Direct Delta Sigma Signal Processing for Control of Power Electronics

A new approach for the signal processing in control loops is the direct signal processing of a delta sigma (DeltaSigma) bit stream. The advantages are a high bandwidth in the control loop and lower timing constraints for measurement synchronization. In this paper, the main focus is on the performance improvement of delta sigma signal processing (DSSP) structures. Different architectures and modulator orders are analyzed regarding signal to noise and distortion ratio (SNDR) and dynamic performance of a single DSSP operation. Furthermore, the SNDR decline in a cascade of DSSP operation is examined and the step response of a phase current control loop of a permanent magnet synchronous machine using DSSP is shown.