An exponential-function-based droop control strategy for the distributed energy resources(DERs)is proposed to reduce the reactive power-sharing deviation,limit the minimum value of frequency/voltage,whilst improving t...An exponential-function-based droop control strategy for the distributed energy resources(DERs)is proposed to reduce the reactive power-sharing deviation,limit the minimum value of frequency/voltage,whilst improving the utilization rate of renewable energy.Both DERs and loads are interconnected to achieve a power exchange by converters,where the power management system should accurately share the active/reactive power demand.However,the proportional reactive power sharing often deteriorates due to its dependence on the line impedances.Thus,an exponential-function-based droop control is proposed to(1)prevent voltage and frequency from falling to the lower restraint,(2)achieve accurate reactive power sharing,(3)eliminate communication and improve the usage ratio of renewable energy.Furthermore,its stability is analyzed,and the application in islanded AC/DC hybrid microgrids is investigated to achieve the bidirectional power flow.The simulation and experimental results show that the reactive power sharing deviation can be reduced,and the utilization rate of renewable energy is improved by using the proposed method.Moreover,the simulation results illustrate that the system can maintain stable operation when the microgrid is switched from one supplied energy operation condition to another absorbed one.展开更多
电机是飞轮系统实现电能与机械能相互转换的核心。BLDC(brushless direct current)电机具有体积小、噪声低、经济效益高等优点,在储能中得到了应用。为避免电机在充放电过程中产生较大绕组损耗或引入辅助电路稳定输出电压,在搭建应用于...电机是飞轮系统实现电能与机械能相互转换的核心。BLDC(brushless direct current)电机具有体积小、噪声低、经济效益高等优点,在储能中得到了应用。为避免电机在充放电过程中产生较大绕组损耗或引入辅助电路稳定输出电压,在搭建应用于飞轮储能的BLDC电机模型基础上,提出改变晶闸管导通与关断顺序的电机充放电控制策略,改变绕组反电势与流经电流方向,实现电机充放电功能。仿真结果表明搭建的BLDC电机模型能够正确表示飞轮运行特性,也表明提出的电机充放电控制策略在不引入额外的电路拓扑结构情况下,能够使电机在充电状态吸收功率,将电能转换为飞轮动能,电机在放电状态释放功率,将飞轮动能转换为电能,并且充放电过程中相关电气量可控,从而实现功率双向流动过程,此控制策略的设计为飞轮储能的机电一体化产品实现提供一定的理论基础。展开更多
In this paper, analysis, design and implementation of non-isolated soft-switching bidirectional DC-DC converter with an active switch are described. The proposed topology gives the output voltage as twice as the input...In this paper, analysis, design and implementation of non-isolated soft-switching bidirectional DC-DC converter with an active switch are described. The proposed topology gives the output voltage as twice as the input voltage and enhances the efficiency up to 94.5% and 92.9% for boost and buck mode operation by proper selection of the duty cycle. Soft switching can be achieved at both steps up and step down operating modes. Small signal analysis based on state space averaging and transfer functions have been presented in detail for the proposed converter. Finally, the feasibility of the desired converter is confirmed to mat lab simulation and investigational results.展开更多
基金国家"十二五"科技支撑计划(2013BAG24B02)国家电网公司科技项目(DG71–15–039)+1 种基金Project supported by Key Project of the National Eleventh-five Year Science and Technology Supporting Program of China(2013BAG24B02)Science and Technology Project of SGCC(DG71–15–039)
基金supported by National Key Research and Development Program of China(No.2017YFF0108800)National Natural Science Foundation of China(Nos.61773109,6143304)Major Program of National Natural Foundation of China(No.61573094).
文摘An exponential-function-based droop control strategy for the distributed energy resources(DERs)is proposed to reduce the reactive power-sharing deviation,limit the minimum value of frequency/voltage,whilst improving the utilization rate of renewable energy.Both DERs and loads are interconnected to achieve a power exchange by converters,where the power management system should accurately share the active/reactive power demand.However,the proportional reactive power sharing often deteriorates due to its dependence on the line impedances.Thus,an exponential-function-based droop control is proposed to(1)prevent voltage and frequency from falling to the lower restraint,(2)achieve accurate reactive power sharing,(3)eliminate communication and improve the usage ratio of renewable energy.Furthermore,its stability is analyzed,and the application in islanded AC/DC hybrid microgrids is investigated to achieve the bidirectional power flow.The simulation and experimental results show that the reactive power sharing deviation can be reduced,and the utilization rate of renewable energy is improved by using the proposed method.Moreover,the simulation results illustrate that the system can maintain stable operation when the microgrid is switched from one supplied energy operation condition to another absorbed one.
文摘电机是飞轮系统实现电能与机械能相互转换的核心。BLDC(brushless direct current)电机具有体积小、噪声低、经济效益高等优点,在储能中得到了应用。为避免电机在充放电过程中产生较大绕组损耗或引入辅助电路稳定输出电压,在搭建应用于飞轮储能的BLDC电机模型基础上,提出改变晶闸管导通与关断顺序的电机充放电控制策略,改变绕组反电势与流经电流方向,实现电机充放电功能。仿真结果表明搭建的BLDC电机模型能够正确表示飞轮运行特性,也表明提出的电机充放电控制策略在不引入额外的电路拓扑结构情况下,能够使电机在充电状态吸收功率,将电能转换为飞轮动能,电机在放电状态释放功率,将飞轮动能转换为电能,并且充放电过程中相关电气量可控,从而实现功率双向流动过程,此控制策略的设计为飞轮储能的机电一体化产品实现提供一定的理论基础。
文摘In this paper, analysis, design and implementation of non-isolated soft-switching bidirectional DC-DC converter with an active switch are described. The proposed topology gives the output voltage as twice as the input voltage and enhances the efficiency up to 94.5% and 92.9% for boost and buck mode operation by proper selection of the duty cycle. Soft switching can be achieved at both steps up and step down operating modes. Small signal analysis based on state space averaging and transfer functions have been presented in detail for the proposed converter. Finally, the feasibility of the desired converter is confirmed to mat lab simulation and investigational results.
