由于统一潮流控制器的广泛应用受制其可靠性及成本高昂等不足,分布式潮流控制器（unified power flow controller,DPFC）应运而生。为分析DPFC提升最大输电能力期望和供电可靠性的效能,需要将该装置纳入大电网可靠性评估中。针对其分布...由于统一潮流控制器的广泛应用受制其可靠性及成本高昂等不足,分布式潮流控制器（unified power flow controller,DPFC）应运而生。为分析DPFC提升最大输电能力期望和供电可靠性的效能,需要将该装置纳入大电网可靠性评估中。针对其分布式串联侧进行结构解析,从而确定DPFC的运行状态及空间转移模型,通过马尔科夫过程可求解出DPFC各状态平稳概率与故障/修复率。基于此,建立含DPFC的系统潮流计算模型,并提出从断面最大输电能力期望和供电可靠性两大角度来综合评价DPFC效能的研究方法。经IEEE-RTS79算例分析表明：所述方法能够有效评价DPFC在电网可靠性方面的改善能力,可以从可靠性角度来确定DPFC最优配置方案,从而为实际工程提供一定指导意义。展开更多
针对在不同位置安装差异化容量的分布式潮流控制器(distributed power flow controller,DPFC)会带来不同的调控效能这一问题,提出选址定容两阶段DPFC优化方法。阐述了DPFC结构演变及其装置原理,对比统一潮流控制器分析DPFC的特点及优势...针对在不同位置安装差异化容量的分布式潮流控制器(distributed power flow controller,DPFC)会带来不同的调控效能这一问题,提出选址定容两阶段DPFC优化方法。阐述了DPFC结构演变及其装置原理,对比统一潮流控制器分析DPFC的特点及优势。基于串联侧的分布式结构,研究DPFC运行状态及空间转移模型。考虑到在电网不同位置安装差异化容量的DPFC将产生不同效能,制订选址定容两阶段DPFC优化方法,以最优成本获得电网性能提升的最佳效果和最大经济效益。基于DPFC对断面潮流均衡的影响度、对母线电压稳定贡献度来选取最优安装点,应用经济性成本/效益分析来迭代优化其容量。选取某省220 kV地区电网开展仿真分析,在该电网中进行DPFC优化配置以验证策略的可行性与正确性。仿真试验表明:优选地点能够有效改善断面潮流均衡性,优选装置容量可大幅提升断面输电能力期望,且该方式下DPFC效能比最大,电网总效益能够取得极大值。展开更多
By means of the relationship between speed and distance headway, this paperattempts to directly determine the road capacity based on a new concept. At first it makes acomprehensive analysis of distance headway, includ...By means of the relationship between speed and distance headway, this paperattempts to directly determine the road capacity based on a new concept. At first it makes acomprehensive analysis of distance headway, including safe distance headway and desired one. Theformer is decided by the demand for the degree of safety, and the latter depends on the motorists'behavior, i.e. the model of traffic flow. Both of them are functions of speed. According to thecharacteristics of their curves, we can find a crossing point that is the capacity of a roadsegment. This capacity represents the maximum flow rate meeting the minimum safety requirement.展开更多
Kolmogorov's exponential inequalities are basic tools for studying the strong limit theorems such as the classical laws of the iterated logarithm for both independent and dependent random variables. This paper est...Kolmogorov's exponential inequalities are basic tools for studying the strong limit theorems such as the classical laws of the iterated logarithm for both independent and dependent random variables. This paper establishes the Kolmogorov type exponential inequalities of the partial sums of independent random variables as well as negatively dependent random variables under the sub-linear expectations. As applications of the exponential inequalities, the laws of the iterated logarithm in the sense of non-additive capacities are proved for independent or negatively dependent identically distributed random variables with finite second order moments.For deriving a lower bound of an exponential inequality, a central limit theorem is also proved under the sublinear expectation for random variables with only finite variances.展开更多
文摘由于统一潮流控制器的广泛应用受制其可靠性及成本高昂等不足,分布式潮流控制器（unified power flow controller,DPFC）应运而生。为分析DPFC提升最大输电能力期望和供电可靠性的效能,需要将该装置纳入大电网可靠性评估中。针对其分布式串联侧进行结构解析,从而确定DPFC的运行状态及空间转移模型,通过马尔科夫过程可求解出DPFC各状态平稳概率与故障/修复率。基于此,建立含DPFC的系统潮流计算模型,并提出从断面最大输电能力期望和供电可靠性两大角度来综合评价DPFC效能的研究方法。经IEEE-RTS79算例分析表明：所述方法能够有效评价DPFC在电网可靠性方面的改善能力,可以从可靠性角度来确定DPFC最优配置方案,从而为实际工程提供一定指导意义。
文摘针对在不同位置安装差异化容量的分布式潮流控制器(distributed power flow controller,DPFC)会带来不同的调控效能这一问题,提出选址定容两阶段DPFC优化方法。阐述了DPFC结构演变及其装置原理,对比统一潮流控制器分析DPFC的特点及优势。基于串联侧的分布式结构,研究DPFC运行状态及空间转移模型。考虑到在电网不同位置安装差异化容量的DPFC将产生不同效能,制订选址定容两阶段DPFC优化方法,以最优成本获得电网性能提升的最佳效果和最大经济效益。基于DPFC对断面潮流均衡的影响度、对母线电压稳定贡献度来选取最优安装点,应用经济性成本/效益分析来迭代优化其容量。选取某省220 kV地区电网开展仿真分析,在该电网中进行DPFC优化配置以验证策略的可行性与正确性。仿真试验表明:优选地点能够有效改善断面潮流均衡性,优选装置容量可大幅提升断面输电能力期望,且该方式下DPFC效能比最大,电网总效益能够取得极大值。
文摘By means of the relationship between speed and distance headway, this paperattempts to directly determine the road capacity based on a new concept. At first it makes acomprehensive analysis of distance headway, including safe distance headway and desired one. Theformer is decided by the demand for the degree of safety, and the latter depends on the motorists'behavior, i.e. the model of traffic flow. Both of them are functions of speed. According to thecharacteristics of their curves, we can find a crossing point that is the capacity of a roadsegment. This capacity represents the maximum flow rate meeting the minimum safety requirement.
基金supported by National Natural Science Foundation of China (Grant No. 11225104)the National Basic Research Program of China (Grant No. 2015CB352302)the Fundamental Research Funds for the Central Universities
文摘Kolmogorov's exponential inequalities are basic tools for studying the strong limit theorems such as the classical laws of the iterated logarithm for both independent and dependent random variables. This paper establishes the Kolmogorov type exponential inequalities of the partial sums of independent random variables as well as negatively dependent random variables under the sub-linear expectations. As applications of the exponential inequalities, the laws of the iterated logarithm in the sense of non-additive capacities are proved for independent or negatively dependent identically distributed random variables with finite second order moments.For deriving a lower bound of an exponential inequality, a central limit theorem is also proved under the sublinear expectation for random variables with only finite variances.
