PWM INVERTER WITH DEAD TIME CORRECTION FUNCTION

摘要

PURPOSE: To provide high accuracy control with torque and speed ripple suppressed by obtaining a dead time correction signal from multiplication of dead time correction amount computing means output by the current polarity discrimination signal correspondingly to the inverter frequency. CONSTITUTION: This device is provided with a correction amount computing device 8 which inputs the inverter frequency F1 from a control circuit 62. A multiplier 52 provides a correction signal Vd from multiplication of the dead time correction amount K of the output of the correction amount computing device 8 by the polarity discrimination signal Sp of the output of the polarity discriminator 4. An adder 72 adds the voltage command signal V* of the output of the control circuit 62 to the correction signal Vd of the output of the multiplier 52 to generate a correction voltage command V**. It is thus possible to provide a dead time correction amount to make an operating condition appropriate according to the inverter frequency, and attain high accuracy control with torque and speed ripple suppressed.