| A phase and an amplitude improving method includes performing a model establishing step, a phase compensating step, an amplitude compensating step and a compensation information generating step.  The model establishing step includes establishing an inverter model.  A voltage command is inputted to the inverter model to generate an actual voltage information.  The voltage command includes a phase command information and an amplitude command information.  The phase compensating step includes computing the phase command information and the actual voltage information to generate a compensating phase information.  The amplitude compensating step includes computing the amplitude command information and the actual voltage information to generate a compensating amplitude information.  The compensation information generating step includes generating a compensating voltage command.  The compensating voltage command is inputted to the inverter model to generate a compensating actual voltage information. |