When a wind turbine is struck by lightning,its blades are usually rotating.The effect of blade rotation on a turbine＇s ability to trigger a lightning strike is unclear.Therefore,an arching electrode was used in a win...When a wind turbine is struck by lightning,its blades are usually rotating.The effect of blade rotation on a turbine＇s ability to trigger a lightning strike is unclear.Therefore,an arching electrode was used in a wind turbine lightning discharge test to investigate the difference in lightning triggering ability when blades are rotating and stationary.A negative polarity switching waveform of 250/2500 μs was applied to the arching electrode and the up-and-down method was used to calculate the 50%discharge voltage.Lightning discharge tests of a 1：30 scale wind turbine model with 2,4,and 6 m air gaps were performed and the discharge process was observed.The experimental results demonstrated that when a 2 m air gap was used,the breakdown voltage increased as the blade speed was increased,but when the gap length was 4 m or longer,the trend was reversed and the breakdown voltage decreased.The analysis revealed that the rotation of the blades changes the charge distribution in the blade-tip region,promotes upward leader development on the blade tip,and decreases the breakdown voltage.Thus,the blade rotation of a wind turbine increases its ability to trigger lightning strikes.展开更多
随着风电渗透率的提高,大功率风电爬坡可造成系统功率不平衡,甚至导致停电事故。提出了基于信息差距决策理论(information gap decision theory,IGDT)鲁棒模型的风电爬坡事件协调调度决策方法。分析了各参与方的调度成本及约束条件,采...随着风电渗透率的提高,大功率风电爬坡可造成系统功率不平衡,甚至导致停电事故。提出了基于信息差距决策理论(information gap decision theory,IGDT)鲁棒模型的风电爬坡事件协调调度决策方法。分析了各参与方的调度成本及约束条件,采用常规机组、风电场及需求侧协调调度的方式,降低风电爬坡事件的不利影响,并保证决策方案的经济性;利用IGDT方法处理风电功率的不确定性,构建最恶劣爬坡场景,制定针对预期成本具有鲁棒性的决策方案。算例及实际系统不同情形下调度决策方案的分析和比较,验证了所提调度决策方法的鲁棒性和经济性。展开更多
随着社会的发展,具有随机性、间歇性的风电等新能源大规模接入电网。同时,负荷侧结构变动、用电主观性以及预测技术的限制使得调度中的负荷需求难以准确获取。这些因素导致电力系统中的不确定性愈发呈现"奈特氏不确定性"的特...随着社会的发展,具有随机性、间歇性的风电等新能源大规模接入电网。同时,负荷侧结构变动、用电主观性以及预测技术的限制使得调度中的负荷需求难以准确获取。这些因素导致电力系统中的不确定性愈发呈现"奈特氏不确定性"的特性,使得电力系统调度成为一项十分具有挑战性的工作。为此,该文采用一种新的非概率性方法——信息间隙决策理论(information gap decision theory,IGDT)对风电输出功率和系统负荷需求的不确定性进行建模,建立了风险规避和机会寻求2种策略下的IGDT调度模型,解决了电力系统调度中风电和负荷的奈特氏不确定性。最后在改进的IEEE-39节点系统上对所提模型进行算例分析,结果分析以及蒙特卡洛模拟证明了所提IGDT模型的有效性。展开更多
基金supported by the China State Grid Corp headquarters project in 2015(SGTYHT/14JS-188)
文摘When a wind turbine is struck by lightning,its blades are usually rotating.The effect of blade rotation on a turbine＇s ability to trigger a lightning strike is unclear.Therefore,an arching electrode was used in a wind turbine lightning discharge test to investigate the difference in lightning triggering ability when blades are rotating and stationary.A negative polarity switching waveform of 250/2500 μs was applied to the arching electrode and the up-and-down method was used to calculate the 50%discharge voltage.Lightning discharge tests of a 1：30 scale wind turbine model with 2,4,and 6 m air gaps were performed and the discharge process was observed.The experimental results demonstrated that when a 2 m air gap was used,the breakdown voltage increased as the blade speed was increased,but when the gap length was 4 m or longer,the trend was reversed and the breakdown voltage decreased.The analysis revealed that the rotation of the blades changes the charge distribution in the blade-tip region,promotes upward leader development on the blade tip,and decreases the breakdown voltage.Thus,the blade rotation of a wind turbine increases its ability to trigger lightning strikes.
文摘随着风电渗透率的提高,大功率风电爬坡可造成系统功率不平衡,甚至导致停电事故。提出了基于信息差距决策理论(information gap decision theory,IGDT)鲁棒模型的风电爬坡事件协调调度决策方法。分析了各参与方的调度成本及约束条件,采用常规机组、风电场及需求侧协调调度的方式,降低风电爬坡事件的不利影响,并保证决策方案的经济性;利用IGDT方法处理风电功率的不确定性,构建最恶劣爬坡场景,制定针对预期成本具有鲁棒性的决策方案。算例及实际系统不同情形下调度决策方案的分析和比较,验证了所提调度决策方法的鲁棒性和经济性。
文摘随着社会的发展,具有随机性、间歇性的风电等新能源大规模接入电网。同时,负荷侧结构变动、用电主观性以及预测技术的限制使得调度中的负荷需求难以准确获取。这些因素导致电力系统中的不确定性愈发呈现"奈特氏不确定性"的特性,使得电力系统调度成为一项十分具有挑战性的工作。为此,该文采用一种新的非概率性方法——信息间隙决策理论(information gap decision theory,IGDT)对风电输出功率和系统负荷需求的不确定性进行建模,建立了风险规避和机会寻求2种策略下的IGDT调度模型,解决了电力系统调度中风电和负荷的奈特氏不确定性。最后在改进的IEEE-39节点系统上对所提模型进行算例分析,结果分析以及蒙特卡洛模拟证明了所提IGDT模型的有效性。
