| 摘要 |
PURPOSE:To reduce low harmonic component by using pulse width modulation wave and the prescribed angular range which has a pulse. CONSTITUTION:The output of a clock pulse generator 1 is supplied through a waveform shaper 2 to a counter 3, and angle setters 4-11 sets the angles of the PWM wave based on the output of the counter. The outputs of the setters 4- 11 are supplied through an angle synthesizer 12 and a distributor 13 to latch circuits 14-16, which produce PWM waves, R, S, T. The PWM waves R, S, T respectively have pulses at approx. 0-4.5 deg., 7.5-12 deg., 15-21 deg., 22.5-28.5 deg., 30-150 deg., 151.5-157.5 deg., 159-165 deg., 168-172.5 deg., 175.5-180 deg., 184.5-187.5 deg., 192-195 deg., 201- 202.5 deg., 208.5-210 deg., 330-331.5 deg., 337.5-339 deg., 345-348 deg., and 352.5-355.5 deg.. These PWM waves are used to control an inverter. |
