Sensorless control method and apparatus of permanent magnet synchronous motor

A sensorless control apparatus of a permanent magnet synchronous machine, comprising:

• a distribution gain generator setting a distribution gain K1 to be decreased as the absolute value of a rotation speed command .omega..sub.RREF becomes large and a distribution gain K2 to be increased as the absolute value of a rotation speed command .omega..sub.RREF becomes large;
• .gamma. axis current command generator generating the .gamma. axis command i.sub..gamma..spsb.REF based on the .gamma. axis current command i.sub..gamma..spsb.REFL at low speed state, the .gamma. axis current command i.sub..gamma..spsb.REFH at high speed state and the distribution gains K1, K2;
• a speed controller outputting the .delta. axis current i.sub..delta..spsb.REF based on the rotation speed command .omega..sub.RREF ;
• .delta. axis current controller outputting the .delta. axis voltage command v.sub..delta..spsb.REF based on the .delta. axis current i.sub..gamma..spsb.REF ;
• .gamma. axis current controller outputting the .gamma. axis current command v.sub..gamma..spsb.REF based on the .gamma. axis current command i.sub..gamma..spsb.REF ;
• a vector control circuit outputting amount of voltage and position angle to an inverter circuit of the synchronous motor based on the .delta. axis voltage command V.sub..delta..spsb.REF and the .gamma. axis voltage command v.sub..gamma..spsb.REF ;
• a three phases/two phases converter generating the .delta. axis current i.sub..delta. and the .gamma. axis current i.gamma. based on currents i.sub.u, i.sub.w of two phases of the synchronous motor;
• .gamma.-.delta. axis, current, induced voltage estimator outputting the induced voltage estimated values .epsilon..sub..delta..spsb.est (k+1) and .epsilon..sub..gamma..spsb.est (k+1) based on the voltage commands v.sub..delta..spsb.REF, v.sub..gamma..spsb.REF, the .delta. axis current i.sub..delta. and the .gamma. axis current i.sub..gamma. and also outputting the .gamma. axis current estimated value i.sub..gamma..spsb.est (k+1) to the .gamma. axis current controller and the .delta. axis current estimated value i.sub.67 .spsb.est (k+1) to the .delta. axis current controller respectively;
• a proportion control speed operator operating the command control speed .omega..sub.RPest based on the induced voltage estimated values .epsilon..sub..delta..spsb.est (k+1), .epsilon..sub..gamma..spsb.est (k+1);
• an integral magnetic axis rotation speed operator outputting the rotation speed .omega..sub.R.sbsb..gamma..sub.est of the magnetic axis based on the distribution gains K1, K2 and the command control speed .omega..sub.RPest ;
• and
• a magnetic axis operator inputting amount of voltage and position angle to the inverter circuit based on the rotation speed .omega..sub.R.sbsb..gamma..sub.est of the magnetic axis.