There are many motors in operation or on standby in nuclear power plants,and the startup of group motors will have a great impact on the voltage of the emergency bus.At present,there is no special or inexpensive softw...There are many motors in operation or on standby in nuclear power plants,and the startup of group motors will have a great impact on the voltage of the emergency bus.At present,there is no special or inexpensive software to solve this problem,and the experience of engineers is not accurate enough.Therefore,this paper developed a method and system for the startup calculation of group motors in nuclear power plants and proposed an automatic generation method of circuit topology in nuclear power plants.Each component in the topology was given its unique number,and the component class could be constructed according to its type and upper and lower connections.The subordination and topology relationship of switches,buses,and motors could be quickly generated by the program according to the component class,and the simplified direct power flow algorithm was used to calculate the power flow for the startup of group motors according to the above relationship.Then,whether the bus voltage is in the safe range and whether the voltage exceeds the limit during the startup of the group motor could be judged.The practical example was used to verify the effectiveness of the method.Compared with other professional software,the method has high efficiency and low cost.展开更多
提出了两种含VSC-MTDC的交、直流系统潮流控制算法,即节点注入电流法和改进序列潮流算法。节点注入电流法中,以各端公共耦合点PCC(point of common coupling)作为交替求解的接口,VSC-MTDC系统对交流系统的影响通过改变PCC点的注入电流...提出了两种含VSC-MTDC的交、直流系统潮流控制算法,即节点注入电流法和改进序列潮流算法。节点注入电流法中,以各端公共耦合点PCC(point of common coupling)作为交替求解的接口,VSC-MTDC系统对交流系统的影响通过改变PCC点的注入电流来实现。针对节点注入电流法中由于接口变量数目较多而导致收敛性能变差的问题,改进了序列潮流算法,只需设置主站PCC点传输的有功功率作为接口变量进行迭代更新,直至收敛。在新英格兰系统上验证了两种所提算法的有效性和可行性。对比分析两种方法可知,改进序列潮流算法总体性能优于节点注入电流法,为含VSC-MTDC的交、直流系统潮流算法的选择提供参考。展开更多
进化类算法和内点法交替迭代的混合算法在求解含电压源换流器的高压直流输电(voltage source converter basedhigh voltage direct current,VSC-HVDC)的交直流系统最优潮流(optimal power flow,OPF)问题时由于截断误差的影响和VSC-HVDC...进化类算法和内点法交替迭代的混合算法在求解含电压源换流器的高压直流输电(voltage source converter basedhigh voltage direct current,VSC-HVDC)的交直流系统最优潮流(optimal power flow,OPF)问题时由于截断误差的影响和VSC-HVDC控制方式的限制,容易发生振荡,因此提出一种基于差分进化(differential evolution,DE)和原—对偶内点法(primal-dual interior point method,PDIPM)的统一混合迭代算法。算法的主要思想是以DE算法为框架,对离散变量进行优化,在DE算法的每一次迭代过程中,采用PDIPM对每个DE个体进行连续变量的优化和适应度评估。由于采用PDIPM进行DE种群适应度评估,无需设定VSC-HVDC的控制方式,因此提高了算法的全局寻优能力。多个算例结果表明,该混合算法数值稳定性高,寻优能力强,能很好地解决含两端、多端、多馈入VSC-HVDC的交直流系统最优潮流问题。展开更多
基金Key Project of National Natural Science Foundation of China(52237008)Beijing Municipal Education Commission Research Program Funding Project(KM202111232022)。
文摘There are many motors in operation or on standby in nuclear power plants,and the startup of group motors will have a great impact on the voltage of the emergency bus.At present,there is no special or inexpensive software to solve this problem,and the experience of engineers is not accurate enough.Therefore,this paper developed a method and system for the startup calculation of group motors in nuclear power plants and proposed an automatic generation method of circuit topology in nuclear power plants.Each component in the topology was given its unique number,and the component class could be constructed according to its type and upper and lower connections.The subordination and topology relationship of switches,buses,and motors could be quickly generated by the program according to the component class,and the simplified direct power flow algorithm was used to calculate the power flow for the startup of group motors according to the above relationship.Then,whether the bus voltage is in the safe range and whether the voltage exceeds the limit during the startup of the group motor could be judged.The practical example was used to verify the effectiveness of the method.Compared with other professional software,the method has high efficiency and low cost.
文摘提出了两种含VSC-MTDC的交、直流系统潮流控制算法,即节点注入电流法和改进序列潮流算法。节点注入电流法中,以各端公共耦合点PCC(point of common coupling)作为交替求解的接口,VSC-MTDC系统对交流系统的影响通过改变PCC点的注入电流来实现。针对节点注入电流法中由于接口变量数目较多而导致收敛性能变差的问题,改进了序列潮流算法,只需设置主站PCC点传输的有功功率作为接口变量进行迭代更新,直至收敛。在新英格兰系统上验证了两种所提算法的有效性和可行性。对比分析两种方法可知,改进序列潮流算法总体性能优于节点注入电流法,为含VSC-MTDC的交、直流系统潮流算法的选择提供参考。
文摘进化类算法和内点法交替迭代的混合算法在求解含电压源换流器的高压直流输电(voltage source converter basedhigh voltage direct current,VSC-HVDC)的交直流系统最优潮流(optimal power flow,OPF)问题时由于截断误差的影响和VSC-HVDC控制方式的限制,容易发生振荡,因此提出一种基于差分进化(differential evolution,DE)和原—对偶内点法(primal-dual interior point method,PDIPM)的统一混合迭代算法。算法的主要思想是以DE算法为框架,对离散变量进行优化,在DE算法的每一次迭代过程中,采用PDIPM对每个DE个体进行连续变量的优化和适应度评估。由于采用PDIPM进行DE种群适应度评估,无需设定VSC-HVDC的控制方式,因此提高了算法的全局寻优能力。多个算例结果表明,该混合算法数值稳定性高,寻优能力强,能很好地解决含两端、多端、多馈入VSC-HVDC的交直流系统最优潮流问题。
