Direct sliding mode current control of feed drives

Dealing with cascade control of electrical feed drives involves optimizing the current loop regarding precision, dynamics, robustness and energy efficiency. This is challenging using switching inverters with pulse width modulation. A direct method based on a switching controller is presented, which needs no downstream modulator. Control takes place in field-oriented as well as in phase-oriented coordinates of the machine, providing benefits compared to other direct methods. Control rules and structures are derived and a comparison between conventional and novel approach is shown. Implementation and measurement were performed in a practical setup, proving higher dynamics and less energy consumption.