Interleaved multi‐level power converter for a battery energy storage system

Abstract

This study proposes an interleaved multi-level power converter (IMPC) for a battery energy storage system. The proposed IMPC is composed of two power-electronic legs. The first power-electronic leg is an interleaved multi-level leg that contains eight power-electronic switches. Four power-electronic switches constitute a two-phase interleaved switch set and these are switched in a high-frequency interleaved pulse-width modulation. The other four power-electronic switches constitute a level-selection switch set that determines the dc bus voltage for the two-phase interleaved switch set according to the magnitude of the utility voltage. The second power-electronic leg is the low-frequency switching leg, which is composed of two power-electronic switches. Since the proposed IMPC integrates the performances of the multi-level power converter and interleaved power converter, the effective switching frequency is twice the practical switching frequency and the output voltage has five voltage levels. The ripple of the output current is significantly attenuated and the power capacity of the output filter is reduced. The proposed IMPC can also be used to adjust the real and the reactive power flows, in order to control the charging/ discharging of battery sets and to compensate for the reactive power. A hardware prototype is developed to verify the performance of the proposed IMPC.

Design and development of a cascaded modular multi‐level converter based on current‐fed quadruple‐active bridge converters for grid integration of photovoltaic systems

“…The operation modes of the QAB converter depends on the variation range of duty ratio D (from 0 to 1) and phase shift angle φ (from 0 to π ). In the proposed converter the practical phase shift angle is less than π /2, and the duty cycle, D , is changed around 0.5 to achieve higher efficiency [4].…”

“…However, effective integration of this low-voltage (LV) systems into the medium voltage (MV) distribution grids still remained a challenge and attractive research interest [3]. Modular multi-level converters (MMCs) have been the most feasible topology for this application so far [2][3][4][5]. The main advantage of these topologies is utilising low rating switching components for high voltage applications which leads to higher reliability, modularity and redundancy.…”

A Bidirectional LLCL Resonant DC-DC Converter With Reduced Resonant Tank Currents and Reduced Voltage Stress of the Resonant Capacitor

“…For promotion of the energy revolution, development of the energy storage systems (ESSs) has become one of the mainstream solutions [1]- [3]. In these systems, bidirectional dc-dc converters (BDCs) usually play an important role.…”