This paper presents a new type of fault current limiter (FCL) based on fast closing switch, which is composed of a capacitor bank and a reactor in series. The main control component is a fast closing switch connecte...This paper presents a new type of fault current limiter (FCL) based on fast closing switch, which is composed of a capacitor bank and a reactor in series. The main control component is a fast closing switch connected in parallel with the capacitors, which is driven by the electromagnetic repulsion force. It can response the order within 1 ms. When fault occurs, the switch closes and the capacitors are bypassed, and the fault current is limited by the reactor. Simulation analysis and experiment show that the electromagnetic repulsion force actuator can meet the demand of fast closing switch, it is feasible to develop the FCL with low cost and high reliability.展开更多
A coaxial multi-gap multi-channel spark switch with stainless-steel-spring ring gap electrodes is designed and investigated. The switch is triggered by a pulse applied to the cylindrical electrode outside the discharg...A coaxial multi-gap multi-channel spark switch with stainless-steel-spring ring gap electrodes is designed and investigated. The switch is triggered by a pulse applied to the cylindrical electrode outside the discharging channel through a parasitic capacitance coupling. The jitter of the switch is reduced by several short-distance gas gaps in series, and its inductance is reduced by a multi-channel discharge on account of the inductance isolation between the coils of the spring ring electrode. The experimental results indicate that the switch is of low inductance (15-30 nH), low jitter (-3 ns), and stable breakdown performance展开更多
This paper explores the model reference adaptive control problem for a class of switched linear systems under arbitrary switching with no need for the measurability of the system state.Based on the state of reference ...This paper explores the model reference adaptive control problem for a class of switched linear systems under arbitrary switching with no need for the measurability of the system state.Based on the state of reference model and the measurable output error, adaptive laws and controllers are designed for switched systems.Each subsystem may have its individual reference model and controller, which increases the design flexibility.The introduction of the closed-loop reference model is to get a better transient performance of the whole switched systems.A numerical example is provided to verify the effectiveness of the main results.展开更多
An analysis technique of steady state and stability for closed-loop PWM DC/DC switching converters is presented. Using this method, the closed-loop switching converter is transformed into an open-loop system. By means...An analysis technique of steady state and stability for closed-loop PWM DC/DC switching converters is presented. Using this method, the closed-loop switching converter is transformed into an open-loop system. By means of the fact that in steady state, the two boundary values are equal in one switching period. The exponential matrix is evaluated by precise time-domain-integration method, and then the related curve between feedback duty cycle and the input one is obtained. Not only can the steady-state duty cycle be found from the curve, but also the stability and stable domain of the system. Compared with other methods, it features with simplicity and less calculation, and fit for numerical simulation and analysis for closed-loop switching converters. The simulation results of examples indicate the correctness of the presented method.展开更多
A new type of fault current limiter (FCL) with series compensation based fast-closing switch is proposed. It is composed of a capacitor bank and a reactor in series. The main control component is a fast-closing switch...A new type of fault current limiter (FCL) with series compensation based fast-closing switch is proposed. It is composed of a capacitor bank and a reactor in series. The main control component is a fast-closing switch connected in parallel with the capacitors, which is driven by the electromagnetic repulsion force. When fault occurs, the switch closes and bypasses the capacitors, and the fault is limited by the reactor then. Simulated analysis and experiments show that it is feasible to develop the FCL with low cost and high reliability. The effectiveness of transient stability for power system is evaluated by digital simulation.展开更多
随着光伏和风能等可再生能源在柔性配电网中的比例不断提高,可再生能源发电的间歇性输出给电力系统带来了不稳定性与波动性。现有的柔性合环开关因为硬件参数和容量限制,无法应对负荷超容量波动带来的频率超限及潮流转移造成的电网开路...随着光伏和风能等可再生能源在柔性配电网中的比例不断提高,可再生能源发电的间歇性输出给电力系统带来了不稳定性与波动性。现有的柔性合环开关因为硬件参数和容量限制,无法应对负荷超容量波动带来的频率超限及潮流转移造成的电网开路问题。因此,有必要将柔性合环开关与储能技术相结合,构建新型柔性互联配电网,对带电池储能系统的多端口柔性合环开关设计相应的控制策略。首先,对于硬件参数不同和工作状态差异造成的储能单元荷电状态(state of charge,SOC)不均衡,设计自适应的SOC均衡控制策略。其次,对负荷大波动和稳压侧开路故障,设计切换策略以调节电网频率并进行短时直流电压支撑,确保下级负荷的稳定运行。最后,利用基于MATLAB/Simulink平台的仿真模型和RTLAB硬件在环平台验证了所提协调控制策略的有效性和实用性。展开更多
文摘This paper presents a new type of fault current limiter (FCL) based on fast closing switch, which is composed of a capacitor bank and a reactor in series. The main control component is a fast closing switch connected in parallel with the capacitors, which is driven by the electromagnetic repulsion force. It can response the order within 1 ms. When fault occurs, the switch closes and the capacitors are bypassed, and the fault current is limited by the reactor. Simulation analysis and experiment show that the electromagnetic repulsion force actuator can meet the demand of fast closing switch, it is feasible to develop the FCL with low cost and high reliability.
