In　the　modulation　strategies　for　three-level　NPC　converter,　neutral　point　voltage　control　under　the　entire　modulation　index　and　full　power　factor　can　be　achieved　by　virtual　space　vector　pulse　width　modulation　(VSVPWM)　strategy.　In　this　paper　the　basic　principle　of　VSVPWM　is　analyzed,　then　the　internal　relation　between　three-level　VSVPWM　strategy　and　single-phase　dual　modulation　based　three-level　sinusoidal　pulse　width　modulation　(SPWM)　strategy　is　derived　and　the　modulation-wave　equivalence　between　the　two　modulation　strategies　is　established.　Using　the　established　modulation-wave　equivalent　relation,　the　total　harmonic　distortion　(THD)　of　output　voltage,　DC　voltage　utilization　rate　and　switch　device　losses　under　VSVPWM　strategy　are　analyzed.　Finally,　a　fast　implementation　of　three-level　VSVPWM　strategy　based　on　modulation-wave　equivalence　is　proposed.　The　correctness　of　the　theoretical　analysis　is　verified　by　both　results　from　simulation　and　experiments.