Self-commissioning of the current control loop in AC drives

This paper proposes a self-identification algorithm and autotuning concept for the current loop of electrical machines which requires no additional testing hardware or a position sensor. The paper introduces three concepts. First, it is shown how the machine inductance and resistance can be estimated by the recursive least squares algorithm during a self-identification process of an unknown machine. Secondly, a novel and simple auto tuning controller is proposed which allows the field engineer to define the closed loop dynamics by specification of the current peak response time and overshoot. In order to obtain an exact match with the specified dynamics, a novel inverter voltage error compensation approach is shown. Finally, the proposed concepts are validated through measurements on anisotropic and isotropic synchronous machines.