Online PI Current Controller Tuning Based on Machine High-Frequency Parameters

Synchronous PI current regulators are the preferred option for the current control of ac electric drives. The controller tuning requires knowledge of machine parameters that can change during normal operation, e.g. due to saturation and temperature variations, leading to changes in the current regulator dynamic response. This paper proposes the use of high-frequency signal injection (HFI) for parameter identification. This will enable online adaptation of the current regulator gains, eventually making their response robust against parameter variations.