Bandwidth Improvements for Current Control Loops with a 100 kHz PWM Frequency and GaN Power Semiconductors

A discrete-time design method for a robust current controller of a servo drive was developed. It takes the sampling time, the processing dead time and the dynamical behavior of the A/D-converter into account. With a test stand for high dynamics, the theoretical calculations are verified. The test stand includes a voice coil motor and a power electronics with Gallium Nitride (GaN) power semiconductors for switching frequencies of more than 100 kHz. The bandwidth of the current control loop can be improved from typically 1 to 1.5 kHz with insulated-gate bipolar transistor (IGBT) power semiconductors in state of the art motion control systems to more than 15 kHz, with a potential up to 30 kHz.     «

A discrete-time design method for a robust current controller of a servo drive was developed. It takes the sampling time, the processing dead time and the dynamical behavior of the A/D-converter into account. With a test stand for high dynamics, the theoretical calculations are verified. The test stand includes a voice coil motor and a power electronics with Gallium Nitride (GaN) power semiconductors for switching frequencies of more than 100 kHz. The bandwidth of the current control loop ca...     »