دانلود رایگان مقاله انگلیسی تکنیک های DPWM در مبدل های DC-DC سازگار با EMI با کنترل دیجیتال - الزویر 2018

Abstract

This paper aims to present a combined, DPWM based control method and spectrum flattening technique of a mid-power range DC-DC converter. The research goal was to obtain sustainable results in both switching control and EMI compliance, using one 8 or 16 bits RISC MCU as main control unit running a performance- and speed-optimized firmware. This approach describes a hybrid method preserving the good dynamic performances of an analog switching regulator controller and adding the flexibility of controlling the output voltage by adjusting the duty cycle value of a DPWM signal and thus controlling the average voltage value of the signal applied in the feedback circuit of a DC-DC converter. Beside the feedback control of the DC-DC converter an active EMI reduction technique applies on this design by taking advantage on the constant-frequency, forced-continuous current mode architecture of the switching regulator controller, which allows its frequency to be synchronized with an external control clock dithered by a software implemented pseudo-random sequence generator. All this efforts concludes in reducing the noise power considerably at the main peak and at the next peaks.

5. Conclusions

A series of experimental measurements validates the previously presented mathematical models, resulting from computer-aided simulations offering practical advises about the linearity, resolution and code efficiency for real applications. Regarding the EMI mitigation technique there are many applications and articles addressing the same problem but few with immediate applicability in a mid-range MCU domain. This work intends to add some applicative details in that less covered domain. Practical measurements also prove that the DC-DC converter efficiency is not affected considerably, but the EMI reduction increases by this technique.