Interleaved Pulse Width Modulation Based on Modified Carrier in Parallel Operation

Abstract

An interleaved pulse width modulation (PWM) can be employed in a parallel operation of three-phase converters because the interleaved PWM increases the equivalent switching frequency and significantly enhances the output current harmonics. However, interleaved voltage pulse patterns provoke a huge circulating current, and a coupled inductor is employed to suppress the circulating current. Therefore, this study aims to improve the harmonics of voltage and current in parallel operation with a coupled inductor. For the aim, the harmonics of the interleaved PWM have been analyzed. Based on the analysis, a new PWM strategy has been devised by modifying the interleaved carrier. The proposed PWM improves the harmonics of voltage and current. However, unintended additional device switching occurs in the proposed method. Accordingly, a cost index (CI) is defined to show the improvement in the harmonics considering the additional device switching. The validity, feasibility, and effectiveness of the proposed method have been demonstrated by using CI. As a result, the computer simulation and experimental results show that the proposed PWM has efficiently improved the harmonics in various modulation indices.

A Comprehensive Survey on Fault Tolerance in Multiphase AC Drives, Part 1: General Overview Considering Multiple Fault Types

“…This feature can be very appropriate for high-power applications [340]. Furthermore, interleaving PWM can be implemented in the parallel VSCs to decrease current harmonics [485]. Although there are other topologies based on installing redundant legs connected in parallel [275,465], in those ones the extra legs are not used during normal operation (lacking the associated benefits), and postfault reconfiguration is applied by means of additional bidirectional switches.…”

Modelling and Control Development of a Cascaded NPC-Based MVDC Converter for Harmonic Analysis Studies in Power Distribution Networks

“…The main reason for adopting this topology is to improve the system's power density, dynamic performance, and efficiency. The interleaved topology has also been applied to power inverters [39] and rectifiers [40]. Interleaved configurations are formed by connecting an N power converter in parallel and imposing an equal phase shift between their switching instants over the switching period.…”

“…The interleaved SPWM technique for six MVDC converters is depicted in Figure 23, with just the upper carriers displayed for demonstration purposes. The detailed mathematical models of the interleaved SPWM introduced for the MVDC converter model developed in this paper are provided in [39], which are not included here for the sake of article length.…”