Twist buck mode - owntech-foundation/Tutorials GitHub Wiki

Prerequisite

In this tutorial part, you will learn how to use the TWIST as a buck converter voltage mode control. The purpose is then to learn how to step down the voltage of a power supply to power a load.

Electrical information

The TWIST will be configured in a buck configuration. Its NGND switch will be ON and its legs will be interleaved, as shown below. Twist Circuit Diagram

The connections and circuit of the TWIST board together with its duty cycle.

Connections

For that purpose, you will need a laboratory power supplies to feed your TWIST. Twist circuit connection

The electrical connections of the TWIST board with a power supply and a load.

The power source has to be connected with one cable to the Power connectors (in red) and one to the ground (in blue). The load, which will received the converted power, need to be connected to one leg (either in yellow or blue) and to the neutral connector (in black). In these tutorials, legs will be interleaved, which means they both will be dedicated to the same power conversion. For that purpose, they need to be interconnected (from one blue to one yellow cable).

Application of the TWIST as a Buck converter

  • Create your first PWM - You will set up the TWIST as a buck converter on open-loop operation. You will be able to rise and lower the duty cycle and observe its value on the Serial Monitor.
  • Activating measurements - You will setup all the measurements available on the TWIST by default. You will then monitor these measurements using the OwnPlot while changing the duty cycle of the converter by hand.
  • Closed-loop voltage mode control - You will setup the TWIST as a buck converter on closed-loop operation. You will use the low-side voltage measurement together with a PID controller to track the low-side voltage according to a reference.