposed methods can be applicable to other forms of smart grids.
