Neurons at rest can exhibit diverse firing activities patterns in response to various external deterministic and random stimuli, especially additional currents. In this paper, neuronal firing patterns from bursting to...Neurons at rest can exhibit diverse firing activities patterns in response to various external deterministic and random stimuli, especially additional currents. In this paper, neuronal firing patterns from bursting to spiking, induced by additional direct and stochastic currents, are explored in rest states corresponding to two values of the parameter VK in the Chay neuron system. Three cases are considered by numerical simulation and fast/slow dynamic analysis, in which only the direct current or the stochastic current exists, or the direct and stochastic currents coexist. Meanwhile, several important bursting patterns in neuronal experiments, such as the period-1 ＂circle/homoclinic＂ bursting and the integer multiple ＂fold/homoclinic＂ bursting with onc spike per burst, as well as the transition from integer multiple bursting to period-1 ＂circle/homoclinic＂ bursting and that from stochastic ＂Hopf/homoclinic＂ bursting to ＂Hopf/homoclinic＂ bursting, are investigated in detail.展开更多
混合式高压直流断路器分断速度快且通态损耗低,能够保证不闭锁换流站的情况下实现线路故障的快速隔离,减小故障范围,是直流电网保护的关键设备之一。首先研究了含混合式直流断路器的柔直系统直流故障限流机理,分析影响直流故障电流峰值...混合式高压直流断路器分断速度快且通态损耗低,能够保证不闭锁换流站的情况下实现线路故障的快速隔离,减小故障范围,是直流电网保护的关键设备之一。首先研究了含混合式直流断路器的柔直系统直流故障限流机理,分析影响直流故障电流峰值以及故障电流持续时间的关键因素,并在现有混合式高压直流断路器基础上,提出一种快速限流的优化技术方案,在转移支路加入故障限流子模块(fault current limiter submodule,FCL_SM),FCL_SM由二极管桥、限流电阻以及限压电路组成,通过在故障过程中投入FCL_SM来降低故障电流峰值以及MOV吸收能量。最后通过PSCAD/EMTDC仿真分析,验证了所提优化方案的可行性与有效性。仿真结果表明,优化方案可有效降低直流故障电流峰值(降低幅度达14%)、故障电流持续时间以及直流断路器MOV吸收能量(降低幅度达16.2%),并可有效降低设备设计成本。展开更多
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10432010 and 10526002）.Acknowledgement The bifurcation diagrams in this paper are obtained by means of the package C0NTENT.
文摘Neurons at rest can exhibit diverse firing activities patterns in response to various external deterministic and random stimuli, especially additional currents. In this paper, neuronal firing patterns from bursting to spiking, induced by additional direct and stochastic currents, are explored in rest states corresponding to two values of the parameter VK in the Chay neuron system. Three cases are considered by numerical simulation and fast/slow dynamic analysis, in which only the direct current or the stochastic current exists, or the direct and stochastic currents coexist. Meanwhile, several important bursting patterns in neuronal experiments, such as the period-1 ＂circle/homoclinic＂ bursting and the integer multiple ＂fold/homoclinic＂ bursting with onc spike per burst, as well as the transition from integer multiple bursting to period-1 ＂circle/homoclinic＂ bursting and that from stochastic ＂Hopf/homoclinic＂ bursting to ＂Hopf/homoclinic＂ bursting, are investigated in detail.
文摘混合式高压直流断路器分断速度快且通态损耗低,能够保证不闭锁换流站的情况下实现线路故障的快速隔离,减小故障范围,是直流电网保护的关键设备之一。首先研究了含混合式直流断路器的柔直系统直流故障限流机理,分析影响直流故障电流峰值以及故障电流持续时间的关键因素,并在现有混合式高压直流断路器基础上,提出一种快速限流的优化技术方案,在转移支路加入故障限流子模块(fault current limiter submodule,FCL_SM),FCL_SM由二极管桥、限流电阻以及限压电路组成,通过在故障过程中投入FCL_SM来降低故障电流峰值以及MOV吸收能量。最后通过PSCAD/EMTDC仿真分析,验证了所提优化方案的可行性与有效性。仿真结果表明,优化方案可有效降低直流故障电流峰值(降低幅度达14%)、故障电流持续时间以及直流断路器MOV吸收能量(降低幅度达16.2%),并可有效降低设备设计成本。
