Many conventional switching power supplies in input AC line voltage and filtering it with large electrolytic computers and low power motor drive systems operate by rectifying the capacitors. This results in undesirabl...Many conventional switching power supplies in input AC line voltage and filtering it with large electrolytic computers and low power motor drive systems operate by rectifying the capacitors. This results in undesirable side effects such as the generation of distorted input current waveform. The input power factor is also poor. Further, the input current has the shape of narrow pulses, which in turn increases its value. The reduction in input current harmonics and improved power factor operation of motor drive systems and switching power supplies are important from the energy saving point of view and also to satisfy the harmonic standards. This paper proposes a full bridge PWM rectifier with load current feedforward. The proposed approach has some advantages, including a quick response for the load fluctuation, the reduction of the number of sensors and simplified control, as compared with the conventional methods. From simulated results, it is clarified that the proposed control method is effective and useful.展开更多
We propose a potential scheme to generate a genuine six-atom entangled state [J. Phys. A 42 (2009) 415301] by using atoms in cavity QED system, where the atoms interact simultaneously with the highly detuned single-mo...We propose a potential scheme to generate a genuine six-atom entangled state [J. Phys. A 42 (2009) 415301] by using atoms in cavity QED system, where the atoms interact simultaneously with the highly detuned single-mode cavity and the strong classical driving field. Thus our approach is insensitive to both the cavity decay and thermal field.展开更多
文摘Many conventional switching power supplies in input AC line voltage and filtering it with large electrolytic computers and low power motor drive systems operate by rectifying the capacitors. This results in undesirable side effects such as the generation of distorted input current waveform. The input power factor is also poor. Further, the input current has the shape of narrow pulses, which in turn increases its value. The reduction in input current harmonics and improved power factor operation of motor drive systems and switching power supplies are important from the energy saving point of view and also to satisfy the harmonic standards. This paper proposes a full bridge PWM rectifier with load current feedforward. The proposed approach has some advantages, including a quick response for the load fluctuation, the reduction of the number of sensors and simplified control, as compared with the conventional methods. From simulated results, it is clarified that the proposed control method is effective and useful.
基金Supported by the National Natural Science Foundation of China under Grant No. 61265001the Natural Science Foundation of Jiangxi Province under Grant No. 20122BAB202005+1 种基金the Research Foundation of State Key Laboratory of Advanced Optical Communication Systems and Networks, Shanghai Jiao Tong University under Grant No. 2011GZK031104the Research Foundation of the Education Department of Jiangxi Province
文摘We propose a potential scheme to generate a genuine six-atom entangled state [J. Phys. A 42 (2009) 415301] by using atoms in cavity QED system, where the atoms interact simultaneously with the highly detuned single-mode cavity and the strong classical driving field. Thus our approach is insensitive to both the cavity decay and thermal field.
