Improved dynamic performance with discrete sampling in digital ACM controlled DC‐DC boost converter with capacitor ESR inclusion

Abstract

A classical symmetrical carrier-based digital Average Current Mode (ACM) control has two sampling choices, peak point and valley point, to control the average inductor current. If it is employed to regulate the DC-DC boost converter, there will be a difference in the dynamic performance at peak and valley point sampling instants because of discontinuous output voltage ripple due to Equivalent Series Resistance (ESR) of the output capacitor. Therefore, this paper investigates the effect of sampling instant on the dynamic performance of the PWM DC-DC boost converter in consideration of capacitor ESR. The small-signal transfer functions of a boost converter for both sampling positions are prominent to analyze each sampling impact on its dynamics. They are derived by using discrete-time modeling. Further, the choices of sampling instant are investigated related to the RHP zero elimination, voltage stability, and peak-to-peak ripple current of the DC-DC boost converter. The boost converter has improved stability performance by synchronizing the ADC sampling at starting position (valley point) of the symmetrical carrier signal, as evident by the analytical and hardware results of both sampling techniques working from 25% to 100% load working conditions.

Selection of power sharing factor for hybrid battery/ultracapacitor energy storage‐based EV through load emulation technique

“…It has a particular application for digital average current mode (DACM) controller. 22,23 The effect of sampling position on the DC-DC converter is presented in Balapanuru et al 23 In the literature, the EV load dynamics as seen by the drive motor (DM), DC-AC converter is emulated to test the different DM, novel motor control strategies, and energy source (battery) performance characteristics for EV application. [24][25][26][27] In addition, the load dynamics seen by the DC-DC power converter with its control strategies must be evaluated with the laboratory testbench setup.…”

“…In addition to trailing edge and leading edge carrier signals, another carrier signal is available, called a double edge or symmetrical carrier signal. It has a particular application for digital average current mode (DACM) controller 22,23 . The effect of sampling position on the DC‐DC converter is presented in Balapanuru et al 23 In the literature, the EV load dynamics as seen by the drive motor (DM), DC‐AC converter is emulated to test the different DM, novel motor control strategies, and energy source (battery) performance characteristics for EV application 24–27 .…”