Considering the high DC current and high pulse frequency characteristic of ultrasonic frequency fast-convert pulse plasma spraying process,a special power supply topology was proposed,which was composed of the mutual ...Considering the high DC current and high pulse frequency characteristic of ultrasonic frequency fast-convert pulse plasma spraying process,a special power supply topology was proposed,which was composed of the mutual independent base current circuit and peak current circuit.Base current circuit was consisted of four parallel direct current power supplies,which was not only to meet the requirements of high power output,but also improved the reliability of power supply.Base on the Boost circuit topology,a peak current circuit was designed,which could reduce effectively the output inductance influence and output ultrasonic frequency pulse high current with fast-convert rising and falling edge.Based on the above techniques,the Ultrasonic frequency fast-convert pulse plasma spraying power supply was established.It can output 5-1000A base current,0-250A peak current,and the pulse current frequency band is 20-100kHz,10%～80% duty ratio and pulse current change rate over 50A/μs.展开更多
由于光储直流微网输出功率在孤岛模式下受外部环境影响较大,为提高系统的最大功率跟踪特性,采用了正反激变换器的独立光伏发电拓扑结构。针对传统滑模控制在光伏最大功率跟踪(maximum power point tracking,MPPT)中存在的滑模抖振和响...由于光储直流微网输出功率在孤岛模式下受外部环境影响较大,为提高系统的最大功率跟踪特性,采用了正反激变换器的独立光伏发电拓扑结构。针对传统滑模控制在光伏最大功率跟踪(maximum power point tracking,MPPT)中存在的滑模抖振和响应速度慢等问题,提出一种基于改进型超螺旋趋近律的MPPT滑模控制实现方法。该方法利用Sigmoid函数的连续性并与快速终端滑模面相结合,优化了超螺旋趋近律,改善了抖振效果,提高了响应速度,并利用Matlab/Simulink仿真平台与其他控制策略进行对比验证。结果表明:当系统不存在外界扰动时,所提方法均能实现对最大功率点的快速跟踪,同时具有较小的抖振。当辐照度、温度发生变化时,系统具有更好的动态响应速度和抗扰能力。展开更多
文摘Considering the high DC current and high pulse frequency characteristic of ultrasonic frequency fast-convert pulse plasma spraying process,a special power supply topology was proposed,which was composed of the mutual independent base current circuit and peak current circuit.Base current circuit was consisted of four parallel direct current power supplies,which was not only to meet the requirements of high power output,but also improved the reliability of power supply.Base on the Boost circuit topology,a peak current circuit was designed,which could reduce effectively the output inductance influence and output ultrasonic frequency pulse high current with fast-convert rising and falling edge.Based on the above techniques,the Ultrasonic frequency fast-convert pulse plasma spraying power supply was established.It can output 5-1000A base current,0-250A peak current,and the pulse current frequency band is 20-100kHz,10%～80% duty ratio and pulse current change rate over 50A/μs.
文摘由于光储直流微网输出功率在孤岛模式下受外部环境影响较大,为提高系统的最大功率跟踪特性,采用了正反激变换器的独立光伏发电拓扑结构。针对传统滑模控制在光伏最大功率跟踪(maximum power point tracking,MPPT)中存在的滑模抖振和响应速度慢等问题,提出一种基于改进型超螺旋趋近律的MPPT滑模控制实现方法。该方法利用Sigmoid函数的连续性并与快速终端滑模面相结合,优化了超螺旋趋近律,改善了抖振效果,提高了响应速度,并利用Matlab/Simulink仿真平台与其他控制策略进行对比验证。结果表明:当系统不存在外界扰动时,所提方法均能实现对最大功率点的快速跟踪,同时具有较小的抖振。当辐照度、温度发生变化时,系统具有更好的动态响应速度和抗扰能力。
