| Abstract |
This paper presents a comparative study of 2 and 3-level pulse-width modulated precalculated waveforms, applied to voltage source inverters. Two aspects have been investigated: global optimization of the loss factor o (up to 7 angles per quarter of cycle) and selective harmonic elimination (up to 5 angles per quarter of cycle) are taken into account. This research is intended to modulators implementing both sinusoidal and precalculated modulations together in a same strategy. The harmonics rejected in the DC link are analyzed through a newly defined rejection factor p, as well as the effect of PWM on the current going through the DC-side capacitors of the 3-level inverter. A whole strategy of modulation, which is implemented in C language on a 8097 microcontroller, is presented, completed by practical measurements on a 8 kW 3-level inverter. |
