可控串联补偿(thyristor controlled series capacitor,TCSC)的模式切换对电力系统的稳定控制具有重要意义。TCSC阻抗双解现象的存在对其模式切换提出了更高的要求,单一改变触发角的方法无法实现模式切换。在考虑阻抗双解现象影响的基础...可控串联补偿(thyristor controlled series capacitor,TCSC)的模式切换对电力系统的稳定控制具有重要意义。TCSC阻抗双解现象的存在对其模式切换提出了更高的要求,单一改变触发角的方法无法实现模式切换。在考虑阻抗双解现象影响的基础上,提出了一套相应的TCSC模式切换控制方法。通过强制晶闸管支路电流与线路电流同步,实现由容性区到Bypass模式的切换;在由容性区到感性微调模式切换的过程中提出了晶闸管条件触发的方法,即当线路电流和电容电压满足同向条件时晶闸管才触发导通。同时为及时向切换控制提供线路电流同步信号,提出了一种预测电流过零的新方法。数字仿真及动模实验结果表明,提出的切换方法能使切换过程平稳迅速,且动态特性良好。展开更多
In recent years, population growth models with spatial diffusion have beenextensively studied by many authors (for example, see [1-5]). In this paper, a populationgrowth model is considered with a discrete age-depende...In recent years, population growth models with spatial diffusion have beenextensively studied by many authors (for example, see [1-5]). In this paper, a populationgrowth model is considered with a discrete age-dependence and spatial diffusion, and isinvestigated in a semigroup framework. The spectral properties of the population oper-ator are given. On the basis of such spectral consideration, the asymptotic behaviourof the semigroup generated by the population operator is obtained. Finally, a nonlinearpopulation growth model is considered and its stability is analyzed.展开更多
文摘可控串联补偿(thyristor controlled series capacitor,TCSC)的模式切换对电力系统的稳定控制具有重要意义。TCSC阻抗双解现象的存在对其模式切换提出了更高的要求,单一改变触发角的方法无法实现模式切换。在考虑阻抗双解现象影响的基础上,提出了一套相应的TCSC模式切换控制方法。通过强制晶闸管支路电流与线路电流同步,实现由容性区到Bypass模式的切换;在由容性区到感性微调模式切换的过程中提出了晶闸管条件触发的方法,即当线路电流和电容电压满足同向条件时晶闸管才触发导通。同时为及时向切换控制提供线路电流同步信号,提出了一种预测电流过零的新方法。数字仿真及动模实验结果表明,提出的切换方法能使切换过程平稳迅速,且动态特性良好。
基金This research is supported by the National Natural Science Foundation of China.
文摘In recent years, population growth models with spatial diffusion have beenextensively studied by many authors (for example, see [1-5]). In this paper, a populationgrowth model is considered with a discrete age-dependence and spatial diffusion, and isinvestigated in a semigroup framework. The spectral properties of the population oper-ator are given. On the basis of such spectral consideration, the asymptotic behaviourof the semigroup generated by the population operator is obtained. Finally, a nonlinearpopulation growth model is considered and its stability is analyzed.
