AC / DC converter is a kind of devices applicable to reactive power compensation. Three parameters including losses, Total Harmonic Distortion （THD） and compensation capacity have important role in designing procedu...AC / DC converter is a kind of devices applicable to reactive power compensation. Three parameters including losses, Total Harmonic Distortion （THD） and compensation capacity have important role in designing procedure that these parameters are affected by the firing angle. Consideration trade of between these parameters can cause be selected suitable firing angle for optimal working of the compensator. In this paper is defined an objective function which includes the above parameters. This objective function is optimized through appropriate weighting factor for any parameters and the optimal firing angle will be obtained. So, the mention parameters can be selected optimally.展开更多
Multilevel inverter has become increasingly popular in recent years due to advantages of high power quality waveforms, low switching losses, and high-voltage capability. A novel multilevel inverter with minimum number...Multilevel inverter has become increasingly popular in recent years due to advantages of high power quality waveforms, low switching losses, and high-voltage capability. A novel multilevel inverter with minimum number of separated DC sources is presented in this paper. Three-phase output voltages of this inverter can easily be balanced because they are synthesized by using the same DC sources. A harmonic reduction method eliminating both the 5th and 7th harmonics is proposed. Finally, comparison results and spectral analysis are presented. Key words multilevel inverter - topology - DC source - harmonic reduction - spectrum Project supported by the Postdoctoral Science Foundation of Shanghai (Grant No. kO7)展开更多
This paper presents an advanced three-phase four-wire interlinking niicrogrid system with an improved harmonics reduction feature.Due to their robustness and simplicity features,time-domain second-order notch-filter e...This paper presents an advanced three-phase four-wire interlinking niicrogrid system with an improved harmonics reduction feature.Due to their robustness and simplicity features,time-domain second-order notch-filter equivalent techniques have drawn a great deal of research attention.However,the drawbacks of non-satisfactory harmonics rejection characteristics and dynamic response limits their applications.In this context,this paper proposes an advanced control system with an enhanced harmonics reduction feature for microgrid applications.The proposed control system exhibits a superior harmonics reduction feature and better dynamic response than the conventional notch-filter based techniques.In addition,a control scheme is developed for a three-phase power system application which presents higher accuracy in compensating both balanced and unbalanced harmonics.The performance of the proposed system is validated through simulations and tested on the hardware of a real microgrid system.From the results,it is evident that the proposed approach provides excellent performance in terms of harmonics reduction in microgrid systems.展开更多
文摘AC / DC converter is a kind of devices applicable to reactive power compensation. Three parameters including losses, Total Harmonic Distortion （THD） and compensation capacity have important role in designing procedure that these parameters are affected by the firing angle. Consideration trade of between these parameters can cause be selected suitable firing angle for optimal working of the compensator. In this paper is defined an objective function which includes the above parameters. This objective function is optimized through appropriate weighting factor for any parameters and the optimal firing angle will be obtained. So, the mention parameters can be selected optimally.
文摘Multilevel inverter has become increasingly popular in recent years due to advantages of high power quality waveforms, low switching losses, and high-voltage capability. A novel multilevel inverter with minimum number of separated DC sources is presented in this paper. Three-phase output voltages of this inverter can easily be balanced because they are synthesized by using the same DC sources. A harmonic reduction method eliminating both the 5th and 7th harmonics is proposed. Finally, comparison results and spectral analysis are presented. Key words multilevel inverter - topology - DC source - harmonic reduction - spectrum Project supported by the Postdoctoral Science Foundation of Shanghai (Grant No. kO7)
文摘This paper presents an advanced three-phase four-wire interlinking niicrogrid system with an improved harmonics reduction feature.Due to their robustness and simplicity features,time-domain second-order notch-filter equivalent techniques have drawn a great deal of research attention.However,the drawbacks of non-satisfactory harmonics rejection characteristics and dynamic response limits their applications.In this context,this paper proposes an advanced control system with an enhanced harmonics reduction feature for microgrid applications.The proposed control system exhibits a superior harmonics reduction feature and better dynamic response than the conventional notch-filter based techniques.In addition,a control scheme is developed for a three-phase power system application which presents higher accuracy in compensating both balanced and unbalanced harmonics.The performance of the proposed system is validated through simulations and tested on the hardware of a real microgrid system.From the results,it is evident that the proposed approach provides excellent performance in terms of harmonics reduction in microgrid systems.
