Module and Assembly with Dual DC-Links for Three-Level NPC Applications

Abstract

A power semiconductor module has four power terminals. An IGBT has a collector connected to the first power terminal and an emitter coupled to the third power terminal. An anti-parallel diode is coupled in parallel with the IGBT. A DC-link is connected between the second and fourth power terminals. The DC-link may involve two diodes and two IGBTs, where the IGBTs are connected in a common collector configuration. The first and second power terminals are disposed in a first line along one side of the module, and the third and fourth power terminals are disposed in a second line along the opposite side of the module. Two identical instances of the module can be interconnected together to form a three-level NPC phase leg having low stray inductances, where the phase leg has two parallel DC-links.

Description

TECHNICAL FIELD[0001]The described embodiments relate to power semiconductor modules usable in three-level NPC phase leg applications.BACKGROUND INFORMATION[0002]FIG. 1 (Prior Art) is a diagram of a T-type three-level Neutral-Point-Clamped (NPC) phase leg module 1. Such a module sees use in applications including solar inverter, motor drive and UPS applications. The module is referred to as a “three-level” module because the module couples an output node AC to a selected one of three DC voltage power terminals. As compared to conventional two-level topologies, a T-type three-level topology may provide advantages in a given application. For example, a T-type three-level topology may allow transistors within the module to have lower breakdown voltages than they would otherwise be required to have were a two-level topology used, with the added advantages of better conduction and switching performance resulting in lower losses. Also a T-type three-level topology may allow a motor to be ...

AI Technical Summary

Benefits of technology

This patent describes a circuit design called a T-type three-level NPC phase leg, which is commonly used in power circuits. The design involves using two identical modules and connecting them together with metal bus bars to create a three-level circuit with low stray inductance. By splitting the circuitry and reducing the area enclosed by current loops, stray inductance is reduced compared to other multi-module designs. Using identical modules reduces the number of module types needed and increases manufacturing efficiency, lowering overall costs. The design also allows for the use of the same module in other power circuits, such as in a power circuit called a T-type three-level NPC phase leg. The design also splits power dissipation over both modules, eliminating the need for snubber circuits in some applications.

Problems solved by technology

In a higher power application, a T-type three-level NPC phase leg circuit may have to be realized in multiple module packages due to heat dissipation limitations of a single module package and due to a lack of mounting area because of the required die size for the high current.

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