PROJECT TITLE :

Reconfigurable Periodic Bifrequency DPWM With Custom Harmonic Reduction in DC–DC Converters

ABSTRACT:

Majority of spectral spreading techniques use chaos-based pulsewidth-modulation (PWM) schemes in a switching dc–dc converter, in which neither dynamic performance nor ripple parameter will be correctly predicted therefore as for efficiency. Periodic frequency modulation employing a triangular carrier wave can achieve custom spectral spreading and harmonic reduction. This paper proposes a periodic bifrequency digital PWM (BF-DPWM) technique in a very dc–dc converter, that uses two discrete frequencies $f_rm 1$ and $f_rm 2$ as guided by a modulating signal $f_rm m$. Fourier analysis shows that $f_rm 1$ and $f_rm 2$ do not exist; however, they contribute to power spectrum of $f_rm m$. This technique achieves considerable harmonic reduction and improved DPWM resolution with an insignificant ripple impact, compared to a dither-primarily based periodic modulation theme. Style tips using simulation study are presented. A buck converter prototype has been created, and totally different management schemes are implemented using a field-programmable gate array device. Check results show that the BF-DPWM has insignificant impacts on transient performance. Finally, the proposed scheme is extended to the triangular-wave modulation scheme, which leads to further harmonic reduction.