IGBT Half Bridge
Purpose
2-level half-bridge IGBT module
Library
Electrical / Power Modules
Description
These power module implements a single leg of 2-level voltage source inverter. It offers two configurations:
Switched The 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 module as a whole is modeled with controlled voltage and current sources. The DC side of the inverter has current source behavior and must be connected to a capacitor or voltage source. The output terminal is 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 half bridge can be operated in two ways:
- The control signals are instantaneous logical gate signals having the values 0 and 1.
- The control signals are the duty cycles of the individual IGBTs. They are either computed directly from the modulation index or by periodically averaging the digital gate signals over a fixed period of time, e.g. using the Periodic Average block. The averaging period does not need to be synchronized with the PWM and can be as large as the inverse of the switching frequency.
In both use cases, the average implementation correctly accounts for blanking times, i.e. when during commutation both IGBTs are turned off. It also supports discontinuous conduction mode, e.g. when charging the DC link capacitor 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.
Parameter
- Configuration
- Switched or averaged circuit model.