A Transformerless Back-To-Back (BTB) System Using Modular Multilevel Cascade Converters For Power Distribution Systems

Author

Khamphakdi, Pracha ; Sekiguchi, Kazuma ; Hagiwara, Manabu ; Akagi, Hirofumi

Author_Institution

Dept. of Electr. & Electron. Eng., Tokyo Inst. of Technol., Tokyo, Japan

Volume

30

Issue

4

fYear

2015

fDate

Apr-15

Firstpage

1866

Lastpage

1875

Abstract

This paper presents an intensive discussion on a transformerless back-to-back (BTB) system using modular multilevel cascade converters based on double-star chopper cells (MMCC-DSCC). It is expected to be applied to a power distribution system with many distributed power generators. This paper designs, constructs, and tests a three-phase 200-V, 10-kW DSCC-based BTB system installed on a 200-V, 40-kW power distribution simulator consisting of two radial feeders. Experimental results show that the BTB system can mitigate power-flow imbalance between the two feeders. Moreover, the zero-sequence current circulating between the two feeders can be suppressed to be as small as 10 mA (0.02%) in rms by connecting a common-mode choke to the common dc link of the BTB system.

Keywords

choppers (circuits); distributed power generation; power convertors; BTB system; MMCC-DSCC; common dc link; common-mode choke; distributed power generators; double-star chopper cells; modular multilevel cascade converters; power 10 kW; power 40 kW; power distribution systems; power-flow imbalance; radial feeders; transformerless back-to-back system; voltage 200 V; zero-sequence current; Capacitors; Choppers (circuits); Equations; Generators; Inductors; Power distribution; Voltage control; Back-to-back (BTB) systems; distributed power generators; grid-connected converters; modular multilevel cascade converters (MMCCs);

fLanguage

English

Journal_Title

Power Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0885-8993

Type

jour

DOI

10.1109/TPEL.2014.2327986

Filename

6824816