For years, capacitive effects have been the subject of research [1] and [2]. The capacitive effects are discrete capacitors that appear between active conductors of power lines and between them with the ground plane, ...For years, capacitive effects have been the subject of research [1] and [2]. The capacitive effects are discrete capacitors that appear between active conductors of power lines and between them with the ground plane, generating capacitive reactive power to the network [1] and [2]. Indeed, it must be noted that these effects affect the windings of the transformer when the coupling is in star or triangle. This study is conducted to show that capacitive effects affect transformer windings differently when coupling is in stars or triangles. The results obtained are interesting and can be exploited in electrical transmission networks to ensure a long lifespan of transformers.展开更多
采用多电平电路构建的双有源桥(dual active bridge,DAB)DC/DC变换器可适用于更高的电压等级并能显著地提高功率密度及性能。基于九开关管五电平有源中点钳位(five-level active neutral point clamed,5L ANPC)电路构建DAB变换器,消除...采用多电平电路构建的双有源桥(dual active bridge,DAB)DC/DC变换器可适用于更高的电压等级并能显著地提高功率密度及性能。基于九开关管五电平有源中点钳位(five-level active neutral point clamed,5L ANPC)电路构建DAB变换器,消除传统的八开关管5L ANPC电路所存在的电平跳变问题。通过分析开关状态之间的切换过程,选取的零开关状态实现所有高压开关管的软开关运行;通过分析不同开关序列对飞跨电容电压和直流侧中点电压的影响,提出一种飞跨电容电压的平衡控制方法。基于1kW样机的实验结果表明,该文构建的5L ANPC DAB变换器获得了优良的性能。展开更多
文摘For years, capacitive effects have been the subject of research [1] and [2]. The capacitive effects are discrete capacitors that appear between active conductors of power lines and between them with the ground plane, generating capacitive reactive power to the network [1] and [2]. Indeed, it must be noted that these effects affect the windings of the transformer when the coupling is in star or triangle. This study is conducted to show that capacitive effects affect transformer windings differently when coupling is in stars or triangles. The results obtained are interesting and can be exploited in electrical transmission networks to ensure a long lifespan of transformers.
文摘采用多电平电路构建的双有源桥(dual active bridge,DAB)DC/DC变换器可适用于更高的电压等级并能显著地提高功率密度及性能。基于九开关管五电平有源中点钳位(five-level active neutral point clamed,5L ANPC)电路构建DAB变换器,消除传统的八开关管5L ANPC电路所存在的电平跳变问题。通过分析开关状态之间的切换过程,选取的零开关状态实现所有高压开关管的软开关运行;通过分析不同开关序列对飞跨电容电压和直流侧中点电压的影响,提出一种飞跨电容电压的平衡控制方法。基于1kW样机的实验结果表明,该文构建的5L ANPC DAB变换器获得了优良的性能。
