A　key　issue　in　the　direct　torque　control　(DTC)　of　permanent　magnet　brushless　DC　motor　(BLDCM)　is　the　estimation　of　the　instantaneous　electromagnetic　torque.　Additionally,　some　BLDCMs　also　have　saliency　phenomenon　which　augments　the　difficulty　of　torque　estimation.　A　sensorless　toque　estimator　was　proposed　in　this　paper.　A　stator　current　estimator　with　rotor　back-electromotive-force　(BEMF)　self-adaptation　was　firstly　constructed　according　to　stator　current　state　equations　and　the　rotor　BEMF　was　gained　by　adaptive　law.　Then,　a　lock-phase　loop　was　used　to　output　smooth　rotor　position　angle　estimation　value　on　basic　of　identified　rotor　BEMF.　At　last,　the　torque　was　calculated　to　realize　saliency　BLDCM-DTC　based　on　the　estimated　rotor　position　angle.　The　experimental　results　show　the　estimated　torque　is　very　close　to　the　actual　value,　and　the　novel　sensorless　DTC　drive　has　quick　dynamic　response　and　smooth　operation　with　a　minimum　steady-state　speed　lowering　to　33　r/min.　©　2013　Chinese　Society　for　Electrical　Engineering.