Space Vector Modulation for Two-Level Unidirectional PWM Rectifiers

This paper presents the concepts for application of space vector modulation to two-level unidirectional pulsewidth modulation (PWM) rectifiers, and a methodology for the use of this modulation is proposed and applied in three different groups of rectifiers. For each group of rectifiers, the converter switching stages are analyzed to determine switch control signals for space vector modulation. One switching sequence is proposed for all rectifiers in order to minimize the number of switch commutations and reduce the switching losses. Duty cycle functions are determined, and the desired switching sequences are performed by a simple PWM, without the need to determine the present sector of the vector. For this purpose, it is necessary to impose the desired current sectors from input voltage references only. In order to validate the proposed modulation techniques, simulation and experimental results are presented for a 20-kW prototype.