One of the main problems in wind energy conversion system (WECS) is how to achieve maxim­u­m output power in different wind speeds. Maximum methods for maximum power point tracking in wind energy conversion syst­e­ms require the knowledge of system characteristics and mechanic sensors. So, using these methods practically will follow with high price and an abundant difficulties. In this pape...

A multilevel inverter is a power electronic device made to synthesize a desired AC voltage from several levels of DC voltages. Some industrial drives require medium voltage and megawatt power level. For a medium voltage grid, it is troublesome to connect only one power semiconductor switch directly. A multilevel power converter structure has been introduced as an alternative in high power and m...

Electric power quality problem has become an important problem in modern society, which effects industrial production and product quality, etc. So, we urgently need monitor and analyze electric power parameter to solve electric power quality problem. In this paper, we design a kind of electric power parameter detection system based on visual instrument (VI) technology, etc. System uses voltage/...

the harmonic in distribution systems becomes an important problem due to an increase in nonlinear loads. this paper presents a new approach based on a graph algorithm for optimum placement of passive harmonic filters in a multi-bus system, which suffers from harmonic current sources. the objective of this paper is to minimize the network loss, the cost of the filter and the total harmonic disto...

We study optical second harmonic generation from metallic dipole antennas with narrow gaps. Enhancement of the fundamental-frequency field in the gap region plays a marginal role on conversion efficiency. In the symmetric configuration, i.e., with the gap located at the center of the antenna axis, reducing gap size induces a significant red-shift of the maximum conversion efficiency peak. Eithe...