Stability performance of multi-connected inverters with global synchronous pulse width modulation

The resonance problems may arise among multi-connected LCL-filtered inverters and make the system instable. The recently proposed GSPWM can reduce the filter order without reducing other performance in large-scale application, which has potential to avoid the resonance. But GSPWM will introduce specific phase delay to PWM sequences and it may influence the response character in different grid conditions. These issues have effect on the application of GSPWM and have not been analyzed before. So this paper investigates the stability performance of multi-connected L-filtered inverters with considering the influence of GSPWM in different grid condition. Firstly, this paper briefly introduces the basic principle of GSPWM and the principle of reducing the filter order. Then, this paper analyzes the stability performance of GSPWM in normal operation and fault operation with different grid conditions. And the conclusion indicates that multi-connected L-filtered inverters with GSPWM can get better stability performance in different grid condition when the quantity of inverters is large. Finally, simulation and experimental results are proposed to verify the stability performance of multi-connected L-filtered with GSPWM.