IGBT Chopper (High-Side Switch with Reverse Diode)
Purpose
Buck converter IGBT module with reverse diode
Library
Electrical / Power Modules
Description
This power module implements a chopper used in buck converters. It offers two configurations:
Switched The power semiconductors inside the module are modeled with ideal switches. The IGBT is controlled with a logical gate signal; it is on if the 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 electrical input of the chopper 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 input is the relative on-time of the IGBT with values between 0 and 1.
In the average configuration the chopper can be operated in two ways:
- The control signal is the instantaneous logical gate signal having the values 0 and 1.
- The control signal is the duty cycle of the IGBT. It is either computed directly from the modulation index or by periodically averaging the digital gate signal 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 supports continuous and discontinuous conduction mode.
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. If the reversed diode is not needed, the alternative chopper module is preferred to minimize model complexity.
Parameter
- Configuration
- Switched or averaged circuit model.