Digital implementation of GaN-based inverter for permanent magnet electrodynamic shaker

The maximum operation frequency of a permanent magnet electrodynamic shaker (PMEDS) is 2kHz. To provide good current tracking performance in digital implementation, the PWM frequency is chosen to be 100kHz. Due to the finite turning-on time and the turning-off time of the conventional semiconductor devices, the dead-time has a great effect on the current tracking performance and thus, the dead-time compensation loops need to be included to the current control loop. By using the high-speed high-efficiency GaN devices, the dead-time is near zero and no dead-time compensation loop is required, which simplifies the current control design and saves the calculating time of digital current loop. In addition, the results also show that the GaN devices contribute to less acceleration harmonics and less input power in the application of PMEDS.