Random Pulse Width PWM Modulator for Inverter-fed Induction Motor Based on the TMS 320 F 240 DSP Controller

A novel random pulse width modulator with varying switching frequency but constant sampling frequency is proposed for application in voltage source inverters for adjustable-speed ac drives. Harmonic Spread Factor is introduced for quality evaluation of voltage spectra of inverters with the random PWM. Realization of the modulator using the Texas Instruments' TMS320F240 DSP controller is described and the results of simulations and experiments are presented.

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