Carrier-Based Double Integral Sliding-Mode Controller of Class-D Amplifier

This paper presents a carrier-based double integral sliding-mode (CBDISM) controller for a SiC class-D amplifier to compensate the
$Q$
-factor and ensure a flatter frequency response. The carrier-based approach guarantees the fixation of switching frequency and improves the total harmonic distortion plus noise (THD + N) by reducing the effect of nonlinearities in the power stage. In addition to the output voltage, the CBDISM controller requires current feedback from the capacitive filter, which is advantageous as the capacitor current is bidirectional and enables the use of a current transformer for feedback, thereby not affecting the cost and overall efficiency. The effectiveness of the proposed CBDISM controller is verified using computer simulation and experimental study.