A Novel Single DC Source Three-Phase Wye Packed U-Cell (Y-PUC) Converter

Saeed Arazm,Kamal Al-Haddad

doi:10.1109/ojies.2021.3131914

Abstract

A new configuration of three-phase Wye Packed U-cells (Y-PUC) with a single DC source is proposed in this paper. In fact, this configuration represents a single DC source modular three-phase PUC converter. The DC source on PUC topology is replaced by a flying capacitor to obtain a suitable submodule. Moreover, the modularity of the Y-PUC configuration makes it an appropriate alternative for MMC applications. Furthermore, the proposed structure is an advantageous configuration for high voltage applications such as high voltage direct current (HVDC) transmission lines with the capability of DC fault handling. All PUC topologies such as PUC5, PUC7, PUC9, PUC15 can be replaced in the modules of this proposed single-phase and three-phase configuration to multiply the load voltage levels for improving the output waveform. Active voltage balancing technique through carrier-based modulation is applied. System modeling and operating sequences are developed. Simulation and experimental results are presented and discussed to validate the performance of the proposed structure.

Highlights

Nowadays, Multilevel type of converters are used in several industrial applications such as transportations including electrified railway, motor drives, electrical vehicles charging stations [1, 2], as well as in renewable energy integration to the grid such as wind farms and photovoltaic plants [3]
It should be noted that all the references in [23,24,25,26] propose the topologies with the capability of DC fault handling with lower devices compared to Full Bridge (FB)-modular multilevel converters (MMCs)
EXPERIMENTAL RESULTS The algorithm of combined voltage balancing integrated with PS-PWM is implemented on single-phase double star configuration of Y-PUC to validate the performance of the configuration

Summary

TOPOLOGY DESCRIPTION AND ANALYSIS

A modular Y-PUC converter topology is illustrated in figure. in which a PUC converter is located as a submodule (SM). This configuration, address the problem of isolated DC source requirements in three-phase PUC for medium voltage applications, and, is an instrumental MMC with the capability of DC fault handling in high voltage applications such as HVDC. In proposed configuration the single DC source double star, Y-PUC can be connected to the three-phase load or to the grid. A Novel Single DC Source Three-Phase Wye Packed U-Cell (Y-PUC) Converter link capacitor is not required unless for direct grounding system

Switching States and Voltage Balancing in Single

Voltage balancing integrated with phase-shift modulation on Y-PUC

EXPERIMENTAL RESULTS

CONCLUSION