For the low voltage direct current (LVDC) distribution system, the advantages and disadvantages of the different grounding modes of the voltage source converter are analyzed and compared. In the converter capacitor directly grounding and high resistance grounding mode, the converter AC outlet of asymmetric fault characteristics and DC line pole grounding fault characteristics are analyzed, and the LVDC electromagnetic transient model is established and studied by simulation. Comparison of the system transient performance under different operating conditions shows that voltage source converter capacitor high resistance grounding mode is better than the direct grounding way. High resistance grounding to limit fault current is more favorable, and it is also beneficial to the rapid recovery after the DC power distribution system is eliminated, which lays the foundation for the protection scheme of DC power distribution system in the future. This work is supported by Shanghai Engineering Research Center of Green Energy Grid Connected Technology (No. 13DZ2251900).