Pulse width modulation inverter system.

摘要

A PWM inverter system for converting DC power to AC power comprises an output voltage setting circuit (12) for generating a pattern of output voltage value corresponding to a speed command value, an oscillator (13) for generating a pulse train having a frequency proportional to the speed command value, a frequency division circuit (14) for dividing the frequency of the pulse train produced by the oscillator to produce interrupt pulses, a pulse interval measuring circuit (15) for measuring a pulse interval between predetermined ones of the interrupt pulses supplied from the frequency division circuit, an arithmetic unit (17) responding to the input of the interrupt pulses from the frequency division circuit to produce a timing signal corresponding to the timing at which said interrupt pulse is inputted and updata data associated with current operating phase relative to a fundamental wave, to thereby produce pulse width data corresponding to the result of multiplication of a value associated with the output voltage value supplied from the output voltage setting circuit, a value associated with the pulse interval supplied from the pulse interval measuring circuit and a value associated with the operating phase relative to said fundamental wave, a pulse width conversion circuit (19) supplied with the pulse width data from the arithmetic unit for producing a width pulse train conforming to the pulse width data at every timing signal supplied from the arithmetic unit, and a waveform processing circuit (20) supplied with the width pulse train from the pulse width conversion circuit and the timing signal from the arithmetic unit to produce sequentially phase output pulse trains.