This article proposes a new active thermal control method for power semiconductor devices in parallel grid-tied inverters using coordinated pulsewidth modulation (PWM), which breaks the limitation that the PWM-based active thermal control cannot reduce the switching frequency below rated value, and therefore provides more regulation freedom to improve the reliability of power semiconductor devices. In specific, both frequency and phase shift values of PWM sequences will be adjusted coordinately to relieve the junction temperature of parallel inverters while keeping the total high-frequency harmonics at point of common coupling (PCC) to meet the quality requirement. The presented method is applicable to parallel inverters with identical or different input power. Finally, experimental results verified the performance of the proposed method.

中文翻译：

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并联并网逆变器中功率半导体器件基于 PWM 的协调主动热控制


本文提出了一种采用协调脉宽调制（PWM）的并联并网逆变器中功率半导体器件的主动热控制方法，突破了基于PWM的主动热控制无法将开关频率降低到额定值以下的限制，因此提供更多的调节自由度以提高功率半导体器件的可靠性。具体来说，将协调调整PWM序列的频率和相移值，以降低并联逆变器的结温，同时将总高频谐波保持在公共耦合点（PCC）以满足质量要求。该方法适用于具有相同或不同输入功率的并联逆变器。最后，实验结果验证了所提方法的性能。