将一种新型MMC的拓扑结构应用于静止同步补偿器(STATCOM),与传统MMC相比,在相同子模块数量时能多一个电平输出。介绍了该新型MMC的拓扑结构,分析了其输出N+2电平的原理,得到了MMC的等效电路;以STATCOM补偿无功电流和三相不平衡电流为目...将一种新型MMC的拓扑结构应用于静止同步补偿器(STATCOM),与传统MMC相比,在相同子模块数量时能多一个电平输出。介绍了该新型MMC的拓扑结构,分析了其输出N+2电平的原理,得到了MMC的等效电路;以STATCOM补偿无功电流和三相不平衡电流为目的,设计了相应的指令电流获取策略;采用直接电流跟踪控制策略;为保证MMC子模块直流电容电压恒定,采用电压分层控制策略,能量均分控制保证每相子模块电容电压之和恒定,电压均衡控制保证每相中各子模块电容电压均衡;采用载波移相PWM策略。最后在PSCAD/EMTDC软件中,搭建了三相10k V 8电平的STATCOM,仿真结果验证了控制策略的有效性。展开更多
Aluminum 6061 alloy metal matrix composites (MMCs) reinforced with four different weight fractions of (Al<sub>2</sub>O<sub>3</sub> + red mud) particles up to 10 wt% were fabricated by a vortex ...Aluminum 6061 alloy metal matrix composites (MMCs) reinforced with four different weight fractions of (Al<sub>2</sub>O<sub>3</sub> + red mud) particles up to 10 wt% were fabricated by a vortex method. The effects of reinforcement content on the mechanical properties of the composites such as hardness and tensile strength were investigated. The density measurements showed that the samples contained little porosity, and the amount of porosity in the composites increased with increasing weight fraction of particles. Scanning electron microscopic observations of the microstructures revealed that the dispersion of the particles was uniform with small clusters at some places and porosity. The results showed that the hardness and the tensile strength of the composites increased with increasing weight fraction of particles.展开更多
文摘将一种新型MMC的拓扑结构应用于静止同步补偿器(STATCOM),与传统MMC相比,在相同子模块数量时能多一个电平输出。介绍了该新型MMC的拓扑结构,分析了其输出N+2电平的原理,得到了MMC的等效电路;以STATCOM补偿无功电流和三相不平衡电流为目的,设计了相应的指令电流获取策略;采用直接电流跟踪控制策略;为保证MMC子模块直流电容电压恒定,采用电压分层控制策略,能量均分控制保证每相子模块电容电压之和恒定,电压均衡控制保证每相中各子模块电容电压均衡;采用载波移相PWM策略。最后在PSCAD/EMTDC软件中,搭建了三相10k V 8电平的STATCOM,仿真结果验证了控制策略的有效性。
文摘Aluminum 6061 alloy metal matrix composites (MMCs) reinforced with four different weight fractions of (Al<sub>2</sub>O<sub>3</sub> + red mud) particles up to 10 wt% were fabricated by a vortex method. The effects of reinforcement content on the mechanical properties of the composites such as hardness and tensile strength were investigated. The density measurements showed that the samples contained little porosity, and the amount of porosity in the composites increased with increasing weight fraction of particles. Scanning electron microscopic observations of the microstructures revealed that the dispersion of the particles was uniform with small clusters at some places and porosity. The results showed that the hardness and the tensile strength of the composites increased with increasing weight fraction of particles.
