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IGBT Half Bridges (Low-/High-Side Connected)

Purpose

Series-connected IGBT half-bridge inverters

Library

Electrical / Power Modules

Description

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These components implement multiple series-connected inverter cells for use in modular multilevel converters. All control signals as well as the DC link terminals are vectorized with their width matching the number of cells. The components offer two configurations:

Switched All power semiconductors are modeled with ideal switches. The individual IGBTs are controlled with logical gate signals. An IGBT is on if the corresponding gate signal is not zero. For compatibility with the averaged configuration it is recommended to use the value 1 for non-zero gate signals.

Averaged The component as a whole is modeled with controlled voltage and current sources. The DC sides of the inverter cells have current source behavior and must remain galvanically isolated from each other. The output terminals are typically connected to an inductor. The control inputs are the relative on-times of the IGBTs with values between 0 and 1.

In the average configuration the inverters can be operated in two ways:

In both use cases, the average implementation correctly accounts for blanking times, i.e. when during commutation both IGBTs in one inverter cell are turned off. It also supports discontinuous conduction mode, e.g. when charging the DC link capacitors via the reverse diodes.

Since the duty cycle is simulated accurately even with relatively large time steps, the average configuration is particularly well suited for real-time simulations with high switching frequencies. It can also increase the speed of offline simulations, because the number of internal switches is greatly reduced.

Parameters

Configuration
Switched or averaged circuit model.
Number of cells
Number of series-connected half-bridge inverters.