Accuracy Comparison Between ZVS, DB and Conventional Interleaved Class D Power Amplifiers

This paper investigates the closed-loop performance of a conventional two-phase half-bridge class D power amplifier compared to Dual Buck (DB) and Zero-Voltage-Switching (ZVS) variations when driving a Lorentz actuator that moves a mass in a dynamic motion loop. This actuator is modeled as an inductive load. Two different reference currents—sinusoidal and fourth order—are examined to assess the Total Harmonic Distortion (THD) and the Moving Root Mean Square (MRMS) of position errors, respectively. Results show that DB and ZVS converters achieve about a 40 % reduction in THD compared to the conventional converter. When the dead time is small—as with GaN FETs—the MRMS error remains nearly the same for all variations, indicating that the position loop is not sensitive to dead-time-related errors.