Four-Quadrant Chopper Control

This example shows how to control a four-quadrant chopper. The Control subsystem implements a simple PI-based control algorithm for controlling the output current. The simulation uses both positive and negative references. The total simulation time (t) is 1 second. At t = 0.5 seconds, the polarity of the load DC source E is changed.

Model

Simulation Results from Simscape Logging

The plot below shows the requested and measured current for the test and the output voltage in the circuit.

Results from Real-Time Simulation

This example has been tested on these platforms:

• Speedgoat™ Performance real-time target machine with an Intel® 3.5 GHz i7 multi-core CPU and 4 GB RAM.

• dSPACE® SCALEXIO LabBox with Intel® Core XEON E3-1275v3 at 3.5GHz and 4 GB RAM.

You can run this model in real time with a step size of 20 microseconds by using the Simscape local solver. For small sample rates, a task overrun might occur during the initial task execution due to a cold cache. To avoid this overrun, if the selected platform supports these options, relax the start-up behavior by specifying a limited number of task overruns or increasing the sample time of periodic tasks during the start-up phase of the real-time application.