http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
An Optimal Random Carrier Pulse Width Modulation Technique Based on a Genetic Algorithm
Xu, Jie,Nie, Zi-Ling,Zhu, Jun-Jie The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2
Since the carrier sequence is not reproducible in a period of the random carrier pulse width modulation (RCPWM) and a higher harmonic spectrum amplitude is likely to affect the quality of the power supply. In addition, electromagnetic interference (EMI) and mechanical vibration will appear. To solve these problems, this paper has proposed an optimal RCPWM based on a genetic algorithm (GA). In the optimal modulation, the range of the random carrier frequency is taken as a constraint and the reciprocal of the maximum harmonic spectrum amplitude is used as a fitness function to decrease the EMI and mechanical vibration caused by the harmonics concentrated at the carrier frequency and its multiples. Since the problems of the hardware make it difficult to use in practical engineering, this paper has presented a hardware system. Simulations and experiments show that the RCPWM is effective. Studies show that the harmonic spectrum is distributed more uniformly in the frequency domain and that there is no obvious peak in the wave spectra. The proposed method is of great value to research on RCPWM and integrated power systems (IPS).
An Optimal Random Carrier Pulse Width Modulation Technique Based on a Genetic Algorithm
Jie Xu,Zi-Ling Nie,Jun-Jie Zhu 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2
Since the carrier sequence is not reproducible in a period of the random carrier pulse width modulation (RCPWM) and a higher harmonic spectrum amplitude is likely to affect the quality of the power supply. In addition, electromagnetic interference (EMI) and mechanical vibration will appear. To solve these problems, this paper has proposed an optimal RCPWM based on a genetic algorithm (GA). In the optimal modulation, the range of the random carrier frequency is taken as a constraint and the reciprocal of the maximum harmonic spectrum amplitude is used as a fitness function to decrease the EMI and mechanical vibration caused by the harmonics concentrated at the carrier frequency and its multiples. Since the problems of the hardware make it difficult to use in practical engineering, this paper has presented a hardware system. Simulations and experiments show that the RCPWM is effective. Studies show that the harmonic spectrum is distributed more uniformly in the frequency domain and that there is no obvious peak in the wave spectra. The proposed method is of great value to research on RCPWM and integrated power systems (IPS).
Jun-Jie Zhu,Zi-Ling Nie,Yin-Feng Zhang,Yi Han 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6
The mode-switching control of transient process is important to grid-connected 400 ㎐ solid-state power supply systems. Therefore, this paper analyzes the principle of on-grid and islanding operation of the system with or without local loads in the grid-connected process and provides a theoretical study of the effect of different switching sequences on the mode-switching transient process. The conclusion is that the mode switch (MS) must be turned on before the solid-state switch (STS) in the on-grid process and that STS must be turned off before the MS in the off-grid process. A strategy of mode-switching smooth control for transient process of the system is proposed, including its concrete steps. The strategy utilizes the average distribution of peak currents and the smooth adjustment of peak currents and phases to achieve a no-shock grid connection. The simulation and experimental results show that the theoretical analysis is correct and that the method is effective.
Zhu, Jun-Jie,Nie, Zi-Ling,Zhang, Yin-Feng,Han, Yi The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6
The mode-switching control of transient process is important to grid-connected 400 Hz solid-state power supply systems. Therefore, this paper analyzes the principle of on-grid and islanding operation of the system with or without local loads in the grid-connected process and provides a theoretical study of the effect of different switching sequences on the mode-switching transient process. The conclusion is that the mode switch (MS) must be turned on before the solid-state switch (STS) in the on-grid process and that STS must be turned off before the MS in the off-grid process. A strategy of mode-switching smooth control for transient process of the system is proposed, including its concrete steps. The strategy utilizes the average distribution of peak currents and the smooth adjustment of peak currents and phases to achieve a no-shock grid connection. The simulation and experimental results show that the theoretical analysis is correct and that the method is effective.
Cao Mei-He,Nie Zi-Ling,Ai Sheng,Xu Jie 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.3
Phase-shifted full-bridge DC/DC converter is widely used in the medium and high power DC/DC conversion, and its efciency is an important index to evaluate the performance of the converter. Phase-shifted full-bridge circuit can easily realize the zero voltage switching (ZVS) of the power devices, but there are also problems such as duty-cycle loss and lagging bridge arms that make it difcult to achieve a wide range of ZVS. The application of active auxiliary network can efectively solve the above problems, but it introduces additional loss. This paper analyzes the phase-shifted full-bridge DC/DC converter with active auxiliary network, the duty cycle-loss suppression and the additional circuit loss, optimizes the circuit parameters to reduce the loss and improve the overall efciency of the converter, verifes the theoretical analysis through experiments. Finally, the efciency advantages of the study for high current output applications are clarifed.