Control apparatus, dual chip inverter and single chip inverter of AC motors

Abstract

A control apparatus and a semiconductor apparatus of AC motors capable of reducing torque ripple with a comparatively simple circuit corresponding to a high withstand voltage and capable of driving a motor at high efficiency even when the rotational speed or load has changed. The control apparatus detects first phase signals fixed in relative phase to induced voltages of the motor and current polarity signals, recognizes phase differences between them, generates second phase signals so as to make the phase differences approach zero to drive the motor at high efficiency, generates modulation wave signals having quasi-sinusoidal waveforms or trapezoidal waveforms on the basis of the second phase signals, compares the modulation wave signals with a carrier wave signal, and conducts PWM control on an inverter.

1 - 9 . (canceled)  
   
   
       10 . A single chip inverter comprising: 
 an inverter for driving an AC motor having a load connected thereto; and    a control apparatus for controlling said inverter,    wherein said control apparatus comprises an analog circuit and operates to make phase difference between an induced voltage and associated current of said motor approach zero, for each phase.    
   
   
       11 . A single chip inverter according to  claim 10 , wherein a d-axis current value of the motor is made to become zero in order to make the phase difference between the induced voltage and associated current of said motor approach zero, for each phase.