Chapter 1: Introduction; 3-Level Topology - Broadcom ACPL-352J Reference Manual

ACPL-352J Reference Manual Vincotech H6.5 3-Level IGBT flowPACK Module Evaluation Board

Chapter 1: Introduction

1.1 3-Level Topology

3-Level topology has two main advantages over conventional 2-Level topology, namely higher efficiency and reduction in
filtering effort. 2-Level topology requires a large output filter and regenerates energy back to the DC bulk capacitor during
freewheeling. The regenerated energy has to pass the inverter twice and will cause additional power dissipation.
Figure 1: 2-Level Topology during Excitation and Freewheeling
Excitation Freewheeling
In a 3-Level topology, the excitation works the same as the 2-Level, but during freewheeling, the H-bridge is turned off and
the filter's primary output is shorted. The switch voltage is reduced and the switching losses and the size of the output filter
are minimized.
Figure 2: 3-Level Topology with H-bridge Turned Off and Output Shorted during Freewheeling
This reference design will discuss the evaluation board of Vincotech H6.5 3-Level IGBT module for 3-Level topology.
Broadcom Confidential ACPL-352J-Ref-RM100
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