围绕通信不间断电源(Uninterruptible Power Supply,UPS)系统中多电平脉冲宽度调制(Pulse Width Modulation,PWM)逆变拓扑的谐波控制展开研究,深入分析多电平逆变结构在提升输出波形质量和降低谐波失真方面的技术优势。结合通信电源对...围绕通信不间断电源(Uninterruptible Power Supply,UPS)系统中多电平脉冲宽度调制(Pulse Width Modulation,PWM)逆变拓扑的谐波控制展开研究,深入分析多电平逆变结构在提升输出波形质量和降低谐波失真方面的技术优势。结合通信电源对高可靠性和低干扰的实际需求,构建基于PWM优化与滤波器参数设计的复合型谐波控制策略。通过建模仿真实验对不同调制方式与滤波结构进行对比分析,结果表明所提方法在降低总谐波失真、提升系统稳定性与电能质量方面具有明显优势,可为通信UPS系统的结构优化和工程应用提供理论支撑与实践参考。展开更多
The photovoltaic performance of metal halide perovskite solar cells often respond divergently to environmental conditions during storage.In particular,light exposure can either enhance or degrade device efficiency,yet...The photovoltaic performance of metal halide perovskite solar cells often respond divergently to environmental conditions during storage.In particular,light exposure can either enhance or degrade device efficiency,yet the mechanisms underlying these antithetical behaviors are still under investigation.In this study,we explore the modulation of the open-circuit voltage(Voc)in triple-cation mixed-halide perovskite solar cells by systematically controlling storage environments.While light intensity exhibits minimal impact during storage,the spectral composition of illumination selectively enhances Voc comprising reversible and irreversible contributions.Structural characterization reveals that prolonged storage degrades the quality of perovskite crystals in the upper region of the perovskite layer,whereas light storage promotes the relaxation of microstrain at the buried interface with a p-type organic layer.This structural reorganization at the interface,accompanied by lattice expansion,accounts for suppressed nonradiative recombination and a corresponding increase in quasi-Fermi level splitting.Consequently,devices fabricated without chemical defect passivation achieve a power conversion efficiency of higher than 40%under indoor lighting conditions after preconditioned by continuous exposure to ambient light during storage.These findings highlight the critical role of controlled light exposure during storage not only in enhancing efficiency,but also in ensuring reproducibility of perovskite solar cell characterization.展开更多
文摘围绕通信不间断电源(Uninterruptible Power Supply,UPS)系统中多电平脉冲宽度调制(Pulse Width Modulation,PWM)逆变拓扑的谐波控制展开研究,深入分析多电平逆变结构在提升输出波形质量和降低谐波失真方面的技术优势。结合通信电源对高可靠性和低干扰的实际需求,构建基于PWM优化与滤波器参数设计的复合型谐波控制策略。通过建模仿真实验对不同调制方式与滤波结构进行对比分析,结果表明所提方法在降低总谐波失真、提升系统稳定性与电能质量方面具有明显优势,可为通信UPS系统的结构优化和工程应用提供理论支撑与实践参考。
基金supported by a National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(RS-2023-NR076521,RS-2025-00519481)the Research Grant of Kwangwoon University in 2023.
文摘The photovoltaic performance of metal halide perovskite solar cells often respond divergently to environmental conditions during storage.In particular,light exposure can either enhance or degrade device efficiency,yet the mechanisms underlying these antithetical behaviors are still under investigation.In this study,we explore the modulation of the open-circuit voltage(Voc)in triple-cation mixed-halide perovskite solar cells by systematically controlling storage environments.While light intensity exhibits minimal impact during storage,the spectral composition of illumination selectively enhances Voc comprising reversible and irreversible contributions.Structural characterization reveals that prolonged storage degrades the quality of perovskite crystals in the upper region of the perovskite layer,whereas light storage promotes the relaxation of microstrain at the buried interface with a p-type organic layer.This structural reorganization at the interface,accompanied by lattice expansion,accounts for suppressed nonradiative recombination and a corresponding increase in quasi-Fermi level splitting.Consequently,devices fabricated without chemical defect passivation achieve a power conversion efficiency of higher than 40%under indoor lighting conditions after preconditioned by continuous exposure to ambient light during storage.These findings highlight the critical role of controlled light exposure during storage not only in enhancing efficiency,but also in ensuring reproducibility of perovskite solar cell characterization.
