Aimed at information overload and personalized characteristic of user information requirement, this letter presents a type of multilevel index structure and algorithm which is applied to large scale information filter...Aimed at information overload and personalized characteristic of user information requirement, this letter presents a type of multilevel index structure and algorithm which is applied to large scale information filtering system and has better performance and stronger scalability.展开更多
Harmonic content of the voltage source inverters is important and must be in the allowed ranges. Different method are proposed to decrease the Total Harmonic Distortion (THD) and caused to be sinusoidal the output vol...Harmonic content of the voltage source inverters is important and must be in the allowed ranges. Different method are proposed to decrease the Total Harmonic Distortion (THD) and caused to be sinusoidal the output voltage of inverters. One of these methods is using multilevel structure. In this structure many important parameters which are effective on voltage source inverter operation that among them we can mention to modulation index (MI). Variation of modulation index can change the THD. One of the harmonic reduction methods is using multilevel structure. In this paper, a sample 5-level SHE-PWM voltage source inverter is presented and all equation and choosing switching angles for elimination desired harmonics from different order. To investigate the effective parameters on the inverter operation, a typical 5-level inverter is simulated in PSPICE software. The simulation has been done for different values of modulation and its effect on the inverter operation is evaluated.展开更多
基金Supported by key project 972044 of China Academy of Engineering Physics
文摘Aimed at information overload and personalized characteristic of user information requirement, this letter presents a type of multilevel index structure and algorithm which is applied to large scale information filtering system and has better performance and stronger scalability.
文摘Harmonic content of the voltage source inverters is important and must be in the allowed ranges. Different method are proposed to decrease the Total Harmonic Distortion (THD) and caused to be sinusoidal the output voltage of inverters. One of these methods is using multilevel structure. In this structure many important parameters which are effective on voltage source inverter operation that among them we can mention to modulation index (MI). Variation of modulation index can change the THD. One of the harmonic reduction methods is using multilevel structure. In this paper, a sample 5-level SHE-PWM voltage source inverter is presented and all equation and choosing switching angles for elimination desired harmonics from different order. To investigate the effective parameters on the inverter operation, a typical 5-level inverter is simulated in PSPICE software. The simulation has been done for different values of modulation and its effect on the inverter operation is evaluated.
