Auto-Tuning of PID Controller for a Boost Converter using Modified Relay Feedback Test

This paper investigates the application of the modified relay feedback test (MRFT) to a DC-DC boost converter. Nonvanishing oscillations can be generated with MRFT in the control loop. Subsequently, a two-stage process, involving the test and the tuning parameters calculation, is employed for the tuning of the proportional-integral-derivative (PID) controller. The test stage generates self-sustained oscillations. The tuning stage calculates PID parameters based on the homogeneous tuning rules and the amplitude and frequency of the oscillations obtained from the test stage. The auto-tuning can be done online in a few milliseconds and does not require any prior knowledge of the plant. With properly designed tuning rules, the proposed auto-tuning method can guarantee specified gain margin. Performance of the proposed method is evaluated through simulations using Matlab/Simulink. Results show the effectiveness of the proposed method.