Nowadays,　with　the　rapid　development　of　high-performance　servo　system,　As　the　newly　rich　of　servo　motor,　Permanent　magnet　synchronous　motor　(PMSM)　control　requirements　also　become　higher　and　higher.　It　is　worth　noting　that　the　sensorless　PMSM　control　system　has　gradually　become　the　research　hot　spot.　The　key　reason　is　there　is　a　lot　of　inconvenience　in　many　industrial　fields　to　install　motor　speed　encoder　to　measure　the　speed　of　PMSM　(Casadei　et　al.,　2000).　For　the　purpose　of　realizing　the　sensorless　vector　control　of　PMSM,　this　study　proposed　a　rotor　speed　and　position　estimation　method　based　on　the　instantaneous　power　angle　detection,　targeted　on　the　most　common　vector　control　method-id　=　0　control　algorithm.　The　study　discussed　the　basic　principles　of　the　sensorless　control　of　PMSM　technology,　established　a　PMSM　sensorless　vector　control　system　simulation　model.　The　simulation　results　showed　that　rotor　speed　sensorless　vector　control　system　has　good　dynamic　and　static　performance　and　robustness　characteristics.　The　sensorless　control　algorithm　is　simple　and　easy　to　implement.　©　2013　Asian　Network　for　Scientific　Information.