基金This work was supported by the National Natural Science Foundation of China, Grant No. 10035020
文摘A coaxial multi-gap multi-channel spark switch with stainless-steel-spring ring gap electrodes is designed and investigated. The switch is triggered by a pulse applied to the cylindrical electrode outside the discharging channel through a parasitic capacitance coupling. The jitter of the switch is reduced by several short-distance gas gaps in series, and its inductance is reduced by a multi-channel discharge on account of the inductance isolation between the coils of the spring ring electrode. The experimental results indicate that the switch is of low inductance (15-30 nH), low jitter (-3 ns), and stable breakdown performance
基金Sponsored by the National Natural Science Foundation of China(Grant No.61233002)the 111 Project(Grant No.B16009)the IAPI Fundamental Research Funds(Grant No.2013ZCX03-01)
文摘This paper explores the model reference adaptive control problem for a class of switched linear systems under arbitrary switching with no need for the measurability of the system state.Based on the state of reference model and the measurable output error, adaptive laws and controllers are designed for switched systems.Each subsystem may have its individual reference model and controller, which increases the design flexibility.The introduction of the closed-loop reference model is to get a better transient performance of the whole switched systems.A numerical example is provided to verify the effectiveness of the main results.
文摘An analysis technique of steady state and stability for closed-loop PWM DC/DC switching converters is presented. Using this method, the closed-loop switching converter is transformed into an open-loop system. By means of the fact that in steady state, the two boundary values are equal in one switching period. The exponential matrix is evaluated by precise time-domain-integration method, and then the related curve between feedback duty cycle and the input one is obtained. Not only can the steady-state duty cycle be found from the curve, but also the stability and stable domain of the system. Compared with other methods, it features with simplicity and less calculation, and fit for numerical simulation and analysis for closed-loop switching converters. The simulation results of examples indicate the correctness of the presented method.
文摘A new type of fault current limiter (FCL) with series compensation based fast-closing switch is proposed. It is composed of a capacitor bank and a reactor in series. The main control component is a fast-closing switch connected in parallel with the capacitors, which is driven by the electromagnetic repulsion force. When fault occurs, the switch closes and bypasses the capacitors, and the fault is limited by the reactor then. Simulated analysis and experiments show that it is feasible to develop the FCL with low cost and high reliability. The effectiveness of transient stability for power system is evaluated by digital simulation.
文摘随着光伏和风能等可再生能源在柔性配电网中的比例不断提高,可再生能源发电的间歇性输出给电力系统带来了不稳定性与波动性。现有的柔性合环开关因为硬件参数和容量限制,无法应对负荷超容量波动带来的频率超限及潮流转移造成的电网开路问题。因此,有必要将柔性合环开关与储能技术相结合,构建新型柔性互联配电网,对带电池储能系统的多端口柔性合环开关设计相应的控制策略。首先,对于硬件参数不同和工作状态差异造成的储能单元荷电状态(state of charge,SOC)不均衡,设计自适应的SOC均衡控制策略。其次,对负荷大波动和稳压侧开路故障,设计切换策略以调节电网频率并进行短时直流电压支撑,确保下级负荷的稳定运行。最后,利用基于MATLAB/Simulink平台的仿真模型和RTLAB硬件在环平台验证了所提协调控制策略的有效性和实用性。
