A SINGJX-CHIP MICROPROCESSOR-BASED PWM TKH"QIJE FOR SINUSOIDAL INVERTWS

This paper describes a sinusoidal pulse width modulation (PWM) technique suitable f or a single-chip microprocessor-b ased control. The proposed s cheme can be considered as a digital alternative of the analog subharmonic method (SHM) in the sense that 1) on-line real-time PWM control is possible, 2) synchronization between carrier wave and signal wave is unnecessary, 3) l ow-order harmonics in the output v oltage are well suppressed. F urthermore, the scheme has features that t he maximum output voltage is 15% larger than the one obtained by SHM if compared at the same carrier frequency.