| 摘要 |
Switching waveform generator for pulse width modulation triggering of static inverters producing variable frequency output. The number of chops per half-cycle of output fundamental frequency is decreased as fundamental frequency is increased so as to keep the switching frequency of the inverter within the capabilities of the power switching devices used while obtaining maximum harmonic suppression. The chop number is changed between sequential frequency ranges. In a preferred form the chop width is continuously varied as output frequency is varied to decrease output amplitude with decreasing frequency to enable constant torque operation of an induction motor load. |
