Design of DC bus voltage high dynamic performance control for single-phase converters

Abstract

The DC bus voltage in single-phase converters inherently exhibits a second harmonic ripple. To accurately track the current reference value, notch filters are typically incorporated into the software control loop for suppression. However, traditional notch filters suffer from slow response times and significant oscillations. This paper presents an enhanced DC bus voltage extraction algorithm that estimates the second harmonic component in the DC bus voltage using system parameters and variables, without modifying the basic circuit structure or adding additional notch filters to the bus voltage control loop. By redesigning the voltage outer loop, the algorithm aims to reduce the overshoot and oscillations during voltage adjustments, improving the response speed. When integrated with a quasi-PR regulator-based current inner loop, this dual-loop control strategy effectively minimizes the overshoot and oscillations during voltage adjustments, enhances the response speed, and improves system stability. The effectiveness and validity of the proposed control strategy are demonstrated through MATLAB simulations and prototype experiments.