Harmonics　and　drifts　are　found　in　the　position　estimation　errors　of　high-frequency　signal　injection　(HFI)　methods.　To　suppress　the　position　estimation　error,　a　hybrid　active　flux　observer　with　disturbance　rejection　for　both　HFI　method　and　model-based　method　is　proposed.　It　fuses　the　position　information　from　traditional　HFI　method　and　model-based　method　as　the　input　of　a　disturbance　observer,　the　estimated　disturbance　output　can　compensate　measurement　error　for　the　two　methods.　Then　a　reduced-order　natural　speed　observer　is　connected　in　a　cascaded　form　to　reject　motor　mechanical　disturbance　by　estimating　the　load　torque.　Besides,　a　stator　resistance　identification　algorithm　is　proposed,　which　is　proved　stable　near　zero　frequency　under　persistent　excitation　condition.　A　tuning　guideline　for　the　whole　algorithm　is　elaborated　based　on　a　rigorous　stability　analysis.　Effective　experiments　and　simulations　verify　the　feasibility　of　the　proposed　scheme　on　a　0.75-kW　interior　permanent　magnet　synchronous　motor　drive　platform.　©　1986-2012　IEEE.