Comparison of nonlinear and linear control schemes for independent stabilization of parallel multi-phase converters

Abstract

Using a parallel three-phase boost converter consisting of two modules, we compare the performances of three recently proposed nonlinear control schemes. The basic idea, however, can be extended to a system with N modules and other multi-phase converters. All of the control schemes are developed in a synchronous frame and each of the closed-loop power-converter modules operates asynchronously without any communication with the other module. The control schemes stabilize the currents on the dq axes and limit the zero-axis disturbance by preventing the flow of the pure-zero sequence current. One of the control schemes is developed purely in the discrete domain. It combines the space-vector modulation scheme with a variable-structure control, thereby keeping the switching frequency constant and achieving satisfactory dynamic performance. The performances of the other control schemes are also satisfactory.

Mitigating Circulating Common-Mode Currents Between Parallel Soft-Switched Drive Systems

“…If no common-mode impedance exists between the sysPaper IPCSD-06-100, presented at the 2003 Industry Applications Society Annual Meeting, Salt Lake City, UT, October 12-16, and approved for publication in the IEEE TRANSACTIONS ON tems, it is necessary to actively control common-mode current. Various control techniques have been proposed to control this common-mode circulating current [6], [7], [10]- [13]. This paper describes an ac-dc-ac drive system with an active rectifier and an inverter based on the actively clamped resonant dc-link (ACRDCL) converter.…”