The excessive mean value and large fluctuation amplitude of junction temperature are the main reasons for the failure of power semiconductor devices. The traditional active thermal control (ATC) for single inverter can reduce the fluctuation amplitude. But it has to increase the switching frequency due to the harmonic standard, which will increase the mean value of junction temperature. Focusing on the parallel-connected inverters, the recently proposed global synchronous pulse width modulation (GSPWM) method brings a new way to reduce the switching frequency while meeting the harmonic standard by coordinating the PWM sequences among inverters. Based on the GSPWM, this paper further proposes a general coordinated active thermal control (GC-ATC) method for parallel-connected inverters with different parameter variations. In this paper, a weighted switching frequency regulation method is firstly proposed to generate the same switching frequency, where the basic principles and main details of the proposed method are introduced. Furthermore, a correlation grouping method is introduced to improve the effect of the proposed method. Finally, the simulation and experimental results verify the proposed method.
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