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The parallel connection of IGBTs is being applied in various low- and medium-voltage converters. The selection of the devices, the manual parametrization of gate units, and the substantial device derating are substantial disadvantages of state-of-the-art converters with parallel-connected insulated-gate bipolar transistors (IGBTs). A new, low-expensive, and automated delay-time compensation method without additional current measurements was introduced in the 2011 IEEE Energy Conversion Congress and Exposition. This paper briefly reviews the structure and function of this new scheme, shows the extension of the scheme for three parallel-connected IGBTs, and investigates the performance of the new delay-time compensation principle for sinusoidal current operation at different $\cos\phi$ and m_{a} values, as in a converter for drives. [ABSTRACT FROM AUTHOR]

This paper introduces a 6.5-kV 1-kA SiC PiN diode module for megawatt-range medium voltage converters. The analysis comprises a short description of the die and module technology and a device characterization. The effects of di/dt and temperature variation, as well as parasitic oscillations are discussed. A comparison of the results with a commercial Si diode (6.5 kV and 1.2 kA) is included. In the last section, an estimation of maximum converter output power, maximum switching frequency, losses and efficiency in a 3L-NPC converter operating with SiC and Si diodes is presented. The analyzed diode module exhibits a very good performance regarding switching loss reduction, which allows an increase of at least 16% in the output power of a 6-MVA converter. Alternatively, the switching frequency can be increased by 46%. [ABSTRACT FROM AUTHOR]

This paper compares the expense of power semiconductors and passive components of a (2.3 kV, 2.4 MVA) two-level, three-level neutral-point-clamped, three-level flying-capacitor, four-level flying-capacitor, and five-level series- connected H-bridge voltage source converter on the basis of the state-of-the-art 6.5-, 3.3-, 2.5-, and 1.7-kV insulated gate bipolar transistors for industrial medium-voltage drives. The power semiconductor losses, the loss distribution, the installed switch power, the design of flying capacitors, and the components of an LC sine filter for retrofit applications are considered. [ABSTRACT FROM AUTHOR]

This paper presents a technology review of voltage-source-converter topologies for industrial medium-voltage drives. In this highly active area, different converter topologies and circuits have found their application in the market. This paper covers the high-power voltage-source inverter and the most used multilevel-inverter topologies, including the neutral-point- clamped, cascaded H-bridge, and flying-capacitor converters. This paper presents the operating principle of each topology and a review of the most relevant modulation methods, focused mainly on those used by industry. In addition, the latest advances and future trends of the technology are discussed. It is concluded that the topology and modulation-method selection are closely related to each particular application, leaving a space on the market for all the different solutions, depending on their unique features and limitations like power or voltage level, dynamic performance, reliability, costs, and other technical specifications. [ABSTRACT FROM AUTHOR]

The design of a power converter must guarantee that the operating junction temperatures ϑj of all devices do not exceed their limits under all specified operating conditions. Usually, this is ensured by a simulative or analytical junction temperature estimation based on simple electrical and thermal models and semi-conductor datasheet values. This paper discusses the difficulties and quantifies the limitations of this approach on the example of a three-level neutral point clamped voltage source converter (NPC VSC) with insulated gate bipolar transistors. The calculations are compared to the results of direct junction temperature measurements with an infrared camera. The paper also provides the experimental proof for the unequal loss and junction temperature distribution in the three-level NPC VSC. [ABSTRACT FROM AUTHOR]

In this paper, a design driven comparison between two 190 kVA industrial three-phase two-level voltage source converter (2L-VSC) designs based in silicon carbide (SiC) and silicon (Si) for 690 V grids is presented. These two designs were conceived to have the same nominal power, while switching at reasonable switching speeds and requiring the same case to ambient thermal impedance. Under these conditions, the designs were studied to detect the potential gains and limitations that a pragmatic converter design could feature when using these two technologies regarding cost, efficiency, size and weight. To achieve this, experimentally determined semiconductor characteristics were used to perform simulations, the results of which were then used to design the essential parts of the converter. These designed parts were then corroborated with manufacturers, from which physical characteristics of all designed components were obtained. The results show that the SiC based design presents substantial weight savings and an 11% system cost reduction, while preserving its traditional characteristics such as improved overall efficiency when compared to the silicon based design under the given design requirements and constraints. [ABSTRACT FROM AUTHOR]