The coordinated pulse width modulation (PWM) schemes feature the intricated vector sequences for the optimization of the switching related performance indicators. Existing common-mode injections disrupt the optimized switching sequence

compromising the benefits of coordinated PWM. To address this

this paper proposes a differential signal injection method to suppress low-frequency ZSCC without disrupting the original switching sequence. By injecting differential-mode signals at specific vector angles into individual phases

the proposed method maintains the original switching-related performance while mitigating low-frequency circulating currents. Experimental validation with two typical coordinated modulation schemes confirms that the proposed method achieves both effective ZSCC suppression and preservation of high-frequency optimization.