We analyzed the four-quadrant converter commutation loop which operates with high frequency high power three-level active neutral point clamped（ANPC） converter. Considering the influence of different commutation loops on ANPC under high stray inductance

we obtained the voltage stress of small commutation loop and large commutation loop

respectively. By comparing two modulation strategies of sinusoidal pulse width modulation（SPWM） in three-level ANPC

namely

phase disposition pulse width modulation（PDPWM） and phase shift pulse width modulation（PSPWM）

the PDPWM modulation strategy is adopted to avoid large commutation loop as much as possible. In the case of high stray parameters

the resonance will be generated after the absorption capacitor is added. By analyzing the commutation loop in detail

the causes of resonance are summarized

and the improved PDPWM modulation strategy is put forward. Simulation and experimental results show that the theoretical analysis is verified and the resonance is effectively suppressed.