Critical analysis of random frequency inverted sine carrier PWM fortification for half-controlled bipolar three-phase inverters

摘要

The inverted sine carrier-based pulse width modulation scheme has been acknowledged for fundamental fortification in DC-AC conversion. This paper suggests a randomized inverted sine carrier for the half-controlled PWM switching strategy of a three-phase voltage source inverter to enhance its ability to spread harmonic power. A detailed study of the proposed modulation technique is presented through MATLAB-Simulink, and switching pulses are generated in the ModelSim digital environment. Harmonic analyses and assessments of different performance measures such as power spectrum density, harmonic spread factor, total harmonic distortion and dominating harmonic orders for various modulation indices have been carried out. Simulation and experimental results show that the proposed PWM method can spread harmonic power in output voltage better than the conventional SPWM or SVPWM. For real-time digital implementation, the gating signals are generated using a field-programmable gate array Spartan XC3S500E - 320F device.