Dynamic Modeling and Robust Control of Multi-Module Parallel Soft-Switching-Mode Rectifiers

In this paper, small-signal modeling and robust controller design for multi-module parallel soft-switching mode rectifiers (SSMRs) are presented. First, a single-phase boost-type SSMR is formed from the traditional boost-type switching mode rectifier (SMR) with auxiliary resonant branch to achieve zero-voltage-transition (ZVT) soft switching for the main and auxiliary switches. Based on the proposed single-phase SSMR, parallel operation of multi-module single-phase SSMR is made for increasing the total power capacity and the reliability of the SSMRs. The state-space averaging method is employed to derive the small signal model of the SSMR in current control loop for performing its current controller design. As for the voltage control loop, the dynamic model of the multi-module SSMR is derived at nominal case by averaging method for two-time-scale (AM-TTS) and averaged power method. Then, the quantitative and robust voltage regulation controls are proposed for multi-module SSMR to improve the control performance when the parameter variations caused by system configuration change and operating point shift have occurred. The accuracy of the derived SSMR dynamic model and the effectiveness of the proposed controller are demonstrated by some simulation and experimental results. Key-Words: Soft-Switching-Mode Rectifier, Small-Signal Model, Quantitative Controller Design, Parallel Operation, Robust Control.